Bump up the version to v0.15.5

Signed-off-by: Tao He <linzhu.ht@alibaba-inc.com>

.clang-format

@@ -0,0 +1,15 @@
+BasedOnStyle: Google
+DerivePointerAlignment: false
+PointerAlignment: Left
+Cpp11BracedListStyle: true
+IndentCaseLabels: false
+AllowShortBlocksOnASingleLine: true
+AllowShortLoopsOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: false
+Standard: 'Cpp11'
+SpaceAfterCStyleCast: true
+AlignAfterOpenBracket: Align
+SortIncludes: true
+IncludeBlocks: Preserve
+ForEachMacros:
+  - BOOST_FOREACH

.github/workflows/build-deb-package.yml

@@ -0,0 +1,126 @@
+name: Build Deb Package
+
+on: [push, pull_request]
+
+concurrency:
+  group: ${{ github.repository }}-${{ github.event.number || github.head_ref || github.sha }}-${{ github.workflow }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-20.04]
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+
+      - name: Get time
+        run: |
+          date +'%Y-%m' > snapshot.txt
+
+      - name: Cache for cccahe
+        uses: actions/cache@v3
+        with:
+          path: /home/runner/.ccache
+          key: ${{ runner.os }}-deb-ccache-${{ hashFiles('**/snapshot.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-deb-ccache-
+
+      - name: Install dependencies for Linux
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt update -y
+          sudo apt install -y ca-certificates \
+                              ccache \
+                              cmake \
+                              debhelper \
+                              devscripts \
+                              libboost-all-dev \
+                              libcpprest-dev \
+                              libcurl4-openssl-dev \
+                              libssl-dev \
+                              libz-dev \
+                              lsb-release \
+                              openssl \
+                              screenfetch \
+                              wget
+
+      - name: Install grpc for Ubuntu 20.04
+        if: matrix.os == 'ubuntu-20.04'
+        run: |
+          sudo apt install -y libcurl4-openssl-dev \
+                              libprotobuf-dev \
+                              libprotoc-dev \
+                              libgrpc-dev \
+                              libgrpc++-dev \
+                              protobuf-compiler-grpc
+
+      - name: Screen fetch
+        run: |
+          screenfetch
+
+      - name: Setup tmate session
+        if: false
+        uses: mxschmitt/action-tmate@v3
+
+      - name: Prepare gpg environment
+        run: |
+          cat > gpg-script <<EOF
+              %echo Generating a OpenPGP key
+              Key-Type: DSA
+              Key-Length: 1024
+              Subkey-Type: ELG-E
+              Subkey-Length: 1024
+              Name-Real: Tao He
+              Name-Email: sighingnow@gmail.com
+              Expire-Date: 0
+              Passphrase: etcd-passphrase
+              # Do a commit here, so that we can later print "done" :-)
+              %commit
+              %echo done
+          EOF
+
+          gpg --batch --gen-key gpg-script
+
+      - name: CMake
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+
+          mkdir -p build
+          cd build
+          cmake .. -DCMAKE_CXX_STANDARD=17 \
+                   -DCMAKE_CXX_STANDARD_REQUIRED=TRUE \
+                   -DBUILD_ETCD_TESTS=ON \
+                   -DCMAKE_C_COMPILER_LAUNCHER=ccache \
+                   -DCMAKE_CXX_COMPILER_LAUNCHER=ccache
+
+      - name: Generate PPA source tarball
+        if: false
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+
+          mkdir -p build
+          cd build
+
+      - name: Generate Deb package
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+
+          mkdir -p build
+          cd build
+
+          cpack -G DEB
+
+      - name: Upload deb package
+        if: always()
+        uses: actions/upload-artifact@v2
+        with:
+          name: deb package
+          path: build/*.deb
+
+      - name: Check ccache
+        run: |
+          ccache --show-stats

.github/workflows/build-test.yml

@@ -2,17 +2,52 @@ name: Build and Test
 
 on: [push, pull_request]
 
+concurrency:
+  group: ${{ github.repository }}-${{ github.event.number || github.head_ref || github.sha }}-${{ github.workflow }}
+  cancel-in-progress: true
+
+env:
+  SEGFAULT_SIGNALS: all
+
 jobs:
   build:
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
-        # disabled: macos-11.0
-        # why: https://github.com/actions/virtual-environments/issues/2486
-        os: [ubuntu-18.04, ubuntu-20.04, macos-10.15]
-        etcd: [v3.2.26, v3.3.11, v3.4.13]
+        os: [ubuntu-20.04, ubuntu-22.04, macos-11, macos-12]
+        etcd: [v3.2.32, v3.3.27, v3.4.27, v3.5.9]
+        exclude:
+          - os: ubuntu-20.04
+            etcd: v3.2.26
+          - os: ubuntu-20.04
+            etcd: v3.4.13
+          - os: ubuntu-20.04
+            etcd: v3.5.7
+
+          - os: ubuntu-22.04
+            etcd: v3.2.26
+          - os: ubuntu-22.04
+            etcd: v3.3.11
+          - os: ubuntu-22.04
+            etcd: v3.5.7
+
+          - os: macos-11
+            etcd: v3.2.26
+          - os: macos-11
+            etcd: v3.3.11
+          - os: macos-11
+            etcd: v3.4.13
+
+          - os: macos-12
+            etcd: v3.2.26
+          - os: macos-12
+            etcd: v3.3.11
+          - os: macos-12
+            etcd: v3.4.13
+
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           submodules: true
 
@@ -21,7 +56,7 @@ jobs:
           date +'%Y-%m' > snapshot.txt
 
       - name: Cache for cccahe
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: /home/runner/.ccache
           key: ${{ runner.os }}-ccache-${{ hashFiles('**/snapshot.txt') }}
@@ -47,6 +82,10 @@ jobs:
           wget https://github.com/Kitware/CMake/releases/download/v3.19.3/cmake-3.19.3-Linux-x86_64.sh
           sudo bash cmake-3.19.3-Linux-x86_64.sh --prefix /usr --skip-license
 
+          # install clang-format
+          sudo curl -L https://github.com/muttleyxd/clang-tools-static-binaries/releases/download/master-1d7ec53d/clang-format-11_linux-amd64 --output /usr/bin/clang-format
+          sudo chmod +x /usr/bin/clang-format
+
       - name: Install grpc v1.27.x for Ubuntu 18.04
         if: matrix.os == 'ubuntu-18.04'
         run: |
@@ -74,8 +113,8 @@ jobs:
           make -j`nproc`
           sudo make install
 
-      - name: Install grpc for Ubuntu 20.04
-        if: matrix.os == 'ubuntu-20.04'
+      - name: Install grpc for Ubuntu 20.04 or later
+        if: ${{ runner.os != 'macOS' && matrix.os != 'ubuntu-18.04' }}
         run: |
           sudo apt install -y libcurl4-openssl-dev \
                               libprotobuf-dev \
@@ -84,6 +123,10 @@ jobs:
                               libgrpc++-dev \
                               protobuf-compiler-grpc
 
+          # install libsegfault.so
+          sudo apt-get install libc6 || true
+          sudo apt-get install glibc-tools || true
+
       - name: Install dependencies for Mac
         if: runner.os == 'macOS'
         run: |
@@ -127,26 +170,68 @@ jobs:
           make -j`nproc`
           sudo make install
 
-      - name: Build
+      - name: Setup tmate session
+        if: false
+        uses: mxschmitt/action-tmate@v3
+
+      - name: CMake
         run: |
-          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
 
           mkdir -p build
           cd build
-          cmake .. -DCMAKE_BUILD_TYPE=Debug \
+          cmake .. -DCMAKE_CXX_STANDARD=17 \
+                   -DCMAKE_CXX_STANDARD_REQUIRED=TRUE \
+                   -DCMAKE_BUILD_TYPE=Debug \
                    -DBUILD_ETCD_TESTS=ON \
                    -DCMAKE_C_COMPILER_LAUNCHER=ccache \
                    -DCMAKE_CXX_COMPILER_LAUNCHER=ccache
+
+      - name: Format
+        if: runner.os == 'Linux'
+        run: |
+          cd build
+
+          function prepend() { while read line; do echo "${1}${line}"; done; }
+
+          make etcd_cpp_apiv3_clformat
+          GIT_DIFF=$(git diff --ignore-submodules)
+          if [[ -n $GIT_DIFF ]]; then
+              echo "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
+              echo "| clang-format failures found!"
+              echo "|"
+              echo "$GIT_DIFF" | prepend "| "
+              echo "|"
+              echo "| Run: "
+              echo "|"
+              echo "|    make etcd_cpp_apiv3_clformat"
+              echo "|"
+              echo "| to fix this error."
+              echo "|"
+              echo "| Ensure you are working with clang-format-11, which can be obtained from"
+              echo "|"
+              echo "|    https://github.com/muttleyxd/clang-tools-static-binaries/releases "
+              echo "|"
+              echo "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
+              exit -1
+          fi
+
+
+      - name: Build
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
+
+          cd build
           make -j`nproc`
           sudo make install
 
       - name: Setup tmate session
         if: false
-        uses: mxschmitt/action-tmate@v2
+        uses: mxschmitt/action-tmate@v3
 
       - name: Test
         run: |
-          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
 
           # use etcd v3 api
           export ETCDCTL_API="3"
@@ -157,17 +242,99 @@ jobs:
           sleep 5
 
           # tests without auth
+
+          echo "Run the etcd resolver test ........................."
+          # there's no ipv6 on github CI runner
+          # ./build/bin/EtcdResolverTest
+
+          echo "Run the etcd sync test ........................."
           ./build/bin/EtcdSyncTest
+
+          echo "Run the etcd test ........................."
           ./build/bin/EtcdTest
-          ./build/bin/LockTest
+
+          echo "Run the etcd campaign test ........................."
+          ./build/bin/CampaignTest
+
+          echo "Run the etcd memory leak test ........................."
+          ./build/bin/MemLeakTest
+
+          echo "Run the etcd watcher test ........................."
           ./build/bin/WatcherTest
 
-          killall -TERM etcd
+          echo "Run the etcd memory leak in watcher test ........................."
+          ./build/bin/MemLeakWatcherTest
+
+          echo "Run the etcd keepalive test ........................."
+          ./build/bin/KeepAliveTest
+
+          echo "Run the etcd transaction test ........................."
+          ./build/bin/TransactionTest
+
+          echo "Run the etcd election test ........................."
+          ./build/bin/ElectionTest
+
+          echo "Run the etcd with fork test ........................."
+          ./build/bin/ForkTest
+
+          killall -TERM etcd || true
           sleep 5
 
+      - name: Lock Test
+        if: false
+        run: |
+          killall -TERM etcd || true
+          sleep 5
+
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
+
+          # use etcd v3 api
+          export ETCDCTL_API="3"
+
+          rm -rf default.etcd
+          /usr/local/bin/etcd &
+
+          sleep 5
+
+          echo "Run the etcd lock test ........................."
+          ./build/bin/LockTest
+
+          killall -TERM etcd || true
+          sleep 5
+
+      - name: Lock Tests with Debug
+        if: true
+        uses: sighingnow/action-tmate@master
+        with:
+          script-to-run: |
+            killall -TERM etcd || true
+            sleep 5
+
+            # enable coredump for debugging
+            ulimit -c unlimited
+
+            export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
+
+            # use etcd v3 api
+            export ETCDCTL_API="3"
+
+            rm -rf default.etcd
+            /usr/local/bin/etcd &
+
+            sleep 5
+
+            echo "Run the etcd lock test ........................."
+            ./build/bin/LockTest
+
+            killall -TERM etcd || true
+            sleep 5
+
       - name: Authentication Test
         run: |
-          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+          killall -TERM etcd || true
+          sleep 5
+
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
 
           # use etcd v3 api
           export ETCDCTL_API="3"
@@ -183,7 +350,7 @@ jobs:
               printf 'root\nroot\n' | /usr/local/bin/etcdctl user add root || true
           fi
           # for etcd v3.4
-          if [[ "${{ matrix.etcd }}" == v3.4* ]];
+          if [[ "${{ matrix.etcd }}" == v3.4* ]] || [[ "${{ matrix.etcd }}" == v3.5* ]];
           then
               /usr/local/bin/etcdctl user add root --new-user-password="root" || true
           fi
@@ -198,17 +365,20 @@ jobs:
               /usr/local/bin/etcdctl --user="root:root" auth disable || true
           fi
           # for etcd v3.4
-          if [[ "${{ matrix.etcd }}" == v3.4* ]];
+          if [[ "${{ matrix.etcd }}" == v3.4* ]] || [[ "${{ matrix.etcd }}" == v3.5* ]];
           then
               /usr/local/bin/etcdctl auth disable --user="root" --password="root" || true
           fi
 
-          killall -TERM etcd
+          killall -TERM etcd || true
           sleep 5
 
       - name: Transport Security and Authentication Test
         run: |
-          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
+          killall -TERM etcd || true
+          sleep 5
+
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
 
           # use etcd v3 api
           export ETCDCTL_API="3"
@@ -233,6 +403,26 @@ jobs:
           killall -TERM etcd
           sleep 5
 
+      - name: Etcd Member test
+        run: |
+          killall -TERM etcd || true
+          sleep 5
+
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib/x86_64-linux-gnu
+
+          # use etcd v3 api
+          export ETCDCTL_API="3"
+          
+
+          rm -rf default.etcd
+          /usr/local/bin/etcd &
+          sleep 5
+
+          ./build/bin/EtcdMemberTest
+
+          killall -TERM etcd
+          sleep 5
+        
       - name: Check ccache
         run: |
           ccache --show-stats

.github/workflows/centos-latest.yml

@@ -0,0 +1,142 @@
+name: Build & Test on CentOS Latest
+
+on: [push, pull_request]
+
+concurrency:
+  group: ${{ github.repository }}-${{ github.event.number || github.head_ref || github.sha }}-${{ github.workflow }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    container:
+      image: centos:latest
+    strategy:
+      matrix:
+        os: [ubuntu-20.04]
+        etcd: [v3.4.13]
+    steps:
+      - name: Install dependencies for Linux
+        run: |
+          # switch to centos stream
+          dnf -y --disablerepo '*' --enablerepo=extras swap centos-linux-repos centos-stream-repos
+          dnf -y update
+
+          # install required dependencies
+          yum -y group install "Development Tools"
+          yum -y install boost-devel \
+                         cmake \
+                         git \
+                         openssl-devel \
+                         wget
+
+          # install screen fetch
+          wget -O screenfetch-dev https://git.io/vaHfR
+          chmod +x screenfetch-dev
+          mv ./screenfetch-dev /usr/bin/screenfetch
+
+      # the checkout action require new version of git
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+
+      - name: Cache for cccahe
+        uses: actions/cache@v3
+        with:
+          path: /home/runner/.ccache
+          key: ${{ runner.os }}-centos-ccache-${{ hashFiles('/CMakeLists.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-centos-ccache-
+
+      - name: Install grpc v1.27.x for CentOS latest
+        run: |
+          # We simply keep the same version with Ubuntu 18.04
+          #
+          git clone https://github.com/grpc/grpc.git --depth 1 --branch v1.27.x
+          cd grpc/
+          git submodule update --init
+          mkdir cmake-build
+          cd cmake-build/
+          cmake .. -DBUILD_SHARED_LIBS=ON \
+            -DgRPC_INSTALL=ON \
+            -DgRPC_BUILD_TESTS=OFF \
+            -DgRPC_BUILD_CSHARP_EXT=OFF \
+            -DgRPC_BUILD_GRPC_CSHARP_PLUGIN=OFF \
+            -DgRPC_BUILD_GRPC_NODE_PLUGIN=OFF \
+            -DgRPC_BUILD_GRPC_OBJECTIVE_C_PLUGIN=OFF \
+            -DgRPC_BUILD_GRPC_PHP_PLUGIN=OFF \
+            -DgRPC_BUILD_GRPC_PYTHON_PLUGIN=OFF \
+            -DgRPC_BUILD_GRPC_RUBY_PLUGIN=OFF \
+            -DgRPC_BACKWARDS_COMPATIBILITY_MODE=ON \
+            -DgRPC_ZLIB_PROVIDER=package \
+            -DgRPC_SSL_PROVIDER=package
+          make -j`nproc`
+          make install
+
+      - name: Screen fetch
+        run: |
+          screenfetch
+
+      - name: Install etcd for Linux
+        run: |
+          # install etcd
+          wget https://github.com/etcd-io/etcd/releases/download/${{ matrix.etcd }}/etcd-${{ matrix.etcd }}-linux-amd64.tar.gz
+          tar zxvf etcd-${{ matrix.etcd }}-linux-amd64.tar.gz
+          mv etcd-${{ matrix.etcd }}-linux-amd64/etcd /usr/local/bin/
+          mv etcd-${{ matrix.etcd }}-linux-amd64/etcdctl /usr/local/bin/
+
+      - name: Install cpprestsdk
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib64
+
+          mkdir -p build
+          cd build
+          git clone https://github.com/microsoft/cpprestsdk.git --depth=1
+          mkdir -p cpprestsdk/build
+          cd cpprestsdk/build
+          cmake .. -DCMAKE_BUILD_TYPE=Debug \
+                   -DBUILD_TESTS=OFF \
+                   -DBUILD_SAMPLES=OFF \
+                   -DCPPREST_EXCLUDE_WEBSOCKETS=ON
+          make -j`nproc`
+          make install
+
+      - name: Build
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib64
+
+          mkdir -p build
+          cd build
+          cmake .. -DCMAKE_CXX_STANDARD=17 \
+                   -DCMAKE_CXX_STANDARD_REQUIRED=TRUE \
+                   -DCMAKE_BUILD_TYPE=Debug \
+                   -DBUILD_ETCD_TESTS=ON
+          make -j`nproc`
+          make install
+
+      - name: Setup tmate session
+        if: false
+        uses: mxschmitt/action-tmate@v3
+
+      - name: Test
+        run: |
+          export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib:/usr/local/lib64
+
+          # use etcd v3 api
+          export ETCDCTL_API="3"
+
+          rm -rf default.etcd
+          /usr/local/bin/etcd &
+
+          sleep 5
+
+          # tests without auth
+          ./build/bin/EtcdSyncTest
+          ./build/bin/EtcdTest
+          ./build/bin/LockTest
+          ./build/bin/MemLeakTest
+          ./build/bin/WatcherTest
+          ./build/bin/ElectionTest
+
+          killall -TERM etcd
+          sleep 5

.gitignore

@@ -3,3 +3,6 @@ compile_commands.json
 proto/**/*.pb.cc
 proto/**/*.pb.h
 default.etcd/
+
+# vscode-clangd
+.cache/

CMakeLists.txt

@@ -1,15 +1,16 @@
-cmake_minimum_required (VERSION 3.1.3 FATAL_ERROR)
+cmake_minimum_required (VERSION 3.3 FATAL_ERROR)
 project (etcd-cpp-api)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 set(etcd-cpp-api_VERSION_MAJOR 0)
-set(etcd-cpp-api_VERSION_MINOR 2)
-set(etcd-cpp-api_VERSION_PATCH 1)
+set(etcd-cpp-api_VERSION_MINOR 15)
+set(etcd-cpp-api_VERSION_PATCH 5)
 set(etcd-cpp-api_VERSION ${etcd-cpp-api_VERSION_MAJOR}.${etcd-cpp-api_VERSION_MINOR}.${etcd-cpp-api_VERSION_PATCH})
 set(CMAKE_PROJECT_HOMEPAGE_URL https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3)
 
 include(CheckCXXCompilerFlag)
+include(CheckCXXSourceCompiles)
 include(CheckLibraryExists)
 include(GNUInstallDirs)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -25,22 +26,91 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
     )
 endif()
 
-option(BUILD_SHARED_LIBS "Build shared libraries" ON)
-option(BUILD_ETCD_TESTS "Build test cases" OFF)
+option(BUILD_WITH_NO_EXCEPTIONS "Build etcd-cpp-apiv3 with disabling exception handling, i.e., -fno-exceptions" OFF)
+option(BUILD_SHARED_LIBS "Build etcd-cpp-apiv3 shared libraries" ON)
+option(BUILD_ETCD_CORE_ONLY "Build etcd-cpp-apiv3 core library (the synchronous runtime) only" OFF)
+option(BUILD_ETCD_TESTS "Build etcd-cpp-apiv3 test cases" OFF)
+option(CMAKE_POSITION_INDEPENDENT_CODE "Build etcd-cpp-apiv3 with -fPIC" ON)
+option(ETCD_W_STRICT "Build etcd-cpp-apiv3 with -Werror" ON)
+option(ETCD_CMAKE_CXX_STANDARD "Build etcd-cpp-apiv3 with specified C++ standard, e.g., 11, 14, 17, 20" "")
+
+if(NOT "${ETCD_CMAKE_CXX_STANDARD}")
+    if(NOT "${CMAKE_CXX_STANDARD}")
+        set(ETCD_CMAKE_CXX_STANDARD 11)
+    else()
+        set(ETCD_CMAKE_CXX_STANDARD ${CMAKE_CXX_STANDARD})
+    endif()
+endif()
+message(STATUS "Building etcd-cpp-apiv3 with C++${ETCD_CMAKE_CXX_STANDARD}")
 
 # reference: https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling#always-full-rpath
 set(CMAKE_BUILD_WITH_INSTALL_RPATH FALSE)
-set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib:${CMAKE_INSTALL_PREFIX}/lib64")
+set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib:${CMAKE_INSTALL_PREFIX}/lib64:${CMAKE_INSTALL_PREFIX}/lib/x86_64-linux-gnu")
 set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
 
-find_package(Boost REQUIRED COMPONENTS system thread random)
-if (APPLE)
+if(MSVC)
+    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+    set(CMAKE_GNUtoMS ON)
+endif()
+
+if(NOT (CMAKE_CXX_COMPILER_LAUNCHER MATCHES "ccache") AND NOT (CMAKE_C_COMPILER_LAUNCHER MATCHES "ccache"))
+    find_program(ccache_EXECUTABLE ccache)
+    if(ccache_EXECUTABLE)
+        set(CMAKE_C_COMPILER_LAUNCHER ${ccache_EXECUTABLE})
+        set(CMAKE_CXX_COMPILER_LAUNCHER ${ccache_EXECUTABLE})
+        if (NOT TARGET ccache-stats)
+            add_custom_target(ccache-stats
+                COMMAND ${ccache_EXECUTABLE} --show-stats
+            )
+        endif()
+    else()
+        if (NOT TARGET ccache-stats)
+            add_custom_target(ccache-stats
+                COMMAND echo "ccache not found."
+            )
+        endif()
+    endif(ccache_EXECUTABLE)
+endif()
+
+macro(use_cxx target)
+    if(CMAKE_VERSION VERSION_LESS "3.1")
+        if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+            target_compile_options(${target} PRIVATE "-std=gnu++${ETCD_CMAKE_CXX_STANDARD}")
+        else()
+            target_compile_options(${target} PRIVATE "-std=c++${ETCD_CMAKE_CXX_STANDARD}")
+        endif()
+    elseif(CMAKE_VERSION VERSION_LESS "3.8")
+        set_target_properties(${target} PROPERTIES
+            CXX_STANDARD ${ETCD_CMAKE_CXX_STANDARD}
+            CXX_STANDARD_REQUIRED ON
+        )
+    else()
+        target_compile_features(${target} PUBLIC cxx_std_${ETCD_CMAKE_CXX_STANDARD})
+    endif()
+endmacro(use_cxx)
+
+macro(set_exceptions target)
+    if(BUILD_WITH_NO_EXCEPTIONS)
+        if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+            target_compile_options(${target} PRIVATE "-fno-exceptions")
+        elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+            target_compile_options(${target} PRIVATE "-fno-exceptions")
+        elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+            target_compile_options(${target} PRIVATE "-fno-exceptions")
+        elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+            target_compile_options(${target} PRIVATE "/EHs-c-")
+        endif()
+        target_compile_definitions(${target} PUBLIC -D_ETCD_NO_EXCEPTIONS)
+    endif()
+endmacro(set_exceptions)
+
+if(APPLE)
     # If we're on OS X check for Homebrew's copy of OpenSSL instead of Apple's
-    if (NOT OpenSSL_DIR)
+    if(NOT OpenSSL_DIR)
         find_program(HOMEBREW brew)
-        if (HOMEBREW STREQUAL "HOMEBREW-NOTFOUND")
+        if(HOMEBREW STREQUAL "HOMEBREW-NOTFOUND")
             message(WARNING "Homebrew not found: not using Homebrew's OpenSSL")
-            if (NOT OPENSSL_ROOT_DIR)
+            if(NOT OPENSSL_ROOT_DIR)
                 message(WARNING "Use -DOPENSSL_ROOT_DIR for non-Apple OpenSSL")
             endif()
         else()
@@ -52,60 +122,138 @@ if (APPLE)
 endif()
 
 find_package(OpenSSL REQUIRED)
-find_package(Protobuf REQUIRED)
-find_package(cpprestsdk QUIET)
-if(cpprestsdk_FOUND)
-    set(CPPREST_INCLUDE_DIR)
-    set(CPPREST_LIB cpprestsdk::cpprest)
-else()
-    find_library(CPPREST_LIB NAMES cpprest)
-    find_path(CPPREST_INCLUDE_DIR NAMES cpprest/http_client.h)
+find_package(Protobuf CONFIG QUIET)
+if (NOT Protobuf_FOUND)
+    find_package(Protobuf REQUIRED)
+endif()
+if(Protobuf_PROTOC_EXECUTABLE)
+    if(NOT TARGET protobuf::protoc)
+        add_executable(protobuf::protoc IMPORTED)
+        if(EXISTS "${Protobuf_PROTOC_EXECUTABLE}")
+            set_target_properties(protobuf::protoc PROPERTIES
+                IMPORTED_LOCATION "${Protobuf_PROTOC_EXECUTABLE}")
+        endif()
+    endif()
+endif()
+
+# When cross compiling we look for the native protoc compiler
+# overwrite protobuf::protoc with the proper protoc
+if(CMAKE_CROSSCOMPILING)
+    find_program(Protobuf_PROTOC_EXECUTABLE REQUIRED NAMES protoc)
+    if(NOT TARGET protobuf::protoc)
+        add_executable(protobuf::protoc IMPORTED)
+    endif()
+    set_target_properties(protobuf::protoc PROPERTIES
+        IMPORTED_LOCATION "${Protobuf_PROTOC_EXECUTABLE}")
 endif()
 
 find_package(gRPC QUIET)
-if(gRPC_FOUND)
+if(gRPC_FOUND AND TARGET gRPC::grpc)
+    # When cross compiling we look for the native grpc_cpp_plugin
+    if(CMAKE_CROSSCOMPILING)
+        find_program(GRPC_CPP_PLUGIN REQUIRED NAMES grpc_cpp_plugin)
+        if(NOT TARGET gRPC::grpc_cpp_plugin)
+            add_executable(gRPC::grpc_cpp_plugin IMPORTED)
+        endif()
+        set_target_properties(gRPC::grpc_cpp_plugin PROPERTIES
+                IMPORTED_LOCATION "${GRPC_CPP_PLUGIN}")
+    elseif(TARGET gRPC::grpc_cpp_plugin)
+        get_target_property(GRPC_CPP_PLUGIN gRPC::grpc_cpp_plugin LOCATION)
+    else()
+        message(FATAL_ERROR "Found gRPC but no gRPC CPP plugin defined")
+    endif()
+
     set(GRPC_LIBRARIES gRPC::gpr gRPC::grpc gRPC::grpc++)
-    get_target_property(GRPC_CPP_PLUGIN gRPC::grpc_cpp_plugin LOCATION)
+    get_target_property(GRPC_INCLUDE_DIR gRPC::grpc INTERFACE_INCLUDE_DIRECTORIES)
 else()
     include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/FindGRPC.cmake)
     set(GRPC_LIBRARIES ${GPR_LIBRARY} ${GRPC_LIBRARY} ${GRPC_GRPC++_LIBRARY})
 endif()
-
+message(STATUS "Found GRPC: ${GRPC_LIBRARIES}, ${GRPC_CPP_PLUGIN} (found version: \"${gRPC_VERSION}\")")
+# avoid use the apt-get installed libgrpc-dev (version v1.13) on Ubuntu 18.04
+if(gRPC_FOUND AND gRPC_VERSION VERSION_LESS "1.14")
+    message(FATAL_ERROR "gRPC '${gRPC_VERSION}' is not supported, please install a newer gRPC library "
+                        "by following the example below"
+                        "\n"
+                        "    https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/blob/master/.github/workflows/build-test.yml#L50-L75")
+endif()
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/GenerateProtobufGRPC.cmake)
 
+if(gRPC_VERSION VERSION_LESS "1.21" OR gRPC_VERSION VERSION_GREATER "1.31")
+    add_definitions(-DWITH_GRPC_CHANNEL_CLASS)
+endif()
+if(gRPC_VERSION VERSION_LESS "1.17")
+    add_definitions(-DWITH_GRPC_CREATE_CHANNEL_INTERNAL_UNIQUE_POINTER)
+endif()
+
 # will set `PROTOBUF_GENERATES`, indicates all generated .cc files, and a target `protobuf_generates`.
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/GenerateProtobuf.cmake)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/proto)
 
-include_directories(SYSTEM ${Boost_INCLUDE_DIR}
-                           ${CPPREST_INCLUDE_DIR}
+# test cases requires the async runtime
+if(BUILD_ETCD_TESTS)
+    message(STATUS "Building etcd-cpp-apiv3 with tests requires the async runtime, "
+                   "setting BUILD_ETCD_CORE_ONLY to ON ...")
+    set(BUILD_ETCD_CORE_ONLY OFF)
+endif()
+
+if (NOT BUILD_ETCD_CORE_ONLY)
+    find_package(cpprestsdk QUIET)
+    if(cpprestsdk_FOUND)
+        set(CPPREST_INCLUDE_DIR)
+        set(CPPREST_LIB cpprestsdk::cpprest)
+    else()
+        find_library(CPPREST_LIB NAMES cpprest)
+        find_path(CPPREST_INCLUDE_DIR NAMES cpprest/http_client.h)
+    endif()
+else()
+    set(CPPREST_INCLUDE_DIR)
+    set(CPPREST_LIB)
+endif()
+
+include_directories(SYSTEM ${CPPREST_INCLUDE_DIR}
                            ${PROTOBUF_INCLUDE_DIRS}
+                           ${GRPC_INCLUDE_DIR}
                            ${OPENSSL_INCLUDE_DIR})
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 if(NOT CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wpedantic -Werror -Wno-string-compare -std=c++11")
+    if(ETCD_W_STRICT)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror")
+    endif()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wpedantic -Wno-string-compare")
+endif()
+
+check_cxx_compiler_flag(-Wno-c++17-extensions W_NO_CPP17_EXTENSIONS)
+check_cxx_compiler_flag(-Wno-extra-semi W_NO_EXTRA_SEMI)
+if(W_NO_CPP17_EXTENSIONS)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-c++17-extensions")
+endif()
+if(W_NO_EXTRA_SEMI)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-extra-semi")
 endif()
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 
 add_subdirectory(src)
+if(BUILD_ETCD_TESTS)
+  enable_testing()
+  add_subdirectory(tst)
+endif()
 
-if (BUILD_ETCD_TESTS)
-    enable_testing()
-    add_subdirectory(tst)
-endif ()
-
-install (FILES ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Client.hpp
-               ${CMAKE_CURRENT_SOURCE_DIR}/etcd/KeepAlive.hpp
-               ${CMAKE_CURRENT_SOURCE_DIR}/etcd/SyncClient.hpp
-               ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Response.hpp
-               ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Value.hpp
-               ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Watcher.hpp
-               ${CMAKE_CURRENT_BINARY_DIR}/proto/gen/proto/kv.pb.h
-               DESTINATION include/etcd)
-install (FILES ${CMAKE_CURRENT_SOURCE_DIR}/etcd/v3/Transaction.hpp
-               ${CMAKE_CURRENT_BINARY_DIR}/proto/gen/proto/txn.pb.h
-               DESTINATION include/etcd/v3)
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/etcd/KeepAlive.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/SyncClient.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Response.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Value.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Watcher.hpp
+              DESTINATION include/etcd)
+if(NOT BUILD_ETCD_CORE_ONLY)
+    install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/etcd/Client.hpp
+                  DESTINATION include/etcd)
+endif()
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/etcd/v3/action_constants.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/v3/Transaction.hpp
+              ${CMAKE_CURRENT_SOURCE_DIR}/etcd/v3/Member.hpp
+              DESTINATION include/etcd/v3)
 
 configure_file(etcd-cpp-api-config.in.cmake
                "${PROJECT_BINARY_DIR}/etcd-cpp-api-config.cmake" @ONLY
@@ -123,6 +271,17 @@ install(EXPORT etcd-targets
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/etcd-cpp-api
 )
 
+file(GLOB_RECURSE FILES_NEED_FORMAT
+        "etcd/*.hpp"
+        "src/*.cpp"
+        "tst/*.cpp"
+)
+
+add_custom_target(etcd_cpp_apiv3_clformat
+    COMMAND clang-format --style=file -i ${FILES_NEED_FORMAT}
+    COMMENT "Running clang-format, using clang-format-11 from https://github.com/muttleyxd/clang-tools-static-binaries/releases"
+    VERBATIM)
+
 # deb/rpc packaging for Linux
 
 set(CPACK_PACKAGE_NAME ${CMAKE_PROJECT_NAME})
@@ -168,7 +327,7 @@ set(CPACK_DEBIAN_PACKAGE_DEPENDS "libcpprest-dev,
                                   libgrpc++-dev,
                                   libssl-dev")
 
-set(CPACK_DEBIAN_PACKAGE_UPSTREAM_COPYRIGHT_YEAR 2016-2021)
+set(CPACK_DEBIAN_PACKAGE_UPSTREAM_COPYRIGHT_YEAR 2016-2023)
 set(CPACK_DEBIAN_PACKAGE_LICENSE bsd)
 set(CPACK_DEBIAN_PACKAGE_MAINTAINER "Tao He <sighingnow@gmail.com>")
 set(CPACK_DEBIAN_PACKAGE_HOMEPAGE "https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/")
@@ -177,16 +336,22 @@ set(CPACK_DEBIAN_PACKAGE_INSTALL "/usr/lib/lib*.so*"
                                  "/usr/lib/cmake/etcd-cpp-api/*.cmake"
                                  "/usr/include/etcd/*.h"
                                  "/usr/include/etcd/*.hpp"
-                                 "/usr/include/etcd/v3/*.h"
-                                 "/usr/include/etcd/v3/*.hpp"
+                                 "/usr/include/etcd/v3/action_constants.hpp"
+                                 "/usr/include/etcd/v3/Transaction.hpp"
+                                 "/usr/include/etcd/v3/Member.hpp"
 )
 
 set(CPACK_DEBIAN_PACKAGE_BUILD_NUMBER_PREFIX "")
 set(CPACK_DEBIAN_PACKAGE_BUILD_NUMBER 0)
 
 set(CPACK_DEBIAN_PACKAGE_DISTRIBUTION "focal")
-set(DPUT_HOST "ppa:graphscope/etcd-cpp-api")
-set(DPUT_SNAPSHOT_HOST "ppa:graphscope/etcd-cpp-api")
+set(DPUT_HOST "ppa:etcd-cpp-apiv3/etcd-cpp-api")
+set(DPUT_SNAPSHOT_HOST "ppa:etcd-cpp-apiv3/etcd-cpp-api")
 
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
-include(UploadPPA)
+find_program(DEBUILD_EXECUTABLE debuild)
+find_program(DPUT_EXECUTABLE dput)
+
+if(DEBUILD_EXECUTABLE AND DPUT_EXECUTABLE)
+    list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+    include(UploadPPA)
+endif()

README.md

@@ -9,13 +9,16 @@ i.e., `ETCDCTL_API=3`.
 ### Supported OS environments
 
 + **Linux**
-  - Ubuntu 18.04, requires upgrade grpc libraries (has been tested with 1.27.x).
+  - Ubuntu 18.04, requires upgrade gRPC libraries (tested with 1.27.x).
   - Ubuntu 20.04
+  - CentOS 8 (tested with 1.27.x)
+
 + **MacOS**
   - MacOS 10.15
   - MacOS 11.0
+
 + **Windows**
-  - Windows 10, with [vcpkg](https://github.com/microsoft/vcpkg)
+  - Windows 10, with [vcpkg](https://github.com/microsoft/vcpkg/tree/master/ports/etcd-cpp-apiv3)
 
 ### Supported etcd versions:
 
@@ -25,18 +28,17 @@ i.e., `ETCDCTL_API=3`.
 
 ## Requirements
 
-1. boost
+1. boost and openssl (**Note that boost is only required if you need the asynchronous runtime**)
 
    + On Ubuntu, above requirement could be installed as:
 
-         apt-get install libboost-all-dev
+         apt-get install libboost-all-dev libssl-dev
 
    + On MacOS, above requirement could be installed as:
 
-         brew install boost
+         brew install boost openssl
 
-2. protobuf
-3. gRPC
+2. protobuf & gRPC
 
    + On Ubuntu, above requirements related to protobuf and gRPC can be installed as:
 
@@ -47,18 +49,28 @@ i.e., `ETCDCTL_API=3`.
 
    + On MacOS, above requirements related to protobuf and gRPC can be installed as:
 
-
          brew install grpc protobuf
 
+   + When building grpc from source code (e.g., on [Ubuntu 18.04](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/blob/master/.github/workflows/build-test.yml#L73)
+     and on [CentOS](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/blob/master/.github/workflows/centos-latest.yml#L44-L67)),
+     if the system-installed openssl is preferred, you need to add `-DgRPC_SSL_PROVIDER=package`
+     when building gRPC with CMake.
 
-4. [cpprestsdk](https://github.com/microsoft/cpprestsdk), the latest version of master branch
+3. [cpprestsdk](https://github.com/microsoft/cpprestsdk), the latest version of master branch
    on github should work, you can build and install this dependency using cmake with:
 
         git clone https://github.com/microsoft/cpprestsdk.git
         cd cpprestsdk
         mkdir build && cd build
         cmake .. -DCPPREST_EXCLUDE_WEBSOCKETS=ON
-        make -j && make install
+        make -j$(nproc) && make install
+
+## API documentation
+
+The _etcd-cpp-apiv3_ doesn't maintain a website for documentation, for detail usage of the
+etcd APIs, please refer to [the "etcd operations" section](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3#etcd-operations)
+in README, and see the detail C++ interfaces in [Client.hpp](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/blob/master/etcd/Client.hpp)
+and [SyncClient.hpp](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/blob/master/etcd/SyncClient.hpp).
 
 ## Build and install
 
@@ -69,47 +81,103 @@ dependencies have been successfully installed:
     cd etcd-cpp-apiv3
     mkdir build && cd build
     cmake ..
-    make -j && make install
+    make -j$(nproc) && make install
+
+## Using this package in your CMake project
+
+To use this package in your CMake project, you can either
+
+- install, then find the library using `find_package()`:
+
+  ```cmake
+  find_package(etcd-cpp-apiv3 REQUIRED)
+  target_link_libraries(your_target PRIVATE etcd-cpp-api)
+  ```
+
+- or, add this repository as a subdirectory in your project, and link the library directly:
+
+  ```cmake
+  add_subdirectory(thirdparty/etcd-cpp-apiv3)
+  target_link_libraries(your_target PRIVATE etcd-cpp-api)
+  ```
+
+- or, use [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html):
+
+  ```cmake
+  include(FetchContent)
+  FetchContent_Declare(
+    etcd-cpp-apiv3
+    https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3.git
+  )
+  FetchContent_MakeAvailable(etcd-cpp-apiv3)
+  target_link_libraries(your_target PRIVATE etcd-cpp-api)
+  ```
 
 ## Compatible etcd version
 
 The _etcd-cpp-apiv3_ should work well with etcd > 3.0. Feel free to issue an issue to us on
 Github when you encounter problems when working with etcd 3.x releases.
 
+## Sync vs. Async runtime
+
+There are various discussion about whether to support a user-transparent multi-thread executor in
+the background, or, leaving the burden of thread management to the user (e.g., see
+[issue#100](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/issues/100) and
+[issue#207](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/issues/207) for more discussion about
+the implementation of underlying thread model).
+
+The _etcd-cpp-apiv3_ library supports both synchronous and asynchronous runtime, controlled by the
+cmake option `BUILD_ETCD_CORE_ONLY=ON/OFF` (defaults to `OFF`).
+
+- When it is set as `OFF`: the library artifact name will be `libetcd-cpp-api.{a,so,dylib,lib,dll}` and a
+  cmake target `etcd-cpp-api` is exported and pointed to it. The library provides both synchronous runtime
+  (`etcd/SyncClient.hpp`) and asynchronous runtime (`etcd/Client.hpp`), and the `cpprestsdk` is a
+  required dependency.
+- When it is set as `ON`: the library artifact name will be `libetcd-cpp-api-core.{a,so,dylib,lib,dll}`
+  and a cmake target `etcd-cpp-api` is exported and pointed to it. The library provides only the
+  synchronous runtime (`etcd/SyncClient.hpp`), and the `cpprestsdk` won't be required.
+
+We encourage the users to use the asynchronous runtime by default, as it provides more flexibility
+and convenient APIs and less possibilities for errors that block the main thread. Note that the
+asynchronous runtime requires `cpprestsdk` and will setup a thread pool in the background.
+
+**Warning: users cannot link both `libetcd-cpp-api.{a,so,dylib,lib,dll}` and `libetcd-cpp-api-core.{a,so,dylib,lib,dll}`
+to same program.**
+
 ## Usage
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd::Response response = etcd.get("/test/key1").get();
   std::cout << response.value().as_string();
 ```
 
 Methods of the etcd client object are sending the corresponding gRPC requests and are returning
-immediatelly with a ```pplx::task``` object. The task object is responsible for handling the
+immediately with a `pplx::task` object. The task object is responsible for handling the
 reception of the HTTP response as well as parsing the gRPC of the response. All of this is done
 asynchronously in a background thread so you can continue your code to do other operations while the
 current etcd operation is executing in the background or you can wait for the response with the
-```wait()``` or ```get()``` methods if a synchron behaviour is enough for your needs. These methods
-are blocking until the HTTP response arrives or some error situation happens. ```get()``` method
-also returns the ```etcd::Response``` object.
+`wait()` or `get()` methods if a synchronous behavior is enough for your needs. These methods
+are blocking until the HTTP response arrives or some error situation happens. `get()` method
+also returns the `etcd::Response` object.
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   pplx::task<etcd::Response> response_task = etcd.get("/test/key1");
   // ... do something else
   etcd::Response response = response_task.get();
   std::cout << response.value().as_string();
 ```
 
-The pplx library allows to do even more. You can attach continuation ojects to the task if you do
+The pplx library allows to do even more. You can attach continuation objects to the task if you do
 not care about when the response is coming you only want to specify what to do then. This
-can be achieved by calling the ```then``` method of the task, giving a funcion object parameter to
+can be achieved by calling the `then` method of the task, giving a function object parameter to
 it that can be used as a callback when the response is arrived and processed. The parameter of this
-callback should be either a ```etcd::Response``` or a ```pplx::task<etcd:Response>```. You should
-probably use a C++ lambda funcion here as a callback.
+callback should be either a `etcd::Response` or a `pplx::task<etcd:Response>`. You should
+probably use a C++ lambda function here as a callback.
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd.get("/test/key1").then([](etcd::Response response)
   {
     std::cout << response.value().as_string();
@@ -118,22 +186,22 @@ probably use a C++ lambda funcion here as a callback.
   // ... your code can continue here without any delay
 ```
 
-Your lambda function should have a parameter of type ```etcd::Response``` or
-```pplx::task<etcd::Response>```. In the latter case you can get the actual ```etcd::Response```
-object with the ```get()``` function of the task. Calling get can raise exeptions so this is the way
-how you can catch the errors generated by the REST interface. The ```get()``` call will not block in
-this case since the respose has been already arrived (we are inside the callback).
+Your lambda function should have a parameter of type `etcd::Response` or
+`pplx::task<etcd::Response>`. In the latter case you can get the actual `etcd::Response`
+object with the `get()` function of the task. Calling get can raise exceptions so this is the way
+how you can catch the errors generated by the REST interface. The `get()` call will not block in
+this case since the response has been already arrived (we are inside the callback).
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd.get("/test/key1").then([](pplx::task<etcd::Response> response_task)
   {
     try
     {
-      etcd::Response response = response.task.get(); // can throw
+      etcd::Response response = response_task.get(); // can throw
       std::cout << response.value().as_string();
     }
-    catch (std::ecxeption const & ex)
+    catch (std::exception const & ex)
     {
       std::cerr << ex.what();
     }
@@ -142,8 +210,6 @@ this case since the respose has been already arrived (we are inside the callback
   // ... your code can continue here without any delay
 ```
 
-## etcd operations
-
 ### Multiple endpoints
 
 Connecting to multiple endpoints is supported:
@@ -156,6 +222,14 @@ Connecting to multiple endpoints is supported:
   etcd::Client etcd("http://a.com:2379;http://b.com:2379;http://c.com:2379");
 ```
 
+### IPv6
+
+Connecting to IPv6 endpoints is supported:
+
+```c++
+  etcd::Client etcd("http://::1:2379");
+```
+
 Behind the screen, gRPC's load balancer is used and the round-robin strategy will
 be used by default.
 
@@ -171,13 +245,20 @@ the authentication properly.
   etcd::Client etcd("http://127.0.0.1:2379", "root", "root");
 ```
 
-Or the etcd client can be constructed explictly:
+Or the etcd client can be constructed explicitly:
 
 ```c++
   etcd::Client *etcd = etcd::Client::WithUser(
                     "http://127.0.0.1:2379", "root", "root");
 ```
 
+The default authentication token will be expired every 5 minutes (300 seconds), which is controlled by
+the `--auth-token-ttl` flag of etcd. When constructing a etcd client, a customized TTL value is allow:
+
+```c++
+  etcd::Client etcd("http://127.0.0.1:2379", "root", "root", 300);
+```
+
 Enabling v3 authentication requires a bit more work for older versions etcd (etcd 3.2.x and etcd 3.3.x).
 First you need to set the `ETCDCTL_API=3`, then
 
@@ -203,8 +284,8 @@ printf 'root\nroot\n' | /usr/local/bin/etcdctl user add root
 
 Etcd [transport security](https://etcd.io/docs/v3.4.0/op-guide/security/) and certificate based
 authentication have been supported as well. The `Client::Client` could accept arguments `ca` ,
-`cert` and `key` for CA cert, cert and private key files for the SSL/TLS transport and authentication.
-Note that the later arguments `cert` and `key` could be empty strings or omitted if you just need
+`cert` and `privkey` for CA cert, cert and private key files for the SSL/TLS transport and authentication.
+Note that the later arguments `cert` and `privkey` could be empty strings or omitted if you just need
 secure transport and don't enable certificate-based client authentication (using the `--client-cert-auth`
 arguments when launching etcd server).
 
@@ -214,7 +295,7 @@ arguments when launching etcd server).
                     "round_robin");
 ```
 
-Or the etcd client can be constructed explictly:
+Or the etcd client can be constructed explicitly:
 
 ```c++
   etcd::Client *etcd = etcd::Client::WithSSL(
@@ -236,26 +317,148 @@ transport security using openssl.
 
 We also provide a tool [`setup-ca.sh`](./security-config/setup-ca.sh) as a helper for development and testing.
 
+#### transport security & multiple endpoints
+
+If you want to use multiple `https://` endpoints, and you are working with self-signed certificates, you
+may encountered errors like
+
+```
+error: 14: connections to all backends failing
+```
+
+That means your DNS have some problems with your DNS resolver and SSL authority, you could put a domain
+name (a host name) to the `SANS` field when self-signing your certificate, e.g,
+
+```
+"sans": [
+  "etcd",
+  "127.0.0.1",
+  "127.0.0.2",
+  "127.0.0.3"
+],
+```
+
+And pass a `target_name_override` arguments to `WithSSL`,
+
+```cpp
+  etcd::Client *etcd = etcd::Client::WithSSL(
+                    "https://127.0.0.1:2379,https://127.0.0.2:2479",
+                    "example.rootca.cert", "example.cert", "example.key", "etcd");
+```
+
+For more discussion about this feature, see also [#87](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/issues/87),
+[grpc#20186](https://github.com/grpc/grpc/issues/20186) and [grpc#22119](https://github.com/grpc/grpc/issues/22119).
+
+### Fine-grained gRPC channel arguments
+
+By default the etcd-cpp-apiv3 library will set the following arguments for transport layer
+
++ `GRPC_ARG_MAX_SEND_MESSAGE_LENGTH` to `INT_MAX`
++ `GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH` to `INT_MAX`
+
+If _load balancer strategy_ is specified, the following argument will be set
+
++ `GRPC_ARG_LB_POLICY_NAME`
+
+When transport security is enabled and `target_name_override` is specified when working with SSL, the
+following argument will be set
+
++ `GRPC_SSL_TARGET_NAME_OVERRIDE_ARG`
+
+Further, all variants of constructors for `etcd::Client` accepts an extra `grpc::ChannelArguments` argument
+which can be used for fine-grained control the gRPC settings, e.g.,
+
+```cpp
+  grpc::ChannelArguments grpc_args;
+  grpc_args.SetInt(GRPC_ARG_KEEPALIVE_TIME_MS, 2000);
+  grpc_args.SetInt(GRPC_ARG_KEEPALIVE_TIMEOUT_MS, 6000);
+  grpc_args.SetInt(GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS, 1);
+
+  etcd::Client etcd("http://127.0.0.1:2379", grpc_args);
+```
+
+For more motivation and discussion about the above design, please refer to [issue-103](https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/issues/103).
+
+### gRPC timeout when waiting for responses
+
+gRPC Timeout is long-standing missing pieces in the etcd-cpp-apiv3 library. The timeout has been
+supported via a `set_grpc_timeout` interfaces on the client,
+
+```cpp
+  template <typename Rep = std::micro>
+  void set_grpc_timeout(std::chrono::duration<Rep> const &timeout)
+```
+
+Any `std::chrono::duration` value can be used to set the grpc timeout, e.g.,
+
+```cpp
+  etcd.set_grpc_timeout(std::chrono::seconds(5));
+```
+
+Note that the timeout value is the "timeout" when waiting for responses upon the gRPC channel, i.e., `CompletionQueue::AsyncNext`.
+It doesn't means the timeout between issuing a `.set()` method getting the `etcd::Response`, as in the async mode the such a time
+duration is unpredictable and the gRPC timeout should be enough to avoid deadly waiting (e.g., waiting for a `lock()`).
+
+### Error code in responses
+
+The `class etcd::Response` may yield an error code and error message when error occurs,
+
+```cpp
+  int error_code() const;
+  std::string const & error_message() const;
+
+  bool is_ok() const;
+```
+
+The error code would be `0` when succeed, otherwise the error code might be
+
+```cpp
+  extern const int ERROR_GRPC_OK;
+  extern const int ERROR_GRPC_CANCELLED;
+  extern const int ERROR_GRPC_UNKNOWN;
+  extern const int ERROR_GRPC_INVALID_ARGUMENT;
+  extern const int ERROR_GRPC_DEADLINE_EXCEEDED;
+  extern const int ERROR_GRPC_NOT_FOUND;
+  extern const int ERROR_GRPC_ALREADY_EXISTS;
+  extern const int ERROR_GRPC_PERMISSION_DENIED;
+  extern const int ERROR_GRPC_UNAUTHENTICATED;
+  extern const int ERROR_GRPC_RESOURCE_EXHAUSTED;
+  extern const int ERROR_GRPC_FAILED_PRECONDITION;
+  extern const int ERROR_GRPC_ABORTED;
+  extern const int ERROR_GRPC_OUT_OF_RANGE;
+  extern const int ERROR_GRPC_UNIMPLEMENTED;
+  extern const int ERROR_GRPC_INTERNAL;
+  extern const int ERROR_GRPC_UNAVAILABLE;
+  extern const int ERROR_GRPC_DATA_LOSS;
+
+  extern const int ERROR_KEY_NOT_FOUND;
+  extern const int ERROR_COMPARE_FAILED;
+  extern const int ERROR_KEY_ALREADY_EXISTS;
+  extern const int ERROR_ACTION_CANCELLED;
+```
+
+## Etcd operations
+
 ### Reading a value
 
-You can read a value with the ```get``` method of the clinent instance. The only parameter is the
+You can read a value with the `get()` method of the client instance. The only parameter is the
 key to be read. If the read operation is successful then the value of the key can be acquired with
-the ```value()``` method of the response. Success of the operation can be checked with the
-```is_ok()``` method of the response. In case of an error, the ```error_code()``` and
-```error_message()``` methods can be called for some further detail.
+the `value()` method of the response. Success of the operation can be checked with the
+`is_ok()` method of the response. In case of an error, the `error_code()` and
+`error_message()` methods can be called for some further detail.
 
 Please note that there can be two kind of error situations. There can be some problem with the
-communication between the client and the etcd server. In this case the ```get()``` method of the
+communication between the client and the etcd server. In this case the `get()``` method of the
 response task will throw an exception as shown above. If the communication is ok but there is some
-problem with the content of the actual operation, like attemp to read a non-existing key then the
+problem with the content of the actual operation, like attempting to read a non-existing key then the
 response object will give you all the details. Let's see this in an example.
 
 The Value object of the response also holds some extra information besides the string value of the
 key. You can also get the index number of the creation and the last modification of this key with
-the ```created_index()``` and the ```modofied_index()``` methods.
+the `created_index()` and the `modified_index()` methods.
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   pplx::task<etcd::Response> response_task = etcd.get("/test/key1");
 
   try
@@ -266,23 +469,33 @@ the ```created_index()``` and the ```modofied_index()``` methods.
     else
       std::cout << "operation failed, details: " << response.error_message();
   }
-  catch (std::ecxeption const & ex)
+  catch (std::exception const & ex)
   {
     std::cerr << "communication problem, details: " << ex.what();
   }
 ```
 
-### Modifying a value
+### Put a value
 
-Setting the value of a key can be done with the ```set()``` method of the client. You simply pass
-the key and the value as string parameters and you are done. The newly set value object can be asked
-from the response object exactly the same way as in case of the reading (with the ```value()```
-method). This way you can check for example the index value of your modification. You can also check
-what was the previous value that this operation was overwritten. You can do that with the
-```prev_value()``` method of the response object.
+You can put a key-value pair to etcd with the the `put()` method of the client instance. The only
+parameter is the key and value to be put
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
+  pplx::task<etcd::Response> response_task = etcd.put("foo", "bar");
+```
+
+### Modifying a value
+
+Setting the value of a key can be done with the `set()` method of the client. You simply pass
+the key and the value as string parameters and you are done. The newly set value object can be asked
+from the response object exactly the same way as in case of the reading (with the `value()`
+method). This way you can check for example the index value of your modification. You can also check
+what was the previous value that this operation was overwritten. You can do that with the
+`prev_value()` method of the response object.
+
+```c++
+  etcd::Client etcd("http://127.0.0.1:2379");
   pplx::task<etcd::Response> response_task = etcd.set("/test/key1", "42");
 
   try
@@ -294,7 +507,7 @@ what was the previous value that this operation was overwritten. You can do that
     else
       std::cout << "operation failed, details: " << response.error_message();
   }
-  catch (std::ecxeption const & ex)
+  catch (std::exception const & ex)
   {
     std::cerr << "communication problem, details: " << ex.what();
   }
@@ -304,28 +517,29 @@ The set method creates a new leaf node if it weren't exists already or modifies
 There are a couple of other modification methods that are executing the write operation only upon
 some specific conditions.
 
-   * ```add(key, value)``` creates a new value if it's key does not exists and returns a "Key
-     already exists" error otherwise (error code 105)
-   * ```modify(key, value)``` modifies an already existing value or returns a "Key not found" error
-     otherwise (error code 100)
-   * ```modify_if(key, value, old_value)``` modifies an already existing value but only if the previous
-     value equals with old_value. If the values does not match returns with "Compare failed" error
-     (code 101)
-   * ```modify_if(key, value, old_index)``` modifies an already existing value but only if the index of
-     the previous value equals with old_index. If the indices does not match returns with "Compare
-     failed" error (code 101)
+* `add(key, value)` creates a new value if it's key does not exists and returns a "Key
+  already exists" error otherwise (error code `ERROR_KEY_ALREADY_EXISTS`)
+* `modify(key, value)` modifies an already existing value or returns a "etcd-cpp-apiv3: key not found" error
+  otherwise (error code `KEY_NOT_FOUND`)
+* `modify_if(key, value, old_value)` modifies an already existing value but only if the previous
+  value equals with old_value. If the values does not match returns with "Compare failed" error
+  (code `ERROR_COMPARE_FAILED`)
+* `modify_if(key, value, old_index)` modifies an already existing value but only if the index of
+  the previous value equals with old_index. If the indices does not match returns with "Compare
+  failed" error (code `ERROR_COMPARE_FAILED`)
 
 ### Deleting a value
 
-Values can be deleted with the ```rm``` method passing the key to be deleted as a parameter. The key
+Values can be deleted with the `rm` method passing the key to be deleted as a parameter. The key
 should point to an existing value. There are conditional variations for deletion too.
 
-   * ```rm_if(key, value, old_value)``` deletes an already existing value but only if the previous
-     value equals with old_value. If the values does not match returns with "Compare failed" error
-     (code 101)
-   * ```rm_if(key, value, old_index)``` deletes an already existing value but only if the index of
-     the previous value equals with old_index. If the indices does not match returns with "Compare
-     failed" error (code 101)
+* `rm(std::string const& key)` unconditionally deletes the given key
+* `rm_if(key, old_value)` deletes an already existing value but only if the previous
+  value equals with old_value. If the values does not match returns with "Compare failed" error
+  (code `ERROR_COMPARE_FAILED`)
+* `rm_if(key, old_index)` deletes an already existing value but only if the index of
+  the previous value equals with old_index. If the indices does not match returns with "Compare
+  failed" error (code `ERROR_COMPARE_FAILED`)
 
 ### Handling directory nodes
 
@@ -339,78 +553,103 @@ keys defined by the prefix. mkdir method is removed since etcdv3 treats everythi
 
 2. Listing a directory:
 
-  Listing directory in etcd3 cpp client will return all keys that matched the given prefix
-  recursively.
+   Listing directory in etcd3 cpp client will return all keys that matched the given prefix
+   recursively.
 
-  ```c++
-    etcd.set("/test/key1", "value1").wait();
-    etcd.set("/test/key2", "value2").wait();
-    etcd.set("/test/key3", "value3").wait();
-    etcd.set("/test/subdir/foo", "foo").wait();
+   ```c++
+     etcd.set("/test/key1", "value1").wait();
+     etcd.set("/test/key2", "value2").wait();
+     etcd.set("/test/key3", "value3").wait();
+     etcd.set("/test/subdir/foo", "foo").wait();
 
-    etcd::Response resp = etcd.ls("/test/new_dir").get();
-  ```
+     etcd::Response resp = etcd.ls("/test").get();
+   ```
 
-  ```resp.key()``` will have the following values:
+   `resp.key()` will have the following values:
 
-  ```
-  /test/key1
-  /test/key2
-  /test/key3
-  /test/subdir/foo
-  ```
+   ```
+   /test/key1s
+   /test/key2
+   /test/key3
+   /test/subdir/foo
+   ```
 
-  Note: Regarding the returned keys when listing a directory:
+   Note: Regarding the returned keys when listing a directory:
 
-  + In etcdv3 cpp client, resp.key(0) will return "/test/new_dir/key1" since everything is
-    treated as keys in etcdv3.
-  + While in etcdv2 cpp client it will return "key1" and "/test/new_dir" directory should
-    be created first before you can set "key1".
+   + In etcdv3 cpp client, resp.key(0) will return "/test/new_dir/key1" since everything is
+     treated as keys in etcdv3.
+   + While in etcdv2 cpp client it will return "key1" and "/test/new_dir" directory should
+     be created first before you can set "key1".
 
-  When you list a directory the response object's ```keys()``` and ```values()``` methods gives
-  you a vector of key names and values. The ```value()``` method with an integer parameter also
-  returns with the i-th element of the values vector, so ```response.values()[i] ==
-  response.value(i)```.
+   When you list a directory the response object's `keys()` and `values()` methods gives
+   you a vector of key names and values. The `value()` method with an integer parameter also
+   returns with the i-th element of the values vector, so `response.values()[i] == response.value(i)`.
 
-  ```c++
-    etcd::Client etcd("http://127.0.0.1:4001");
-    etcd::Response resp = etcd.ls("/test/new_dir").get();
-    for (int i = 0; i < resp.keys().size(); ++i)
-    {
-      std::cout << resp.keys(i);
-      std::cout << " = " << resp.value(i).as_string() << std::endl;
-    }
-  ```
+   ```c++
+     etcd::Client etcd("http://127.0.0.1:2379");
+     etcd::Response resp = etcd.ls("/test/new_dir").get();
+     for (int i = 0; i < resp.keys().size(); ++i)
+     {
+       std::cout << resp.keys(i);
+       std::cout << " = " << resp.value(i).as_string() << std::endl;
+     }
+   ```
+
+   etcd-cpp-apiv3 supports lists keys only without fetching values from etcd server:
+
+   ```c++
+     etcd::Client etcd("http://127.0.0.1:2379");
+     etcd::Response resp = etcd.keys("/test/new_dir").get();
+     for (int i = 0; i < resp.keys().size(); ++i)
+     {
+       std::cout << resp.keys(i);
+     }
+   ```
 
 3. Removing directory:
 
-If you want the delete recursively then you have to pass a second ```true``` parameter
-to rmdir and supply a key. This key will be treated as a prefix. All keys that match the
-prefix will be deleted. All deleted keys will be placed in ```response.values()``` and
-```response.keys()```. This parameter defaults to ```false```.
+   If you want the delete recursively then you have to pass a second `true` parameter
+   to rmdir and supply a key. This key will be treated as a prefix. All keys that match the
+   prefix will be deleted. All deleted keys will be placed in `response.values()` and
+   `response.keys()`. This parameter defaults to `false`.
+
+   ```c++
+     etcd::Client etcd("http://127.0.0.1:2379");
+     etcd.set("/test/key1", "foo");
+     etcd.set("/test/key2", "bar");
+     etcd.set("/test/key3", "foo_bar");
+     etcd::Response resp = etcd.rmdir("/test", true).get();
+     for (int i = 0; i < resp.keys().size(); ++i)
+     {
+       std::cout << resp.keys(i);
+       std::cout << " = " << resp.value(i).as_string() << std::endl;
+     }
+   ```
+
+   However, if recursive parameter is false, functionality will be the same as just deleting a key.
+   The key supplied will NOT be treated as a prefix and will be treated as a normal key name.
+
+### Using binary data as key and value
+
+Etcd itself support using arbitrary binary data as the key and value, i.e., the key and value
+can contain `\NUL` (`\0`) and not necessary NUL-terminated strings. `std::string` in C++ supports
+embed `\0` as well, but please note that when constructing `std::string` from a C-style string
+the string will be terminated by the first `\0` character. Rather, you need to use the constructor
+with the `count` parameter explicitly. When unpack a `std::string` that contains `\0`, you need
+`.data()`,
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
-  etcd.set("/test/key1", "foo");
-  etcd.set("/test/key2", "bar");
-  etcd.set("/test/key3", "foo_bar");
-  etcd::Response resp = etcd.rmdir("/test", true).get();
-  for (int i = 0; i < resp.keys().size(); ++i)
-  {
-    std::cout << resp.keys(i);
-    std::cout << " = " << resp.value(i).as_string() << std::endl;
-  }
+  std::string key = "key-foo\0bar";
+  std::string value = "value-foo\0bar";
+  etcd.put(key, value).wait();
 ```
 
-However, if recursive parameter is false, functionality will be the same as just deleting a key.
-The key supplied will NOT be treated as a prefix and will be treated as a normal key name.
-
 ### Lock
 
 Etcd lock has been supported as follows:
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd.lock("/test/lock");
 ```
 
@@ -420,28 +659,41 @@ the lock is unlocked.
 Users can also feed their own lease directory for lock:
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd.lock_with_lease("/test/lock", lease_id);
 ```
 
+Note that the arguments for `unlock()` is the the same key that used for `lock()`, but the
+`response.lock_key()` that return by `lock()`:
+
+```c++
+  etcd::Client etcd("http://127.0.0.1:2379");
+
+  // lock
+  auto response = etcd.lock("/test/lock").get();
+
+  // unlock
+  auto _ = etcd.unlock(response.lock_key()).get();
+```
+
 ### Watching for changes
 
-Watching for a change is possible with the ```watch()``` operation of the client. The watch method
+Watching for a change is possible with the `watch()` operation of the client. The watch method
 simply does not deliver a response object until the watched value changes in any way (modified or
 deleted). When a change happens the returned result object will be the same as the result object of
 the modification operation. So if the change is triggered by a value change, then
-```response.action()``` will return "set", ```response.value()``` will hold the new
-value and ```response.prev_value()``` will contain the previous value. In case of a delete
-```response.action()``` will return "delete", ```response.value()``` will be empty and should not be
-called at all and ```response.prev_value()``` will contain the deleted value.
+`response.action()` will return "set", `response.value()` will hold the new
+value and `response.prev_value()` will contain the previous value. In case of a delete
+`response.action()` will return "delete", `response.value()` will be empty and should not be
+called at all and `response.prev_value()` will contain the deleted value.
 
 As mentioned in the section "handling directory nodes", directory nodes are not supported anymore
 in etcdv3.
 
 However it is still possible to watch a whole "directory subtree", or more specifically a set of
-keys that match the prefix, for changes with passing ```true``` to the second ```recursive```
-parameter of ```watch``` (this parameter defaults to ```false``` if omitted). In this case the
-modified value object's ```key()``` method can be handy to determine what key is actually changed.
+keys that match the prefix, for changes with passing `true` to the second `recursive`
+parameter of `watch` (this parameter defaults to `false` if omitted). In this case the
+modified value object's `key()` method can be handy to determine what key is actually changed.
 Since this can be a long lasting operation you have to be prepared that is terminated by an
 exception and you have to restart the watch operation.
 
@@ -468,17 +720,17 @@ void watch_for_changes()
 }
 ```
 
-At first glance it seems that ```watch_for_changes()``` calls itself on every value change but in
-fact it just sends the asynchron request, sets up a callback for the response and then returns. The
+At first glance it seems that `watch_for_changes()` calls itself on every value change but in
+fact it just sends the asynchronous request, sets up a callback for the response and then returns. The
 callback is executed by some thread from the pplx library's thread pool and the callback (in this
-case a small lambda function actually) will call ```watch_for_changes``` again from there.
+case a small lambda function actually) will call `watch_for_changes()` again from there.
 
 #### Watcher Class
 
 Users can watch a key indefinitely or until user cancels the watch. This can be done by
 instantiating a Watcher class. The supplied callback function in Watcher class will be
 called every time there is an event for the specified key. Watch stream will be cancelled
-either by user implicitly calling ```Cancel()``` or when watcher class is destroyed.
+either by user implicitly calling `Cancel()` or when watcher class is destroyed.
 
 ```c++
   etcd::Watcher watcher("http://127.0.0.1:2379", "/test", printResponse);
@@ -487,18 +739,77 @@ either by user implicitly calling ```Cancel()``` or when watcher class is destro
   watcher.Cancel();
   etcd.set("/test/key", "43"); /* print response will NOT be called,
                                   since watch is already cancelled */
+```
+
+#### Watcher re-connection
+
+A watcher will be disconnected from etcd server in some cases, for some examples, the etcd
+server is restarted, or the network is temporarily unavailable. It is users' responsibility
+to decide if a watcher should re-connect to the etcd server.
+
+Here is an example how users can make a watcher re-connect to server after disconnected.
+
+```c++
+// wait the client ready
+void wait_for_connection(etcd::Client &client) {
+  // wait until the client connects to etcd server
+  while (!client.head().get().is_ok()) {
+    sleep(1);
+  }
+}
+
+// a loop for initialized a watcher with auto-restart capability
+void initialize_watcher(const std::string& endpoints,
+                        const std::string& prefix,
+                        std::function<void(etcd::Response)> callback,
+                        std::shared_ptr<etcd::Watcher>& watcher) {
+  etcd::Client client(endpoints);
+  wait_for_connection(client);
+
+  // Check if the failed one has been cancelled first
+  if (watcher && watcher->Cancelled()) {
+    std::cout << "watcher's reconnect loop been cancelled" << std::endl;
+    return;
+  }
+  watcher.reset(new etcd::Watcher(client, prefix, callback, true));
+
+  // Note that lambda requires `mutable`qualifier.
+  watcher->Wait([endpoints, prefix, callback,
+    /* By reference for renewing */ &watcher](bool cancelled) mutable {
+    if (cancelled) {
+      std::cout << "watcher's reconnect loop stopped as been cancelled" << std::endl;
+      return;
+    }
+    initialize_watcher(endpoints, prefix, callback, watcher);
+  });
 }
 ```
 
+The functionalities can be used as
+
+```c++
+std::string endpoints = "http://127.0.0.1:2379";
+std::function<void(Response)> callback = printResponse;
+const std::string prefix = "/test/key";
+
+// the watcher initialized in this way will auto re-connect to etcd
+std::shared_ptr<etcd::Watcher> watcher;
+initialize_watcher(endpoints, prefix, callback, watcher);
+```
+
+For a complete runnable example, see also [./tst/RewatchTest.cpp](./tst/RewatchTest.cpp). Note
+that you shouldn't use the watcher itself inside the `Wait()` callback as the callback will be
+invoked in a separate **detached** thread where the watcher may have been destroyed.
+
 ### Requesting for lease
 
 Users can request for lease which is governed by a time-to-live(TTL) value given by the user.
-Moreover, user can attached the lease to a key(s) by indicating the lease id in ```add()```,
-```set()```, ```modify()``` and ```modify_if()```. Also the ttl will that was granted by etcd
-server will be indicated in ```ttl()```.
+Moreover, user can attached the lease to a key(s) by indicating the lease id in `add()`,
+`set()`, `modify()` and `modify_if()`. Also the ttl will that was granted by etcd
+server will be indicated in `ttl()`.
 
 ```c++
-  etcd::Client etcd("http://127.0.0.1:4001");
+  etcd::Client etcd("http://127.0.0.1:2379");
   etcd::Response resp = etcd.leasegrant(60).get();
   etcd.set("/test/key2", "bar", resp.value().lease());
   std::cout << "ttl" << resp.value().ttl();
@@ -526,13 +837,13 @@ The remaining time-to-live of a lease can be inspected by
 
 #### Keep alive
 
-Keep alive for leases is implemented using a seperate class `KeepAlive`, which can be used as:
+Keep alive for leases is implemented using a separate class `KeepAlive`, which can be used as:
 
 ```c++
   etcd::KeepAlive keepalive(etcd, ttl, lease_id);
 ```
 
-It will perform a periodly keep-alive action before it is cancelled explicitly, or destructed implicitly.
+It will perform a period keep-alive action before it is cancelled explicitly, or destructed implicitly.
 
 `KeepAlive` may fails (e.g., when the etcd server stopped unexpectedly), the constructor of `KeepAlive`
 could accept a handler of type `std::function<std::exception_ptr>` and the handler will be invoked
@@ -559,7 +870,115 @@ is constructed.
 Without handler, the internal state can be checked via `KeepAlive::Check()` and it will rethrow
 the async exception when there are errors during keeping the lease alive.
 
-### TODO
+Note that even with `handler`, the `KeepAlive::Check()` still rethrow if there's an async exception.
+When the library is built with `-fno-exceptions`, the `handler` argument and the `Check()` method
+will abort the program when there are errors during keeping the lease alive.
+
+### Etcd transactions
+
+Etcd v3's [Transaction APIs](https://etcd.io/docs/v3.4/learning/api/#transaction) is supported via the
+`etcdv3::Transaction` interfaces. A set of convenient APIs are use to add operations to a transaction, e.g.,
+
+```cpp
+  etcdv3::Transaction txn;
+  txn.setup_put("/test/x1", "1");
+  txn.setup_put("/test/x2", "2");
+  txn.setup_put("/test/x3", "3");
+  etcd::Response resp = etcd.txn(txn).get();
+```
+
+Transactions in etcd supports set a set of comparison targets to specify the condition of transaction, e.g.,
+
+```cpp
+  etcdv3::Transaction txn;
+
+  // setup the conditions
+  txn.add_compare_value("/test/x1", "1");
+  txn.add_compare_value("/test/x2", "2");
+
+  // or, compare the last modified revision
+  txn.add_compare_mod("/test/x3", 0);  // not exists
+  txn.add_compare_mod("/test/x4", etcdv3::CompareResult::GREATER, 1234);  // the modified revision is greater than 1234
+```
+
+High-level APIs (e.g., `compare_and_create`, `compare_and_swap`) are also provided, e.g.,
+`fetch-and-add` operation can be implemented as
+
+```cpp
+  auto fetch_and_add = [](etcd::Client& client,
+                          std::string const& key) -> void {
+    auto value = stoi(client.get(key).get().value().as_string());
+    while (true) {
+      auto txn = etcdv3::Transaction();
+      txn.setup_compare_and_swap(key, std::to_string(value),
+                                 std::to_string(value + 1));
+      etcd::Response resp = client.txn(txn).get();
+      if (resp.is_ok()) {
+        break;
+      }
+      value = stoi(resp.value().as_string());
+    }
+  };
+```
+
+See full example of the usages of transaction APIs, please refer to [./tst/TransactionTest.cpp](./tst/TransactionTest.cpp),
+for full list of the transaction operation APIs, see [./etcd/v3/Transaction.hpp](./etcd/v3/Transaction.hpp).
+
+### Election API
+
+Etcd v3's [election APIs](https://github.com/etcd-io/etcd/blob/main/server/etcdserver/api/v3election/v3electionpb/v3election.proto)
+are supported via the following interfaces,
+
+```c++
+pplx::task<Response> campaign(std::string const &name, int64_t lease_id,
+                              std::string const &value);
+
+pplx::task<Response> proclaim(std::string const &name, int64_t lease_id,
+                              std::string const &key, int64_t revision,
+                              std::string const &value);
+
+pplx::task<Response> leader(std::string const &name);
+
+std::unique_ptr<SyncClient::Observer> observe(std::string const &name);
+
+pplx::task<Response> resign(std::string const &name, int64_t lease_id,
+                            std::string const &key, int64_t revision);
+```
+
+Note that if grpc timeout is set, `campaign()` will return an timeout error response if it
+cannot acquire the election ownership within the timeout period. Otherwise will block until
+become the leader.
+
+The `Observer` returned by `observe()` can be use to monitor the changes of election ownership.
+The observer stream will be canceled when been destructed.
+
+```c++
+  std::unique_ptr<etcd::SyncClient::Observer> observer = etcd.observe("test");
+
+  // wait one change event, blocked execution
+  etcd::Response resp = observer->WaitOnce();
+
+  // wait many change events, blocked execution
+  for (size_t i = 0; i < ...; ++i) {
+    etcd::Response resp = observer->WaitOnce();
+    ...
+  }
+
+  // cancel the observer
+  observer.reset(nullptr);
+```
+
+for more details, please refer to [etcd/Client.hpp](./etcd/Client.hpp) and [tst/ElectionTest.cpp](./tst/ElectionTest.cpp).
+
+## `-fno-exceptions`
+
+The _etcd-cpp-apiv3_ library supports to be built with `-fno-exceptions` flag, controlled by the
+cmake option `BUILD_WITH_NO_EXCEPTIONS=ON/OFF` (defaults to `OFF`).
+
+When building with `-fno-exceptions`, the library will abort the program under certain circumstances,
+e.g., when calling `.Check()` method of `KeepAlive` and there are errors during keeping the lease alive,
+
+## TODO
 
 1. Cancellation of asynchronous calls(except for watch)
 

cmake/FindGRPC.cmake

@@ -22,51 +22,89 @@ mark_as_advanced(GRPC_INCLUDE_DIR)
 # Find gGPR library
 find_library(GPR_LIBRARY NAMES gpr)
 mark_as_advanced(GRPC_GPR_LIBRARY)
-add_library(gRPC::gpr UNKNOWN IMPORTED)
-set_target_properties(gRPC::gpr PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES "-lpthread;-ldl"
-    IMPORTED_LOCATION ${GPR_LIBRARY}
-)
+if(NOT TARGET gRPC::gpr)
+    add_library(gRPC::gpr UNKNOWN IMPORTED)
+    set_target_properties(gRPC::gpr PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
+        INTERFACE_LINK_LIBRARIES "-lpthread;-ldl"
+        IMPORTED_LOCATION ${GPR_LIBRARY}
+    )
+endif()
 
 # Find gRPC library
 find_library(GRPC_LIBRARY NAMES grpc)
 mark_as_advanced(GRPC_LIBRARY)
-add_library(gRPC::grpc UNKNOWN IMPORTED)
-set_target_properties(gRPC::grpc PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES gRPC::gpr
-    IMPORTED_LOCATION ${GRPC_LIBRARY}
-)
+if(NOT TARGET gRPC::grpc)
+    add_library(gRPC::grpc UNKNOWN IMPORTED)
+    set_target_properties(gRPC::grpc PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
+        INTERFACE_LINK_LIBRARIES gRPC::gpr
+        IMPORTED_LOCATION ${GRPC_LIBRARY}
+    )
+endif()
 
 # Find gRPC C++ library
 find_library(GRPC_GRPC++_LIBRARY NAMES grpc++)
 mark_as_advanced(GRPC_GRPC++_LIBRARY)
-add_library(gRPC::grpc++ UNKNOWN IMPORTED)
-set_target_properties(gRPC::grpc++ PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES gRPC::grpc
-    IMPORTED_LOCATION ${GRPC_GRPC++_LIBRARY}
-)
+if(NOT TARGET gRPC::grpc++)
+    add_library(gRPC::grpc++ UNKNOWN IMPORTED)
+    set_target_properties(gRPC::grpc++ PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
+        INTERFACE_LINK_LIBRARIES gRPC::grpc
+        IMPORTED_LOCATION ${GRPC_GRPC++_LIBRARY}
+    )
+endif()
 
 # Find gRPC C++ reflection library
 find_library(GRPC_GRPC++_REFLECTION_LIBRARY NAMES grpc++_reflection)
 mark_as_advanced(GRPC_GRPC++_REFLECTION_LIBRARY)
-add_library(gRPC::grpc++_reflection UNKNOWN IMPORTED)
-set_target_properties(gRPC::grpc++_reflection PROPERTIES
-    INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES gRPC::grpc++
-    IMPORTED_LOCATION ${GRPC_GRPC++_REFLECTION_LIBRARY}
-)
+if(NOT TARGET gRPC::grpc++_reflection)
+    add_library(gRPC::grpc++_reflection UNKNOWN IMPORTED)
+    set_target_properties(gRPC::grpc++_reflection PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES ${GRPC_INCLUDE_DIR}
+        INTERFACE_LINK_LIBRARIES gRPC::grpc++
+        IMPORTED_LOCATION ${GRPC_GRPC++_REFLECTION_LIBRARY}
+    )
+endif()
 
 # Find gRPC CPP generator
 find_program(GRPC_CPP_PLUGIN NAMES grpc_cpp_plugin)
 mark_as_advanced(GRPC_CPP_PLUGIN)
-add_executable(gRPC::grpc_cpp_plugin IMPORTED)
-set_target_properties(gRPC::grpc_cpp_plugin PROPERTIES
-    IMPORTED_LOCATION ${GRPC_CPP_PLUGIN}
-)
+if(NOT TARGET gRPC::grpc_cpp_plugin)
+    add_executable(gRPC::grpc_cpp_plugin IMPORTED)
+    set_target_properties(gRPC::grpc_cpp_plugin PROPERTIES
+        IMPORTED_LOCATION ${GRPC_CPP_PLUGIN}
+    )
+endif()
+
+file(
+    WRITE "${CMAKE_BINARY_DIR}/get_gRPC_version.cc"
+[====[
+#include <grpc++/grpc++.h>
+#include <iostream>
+int main() {
+  std::cout << grpc::Version(); // no newline to simplify CMake module
+  return 0;
+}
+]====])
+
+try_run(
+    _gRPC_GET_VERSION_STATUS
+    _gRPC_GET_VERSION_COMPILE_STATUS
+    "${CMAKE_BINARY_DIR}"
+    "${CMAKE_BINARY_DIR}/get_gRPC_version.cc"
+    CMAKE_FLAGS
+    -DCMAKE_CXX_STANDARD=11
+    LINK_LIBRARIES
+    gRPC::grpc++
+    gRPC::grpc
+    COMPILE_OUTPUT_VARIABLE _gRPC_GET_VERSION_COMPILE_OUTPUT
+    RUN_OUTPUT_VARIABLE gRPC_VERSION)
+
+file(REMOVE "${CMAKE_BINARY_DIR}/get_gRPC_version.cc")
 
 include(${CMAKE_ROOT}/Modules/FindPackageHandleStandardArgs.cmake)
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(gRPC DEFAULT_MSG
-    GPR_LIBRARY GRPC_LIBRARY GRPC_INCLUDE_DIR GRPC_GRPC++_REFLECTION_LIBRARY GRPC_CPP_PLUGIN)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(gRPC
+  FOUND_VAR gRPC_FOUND
+  REQUIRED_VARS GRPC_LIBRARY GPR_LIBRARY GRPC_INCLUDE_DIR GRPC_GRPC++_REFLECTION_LIBRARY GRPC_CPP_PLUGIN
+  VERSION_VAR gRPC_VERSION)

etcd-cpp-api-config.in.cmake

@@ -14,6 +14,7 @@ if(NOT gRPC_FOUND)
     list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
     find_dependency(GRPC)
 endif()
+
 find_dependency(cpprestsdk)
 if(cpprestsdk_FOUND)
     set(CPPREST_LIB cpprestsdk::cpprest)
@@ -22,12 +23,17 @@ endif()
 set(ETCD_CPP_HOME "${CMAKE_CURRENT_LIST_DIR}/../../..")
 include("${CMAKE_CURRENT_LIST_DIR}/etcd-targets.cmake")
 
+set(etcd-cpp-api_FOUND TRUE)
 set(ETCD_CPP_LIBRARIES etcd-cpp-api)
+set(ETCD_CPP_CORE_LIBRARIES etcd-cpp-api-core)
 set(ETCD_CPP_INCLUDE_DIR "${ETCD_CPP_HOME}/include")
 set(ETCD_CPP_INCLUDE_DIRS "${ETCD_CPP_INCLUDE_DIR}")
 
 include(FindPackageMessage)
 find_package_message(etcd
     "Found etcd: ${CMAKE_CURRENT_LIST_FILE} (found version \"@etcd-cpp-api_VERSION@\")"
-    "etcd-cpp-apiv3 version: @etcd-cpp-api_VERSION@\netcd-cpp-apiv3 libraries: ${ETCD_CPP_LIBRARIES}, include directories: ${ETCD_CPP_INCLUDE_DIRS}"
+    "etcd-cpp-apiv3 version: @etcd-cpp-api_VERSION@\n"
+    "etcd-cpp-apiv3 libraries: ${ETCD_CPP_LIBRARIES}\n"
+    "etcd-cpp-apiv3 core libraries: ${ETCD_CPP_CORE_LIBRARIES}\n"
+    "include directories: ${ETCD_CPP_INCLUDE_DIRS}"
 )

etcd/KeepAlive.hpp

@@ -2,96 +2,122 @@
 #define __ETCD_KEEPALIVE_HPP__
 
 #include <atomic>
+#include <chrono>
+#include <condition_variable>
 #include <exception>
 #include <functional>
+#include <mutex>
 #include <string>
 #include <thread>
 
-#include "etcd/Client.hpp"
 #include "etcd/Response.hpp"
+#include "etcd/SyncClient.hpp"
 
-#include <boost/config.hpp>
-#if BOOST_VERSION >= 106600
-#include <boost/asio/io_context.hpp>
-#else
-#include <boost/asio/io_service.hpp>
-#endif
-#include <boost/asio/steady_timer.hpp>
+namespace etcd {
+// forward declaration to avoid header/library dependency
+class Client;
+
+/**
+ * If ID is set to 0, the library will choose an ID, and can be accessed from
+ * ".Lease()".
+ */
+class KeepAlive {
+ public:
+  KeepAlive(Client const& client, int ttl, int64_t lease_id = 0);
+  KeepAlive(SyncClient const& client, int ttl, int64_t lease_id = 0);
+  KeepAlive(std::string const& address, int ttl, int64_t lease_id = 0);
+  KeepAlive(std::string const& address, std::string const& username,
+            std::string const& password, int ttl, int64_t lease_id = 0,
+            int const auth_token_ttl = 300);
+
+  KeepAlive(Client const& client,
+            std::function<void(std::exception_ptr)> const& handler, int ttl,
+            int64_t lease_id = 0);
+  KeepAlive(SyncClient const& client,
+            std::function<void(std::exception_ptr)> const& handler, int ttl,
+            int64_t lease_id = 0);
+  KeepAlive(std::string const& address,
+            std::function<void(std::exception_ptr)> const& handler, int ttl,
+            int64_t lease_id = 0);
+  KeepAlive(std::string const& address, std::string const& username,
+            std::string const& password,
+            std::function<void(std::exception_ptr)> const& handler, int ttl,
+            int64_t lease_id = 0, int const auth_token_ttl = 300);
+  KeepAlive(std::string const& address, std::string const& ca,
+            std::string const& cert, std::string const& privkey,
+            std::function<void(std::exception_ptr)> const& handler, int ttl,
+            int64_t lease_id = 0, std::string const& target_name_override = "");
+
+  KeepAlive(KeepAlive const&) = delete;
+  KeepAlive(KeepAlive&&) = delete;
+
+  int64_t Lease() const { return lease_id; }
 
-namespace etcd
-{
   /**
-   * If ID is set to 0, the library will choose an ID, and can be accessed from ".Lease()".
+   * Stop the keep alive action.
    */
-  class KeepAlive
-  {
-  public:
-    KeepAlive(Client const &client,
-              int ttl, int64_t lease_id=0);
-    KeepAlive(std::string const & address,
-              int ttl, int64_t lease_id=0);
-    KeepAlive(std::string const & address,
-              std::string const & username, std::string const & password,
-              int ttl, int64_t lease_id=0);
+  void Cancel();
 
-    KeepAlive(Client const &client,
-              std::function<void (std::exception_ptr)> const &handler,
-              int ttl, int64_t lease_id=0);
-    KeepAlive(std::string const & address,
-              std::function<void (std::exception_ptr)> const &handler,
-              int ttl, int64_t lease_id=0);
-    KeepAlive(std::string const & address,
-              std::string const & username, std::string const & password,
-              std::function<void (std::exception_ptr)> const &handler,
-              int ttl, int64_t lease_id=0);
+  /**
+   * Check if the keep alive is still valid (invalid when there's an async
+   * exception).
+   *
+   * Nothing will happen if valid and an exception will be rethrowed if invalid.
+   */
+  void Check();
 
-    KeepAlive(KeepAlive const &) = delete;
-    KeepAlive(KeepAlive &&) = delete;
+  /**
+   * Set a timeout value for grpc operations.
+   */
+  template <typename Rep = std::micro>
+  void set_grpc_timeout(std::chrono::duration<Rep> const& timeout) {
+    this->grpc_timeout =
+        std::chrono::duration_cast<std::chrono::milliseconds>(timeout);
+  }
 
-    int64_t Lease() const { return lease_id; }
+  /**
+   * Get the current timeout value for grpc operations.
+   */
+  std::chrono::microseconds get_grpc_timeout() const {
+    return this->grpc_timeout;
+  }
 
-    /**
-     * Stop the keep alive action.
-     */
-    void Cancel();
+  ~KeepAlive();
 
-    /**
-     * Check if the keep alive is still valid (invalid when there's an async exception).
-     *
-     * Nothing will happen if valid and an exception will be rethrowed if invalid.
-     */
-    void Check();
+ protected:
+  // automatically refresh loop, returns the error message if failed
+  std::string refresh();
+  // refresh once immediately, returns the error message if failed
+  std::string refresh_once();
 
-    ~KeepAlive();
-
-  protected:
-    void refresh();
-
-    struct EtcdServerStubs;
-    struct EtcdServerStubsDeleter {
-      void operator()(EtcdServerStubs *stubs);
-    };
-    std::unique_ptr<EtcdServerStubs, EtcdServerStubsDeleter> stubs;
-
-  private:
-    // error handling
-    std::exception_ptr eptr_;
-    std::function<void (std::exception_ptr)> handler_;
-
-    // Don't use `pplx::task` to avoid sharing thread pool with other actions on the client
-    // to avoid any potential blocking, which may block the keepalive loop and evict the lease.
-    std::thread task_;
-
-    int ttl;
-    int64_t lease_id;
-    std::atomic_bool continue_next;
-#if BOOST_VERSION >= 106600
-    boost::asio::io_context context;
-#else
-    boost::asio::io_service context;
-#endif
-    std::unique_ptr<boost::asio::steady_timer> keepalive_timer_;
+  struct EtcdServerStubs;
+  struct EtcdServerStubsDeleter {
+    void operator()(EtcdServerStubs* stubs);
   };
-}
+  std::unique_ptr<EtcdServerStubs, EtcdServerStubsDeleter> stubs;
+
+ private:
+  // error handling
+  std::exception_ptr eptr_;
+  std::function<void(std::exception_ptr)> handler_;
+
+  // Don't use `pplx::task` to avoid sharing thread pool with other actions on
+  // the client to avoid any potential blocking, which may block the keepalive
+  // loop and evict the lease.
+  std::thread refresh_task_;
+
+  int ttl;
+  int64_t lease_id;
+
+  // protect the initializing status of `timer`.
+  std::mutex mutex_for_refresh_;
+  std::condition_variable cv_for_refresh_;
+  std::atomic_bool continue_next;
+
+  // grpc timeout in `refresh()`
+  mutable std::chrono::microseconds grpc_timeout =
+      std::chrono::microseconds::zero();
+};
+}  // namespace etcd
 
 #endif

etcd/Response.hpp

@@ -1,170 +1,262 @@
 #ifndef __ETCD_RESPONSE_HPP__
 #define __ETCD_RESPONSE_HPP__
 
+#include <chrono>
+#include <functional>
 #include <iostream>
+#include <memory>
 #include <string>
 #include <vector>
 
-#include "pplx/pplxtasks.h"
-
 #include "etcd/Value.hpp"
-#include "kv.pb.h"
+#include "etcd/v3/Member.hpp"
 
 namespace etcdv3 {
-  class AsyncWatchAction;
-  class AsyncLeaseKeepAliveAction;
-  class V3Response;
-}
+class AsyncWatchAction;
+class AsyncLeaseKeepAliveAction;
+class AsyncObserveAction;
+class V3Response;
+}  // namespace etcdv3
 
-namespace etcd
-{
-  typedef std::vector<std::string> Keys;
+namespace etcd {
+typedef std::vector<std::string> Keys;
+
+namespace detail {
+// Compute the duration between given start time point and now
+inline const std::chrono::microseconds duration_till_now(
+    std::chrono::high_resolution_clock::time_point const& start_timepoint) {
+  return std::chrono::duration_cast<std::chrono::microseconds>(
+      std::chrono::high_resolution_clock::now() - start_timepoint);
+}
+}  // namespace detail
+
+// forward declaration
+class KeepAlive;
+class Watcher;
+
+/**
+ * The Response object received for the requests of etcd::Client
+ */
+class Response {
+ public:
+  template <typename T>
+  static etcd::Response create(std::unique_ptr<T> call) {
+    call->waitForResponse();
+    auto v3resp = call->ParseResponse();
+    return etcd::Response(v3resp,
+                          detail::duration_till_now(call->startTimepoint()));
+  }
+
+  template <typename T>
+  static etcd::Response create(std::shared_ptr<T> call) {
+    call->waitForResponse();
+    auto v3resp = call->ParseResponse();
+    return etcd::Response(v3resp,
+                          detail::duration_till_now(call->startTimepoint()));
+  }
+
+  template <typename T>
+  static etcd::Response create(std::unique_ptr<T> call,
+                               std::function<void(Response)> callback) {
+    call->waitForResponse(callback);
+    auto v3resp = call->ParseResponse();
+    return etcd::Response(v3resp,
+                          detail::duration_till_now(call->startTimepoint()));
+  }
+
+  template <typename T>
+  static etcd::Response create(std::function<std::unique_ptr<T>()> fn) {
+    auto call = fn();
+
+    call->waitForResponse();
+    auto v3resp = call->ParseResponse();
+    return etcd::Response(v3resp,
+                          detail::duration_till_now(call->startTimepoint()));
+  }
+
+  template <typename T>
+  static etcd::Response create(std::function<std::shared_ptr<T>()> fn) {
+    auto call = fn();
+
+    call->waitForResponse();
+    auto v3resp = call->ParseResponse();
+    return etcd::Response(v3resp,
+                          detail::duration_till_now(call->startTimepoint()));
+  }
+
+  Response();
+
+  Response(const Response&);
 
   /**
-   * The Reponse object received for the requests of etcd::Client
+   * Returns the error code received from the etcd server. In case of success
+   * the error code is 0.
    */
-  class Response
-  {
-  public:
+  int error_code() const;
 
-    template <typename T>
-    static pplx::task<etcd::Response> create(std::shared_ptr<T> call)
-    {
-      return pplx::task<etcd::Response>([call]()
-      {
-        call->waitForResponse();
-        auto v3resp = call->ParseResponse();
+  /**
+   * Returns the string representation of the error code
+   */
+  std::string const& error_message() const;
 
-        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-            std::chrono::high_resolution_clock::now() - call->startTimepoint());
-        return etcd::Response(v3resp, duration);
-      });
-    }
+  /**
+   * Returns true if this is a successful response
+   */
+  bool is_ok() const;
 
-    template <typename T>
-    static pplx::task<etcd::Response> create(std::function<std::shared_ptr<T>()> callfn)
-    {
-      return pplx::task<etcd::Response>([callfn]()
-      {
-        auto call = callfn();
+  /**
+   * Returns true if the error is a network unavailable error.
+   */
+  bool is_network_unavailable() const;
 
-        call->waitForResponse();
-        auto v3resp = call->ParseResponse();
+  /**
+   * Check whether the response contains a grpc TIMEOUT error.
+   */
+  bool is_grpc_timeout() const;
 
-        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-            std::chrono::high_resolution_clock::now() - call->startTimepoint());
-        return etcd::Response(v3resp, duration);
-      });
-    }
+  /**
+   * Returns the action type of the operation that this response belongs to.
+   */
+  std::string const& action() const;
 
-    template <typename T>
-    static etcd::Response create_sync(std::shared_ptr<T> call)
-    {
-      call->waitForResponse();
-      auto v3resp = call->ParseResponse();
+  /**
+   * Returns the current index value of etcd
+   */
+  int64_t index() const;
 
-      auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-          std::chrono::high_resolution_clock::now() - call->startTimepoint());
-      return etcd::Response(v3resp, duration);
-    }
+  /**
+   * Returns the value object of the response to a get/set/modify operation.
+   */
+  Value const& value() const;
 
-    Response();
+  /**
+   * Returns the previous value object of the response to a set/modify/rm
+   * operation.
+   */
+  Value const& prev_value() const;
 
-    /**
-     * Returns true if this is a successful response
-     */
-    bool is_ok() const;
+  /**
+   * Returns the index-th value of the response to an 'ls' operation. Equivalent
+   * to values()[index]
+   */
+  Value const& value(int index) const;
 
-    /**
-     * Returns true if the error is a network unavailable error.
-     */
-    bool is_network_unavailable() const;
+  /**
+   * Returns the vector of values in a directory in response to an 'ls'
+   * operation.
+   */
+  Values const& values() const;
 
-    /**
-     * Returns the error code received from the etcd server. In case of success the error code is 0.
-     */
-    int error_code() const;
+  /**
+   * Returns the vector of keys in a directory in response to an 'ls' operation.
+   */
+  Keys const& keys() const;
 
-    /**
-     * Returns the string representation of the error code
-     */
-    std::string const & error_message() const;
+  /**
+   * Returns the index-th key in a directory listing. Same as keys()[index]
+   */
+  std::string const& key(int index) const;
 
-    /**
-     * Returns the action type of the operation that this response belongs to.
-     */
-    std::string const & action() const;
+  /**
+   * Returns the compact_revision if the response is a watch-cancelled revision.
+   * `-1` means uninitialized (the response is not watch-cancelled)
+   */
+  int64_t compact_revision() const;
 
-    /**
-     * Returns the current index value of etcd
-     */
-    int index() const;
+  /**
+   * Returns the watcher id for client.watch() requests. `-1` means
+   * uninitialized (the response is not for watch).
+   */
+  int64_t watch_id() const;
 
-    /**
-     * Returns the value object of the response to a get/set/modify operation.
-     */
-    Value const & value() const;
+  /**
+   * Returns the lock key.
+   */
+  std::string const& lock_key() const;
 
-    /**
-     * Returns the previous value object of the response to a set/modify/rm operation.
-     */
-    Value const & prev_value() const;
+  /**
+   * Return the "name" in response.
+   */
+  std::string const& name() const;
 
-    /**
-     * Returns the index-th value of the response to an 'ls' operation. Equivalent to values()[index]
-     */
-    Value const & value(int index) const;
+  /**
+   * Returns the watched events.
+   */
+  std::vector<Event> const& events() const;
 
-    /**
-     * Returns the vector of values in a directory in response to an 'ls' operation.
-     */
-    Values const & values() const;
+  /**
+   * Returns the duration of request execution in microseconds.
+   */
+  std::chrono::microseconds const& duration() const;
 
-    /**
-     * Returns the vector of keys in a directory in response to an 'ls' operation.
-     */
-    Keys const & keys() const;
+  /**
+   * Returns the current cluster id.
+   */
+  uint64_t cluster_id() const;
 
-    /**
-     * Returns the index-th key in a directory listing. Same as keys()[index]
-     */
-    std::string const & key(int index) const;
+  /**
+   * Returns the current member id.
+   */
+  uint64_t member_id() const;
 
-    /**
-     * Returns the lock key.
-     */
-    std::string const & lock_key() const;
+  /**
+   * Returns ther current raft term.
+   */
+  uint64_t raft_term() const;
 
-    /**
-     * Returns the watched events.
-     */
-    std::vector<mvccpb::Event> const & events() const;
+  /**
+   * Returns ther current raft term.
+   */
+  std::vector<int64_t> const& leases() const;
 
-    /**
-     * Returns the duration of request execution in microseconds.
-     */
-    std::chrono::microseconds const & duration() const;
+  /**
+   * Returns the member list.
+   */
+  std::vector<etcdv3::Member> const& members() const;
 
-  protected:
-    Response(const etcdv3::V3Response& response, std::chrono::microseconds const& duration);
-    Response(int error_code, char const * error_message);
+ protected:
+  Response(const etcdv3::V3Response& response,
+           std::chrono::microseconds const& duration);
+  Response(int error_code, std::string const& error_message);
+  Response(int error_code, char const* error_message);
 
-    int         _error_code;
-    std::string _error_message;
-    int         _index;
-    std::string _action;
-    Value       _value;
-    Value       _prev_value;
-    Values      _values;
-    Keys        _keys;
-    std::string _lock_key; // for lock
-    std::vector<mvccpb::Event> _events; // for watch
-    std::chrono::microseconds _duration; // execute duration (in microseconds), during the action created and response parsed
-    friend class SyncClient;
-    friend class etcdv3::AsyncWatchAction;
-    friend class etcdv3::AsyncLeaseKeepAliveAction;
-    friend class Client;
-  };
-}
+  int _error_code;
+  std::string _error_message;
+  int64_t _index;
+  std::string _action;
+  Value _value;
+  Value _prev_value;
+  Values _values;
+  Keys _keys;
+  int64_t _compact_revision = -1;  // for watch
+  int64_t _watch_id = -1;          // for watch
+  std::string _lock_key;           // for lock
+  std::string _name;               // for campaign (in v3election)
+  std::vector<Event> _events;      // for watch
+  // execute duration (in microseconds), during the action created and response
+  // parsed
+  std::chrono::microseconds _duration;
+
+  // cluster metadata
+  uint64_t _cluster_id;
+  uint64_t _member_id;
+  uint64_t _raft_term;
+
+  // for lease list
+  std::vector<int64_t> _leases;
+
+  // for member list
+  std::vector<etcdv3::Member> _members;
+
+  friend class Client;
+  friend class SyncClient;
+  friend class KeepAlive;
+  friend class Watcher;
+
+  friend class etcdv3::AsyncWatchAction;
+  friend class etcdv3::AsyncLeaseKeepAliveAction;
+  friend class etcdv3::AsyncObserveAction;
+};
+}  // namespace etcd
 
 #endif

etcd/Value.hpp

@@ -5,67 +5,131 @@
 #include <vector>
 
 namespace etcdv3 {
-  class KeyValue;
+class KeyValue;
 }
 
-namespace etcd
-{
+namespace mvccpb {
+class KeyValue;
+class Event;
+}  // namespace mvccpb
+
+namespace electionpb {
+class LeaderKey;
+}
+
+namespace etcd {
+class Value;
+class Event;
+class Response;
+class Client;
+class SyncClient;
+
+/**
+ * Represents a value object received from the etcd server
+ */
+class Value {
+ public:
   /**
-   * Represents a value object received from the etcd server
+   * Returns true if this value represents a directory on the server. If true
+   * the as_string() method is meaningless.
    */
-  class Value
-  {
-  public:
-    /**
-     * Returns true if this value represents a directory on the server. If true the as_string()
-     * method is meaningless.
-     */
-    bool is_dir() const;
+  bool is_dir() const;
 
-    /**
-     * Returns the key of this value as an "absolute path".
-     */
-    std::string const & key() const;
+  /**
+   * Returns the key of this value as an "absolute path".
+   */
+  std::string const& key() const;
 
-    /**
-     * Returns the string representation of the value
-     */
-    std::string const & as_string() const;
+  /**
+   * Returns the string representation of the value
+   */
+  std::string const& as_string() const;
 
-    /**
-     * Returns the creation index of this value.
-     */
-    int created_index() const;
+  /**
+   * Returns the creation index of this value.
+   */
+  int64_t created_index() const;
 
-    /**
-     * Returns the last modification's index of this value.
-     */
-    int modified_index() const;
+  /**
+   * Returns the last modification's index of this value.
+   */
+  int64_t modified_index() const;
 
-    /**
-     * Returns the ttl of this value or 0 if ttl is not set
-     */
-    int ttl() const;
+  /**
+   * Returns the version of this value.
+   */
+  int64_t version() const;
 
-    int64_t lease() const;
+  /**
+   * Returns the ttl of this value or 0 if ttl is not set
+   */
+  int ttl() const;
 
-  protected:
-    friend class Response;
-    friend class BaseResponse; //deliberately done since Value class will be removed during full V3
-    friend class DeleteRpcResponse;
-    friend class AsyncDeleteResponse;
-    Value();
-    Value(etcdv3::KeyValue const & kvs);
-    std::string _key;
-    bool        dir;
-    std::string value;
-    int         created;
-    int         modified;
-    int         _ttl;
-    int64_t     leaseId;
+  int64_t lease() const;
+
+ protected:
+  friend class Client;
+  friend class SyncClient;
+  friend class Response;
+  friend class BaseResponse;  // deliberately done since Value class will be
+                              // removed during full V3
+  friend class DeleteRpcResponse;
+  friend class AsyncDeleteResponse;
+
+  friend class Event;
+
+  Value();
+  Value(etcdv3::KeyValue const& kvs);
+  Value(mvccpb::KeyValue const& kvs);
+  std::string _key;
+  bool dir;
+  std::string value;
+  int64_t created;
+  int64_t modified;
+  int64_t _version;
+  int _ttl;
+  int64_t leaseId;
+};
+
+using Values = std::vector<Value>;
+
+std::ostream& operator<<(std::ostream& os, const Value& value);
+
+class Event {
+ public:
+  enum class EventType {
+    PUT,
+    DELETE_,
+    INVALID,
   };
 
-  typedef std::vector<Value> Values;
-}
+  enum EventType event_type() const;
+
+  bool has_kv() const;
+
+  bool has_prev_kv() const;
+
+  const Value& kv() const;
+
+  const Value& prev_kv() const;
+
+ protected:
+  friend class Response;
+
+  Event(mvccpb::Event const& event);
+
+ private:
+  enum EventType event_type_;
+  Value _kv, _prev_kv;
+  bool _has_kv, _has_prev_kv;
+};
+
+using Events = std::vector<Event>;
+
+std::ostream& operator<<(std::ostream& os, const Event::EventType& value);
+
+std::ostream& operator<<(std::ostream& os, const Event& event);
+
+}  // namespace etcd
 
 #endif

etcd/Watcher.hpp

@@ -6,101 +6,204 @@
 #include <string>
 #include <thread>
 
-#include "etcd/Client.hpp"
 #include "etcd/Response.hpp"
 
-namespace etcd
-{
-  class Watcher
-  {
-  public:
-    Watcher(Client const &client, std::string const & key,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(Client const &client, std::string const & key,
-            std::string const &range_end,
-            std::function<void(Response)> callback);
-    Watcher(Client const &client, std::string const & key, int fromIndex,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(Client const &client, std::string const & key,
-            std::string const &range_end, int fromIndex,
-            std::function<void(Response)> callback);
-    Watcher(std::string const & address, std::string const & key,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(std::string const & address, std::string const & key,
-            std::string const &range_end,
-            std::function<void(Response)> callback);
-    Watcher(std::string const & address, std::string const & key, int fromIndex,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(std::string const & address, std::string const & key,
-            std::string const &range_end, int fromIndex,
-            std::function<void(Response)> callback);
-    Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, std::string const &range_end,
-            std::function<void(Response)> callback);
-    Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, int fromIndex,
-            std::function<void(Response)> callback, bool recursive=false);
-    Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, std::string const &range_end, int fromIndex,
-            std::function<void(Response)> callback);
+namespace etcd {
+// forward declaration to avoid header/library dependency
+class Client;
 
-    Watcher(Watcher const &) = delete;
-    Watcher(Watcher &&) = delete;
+class Watcher {
+ public:
+  Watcher(Client const& client, std::string const& key,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(Client const& client, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback);
+  Watcher(Client const& client, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(SyncClient const& client, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(Client const& client, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback);
+  Watcher(std::string const& address, std::string const& key,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(std::string const& address, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback);
+  Watcher(std::string const& address, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback, bool recursive = false);
+  Watcher(std::string const& address, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::function<void(Response)> callback, bool recursive = false,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          int64_t fromIndex, std::function<void(Response)> callback,
+          bool recursive = false, int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& ca,
+          std::string const& cert, std::string const& privkey,
+          std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback, bool recursive = false,
+          std::string const& target_name_override = "");
+  Watcher(std::string const& address, std::string const& ca,
+          std::string const& cert, std::string const& privkey,
+          std::string const& key, std::string const& range_end,
+          int64_t fromIndex, std::function<void(Response)> callback,
+          std::string const& target_name_override = "");
 
-    /**
-     * Wait util the task has been stopped, actively or passively, e.g., the watcher
-     * get cancelled or the server closes the connection.
-     *
-     * Returns true if the watcher is been normally cancalled, otherwise false.
-     */
-    bool Wait();
+  Watcher(Client const& client, std::string const& key,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(Client const& client, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(Client const& client, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(SyncClient const& client, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(Client const& client, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(SyncClient const& client, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(std::string const& address, std::string const& key,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(std::string const& address, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(std::string const& address, std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false);
+  Watcher(std::string const& address, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::string const& range_end, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          int64_t fromIndex, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& username,
+          std::string const& password, std::string const& key,
+          std::string const& range_end, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback,
+          int const auth_token_ttl = 300);
+  Watcher(std::string const& address, std::string const& ca,
+          std::string const& cert, std::string const& privkey,
+          std::string const& key, int64_t fromIndex,
+          std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback, bool recursive = false,
+          std::string const& target_name_override = "");
+  Watcher(std::string const& address, std::string const& ca,
+          std::string const& cert, std::string const& privkey,
+          std::string const& key, std::string const& range_end,
+          int64_t fromIndex, std::function<void(Response)> callback,
+          std::function<void(bool)> wait_callback,
+          std::string const& target_name_override = "");
 
-    /**
-     * An async wait, the callback will be called when the task has been stopped.
-     *
-     * The callback parameter would be true if the watch is been normally cancalled.
-     */
-    void Wait(std::function<void(bool)> callback);
+  Watcher(Watcher const&) = delete;
+  Watcher(Watcher&&) = delete;
 
-    /**
-     * Stop the watching action.
-     */
-    void Cancel();
+  /**
+   * Wait util the task has been stopped, actively or passively, e.g., the
+   * watcher get cancelled or the server closes the connection.
+   *
+   * Returns true if the watcher is been normally cancelled, otherwise false.
+   */
+  bool Wait();
 
-    ~Watcher();
+  /**
+   * An async wait, the callback will be called when the task has been stopped.
+   *
+   * The callback parameter would be true if the watch is been normally
+   * cancelled.
+   *
+   * Note that you shouldn't use the watcher itself inside the `Wait()` callback
+   * as the callback will be invoked in a separate **detached** thread where the
+   * watcher may have been destroyed.
+   *
+   * @return true if the callback has been set successfully (no existing
+   * callback).
+   */
+  bool Wait(std::function<void(bool)> callback);
 
-  protected:
-    void doWatch(std::string const & key,
-                 std::string const & range_end,
-                 std::string const & auth_token,
-                 std::function<void(Response)> callback);
+  /**
+   * Stop the watching action.
+   */
+  bool Cancel();
 
-    int index;
-    std::function<void(Response)> callback;
-    std::function<void(bool)> wait_callback;
+  /**
+   * Whether the watcher has been cancelled.
+   */
+  bool Cancelled() const;
 
-    // Don't use `pplx::task` to avoid sharing thread pool with other actions on the client
-    // to avoid any potential blocking, which may block the keepalive loop and evict the lease.
-    std::thread task_;
+  ~Watcher();
 
-    struct EtcdServerStubs;
-    struct EtcdServerStubsDeleter {
-      void operator()(etcd::Watcher::EtcdServerStubs *stubs);
-    };
-    std::unique_ptr<EtcdServerStubs, EtcdServerStubsDeleter> stubs;
+ protected:
+  void doWatch(std::string const& key, std::string const& range_end,
+               std::string const& auth_token,
+               std::function<void(Response)> callback);
 
-  private:
-    int fromIndex;
-    bool recursive;
-    std::atomic_bool cancelled;
+  std::function<void(Response)> callback;
+  std::function<void(bool)> wait_callback;
+
+  // Don't use `pplx::task` to avoid sharing thread pool with other actions on
+  // the client to avoid any potential blocking, which may block the keepalive
+  // loop and evict the lease.
+  std::thread task_;
+
+  struct EtcdServerStubs;
+  struct EtcdServerStubsDeleter {
+    void operator()(etcd::Watcher::EtcdServerStubs* stubs);
   };
-}
+  std::unique_ptr<EtcdServerStubs, EtcdServerStubsDeleter> stubs;
+
+ private:
+  int64_t fromIndex;
+  bool recursive;
+  std::atomic_bool cancelled;
+};
+}  // namespace etcd
 
 #endif

etcd/v3/Action.hpp

@@ -2,64 +2,116 @@
 #define __V3_ACTION_HPP__
 
 #include <chrono>
+#include <ostream>
 
 #include <grpc++/grpc++.h>
 #include "proto/rpc.grpc.pb.h"
+#include "proto/v3election.grpc.pb.h"
 #include "proto/v3lock.grpc.pb.h"
 
+#include "etcd/v3/action_constants.hpp"
+
 using grpc::ClientContext;
 using grpc::CompletionQueue;
 using grpc::Status;
 
+using etcdserverpb::Cluster;
 using etcdserverpb::KV;
-using etcdserverpb::Watch;
 using etcdserverpb::Lease;
+using etcdserverpb::Watch;
+using v3electionpb::Election;
 using v3lockpb::Lock;
 
-namespace etcdv3
-{
-  enum Atomicity_Type
-  {
-    PREV_INDEX = 0,
-    PREV_VALUE = 1
-  };
+namespace etcd {
+class Response;
+}
 
-  struct ActionParameters
-  {
-    ActionParameters();
-    bool withPrefix;
-    int revision;
-    int old_revision;
-    int64_t lease_id;
-    int ttl;
-    int limit;
-    std::string key;
-    std::string range_end;
-    std::string value;
-    std::string old_value;
-    std::string auth_token;
-    KV::Stub* kv_stub;
-    Watch::Stub* watch_stub;
-    Lease::Stub* lease_stub;
-    Lock::Stub* lock_stub;
-  };
+namespace etcdv3 {
+enum class AtomicityType { PREV_INDEX = 0, PREV_VALUE = 1 };
 
-  class Action
-  {
-  public:
-    Action(etcdv3::ActionParameters params);
-    void waitForResponse();
-    const std::chrono::high_resolution_clock::time_point startTimepoint();
-  protected:
-    Status status;
-    ClientContext context;
-    CompletionQueue cq_;
-    etcdv3::ActionParameters parameters;
-    std::chrono::high_resolution_clock::time_point start_timepoint;
-  };
+struct ActionParameters {
+  ActionParameters();
+  bool withPrefix;
+  int64_t revision = 0;
+  int64_t old_revision = 0;
+  int64_t lease_id = 0;  // no lease
+  int ttl;
+  int limit;
+  std::string name;  // for campaign (in v3election)
+  std::string key;
+  std::string range_end;
+  bool keys_only;
+  bool count_only;
+  std::string value;
+  std::string old_value;
+  std::string auth_token;
 
-  namespace detail {
-    std::string string_plus_one(std::string const &value);
+  // for cluster management apis
+  std::vector<std::string> peer_urls;
+  bool is_learner;
+  uint64_t member_id;
+
+  std::chrono::microseconds grpc_timeout = std::chrono::microseconds::zero();
+  KV::Stub* kv_stub;
+  Watch::Stub* watch_stub;
+  Cluster::Stub* cluster_stub;
+  Lease::Stub* lease_stub;
+  Lock::Stub* lock_stub;
+  Election::Stub* election_stub;
+
+  bool has_grpc_timeout() const;
+  std::chrono::system_clock::time_point grpc_deadline() const;
+
+  void dump(std::ostream& os) const;
+};
+
+class Action {
+ public:
+  Action(etcdv3::ActionParameters const& params);
+  Action(etcdv3::ActionParameters&& params);
+  virtual ~Action();
+
+  void waitForResponse();
+  const std::chrono::high_resolution_clock::time_point startTimepoint();
+
+ protected:
+  Status status;
+  ClientContext context;
+  CompletionQueue cq_;
+  etcdv3::ActionParameters parameters;
+  std::chrono::high_resolution_clock::time_point start_timepoint;
+
+ private:
+  // Init things like auth token, etc.
+  void InitAction();
+
+  friend class etcd::Response;
+};
+
+namespace detail {
+std::string string_plus_one(std::string const& value);
+std::string resolve_etcd_endpoints(std::string const& default_endpoints);
+
+template <typename Req>
+void make_request_with_ranges(Req& req, std::string const& key,
+                              std::string const& range_end,
+                              bool const recursive) {
+  if (!recursive) {
+    req.set_key(key);
+  } else {
+    if (key.empty()) {
+      req.set_key(etcdv3::NUL);
+      req.set_range_end(etcdv3::NUL);
+    } else {
+      req.set_key(key);
+      req.set_range_end(detail::string_plus_one(key));
+    }
+  }
+  if (!range_end.empty()) {
+    req.set_range_end(range_end);
   }
 }
+
+}  // namespace detail
+}  // namespace etcdv3
 #endif

etcd/v3/AsyncCompareAndDeleteAction.hpp

@@ -1,27 +0,0 @@
-#ifndef __ASYNC_COMPAREANDDELETE_HPP__
-#define __ASYNC_COMPAREANDDELETE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncTxnResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::TxnResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncCompareAndDeleteAction : public etcdv3::Action
-  {
-    public:
-      AsyncCompareAndDeleteAction(etcdv3::ActionParameters param, etcdv3::Atomicity_Type type);
-      AsyncTxnResponse ParseResponse();
-    private:
-      TxnResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncCompareAndSwapAction.hpp

@@ -1,27 +0,0 @@
-#ifndef __ASYNC_COMPAREANDSWAP_HPP__
-#define __ASYNC_COMPAREANDSWAP_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncTxnResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::TxnResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncCompareAndSwapAction : public etcdv3::Action
-  {
-    public:
-      AsyncCompareAndSwapAction(etcdv3::ActionParameters param, etcdv3::Atomicity_Type type);
-      AsyncTxnResponse ParseResponse();
-    private:
-      TxnResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncDeleteAction.hpp

@@ -1,26 +0,0 @@
-#ifndef __ASYNC_DELETE_HPP__
-#define __ASYNC_DELETE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncDeleteRangeResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::DeleteRangeResponse;
-
-namespace etcdv3
-{
-  class AsyncDeleteAction : public etcdv3::Action
-  {
-    public:
-      AsyncDeleteAction(etcdv3::ActionParameters param);
-      AsyncDeleteRangeResponse ParseResponse();
-    private:
-      DeleteRangeResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<DeleteRangeResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncDeleteRangeResponse.hpp

@@ -1,23 +0,0 @@
-#ifndef __ASYNC_DELETERESPONSE_HPP__
-#define __ASYNC_DELETERESPONSE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-#include "etcd/v3/Action.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::DeleteRangeResponse;
-
-namespace etcdv3
-{
-  class AsyncDeleteRangeResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncDeleteRangeResponse(){};
-      void ParseResponse(std::string const& key, bool prefix, DeleteRangeResponse& resp);
-  };
-}
-
-#endif

etcd/v3/AsyncGRPC.hpp

@@ -0,0 +1,491 @@
+#ifndef __ASYNC_GRPC_HPP__
+#define __ASYNC_GRPC_HPP__
+
+#include <atomic>
+#include <mutex>
+
+#include <grpc++/grpc++.h>
+
+#include "proto/rpc.grpc.pb.h"
+#include "proto/rpc.pb.h"
+#include "proto/v3election.grpc.pb.h"
+#include "proto/v3election.pb.h"
+#include "proto/v3lock.grpc.pb.h"
+#include "proto/v3lock.pb.h"
+
+#include "etcd/Response.hpp"
+#include "etcd/v3/Action.hpp"
+#include "etcd/v3/V3Response.hpp"
+
+using grpc::ClientAsyncReader;
+using grpc::ClientAsyncReaderWriter;
+using grpc::ClientAsyncResponseReader;
+
+using etcdserverpb::KV;
+
+using etcdserverpb::DeleteRangeRequest;
+using etcdserverpb::DeleteRangeResponse;
+using etcdserverpb::LeaseCheckpointRequest;
+using etcdserverpb::LeaseCheckpointResponse;
+using etcdserverpb::LeaseGrantRequest;
+using etcdserverpb::LeaseGrantResponse;
+using etcdserverpb::LeaseKeepAliveRequest;
+using etcdserverpb::LeaseKeepAliveResponse;
+using etcdserverpb::LeaseLeasesRequest;
+using etcdserverpb::LeaseLeasesResponse;
+using etcdserverpb::LeaseRevokeRequest;
+using etcdserverpb::LeaseRevokeResponse;
+using etcdserverpb::LeaseTimeToLiveRequest;
+using etcdserverpb::LeaseTimeToLiveResponse;
+using etcdserverpb::MemberAddRequest;
+using etcdserverpb::MemberAddResponse;
+using etcdserverpb::MemberListRequest;
+using etcdserverpb::MemberListResponse;
+using etcdserverpb::MemberRemoveRequest;
+using etcdserverpb::MemberRemoveResponse;
+using etcdserverpb::PutRequest;
+using etcdserverpb::PutResponse;
+using etcdserverpb::RangeRequest;
+using etcdserverpb::RangeResponse;
+using etcdserverpb::TxnRequest;
+using etcdserverpb::TxnResponse;
+using etcdserverpb::WatchRequest;
+using etcdserverpb::WatchResponse;
+using v3electionpb::CampaignRequest;
+using v3electionpb::CampaignResponse;
+using v3electionpb::LeaderRequest;
+using v3electionpb::LeaderResponse;
+using v3electionpb::ProclaimRequest;
+using v3electionpb::ProclaimResponse;
+using v3electionpb::ResignRequest;
+using v3electionpb::ResignResponse;
+using v3lockpb::LockRequest;
+using v3lockpb::LockResponse;
+using v3lockpb::UnlockRequest;
+using v3lockpb::UnlockResponse;
+
+namespace etcd {
+class KeepAlive;
+}
+
+namespace etcdv3 {
+class Transaction;
+}
+
+namespace etcdv3 {
+class AsyncCampaignResponse : public etcdv3::V3Response {
+ public:
+  AsyncCampaignResponse(){};
+  void ParseResponse(CampaignResponse& resp);
+};
+
+class AsyncDeleteResponse : public etcdv3::V3Response {
+ public:
+  AsyncDeleteResponse(){};
+  void ParseResponse(DeleteRangeResponse& resp);
+};
+
+class AsyncHeadResponse : public etcdv3::V3Response {
+ public:
+  AsyncHeadResponse(){};
+  void ParseResponse(RangeResponse& resp);
+};
+
+class AsyncLeaderResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaderResponse(){};
+  void ParseResponse(LeaderResponse& resp);
+};
+
+class AsyncLeaseGrantResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaseGrantResponse(){};
+  void ParseResponse(LeaseGrantResponse& resp);
+};
+
+class AsyncLeaseKeepAliveResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaseKeepAliveResponse(){};
+  void ParseResponse(LeaseKeepAliveResponse& resp);
+};
+
+class AsyncMemberAddResponse : public etcdv3::V3Response {
+ public:
+  AsyncMemberAddResponse(){};
+  void ParseResponse(MemberAddResponse& resp);
+};
+
+class AsyncMemberListResponse : public etcdv3::V3Response {
+ public:
+  AsyncMemberListResponse(){};
+  void ParseResponse(MemberListResponse& resp);
+};
+
+class AsyncMemberRemoveResponse : public etcdv3::V3Response {
+ public:
+  AsyncMemberRemoveResponse(){};
+  void ParseResponse(MemberRemoveResponse& resp);
+};
+
+class AsyncLeaseLeasesResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaseLeasesResponse(){};
+  void ParseResponse(LeaseLeasesResponse& resp);
+};
+
+class AsyncLeaseRevokeResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaseRevokeResponse(){};
+  void ParseResponse(LeaseRevokeResponse& resp);
+};
+
+class AsyncLeaseTimeToLiveResponse : public etcdv3::V3Response {
+ public:
+  AsyncLeaseTimeToLiveResponse(){};
+  void ParseResponse(LeaseTimeToLiveResponse& resp);
+};
+
+class AsyncLockResponse : public etcdv3::V3Response {
+ public:
+  AsyncLockResponse(){};
+  void ParseResponse(LockResponse& resp);
+};
+
+class AsyncObserveResponse : public etcdv3::V3Response {
+ public:
+  AsyncObserveResponse(){};
+  void ParseResponse(LeaderResponse& resp);
+};
+
+class AsyncProclaimResponse : public etcdv3::V3Response {
+ public:
+  AsyncProclaimResponse(){};
+  void ParseResponse(ProclaimResponse& resp);
+};
+
+class AsyncPutResponse : public etcdv3::V3Response {
+ public:
+  AsyncPutResponse(){};
+  void ParseResponse(PutResponse& resp);
+};
+
+class AsyncRangeResponse : public etcdv3::V3Response {
+ public:
+  AsyncRangeResponse(){};
+  void ParseResponse(RangeResponse& resp, bool prefix = false);
+};
+
+class AsyncResignResponse : public etcdv3::V3Response {
+ public:
+  AsyncResignResponse(){};
+  void ParseResponse(ResignResponse& resp);
+};
+
+class AsyncTxnResponse : public etcdv3::V3Response {
+ public:
+  AsyncTxnResponse(){};
+  void ParseResponse(TxnResponse& resp);
+};
+
+class AsyncUnlockResponse : public etcdv3::V3Response {
+ public:
+  AsyncUnlockResponse(){};
+  void ParseResponse(UnlockResponse& resp);
+};
+
+class AsyncWatchResponse : public etcdv3::V3Response {
+ public:
+  AsyncWatchResponse(){};
+  void ParseResponse(WatchResponse& resp);
+};
+}  // namespace etcdv3
+
+namespace etcdv3 {
+class AsyncCampaignAction : public etcdv3::Action {
+ public:
+  AsyncCampaignAction(etcdv3::ActionParameters&& params);
+  AsyncCampaignResponse ParseResponse();
+
+ private:
+  CampaignResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<CampaignResponse>> response_reader;
+};
+
+class AsyncCompareAndDeleteAction : public etcdv3::Action {
+ public:
+  AsyncCompareAndDeleteAction(etcdv3::ActionParameters&& params,
+                              etcdv3::AtomicityType type);
+  AsyncTxnResponse ParseResponse();
+
+ private:
+  TxnResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
+};
+
+class AsyncCompareAndSwapAction : public etcdv3::Action {
+ public:
+  AsyncCompareAndSwapAction(etcdv3::ActionParameters&& params,
+                            etcdv3::AtomicityType type);
+  AsyncTxnResponse ParseResponse();
+
+ private:
+  TxnResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
+};
+
+class AsyncDeleteAction : public etcdv3::Action {
+ public:
+  AsyncDeleteAction(etcdv3::ActionParameters&& params);
+  AsyncDeleteResponse ParseResponse();
+
+ private:
+  DeleteRangeResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<DeleteRangeResponse>>
+      response_reader;
+};
+
+class AsyncHeadAction : public etcdv3::Action {
+ public:
+  AsyncHeadAction(etcdv3::ActionParameters&& params);
+  AsyncHeadResponse ParseResponse();
+
+ private:
+  RangeResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<RangeResponse>> response_reader;
+};
+
+class AsyncLeaderAction : public etcdv3::Action {
+ public:
+  AsyncLeaderAction(etcdv3::ActionParameters&& params);
+  AsyncLeaderResponse ParseResponse();
+
+ private:
+  LeaderResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LeaderResponse>> response_reader;
+};
+
+class AsyncLeaseGrantAction : public etcdv3::Action {
+ public:
+  AsyncLeaseGrantAction(etcdv3::ActionParameters&& params);
+  AsyncLeaseGrantResponse ParseResponse();
+
+ private:
+  LeaseGrantResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LeaseGrantResponse>>
+      response_reader;
+};
+
+class AsyncLeaseKeepAliveAction : public etcdv3::Action {
+ public:
+  AsyncLeaseKeepAliveAction(etcdv3::ActionParameters&& params);
+  AsyncLeaseKeepAliveResponse ParseResponse();
+
+  etcd::Response Refresh();
+  void CancelKeepAlive();
+  bool Cancelled() const;
+
+ private:
+  etcdv3::ActionParameters& mutable_parameters();
+
+  LeaseKeepAliveResponse reply;
+  std::unique_ptr<
+      ClientAsyncReaderWriter<LeaseKeepAliveRequest, LeaseKeepAliveResponse>>
+      stream;
+
+  LeaseKeepAliveRequest req;
+  std::atomic_bool isCancelled;
+  std::recursive_mutex protect_is_cancelled;
+
+  friend class etcd::KeepAlive;
+};
+
+class AsyncAddMemberAction : public etcdv3::Action {
+ public:
+  AsyncAddMemberAction(etcdv3::ActionParameters&& params);
+  AsyncMemberAddResponse ParseResponse();
+
+ private:
+  MemberAddResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<MemberAddResponse>> response_reader;
+};
+
+class AsyncListMemberAction : public etcdv3::Action {
+ public:
+  AsyncListMemberAction(etcdv3::ActionParameters&& params);
+  AsyncMemberListResponse ParseResponse();
+
+ private:
+  MemberListResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<MemberListResponse>>
+      response_reader;
+};
+
+class AsyncRemoveMemberAction : public etcdv3::Action {
+ public:
+  AsyncRemoveMemberAction(etcdv3::ActionParameters&& params);
+  AsyncMemberRemoveResponse ParseResponse();
+
+ private:
+  MemberRemoveResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<MemberRemoveResponse>>
+      response_reader;
+};
+
+class AsyncLeaseLeasesAction : public etcdv3::Action {
+ public:
+  AsyncLeaseLeasesAction(etcdv3::ActionParameters&& params);
+  AsyncLeaseLeasesResponse ParseResponse();
+
+ private:
+  LeaseLeasesResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LeaseLeasesResponse>>
+      response_reader;
+};
+
+class AsyncLeaseRevokeAction : public etcdv3::Action {
+ public:
+  AsyncLeaseRevokeAction(etcdv3::ActionParameters&& params);
+  AsyncLeaseRevokeResponse ParseResponse();
+
+ private:
+  LeaseRevokeResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LeaseRevokeResponse>>
+      response_reader;
+};
+
+class AsyncLeaseTimeToLiveAction : public etcdv3::Action {
+ public:
+  AsyncLeaseTimeToLiveAction(etcdv3::ActionParameters&& params);
+  AsyncLeaseTimeToLiveResponse ParseResponse();
+
+ private:
+  LeaseTimeToLiveResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LeaseTimeToLiveResponse>>
+      response_reader;
+};
+
+class AsyncLockAction : public etcdv3::Action {
+ public:
+  AsyncLockAction(etcdv3::ActionParameters&& params);
+  AsyncLockResponse ParseResponse();
+
+ private:
+  LockResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<LockResponse>> response_reader;
+};
+
+class AsyncObserveAction : public etcdv3::Action {
+ public:
+  AsyncObserveAction(etcdv3::ActionParameters&& params);
+  AsyncObserveResponse ParseResponse();
+  void waitForResponse();
+  void CancelObserve();
+  bool Cancelled() const;
+
+ private:
+  LeaderResponse reply;
+  std::unique_ptr<ClientAsyncReader<LeaderResponse>> response_reader;
+  std::atomic_bool isCancelled;
+  std::mutex protect_is_cancelled;
+};
+
+class AsyncProclaimAction : public etcdv3::Action {
+ public:
+  AsyncProclaimAction(etcdv3::ActionParameters&& params);
+  AsyncProclaimResponse ParseResponse();
+
+ private:
+  ProclaimResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<ProclaimResponse>> response_reader;
+};
+
+class AsyncPutAction : public etcdv3::Action {
+ public:
+  AsyncPutAction(etcdv3::ActionParameters&& params);
+  AsyncPutResponse ParseResponse();
+
+ private:
+  PutResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<PutResponse>> response_reader;
+};
+
+class AsyncRangeAction : public etcdv3::Action {
+ public:
+  AsyncRangeAction(etcdv3::ActionParameters&& params);
+  AsyncRangeResponse ParseResponse();
+
+ private:
+  RangeResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<RangeResponse>> response_reader;
+};
+
+class AsyncResignAction : public etcdv3::Action {
+ public:
+  AsyncResignAction(etcdv3::ActionParameters&& params);
+  AsyncResignResponse ParseResponse();
+
+ private:
+  ResignResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<ResignResponse>> response_reader;
+};
+
+class AsyncSetAction : public etcdv3::Action {
+ public:
+  AsyncSetAction(etcdv3::ActionParameters&& params, bool create = false);
+  AsyncTxnResponse ParseResponse();
+
+ private:
+  TxnResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
+  bool isCreate;
+};
+
+class AsyncTxnAction : public etcdv3::Action {
+ public:
+  AsyncTxnAction(etcdv3::ActionParameters&& params,
+                 etcdv3::Transaction const& tx);
+  AsyncTxnResponse ParseResponse();
+
+ private:
+  TxnResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
+};
+
+class AsyncUnlockAction : public etcdv3::Action {
+ public:
+  AsyncUnlockAction(etcdv3::ActionParameters&& params);
+  AsyncUnlockResponse ParseResponse();
+
+ private:
+  UnlockResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<UnlockResponse>> response_reader;
+};
+
+class AsyncUpdateAction : public etcdv3::Action {
+ public:
+  AsyncUpdateAction(etcdv3::ActionParameters&& params);
+  AsyncTxnResponse ParseResponse();
+
+ private:
+  TxnResponse reply;
+  std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
+};
+
+class AsyncWatchAction : public etcdv3::Action {
+ public:
+  AsyncWatchAction(etcdv3::ActionParameters&& params);
+  AsyncWatchResponse ParseResponse();
+  void waitForResponse();
+  void waitForResponse(std::function<void(etcd::Response)> callback);
+  void CancelWatch();
+  bool Cancelled() const;
+
+ private:
+  int64_t watch_id = -1;
+  WatchResponse reply;
+  std::unique_ptr<ClientAsyncReaderWriter<WatchRequest, WatchResponse>> stream;
+  std::atomic_bool isCancelled;
+};
+}  // namespace etcdv3
+
+#endif

etcd/v3/AsyncGetAction.hpp

@@ -1,26 +0,0 @@
-#ifndef __ASYNC_GET_HPP__
-#define __ASYNC_GET_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncRangeResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::RangeResponse;
-
-namespace etcdv3
-{
-  class AsyncGetAction : public etcdv3::Action
-  {
-    public:
-      AsyncGetAction(etcdv3::ActionParameters param);
-      AsyncRangeResponse ParseResponse();
-    private:
-      RangeResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<RangeResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncLeaseAction.hpp

@@ -1,81 +0,0 @@
-#ifndef __ASYNC_LEASEACTION_HPP__
-#define __ASYNC_LEASEACTION_HPP__
-
-#include <mutex>
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncLeaseResponse.hpp"
-#include "etcd/Response.hpp"
-
-using grpc::ClientAsyncResponseReader;
-using grpc::ClientAsyncReaderWriter;
-using etcdserverpb::LeaseGrantResponse;
-using etcdserverpb::LeaseRevokeResponse;
-using etcdserverpb::LeaseCheckpoint;
-using etcdserverpb::LeaseCheckpointResponse;
-using etcdserverpb::LeaseKeepAliveRequest;
-using etcdserverpb::LeaseKeepAliveResponse;
-using etcdserverpb::LeaseTimeToLiveResponse;
-using etcdserverpb::LeaseStatus;
-using etcdserverpb::LeaseLeasesResponse;
-
-namespace etcdv3
-{
-  class AsyncLeaseGrantAction : public etcdv3::Action {
-    public:
-      AsyncLeaseGrantAction(etcdv3::ActionParameters param);
-      AsyncLeaseGrantResponse ParseResponse();
-    private:
-      LeaseGrantResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<LeaseGrantResponse>> response_reader;
-  };
-
-  class AsyncLeaseRevokeAction: public etcdv3::Action {
-    public:
-      AsyncLeaseRevokeAction(etcdv3::ActionParameters param);
-      AsyncLeaseRevokeResponse ParseResponse();
-    private:
-      LeaseRevokeResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<LeaseRevokeResponse>> response_reader;
-  };
-
-  class AsyncLeaseKeepAliveAction: public etcdv3::Action {
-    public:
-      AsyncLeaseKeepAliveAction(etcdv3::ActionParameters param);
-      AsyncLeaseKeepAliveResponse ParseResponse();
-
-      etcd::Response Refresh();
-      void CancelKeepAlive();
-      bool Cancelled() const;
-
-    private:
-      LeaseKeepAliveResponse reply;
-      std::unique_ptr<ClientAsyncReaderWriter<LeaseKeepAliveRequest, LeaseKeepAliveResponse>> stream;
-
-      LeaseKeepAliveRequest req;
-      bool isCancelled;
-      std::mutex protect_is_cancelled;
-  };
-
-  class AsyncLeaseTimeToLiveAction: public etcdv3::Action {
-    public:
-      AsyncLeaseTimeToLiveAction(etcdv3::ActionParameters param);
-      AsyncLeaseTimeToLiveResponse ParseResponse();
-    private:
-      LeaseTimeToLiveResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<LeaseTimeToLiveResponse>> response_reader;
-  };
-
-  class AsyncLeaseLeasesAction: public etcdv3::Action {
-    public:
-      AsyncLeaseLeasesAction(etcdv3::ActionParameters param);
-      AsyncLeaseLeasesResponse ParseResponse();
-    private:
-      LeaseLeasesResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<LeaseLeasesResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncLeaseResponse.hpp

@@ -1,55 +0,0 @@
-#ifndef __ASYNC_LEASERESPONSE_HPP__
-#define __ASYNC_LEASERESPONSE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-
-using etcdserverpb::LeaseGrantResponse;
-using etcdserverpb::LeaseRevokeResponse;
-using etcdserverpb::LeaseCheckpoint;
-using etcdserverpb::LeaseCheckpointResponse;
-using etcdserverpb::LeaseKeepAliveResponse;
-using etcdserverpb::LeaseTimeToLiveResponse;
-using etcdserverpb::LeaseStatus;
-using etcdserverpb::LeaseLeasesResponse;
-
-namespace etcdv3
-{
-  class AsyncLeaseGrantResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLeaseGrantResponse(){};
-      void ParseResponse(LeaseGrantResponse& resp);
-  };
-
-  class AsyncLeaseRevokeResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLeaseRevokeResponse(){};
-      void ParseResponse(LeaseRevokeResponse& resp);
-  };
-
-  class AsyncLeaseKeepAliveResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLeaseKeepAliveResponse(){};
-      void ParseResponse(LeaseKeepAliveResponse& resp);
-  };
-
-  class AsyncLeaseTimeToLiveResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLeaseTimeToLiveResponse(){};
-      void ParseResponse(LeaseTimeToLiveResponse& resp);
-  };
-
-  class AsyncLeaseLeasesResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLeaseLeasesResponse(){};
-      void ParseResponse(LeaseLeasesResponse& resp);
-  };
-}
-
-#endif

etcd/v3/AsyncLockAction.hpp

@@ -1,41 +0,0 @@
-#ifndef __ASYNC_LOCKACTION_HPP__
-#define __ASYNC_LOCKACTION_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/v3lock.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncLockResponse.hpp"
-#include "etcd/Response.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using v3lockpb::LockRequest;
-using v3lockpb::LockResponse;
-using v3lockpb::UnlockRequest;
-using v3lockpb::UnlockResponse;
-
-
-namespace etcdv3
-{
-  class AsyncLockAction : public etcdv3::Action
-  {
-    public:
-      AsyncLockAction(etcdv3::ActionParameters param);
-      AsyncLockResponse ParseResponse();
-    private:
-      LockResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<LockResponse>> response_reader;   
-  };
-
-  class AsyncUnlockAction : public etcdv3::Action
-  {
-    public:
-      AsyncUnlockAction(etcdv3::ActionParameters param);
-      AsyncUnlockResponse ParseResponse();
-    private:
-      UnlockResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<UnlockResponse>> response_reader;   
-  };
-}
-
-#endif

etcd/v3/AsyncLockResponse.hpp

@@ -1,33 +0,0 @@
-#ifndef __ASYNC_LOCK_HPP__
-#define __ASYNC_LOCK_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/v3lock.grpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using v3lockpb::LockRequest;
-using v3lockpb::LockResponse;
-using v3lockpb::UnlockRequest;
-using v3lockpb::UnlockResponse;
-
-namespace etcdv3
-{
-  class AsyncLockResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncLockResponse(){};
-      void ParseResponse(LockResponse& resp);
-  };
-
-  class AsyncUnlockResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncUnlockResponse(){};
-      void ParseResponse(UnlockResponse& resp);
-  };
-}
-
-#endif
-

etcd/v3/AsyncRangeResponse.hpp

@@ -1,22 +0,0 @@
-#ifndef __ASYNC_RANGERESPONSE_HPP__
-#define __ASYNC_RANGERESPONSE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::RangeResponse;
-
-namespace etcdv3
-{
-  class AsyncRangeResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncRangeResponse(){};
-      void ParseResponse(RangeResponse& resp, bool prefix=false);
-  };
-}
-
-#endif

etcd/v3/AsyncSetAction.hpp

@@ -1,28 +0,0 @@
-#ifndef __ASYNC_SET_HPP__
-#define __ASYNC_SET_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncTxnResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::TxnResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncSetAction : public etcdv3::Action
-  {
-    public:
-      AsyncSetAction(etcdv3::ActionParameters param, bool create=false);
-      AsyncTxnResponse ParseResponse();
-    private:
-      TxnResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
-      bool isCreate;
-  };
-}
-
-#endif

etcd/v3/AsyncTxnAction.hpp

@@ -1,28 +0,0 @@
-#ifndef __ASYNC_TXNACTION_HPP__
-#define __ASYNC_TXNACTION_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncTxnResponse.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::TxnResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncTxnAction : public etcdv3::Action
-  {
-    public:
-      AsyncTxnAction(etcdv3::ActionParameters param, etcdv3::Transaction const &tx);
-      AsyncTxnResponse ParseResponse();
-    private:
-      TxnResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncTxnResponse.hpp

@@ -1,20 +0,0 @@
-#ifndef __ASYNC_TXNRESPONSE_HPP__
-#define __ASYNC_TXNRESPONSE_HPP__
-
-#include "proto/rpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-
-using etcdserverpb::TxnResponse;
-
-namespace etcdv3
-{
-  class AsyncTxnResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncTxnResponse(){};
-      void ParseResponse(TxnResponse& resp);
-      void ParseResponse(std::string const& key, bool prefix, TxnResponse& resp);
-  };
-}
-
-#endif

etcd/v3/AsyncUpdateAction.hpp

@@ -1,27 +0,0 @@
-#ifndef __ASYNC_UPDATE_HPP__
-#define __ASYNC_UPDATE_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncTxnResponse.hpp"
-
-
-using grpc::ClientAsyncResponseReader;
-using etcdserverpb::TxnResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncUpdateAction : public etcdv3::Action
-  {
-    public:
-      AsyncUpdateAction(etcdv3::ActionParameters param);
-      AsyncTxnResponse ParseResponse();
-    private:
-      TxnResponse reply;
-      std::unique_ptr<ClientAsyncResponseReader<TxnResponse>> response_reader;
-  };
-}
-
-#endif

etcd/v3/AsyncWatchAction.hpp

@@ -1,37 +0,0 @@
-#ifndef __ASYNC_WATCHACTION_HPP__
-#define __ASYNC_WATCHACTION_HPP__
-
-#include <atomic>
-#include <mutex>
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "etcd/v3/Action.hpp"
-#include "etcd/v3/AsyncWatchResponse.hpp"
-#include "etcd/Response.hpp"
-
-using grpc::ClientAsyncReaderWriter;
-using etcdserverpb::WatchRequest;
-using etcdserverpb::WatchResponse;
-
-namespace etcdv3
-{
-  class AsyncWatchAction : public etcdv3::Action
-  {
-    public:
-      AsyncWatchAction(etcdv3::ActionParameters param);
-      AsyncWatchResponse ParseResponse();
-      void waitForResponse();
-      void waitForResponse(std::function<void(etcd::Response)> callback); 
-      void CancelWatch();
-      void WatchReq(std::string const & key);
-      bool Cancelled() const;
-    private:
-      WatchResponse reply;
-      std::unique_ptr<ClientAsyncReaderWriter<WatchRequest,WatchResponse>> stream;   
-      std::atomic_bool isCancelled;
-      std::mutex protect_is_cancalled;
-  };
-}
-
-#endif

etcd/v3/AsyncWatchResponse.hpp

@@ -1,25 +0,0 @@
-#ifndef __ASYNC_WATCH_HPP__
-#define __ASYNC_WATCH_HPP__
-
-#include <grpc++/grpc++.h>
-#include "proto/rpc.grpc.pb.h"
-#include "proto/rpc.pb.h"
-#include "etcd/v3/V3Response.hpp"
-
-
-using etcdserverpb::WatchRequest;
-using etcdserverpb::WatchResponse;
-using etcdserverpb::KV;
-
-namespace etcdv3
-{
-  class AsyncWatchResponse : public etcdv3::V3Response
-  {
-    public:
-      AsyncWatchResponse(){};
-      void ParseResponse(WatchResponse& resp);
-  };
-}
-
-#endif
-

etcd/v3/KeyValue.hpp

@@ -3,18 +3,16 @@
 
 #include "proto/kv.pb.h"
 
+namespace etcdv3 {
+class KeyValue {
+ public:
+  KeyValue();
+  mvccpb::KeyValue kvs;
+  void set_ttl(int ttl);
+  int get_ttl() const;
 
-namespace etcdv3
-{
-  class KeyValue
-  {
-  public:
-    KeyValue();
-    mvccpb::KeyValue kvs;
-    void set_ttl(int ttl);
-    int get_ttl() const;
-  private:
-    int ttl;
-  };
-}
+ private:
+  int ttl;
+};
+}  // namespace etcdv3
 #endif

etcd/v3/Member.hpp

@@ -0,0 +1,33 @@
+#ifndef __V3_ETCDV3MEMBERS_HPP__
+#define __V3_ETCDV3MEMBERS_HPP__
+
+#include <cstdint>
+#include <string>
+#include <vector>
+using namespace std;
+
+namespace etcdv3 {
+class Member {
+ public:
+  Member();
+
+  void set_id(uint64_t const& id);
+  uint64_t const& get_id() const;
+  void set_name(std::string const& name);
+  std::string const& get_name() const;
+  void set_peerURLs(std::vector<std::string> const& peerURLs);
+  std::vector<std::string> const& get_peerURLs() const;
+  void set_clientURLs(std::vector<std::string> const& clientURLs);
+  std::vector<std::string> const& get_clientURLs() const;
+  void set_learner(bool isLearner);
+  bool get_learner() const;
+
+ private:
+  uint64_t id;
+  std::string name;
+  std::vector<std::string> peerURLs;
+  std::vector<std::string> clientURLs;
+  bool isLearner;
+};
+}  // namespace etcdv3
+#endif

etcd/v3/Transaction.hpp

@@ -1,42 +1,223 @@
 #ifndef V3_SRC_TRANSACTION_HPP_
 #define V3_SRC_TRANSACTION_HPP_
 
+#include <memory>
 #include <string>
 
-#include "txn.pb.h"
-
 namespace etcdserverpb {
-	class TxnRequest;
+class TxnRequest;
 }
 
 namespace etcdv3 {
 
-class Transaction {
-public:
-	Transaction();
-	Transaction(std::string const&);
-	virtual ~Transaction();
-	void init_compare(etcdserverpb::Compare::CompareResult, etcdserverpb::Compare::CompareTarget);
-	void init_compare(std::string const &, etcdserverpb::Compare::CompareResult, etcdserverpb::Compare::CompareTarget);
-	void init_compare(int, etcdserverpb::Compare::CompareResult, etcdserverpb::Compare::CompareTarget);
-
-	void setup_basic_failure_operation(std::string const &key);
-	void setup_set_failure_operation(std::string const &key, std::string const &value, int64_t leaseid);
-	void setup_basic_create_sequence(std::string const &key, std::string const &value, int64_t leaseid);
-	void setup_compare_and_swap_sequence(std::string const &valueToSwap, int64_t leaseid);
-	void setup_delete_sequence(std::string const &key, std::string const &range_end, bool recursive);
-	void setup_delete_failure_operation(std::string const &key, std::string const &range_end, bool recursive);
-	void setup_compare_and_delete_operation(std::string const& key);
-
-	// update without `get` and no `prev_kv` returned
-	void setup_put(std::string const &key, std::string const &value);
-	void setup_delete(std::string const &key);
-
-	std::unique_ptr<etcdserverpb::TxnRequest> txn_request;
-private:
-	std::string key;
+enum class CompareResult {
+  EQUAL = 0,
+  GREATER = 1,
+  LESS = 2,
+  NOT_EQUAL = 3,
 };
 
-}
+enum class CompareTarget {
+  VERSION = 0,
+  CREATE = 1,
+  MOD = 2,
+  VALUE = 3,
+  LEASE = 4,
+};
+
+class Transaction {
+ public:
+  Transaction();
+  ~Transaction();
+
+  union Value {
+    int64_t version;
+    int64_t create_revision;
+    int64_t mod_revision;
+    std::string value;
+    int64_t lease;
+  };
+
+  void add_compare(std::string const& key, CompareTarget const& target,
+                   CompareResult const& result, Value const& target_value,
+                   std::string const& range_end = "");
+
+  void add_compare_version(std::string const& key, int64_t const& version,
+                           std::string const& range_end = "");
+  void add_compare_version(std::string const& key, CompareResult const& result,
+                           int64_t const& version,
+                           std::string const& range_end = "");
+  void add_compare_create(std::string const& key,
+                          int64_t const& create_revision,
+                          std::string const& range_end = "");
+  void add_compare_create(std::string const& key, CompareResult const& result,
+                          int64_t const& create_revision,
+                          std::string const& range_end = "");
+  void add_compare_mod(std::string const& key, int64_t const& mod_revision,
+                       std::string const& range_end = "");
+  void add_compare_mod(std::string const& key, CompareResult const& result,
+                       int64_t const& mod_revision,
+                       std::string const& range_end = "");
+  void add_compare_value(std::string const& key, std::string const& value,
+                         std::string const& range_end = "");
+  void add_compare_value(std::string const& key, CompareResult const& result,
+                         std::string const& value,
+                         std::string const& range_end = "");
+  void add_compare_lease(std::string const& key, int64_t const& lease,
+                         std::string const& range_end = "");
+  void add_compare_lease(std::string const& key, CompareResult const& result,
+                         int64_t const& lease,
+                         std::string const& range_end = "");
+
+  void add_success_range(std::string const& key,
+                         std::string const& range_end = "",
+                         bool const recursive = false, const int64_t limit = 0);
+  void add_success_put(std::string const& key, std::string const& value,
+                       int64_t const leaseid = 0, const bool prev_kv = false);
+  void add_success_delete(std::string const& key,
+                          std::string const& range_end = "",
+                          bool const recursive = false,
+                          const bool prev_kv = false);
+  void add_success_txn(const std::shared_ptr<Transaction> txn);
+
+  void add_failure_range(std::string const& key,
+                         std::string const& range_end = "",
+                         bool const recursive = false, const int64_t limit = 0);
+  void add_failure_put(std::string const& key, std::string const& value,
+                       int64_t const leaseid = 0, const bool prev_kv = false);
+  void add_failure_delete(std::string const& key,
+                          std::string const& range_end = "",
+                          bool const recursive = false,
+                          const bool prev_kv = false);
+  void add_failure_txn(const std::shared_ptr<Transaction> txn);
+
+  /**
+   * @brief Compare, and create if succeed. If failed, the response will
+   *        contains the previous value in "values()" field.
+   */
+  void setup_compare_and_create(std::string const& key,
+                                std::string const& prev_value,
+                                std::string const& create_key,
+                                std::string const& value,
+                                int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, or create if failed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_or_create(std::string const& key,
+                               std::string const& prev_value,
+                               std::string const& create_key,
+                               std::string const& value,
+                               int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and swap if succeed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_and_swap(std::string const& key,
+                              std::string const& prev_value,
+                              std::string const& value,
+                              int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and swap if failed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_or_swap(std::string const& key,
+                             std::string const& prev_value,
+                             std::string const& value,
+                             int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and delete if succeed. If failed, the response will
+   *        contains the previous value in "values()" field.
+   */
+  void setup_compare_and_delete(std::string const& key,
+                                std::string const& prev_value,
+                                std::string const& delete_key,
+                                std::string const& range_end = "",
+                                const bool recursive = false);
+
+  /**
+   * @brief Compare, or delete if failed. If failed, the response will contains
+   * the previous value in "values()" field.
+   */
+  void setup_compare_or_delete(std::string const& key,
+                               std::string const& prev_value,
+                               std::string const& delete_key,
+                               std::string const& range_end = "",
+                               const bool recursive = false);
+
+  /**
+   * @brief Compare, and create if succeed. If failed, the response will
+   *        contains the previous value in "values()" field.
+   */
+  void setup_compare_and_create(std::string const& key,
+                                const int64_t prev_revision,
+                                std::string const& create_key,
+                                std::string const& value,
+                                int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, or create if failed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_or_create(std::string const& key,
+                               const int64_t prev_revision,
+                               std::string const& create_key,
+                               std::string const& value,
+                               int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and swap if succeed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_and_swap(std::string const& key,
+                              const int64_t prev_revision,
+                              std::string const& value,
+                              int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and swap if failed. If failed, the response will contains
+   *        the previous value in "values()" field.
+   */
+  void setup_compare_or_swap(std::string const& key,
+                             const int64_t prev_revision,
+                             std::string const& value,
+                             int64_t const leaseid = 0);
+
+  /**
+   * @brief Compare, and delete if succeed. If failed, the response will
+   *        contains the previous value in "values()" field.
+   */
+  void setup_compare_and_delete(std::string const& key,
+                                const int64_t prev_revision,
+                                std::string const& delete_key,
+                                std::string const& range_end = "",
+                                const bool recursive = false);
+
+  /**
+   * @brief Compare, or delete if failed. If failed, the response will contains
+   * the previous value in "values()" field.
+   */
+  void setup_compare_or_delete(std::string const& key,
+                               const int64_t prev_revision,
+                               std::string const& delete_key,
+                               std::string const& range_end = "",
+                               const bool recursive = false);
+
+  // Keep for backwards compatibility.
+
+  // update without `get` and no `prev_kv` returned
+  void setup_put(std::string const& key, std::string const& value);
+  void setup_delete(std::string const& key);
+  void setup_delete(std::string const& key, std::string const& range_end,
+                    const bool recursive = false);
+
+  std::shared_ptr<etcdserverpb::TxnRequest> txn_request;
+};
+
+}  // namespace etcdv3
 
 #endif

etcd/v3/V3Response.hpp

@@ -3,41 +3,66 @@
 
 #include <grpc++/grpc++.h>
 #include "proto/kv.pb.h"
+#include "proto/v3election.pb.h"
 
 #include "etcd/v3/KeyValue.hpp"
+#include "etcd/v3/Member.hpp"
 
-namespace etcdv3
-{
-  class V3Response
-  {
-  public:
-    V3Response(): error_code(0), index(0){};
-    void set_error_code(int code);
-    int get_error_code() const;
-    std::string const & get_error_message() const;
-    void set_error_message(std::string msg);
-    void set_action(std::string action);
-    int get_index() const;
-    std::string const & get_action() const;
-    std::vector<etcdv3::KeyValue> const & get_values() const;
-    std::vector<etcdv3::KeyValue> const & get_prev_values() const;
-    etcdv3::KeyValue const & get_value() const;
-    etcdv3::KeyValue const & get_prev_value() const;
-    bool has_values() const;
-    void set_lock_key(std::string const &key);
-    std::string const &get_lock_key() const;
-    std::vector<mvccpb::Event> const & get_events() const;
-  protected:
-    int error_code;
-    int index;
-    std::string error_message;
-    std::string action;
-    etcdv3::KeyValue value;
-    etcdv3::KeyValue prev_value; 
-    std::vector<etcdv3::KeyValue> values;
-    std::vector<etcdv3::KeyValue> prev_values; 
-    std::string lock_key; // for lock
-    std::vector<mvccpb::Event> events; // for watch
-  };
-}
+namespace etcdv3 {
+class V3Response {
+ public:
+  V3Response() : error_code(0), index(0){};
+  void set_error_code(int code);
+  int get_error_code() const;
+  std::string const& get_error_message() const;
+  void set_error_message(std::string msg);
+  void set_action(std::string action);
+  int64_t get_index() const;
+  std::string const& get_action() const;
+  std::vector<etcdv3::KeyValue> const& get_values() const;
+  std::vector<etcdv3::KeyValue> const& get_prev_values() const;
+  etcdv3::KeyValue const& get_value() const;
+  etcdv3::KeyValue const& get_prev_value() const;
+  bool has_values() const;
+  int64_t get_compact_revision() const;
+  void set_compact_revision(const int64_t compact_revision);
+  int64_t get_watch_id() const;
+  void set_watch_id(const int64_t watch_id);
+  void set_lock_key(std::string const& key);
+  std::string const& get_lock_key() const;
+  void set_name(std::string const& name);
+  std::string const& get_name() const;
+  std::vector<mvccpb::Event> const& get_events() const;
+  uint64_t get_cluster_id() const;
+  uint64_t get_member_id() const;
+  uint64_t get_raft_term() const;
+  std::vector<int64_t> const& get_leases() const;
+  std::vector<etcdv3::Member> const& get_members() const;
+
+ protected:
+  int error_code;
+  int64_t index;
+  std::string error_message;
+  std::string action;
+  etcdv3::KeyValue value;
+  etcdv3::KeyValue prev_value;
+  std::vector<etcdv3::KeyValue> values;
+  std::vector<etcdv3::KeyValue> prev_values;
+  int64_t compact_revision = -1;
+  int64_t watch_id = -1;
+  std::string lock_key;               // for lock
+  std::string name;                   // for campaign (in v3election)
+  std::vector<mvccpb::Event> events;  // for watch
+
+  // cluster metadata
+  uint64_t cluster_id;
+  uint64_t member_id;
+  uint64_t raft_term;
+
+  // for lease list
+  std::vector<int64_t> leases;
+  // for member list
+  std::vector<etcdv3::Member> members;
+};
+}  // namespace etcdv3
 #endif

etcd/v3/action_constants.hpp

@@ -1,18 +1,77 @@
 #ifndef __ETCD_ACTION_CONSTANTS_HPP__
 #define __ETCD_ACTION_CONSTANTS_HPP__
 
-namespace etcdv3
-{
-  extern char const * CREATE_ACTION;
-  extern char const * UPDATE_ACTION;
-  extern char const * SET_ACTION;
-  extern char const * GET_ACTION;
-  extern char const * DELETE_ACTION;
-  extern char const * COMPARESWAP_ACTION;
-  extern char const * COMPAREDELETE_ACTION;
-  extern char const * LOCK_ACTION;
-  extern char const * UNLOCK_ACTION;
-  extern char const * TXN_ACTION;
-}
+#include <string>
+
+namespace etcdv3 {
+extern char const* CREATE_ACTION;
+extern char const* UPDATE_ACTION;
+extern char const* SET_ACTION;
+extern char const* GET_ACTION;
+extern char const* PUT_ACTION;
+extern char const* DELETE_ACTION;
+extern char const* COMPARESWAP_ACTION;
+extern char const* COMPAREDELETE_ACTION;
+extern char const* LOCK_ACTION;
+extern char const* UNLOCK_ACTION;
+extern char const* TXN_ACTION;
+extern char const* WATCH_ACTION;
+
+extern char const* LEASEGRANT;
+extern char const* LEASEREVOKE;
+extern char const* LEASEKEEPALIVE;
+extern char const* LEASETIMETOLIVE;
+extern char const* LEASELEASES;
+
+extern char const* ADDMEMBER;
+extern char const* LISTMEMBER;
+extern char const* REMOVEMEMBER;
+
+extern char const* CAMPAIGN_ACTION;
+extern char const* PROCLAIM_ACTION;
+extern char const* LEADER_ACTION;
+extern char const* OBSERVE_ACTION;
+extern char const* RESIGN_ACTION;
+
+extern std::string const NUL;
+
+extern char const* KEEPALIVE_CREATE;
+extern char const* KEEPALIVE_WRITE;
+extern char const* KEEPALIVE_READ;
+extern char const* KEEPALIVE_DONE;
+extern char const* KEEPALIVE_FINISH;
+
+extern char const* WATCH_CREATE;
+extern char const* WATCH_WRITE;
+extern char const* WATCH_WRITE_CANCEL;
+extern char const* WATCH_WRITES_DONE;
+extern char const* WATCH_FINISH;
+
+extern char const* ELECTION_OBSERVE_CREATE;
+extern char const* ELECTION_OBSERVE_FINISH;
+
+extern const int ERROR_GRPC_OK;
+extern const int ERROR_GRPC_CANCELLED;
+extern const int ERROR_GRPC_UNKNOWN;
+extern const int ERROR_GRPC_INVALID_ARGUMENT;
+extern const int ERROR_GRPC_DEADLINE_EXCEEDED;
+extern const int ERROR_GRPC_NOT_FOUND;
+extern const int ERROR_GRPC_ALREADY_EXISTS;
+extern const int ERROR_GRPC_PERMISSION_DENIED;
+extern const int ERROR_GRPC_UNAUTHENTICATED;
+extern const int ERROR_GRPC_RESOURCE_EXHAUSTED;
+extern const int ERROR_GRPC_FAILED_PRECONDITION;
+extern const int ERROR_GRPC_ABORTED;
+extern const int ERROR_GRPC_OUT_OF_RANGE;
+extern const int ERROR_GRPC_UNIMPLEMENTED;
+extern const int ERROR_GRPC_INTERNAL;
+extern const int ERROR_GRPC_UNAVAILABLE;
+extern const int ERROR_GRPC_DATA_LOSS;
+
+extern const int ERROR_KEY_NOT_FOUND;
+extern const int ERROR_COMPARE_FAILED;
+extern const int ERROR_KEY_ALREADY_EXISTS;
+extern const int ERROR_ACTION_CANCELLED;
+}  // namespace etcdv3
 
 #endif

proto/CMakeLists.txt

@@ -14,6 +14,7 @@ protobuf_generate_latest(
 compute_generated_srcs(PROTO_GENERATES_SRCS "${PROTO_GEN_OUT_DIR}" false ${PROTO_SRCS})
 
 set(PROTO_GRPC_SRCS "${CMAKE_CURRENT_SOURCE_DIR}/rpc.proto"
+                    "${CMAKE_CURRENT_SOURCE_DIR}/v3election.proto"
                     "${CMAKE_CURRENT_SOURCE_DIR}/v3lock.proto")
 grpc_generate_cpp(PROTO_GRPC_GENERATES PROTO_GRPC_GENERATES_HDRS
     "${PROTO_GEN_OUT_DIR}"

proto/rpc.proto

@@ -4,7 +4,6 @@ package etcdserverpb;
 import "gogoproto/gogo.proto";
 import "kv.proto";
 import "auth.proto";
-import "txn.proto";
 
 // for grpc-gateway
 import "google/api/annotations.proto";
@@ -533,6 +532,46 @@ message ResponseOp {
   }
 }
 
+message Compare {
+  enum CompareResult {
+    EQUAL = 0;
+    GREATER = 1;
+    LESS = 2;
+    NOT_EQUAL = 3;
+  }
+  enum CompareTarget {
+    VERSION = 0;
+    CREATE = 1;
+    MOD = 2;
+    VALUE = 3;
+    LEASE = 4;
+  }
+  // result is logical comparison operation for this comparison.
+  CompareResult result = 1;
+  // target is the key-value field to inspect for the comparison.
+  CompareTarget target = 2;
+  // key is the subject key for the comparison operation.
+  bytes key = 3;
+  oneof target_union {
+    // version is the version of the given key
+    int64 version = 4;
+    // create_revision is the creation revision of the given key
+    int64 create_revision = 5;
+    // mod_revision is the last modified revision of the given key.
+    int64 mod_revision = 6;
+    // value is the value of the given key, in bytes.
+    bytes value = 7;
+    // lease is the lease id of the given key.
+    int64 lease = 8;
+    // leave room for more target_union field tags, jump to 64
+  }
+
+  // range_end compares the given target to all keys in the range [key, range_end).
+  // See RangeRequest for more details on key ranges.
+  bytes range_end = 64;
+  // TODO: fill out with most of the rest of RangeRequest fields when needed.
+}
+
 // From google paxosdb paper:
 // Our implementation hinges around a powerful primitive which we call MultiOp. All other database
 // operations except for iteration are implemented as a single call to MultiOp. A MultiOp is applied atomically

proto/txn.proto

@@ -1,42 +0,0 @@
-syntax = "proto3";
-package etcdserverpb;
-
-message Compare {
-  enum CompareResult {
-    EQUAL = 0;
-    GREATER = 1;
-    LESS = 2;
-    NOT_EQUAL = 3;
-  }
-  enum CompareTarget {
-    VERSION = 0;
-    CREATE = 1;
-    MOD = 2;
-    VALUE = 3;
-    LEASE = 4;
-  }
-  // result is logical comparison operation for this comparison.
-  CompareResult result = 1;
-  // target is the key-value field to inspect for the comparison.
-  CompareTarget target = 2;
-  // key is the subject key for the comparison operation.
-  bytes key = 3;
-  oneof target_union {
-    // version is the version of the given key
-    int64 version = 4;
-    // create_revision is the creation revision of the given key
-    int64 create_revision = 5;
-    // mod_revision is the last modified revision of the given key.
-    int64 mod_revision = 6;
-    // value is the value of the given key, in bytes.
-    bytes value = 7;
-    // lease is the lease id of the given key.
-    int64 lease = 8;
-    // leave room for more target_union field tags, jump to 64
-  }
-
-  // range_end compares the given target to all keys in the range [key, range_end).
-  // See RangeRequest for more details on key ranges.
-  bytes range_end = 64;
-  // TODO: fill out with most of the rest of RangeRequest fields when needed.
-}

proto/v3election.proto

@@ -0,0 +1,119 @@
+syntax = "proto3";
+package v3electionpb;
+
+import "gogoproto/gogo.proto";
+import "rpc.proto";
+import "kv.proto";
+
+// for grpc-gateway
+import "google/api/annotations.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+
+// The election service exposes client-side election facilities as a gRPC interface.
+service Election {
+  // Campaign waits to acquire leadership in an election, returning a LeaderKey
+  // representing the leadership if successful. The LeaderKey can then be used
+  // to issue new values on the election, transactionally guard API requests on
+  // leadership still being held, and resign from the election.
+  rpc Campaign(CampaignRequest) returns (CampaignResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/campaign"
+        body: "*"
+    };
+  }
+  // Proclaim updates the leader's posted value with a new value.
+  rpc Proclaim(ProclaimRequest) returns (ProclaimResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/proclaim"
+        body: "*"
+    };
+  }
+  // Leader returns the current election proclamation, if any.
+  rpc Leader(LeaderRequest) returns (LeaderResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/leader"
+        body: "*"
+    };
+  }
+  // Observe streams election proclamations in-order as made by the election's
+  // elected leaders.
+  rpc Observe(LeaderRequest) returns (stream LeaderResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/observe"
+        body: "*"
+    };
+  }
+  // Resign releases election leadership so other campaigners may acquire
+  // leadership on the election.
+  rpc Resign(ResignRequest) returns (ResignResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/resign"
+        body: "*"
+    };
+  }
+}
+
+message CampaignRequest {
+  // name is the election's identifier for the campaign.
+  bytes name = 1;
+  // lease is the ID of the lease attached to leadership of the election. If the
+  // lease expires or is revoked before resigning leadership, then the
+  // leadership is transferred to the next campaigner, if any.
+  int64 lease = 2;
+  // value is the initial proclaimed value set when the campaigner wins the
+  // election.
+  bytes value = 3;
+}
+
+message CampaignResponse {
+  etcdserverpb.ResponseHeader header = 1;
+  // leader describes the resources used for holding leadereship of the election.
+  LeaderKey leader = 2;
+}
+
+message LeaderKey {
+  // name is the election identifier that correponds to the leadership key.
+  bytes name = 1;
+  // key is an opaque key representing the ownership of the election. If the key
+  // is deleted, then leadership is lost.
+  bytes key = 2;
+  // rev is the creation revision of the key. It can be used to test for ownership
+  // of an election during transactions by testing the key's creation revision
+  // matches rev.
+  int64 rev = 3;
+  // lease is the lease ID of the election leader.
+  int64 lease = 4;
+}
+
+message LeaderRequest {
+  // name is the election identifier for the leadership information.
+  bytes name = 1;
+}
+
+message LeaderResponse {
+  etcdserverpb.ResponseHeader header = 1;
+  // kv is the key-value pair representing the latest leader update.
+  mvccpb.KeyValue kv = 2;
+}
+
+message ResignRequest {
+  // leader is the leadership to relinquish by resignation.
+  LeaderKey leader = 1;
+}
+
+message ResignResponse {
+  etcdserverpb.ResponseHeader header = 1;
+}
+
+message ProclaimRequest {
+  // leader is the leadership hold on the election.
+  LeaderKey leader = 1;
+  // value is an update meant to overwrite the leader's current value.
+  bytes value = 2;
+}
+
+message ProclaimResponse {
+  etcdserverpb.ResponseHeader header = 1;
+}

src/CMakeLists.txt

@@ -1,31 +1,86 @@
-file(GLOB_RECURSE CPP_CLIENT_SRC
-                  RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}"
-                  "${CMAKE_CURRENT_SOURCE_DIR}/*.cpp"
-                  "${CMAKE_CURRENT_SOURCE_DIR}/**/*.cpp")
-
+# grpc stuffs
 set_source_files_properties(${PROTOBUF_GENERATES} PROPERTIES GENERATED TRUE)
-add_library(etcd-cpp-api ${CPP_CLIENT_SRC} ${PROTOBUF_GENERATES})
-add_dependencies(etcd-cpp-api protobuf_generates)
-set_property(TARGET etcd-cpp-api PROPERTY CXX_STANDARD 11)
 
-target_link_libraries(etcd-cpp-api PUBLIC
-                      ${Boost_LIBRARIES}
-                      ${CPPREST_LIB}
-                      ${PROTOBUF_LIBRARIES}
+macro(include_generated_protobuf_files target)
+    target_include_directories(${target} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen)
+    target_include_directories(${target} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen/proto)
+endmacro()
+
+# prepare common objects
+file(GLOB_RECURSE CPP_CLIENT_CORE_SRC
+                  RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/KeepAlive.cpp"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/Response.cpp"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/SyncClient.cpp"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/Value.cpp"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/Watcher.cpp"
+                  "${CMAKE_CURRENT_SOURCE_DIR}/**/*.cpp"
+)
+
+add_library(etcd-cpp-api-core-objects OBJECT ${CPP_CLIENT_CORE_SRC} ${PROTOBUF_GENERATES})
+use_cxx(etcd-cpp-api-core-objects)
+set_exceptions(etcd-cpp-api-core-objects)
+add_dependencies(etcd-cpp-api-core-objects protobuf_generates)
+include_generated_protobuf_files(etcd-cpp-api-core-objects)
+target_link_libraries(etcd-cpp-api-core-objects PUBLIC
                       ${OPENSSL_LIBRARIES}
-                      ${GRPC_LIBRARIES})
+                      ${GRPC_LIBRARIES}
+)
+if(TARGET protobuf::libprotobuf)
+    target_link_libraries(etcd-cpp-api-core-objects PUBLIC protobuf::libprotobuf)
+else()
+    target_link_libraries(etcd-cpp-api-core-objects PUBLIC ${PROTOBUF_LIBRARIES})
+endif()
 
-target_include_directories(etcd-cpp-api PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen)
-target_include_directories(etcd-cpp-api PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen/proto)
+if(BUILD_ETCD_CORE_ONLY)
+    # add the core library, includes the sycnhronous client only
+    add_library(etcd-cpp-api-core $<TARGET_OBJECTS:etcd-cpp-api-core-objects>)
+    use_cxx(etcd-cpp-api-core)
+    set_exceptions(etcd-cpp-api-core)
+    target_link_libraries(etcd-cpp-api-core PUBLIC
+                          ${OPENSSL_LIBRARIES}
+                          ${GRPC_LIBRARIES}
+    )
+    if(TARGET protobuf::libprotobuf)
+        target_link_libraries(etcd-cpp-api-core PUBLIC protobuf::libprotobuf)
+    else()
+        target_link_libraries(etcd-cpp-api-core PUBLIC ${PROTOBUF_LIBRARIES})
+    endif()
+    include_generated_protobuf_files(etcd-cpp-api-core)
+else()
+    # add the client with asynchronus client
+    add_library(etcd-cpp-api $<TARGET_OBJECTS:etcd-cpp-api-core-objects>
+                            "${CMAKE_CURRENT_SOURCE_DIR}/Client.cpp")
+    use_cxx(etcd-cpp-api)
+    set_exceptions(etcd-cpp-api)
+    target_link_libraries(etcd-cpp-api PUBLIC
+                          ${CPPREST_LIB}  # n.b.: the asynchronous client requires pplx in cpprestsdk
+                          ${OPENSSL_LIBRARIES}
+                          ${GRPC_LIBRARIES}
+    )
+    if(TARGET protobuf::libprotobuf)
+        target_link_libraries(etcd-cpp-api PUBLIC protobuf::libprotobuf)
+    else()
+        target_link_libraries(etcd-cpp-api PUBLIC ${PROTOBUF_LIBRARIES})
+    endif()
+    include_generated_protobuf_files(etcd-cpp-api)
+endif()
+
+if(BUILD_ETCD_CORE_ONLY)
+    add_library(etcd-cpp-api INTERFACE)
+    target_link_libraries(etcd-cpp-api INTERFACE etcd-cpp-api-core)
+else()
+    add_library(etcd-cpp-api-core INTERFACE)
+    target_link_libraries(etcd-cpp-api-core INTERFACE etcd-cpp-api)
+endif()
 
 if("${CMAKE_VERSION}" VERSION_LESS "3.14")
-    install(TARGETS etcd-cpp-api
+    install(TARGETS etcd-cpp-api-core etcd-cpp-api
             EXPORT etcd-targets
             RUNTIME DESTINATION bin
             LIBRARY DESTINATION lib
             ARCHIVE DESTINATION lib)
 else()
-    install(TARGETS etcd-cpp-api
+    install(TARGETS etcd-cpp-api-core etcd-cpp-api
             EXPORT etcd-targets)
 endif()
-

src/KeepAlive.cpp

@@ -1,13 +1,15 @@
 #include <chrono>
+#include <iostream>
+#include <ratio>
 
 #include "etcd/KeepAlive.hpp"
-#include "etcd/v3/AsyncLeaseAction.hpp"
+#include "etcd/v3/AsyncGRPC.hpp"
 
 #include <grpc++/grpc++.h>
 #include "proto/rpc.grpc.pb.h"
 
 namespace etcdv3 {
-  class AsyncLeaseKeepAliveAction;
+class AsyncLeaseKeepAliveAction;
 }
 
 struct etcd::KeepAlive::EtcdServerStubs {
@@ -15,108 +17,144 @@ struct etcd::KeepAlive::EtcdServerStubs {
   std::unique_ptr<etcdv3::AsyncLeaseKeepAliveAction> call;
 };
 
-void etcd::KeepAlive::EtcdServerStubsDeleter::operator()(etcd::KeepAlive::EtcdServerStubs *stubs) {
+void etcd::KeepAlive::EtcdServerStubsDeleter::operator()(
+    etcd::KeepAlive::EtcdServerStubs* stubs) {
   if (stubs) {
     delete stubs;
   }
 }
 
-etcd::KeepAlive::KeepAlive(Client const &client, int ttl, int64_t lease_id):
-    ttl(ttl), lease_id(lease_id), continue_next(true) {
+etcd::KeepAlive::KeepAlive(SyncClient const& client, int ttl, int64_t lease_id)
+    : ttl(ttl),
+      lease_id(lease_id),
+      continue_next(true),
+      grpc_timeout(client.get_grpc_timeout()) {
+  if (ttl > 0 && lease_id == 0) {
+    this->lease_id =
+        const_cast<SyncClient&>(client).leasegrant(ttl).value().lease();
+  }
   stubs.reset(new EtcdServerStubs{});
-  stubs->leaseServiceStub = Lease::NewStub(client.channel);
+  stubs->leaseServiceStub = Lease::NewStub(client.grpc_channel());
 
   etcdv3::ActionParameters params;
-  params.auth_token.assign(client.auth_token);
+  params.auth_token.assign(client.current_auth_token());
+  params.grpc_timeout = grpc_timeout;
   params.lease_id = this->lease_id;
   params.lease_stub = stubs->leaseServiceStub.get();
 
   continue_next.store(true);
 
-  stubs->call.reset(new etcdv3::AsyncLeaseKeepAliveAction(params));
-  task_ = std::thread([this]() {
+  stubs->call.reset(new etcdv3::AsyncLeaseKeepAliveAction(std::move(params)));
+  refresh_task_ = std::thread([this]() {
+#ifndef _ETCD_NO_EXCEPTIONS
     try {
       // start refresh
       this->refresh();
-      context.run();
-    } catch (...) {
+    } catch (const std::exception& e) {
+      // propagate the exception
       eptr_ = std::current_exception();
     }
-    context.stop();  // clean up
+#else
+    const std::string err = this->refresh();
+    if (!err.empty()) {
+      eptr_ = std::make_exception_ptr(std::runtime_error(err));
+    }
+#endif
   });
 }
 
-etcd::KeepAlive::KeepAlive(std::string const & address, int ttl, int64_t lease_id):
-    KeepAlive(Client(address), ttl, lease_id) {
-}
+etcd::KeepAlive::KeepAlive(std::string const& address, int ttl,
+                           int64_t lease_id)
+    : KeepAlive(SyncClient(address), ttl, lease_id) {}
 
-etcd::KeepAlive::KeepAlive(std::string const & address,
-                           std::string const & username, std::string const & password,
-                           int ttl, int64_t lease_id):
-    KeepAlive(Client(address, username, password), ttl, lease_id) {
-}
+etcd::KeepAlive::KeepAlive(std::string const& address,
+                           std::string const& username,
+                           std::string const& password, int ttl,
+                           int64_t lease_id, int const auth_token_ttl)
+    : KeepAlive(SyncClient(address, username, password, auth_token_ttl), ttl,
+                lease_id) {}
 
-etcd::KeepAlive::KeepAlive(Client const &client,
-                           std::function<void (std::exception_ptr)> const &handler,
-                           int ttl, int64_t lease_id):
-    handler_(handler), ttl(ttl), lease_id(lease_id), continue_next(true) {
+etcd::KeepAlive::KeepAlive(
+    std::string const& address, std::string const& ca, std::string const& cert,
+    std::string const& privkey,
+    std::function<void(std::exception_ptr)> const& handler, int ttl,
+    int64_t lease_id, std::string const& target_name_override)
+    : KeepAlive(SyncClient(address, ca, cert, privkey, target_name_override),
+                handler, ttl, lease_id) {}
+
+etcd::KeepAlive::KeepAlive(
+    SyncClient const& client,
+    std::function<void(std::exception_ptr)> const& handler, int ttl,
+    int64_t lease_id)
+    : handler_(handler),
+      ttl(ttl),
+      lease_id(lease_id),
+      continue_next(true),
+      grpc_timeout(client.get_grpc_timeout()) {
+  if (ttl > 0 && lease_id == 0) {
+    this->lease_id =
+        const_cast<SyncClient&>(client).leasegrant(ttl).value().lease();
+  }
   stubs.reset(new EtcdServerStubs{});
-  stubs->leaseServiceStub = Lease::NewStub(client.channel);
+  stubs->leaseServiceStub = Lease::NewStub(client.grpc_channel());
 
   etcdv3::ActionParameters params;
-  params.auth_token.assign(client.auth_token);
+  params.auth_token.assign(client.current_auth_token());
+  // n.b.: keepalive: no need for timeout
   params.lease_id = this->lease_id;
   params.lease_stub = stubs->leaseServiceStub.get();
 
-  stubs->call.reset(new etcdv3::AsyncLeaseKeepAliveAction(params));
-  task_ = std::thread([this]() {
+  stubs->call.reset(new etcdv3::AsyncLeaseKeepAliveAction(std::move(params)));
+  refresh_task_ = std::thread([this]() {
+#ifndef _ETCD_NO_EXCEPTIONS
     try {
       // start refresh
       this->refresh();
-      context.run();
     } catch (...) {
-      if (handler_) {
-        handler_(std::current_exception());
-      } else {
-        eptr_ = std::current_exception();
-      }
-      this->Cancel();
+      // propagate the exception
+      eptr_ = std::current_exception();
+    }
+#else
+    const std::string err = this->refresh();
+    if (!err.empty()) {
+      eptr_ = std::make_exception_ptr(std::runtime_error(err));
+    }
+#endif
+    if (eptr_ && handler_) {
+      handler_(eptr_);
     }
   });
 }
 
-etcd::KeepAlive::KeepAlive(std::string const & address,
-                           std::function<void (std::exception_ptr)> const &handler,
-                           int ttl, int64_t lease_id):
-    KeepAlive(Client(address), handler, ttl, lease_id) {
-}
+etcd::KeepAlive::KeepAlive(
+    std::string const& address,
+    std::function<void(std::exception_ptr)> const& handler, int ttl,
+    int64_t lease_id)
+    : KeepAlive(SyncClient(address), handler, ttl, lease_id) {}
 
-etcd::KeepAlive::KeepAlive(std::string const & address,
-                           std::string const & username, std::string const & password,
-                           std::function<void (std::exception_ptr)> const &handler,
-                           int ttl, int64_t lease_id):
-    KeepAlive(Client(address, username, password), handler, ttl, lease_id) {
-}
+etcd::KeepAlive::KeepAlive(
+    std::string const& address, std::string const& username,
+    std::string const& password,
+    std::function<void(std::exception_ptr)> const& handler, int ttl,
+    int64_t lease_id, const int auth_token_ttl)
+    : KeepAlive(SyncClient(address, username, password, auth_token_ttl),
+                handler, ttl, lease_id) {}
 
-etcd::KeepAlive::~KeepAlive()
-{
-  this->Cancel();
-}
+etcd::KeepAlive::~KeepAlive() { this->Cancel(); }
 
-void etcd::KeepAlive::Cancel()
-{
+void etcd::KeepAlive::Cancel() {
   if (!continue_next.exchange(false)) {
     return;
   }
-  stubs->call->CancelKeepAlive();
-  if (keepalive_timer_) {
-    keepalive_timer_->cancel();
-  }
 
-  // clean up
-  context.stop();
-  if (task_.joinable()) {
-    task_.join();
+  // stop the thread
+  cv_for_refresh_.notify_all();
+  refresh_task_.join();
+
+  // send a cancel request
+  {
+    std::lock_guard<std::mutex> lock(mutex_for_refresh_);
+    stubs->call->CancelKeepAlive();
   }
 }
 
@@ -124,35 +162,97 @@ void etcd::KeepAlive::Check() {
   if (eptr_) {
     std::rethrow_exception(eptr_);
   }
+  // issue an refresh to make sure it still alive
+#ifndef _ETCD_NO_EXCEPTIONS
+  try {
+    this->refresh_once();
+  } catch (...) {
+    // run canceller first
+    this->Cancel();
+
+    // propagate the exception, as we throw in `Check()`, the `handler` won't be
+    // touched
+    eptr_ = std::current_exception();
+  }
+#else
+  const std::string err = this->refresh_once();
+  if (!err.empty()) {
+    // run canceller first
+    this->Cancel();
+
+    // propagate the exception, as we throw in `Check()`, the `handler` won't be
+    // touched
+    eptr_ = std::make_exception_ptr(std::runtime_error(err));
+  }
+#endif
+  if (eptr_ && handler_) {
+    handler_(eptr_);
+  }
+
+#ifndef _ETCD_NO_EXCEPTIONS
+  if (eptr_) {
+    // rethrow in `Check()` to keep the consistent semantics
+    std::rethrow_exception(eptr_);
+  }
+#endif
+  return;
 }
 
-void etcd::KeepAlive::refresh()
-{
-  if (!continue_next.load()) {
-    return;
-  }
-  // minimal resolution: 1 second
-  int keepalive_ttl = std::max(ttl - 1, 1);
-  keepalive_timer_.reset(new boost::asio::steady_timer(
-      context, std::chrono::seconds(keepalive_ttl)));
-  keepalive_timer_->async_wait([this](const boost::system::error_code& error) {
-    if (error) {
+std::string etcd::KeepAlive::refresh() {
+  while (true) {
+    if (!continue_next.load()) {
+      return std::string{};
+    }
+    // minimal resolution: 1 second
+    int keepalive_ttl = std::max(ttl - 1, 1);
+    {
+      std::unique_lock<std::mutex> lock(mutex_for_refresh_);
+      if (cv_for_refresh_.wait_for(lock, std::chrono::seconds(keepalive_ttl)) ==
+          std::cv_status::no_timeout) {
+        if (!continue_next.load()) {
+          return std::string{};
+        }
 #ifndef NDEBUG
-      std::cerr << "keepalive timer cancelled: " << error << ", " << error.message() << std::endl;
+        std::cerr
+            << "[warn] awaked from condition_variable but continue_next is "
+               "not set, maybe due to clock drift."
+            << std::endl;
 #endif
-    } else {
-      if (this->continue_next.load()) {
-        auto resp = this->stubs->call->Refresh();
-        if (!resp.is_ok()) {
-          throw std::runtime_error("Failed to refresh lease: error code: " + std::to_string(resp.error_code()) +
-                                   ", message: " + resp.error_message());
-        }
-        if (resp.value().ttl() == 0) {
-          throw std::out_of_range("Failed to refresh lease due to expiration: the new TTL is 0.");
-        }
-        // trigger the next round;
-        this->refresh();
       }
     }
-  });
+
+    // execute refresh
+    const std::string err = this->refresh_once();
+    if (!err.empty()) {
+      return err;
+    }
+  }
+  return std::string{};
+}
+
+std::string etcd::KeepAlive::refresh_once() {
+  std::lock_guard<std::mutex> scope_lock(mutex_for_refresh_);
+  if (!continue_next.load()) {
+    return std::string{};
+  }
+  this->stubs->call->mutable_parameters().grpc_timeout = this->grpc_timeout;
+  auto resp = this->stubs->call->Refresh();
+  if (!resp.is_ok()) {
+    const std::string err = "Failed to refresh lease: error code: " +
+                            std::to_string(resp.error_code()) +
+                            ", message: " + resp.error_message();
+#ifndef _ETCD_NO_EXCEPTIONS
+    throw std::runtime_error(err);
+#endif
+    return err;
+  }
+  if (resp.value().ttl() == 0) {
+    const std::string err =
+        "Failed to refresh lease due to expiration: the new TTL is 0.";
+#ifndef _ETCD_NO_EXCEPTIONS
+    throw std::out_of_range(err);
+#endif
+    return err;
+  }
+  return std::string{};
 }

src/Response.cpp

@@ -3,118 +3,138 @@
 
 #include <iostream>
 
+etcd::Response::Response() : _error_code(0), _index(0) {}
 
-etcd::Response::Response(const etcdv3::V3Response& reply, std::chrono::microseconds const& duration)
-{
+etcd::Response::Response(const etcd::Response& response) {
+  this->_error_code = response._error_code;
+  this->_error_message = response._error_message;
+  this->_index = response._index;
+  this->_action = response._action;
+  this->_value = response._value;
+  this->_prev_value = response._prev_value;
+  this->_values = response._values;
+  this->_keys = response._keys;
+  this->_compact_revision = response._compact_revision;
+  this->_lock_key = response._lock_key;
+  this->_name = response._name;
+  this->_events = response._events;
+  this->_duration = response._duration;
+
+  this->_cluster_id = response._cluster_id;
+  this->_member_id = response._member_id;
+  this->_raft_term = response._raft_term;
+
+  this->_leases = response._leases;
+  this->_members = response._members;
+}
+
+etcd::Response::Response(const etcdv3::V3Response& reply,
+                         std::chrono::microseconds const& duration) {
   _index = reply.get_index();
   _action = reply.get_action();
   _error_code = reply.get_error_code();
   _error_message = reply.get_error_message();
-  if(reply.has_values())
-  {
+  if (reply.has_values()) {
     auto val = reply.get_values();
-    for(unsigned int index = 0; index < val.size(); index++)
-    {
+    for (unsigned int index = 0; index < val.size(); index++) {
       _values.push_back(Value(val[index]));
       _keys.push_back(val[index].kvs.key());
     }
-  }
-  else
-  {
+    _value = Value(reply.get_values()[0]);
+  } else {
     _value = Value(reply.get_value());
   }
-
   _prev_value = Value(reply.get_prev_value());
 
+  _compact_revision = reply.get_compact_revision();
+  _watch_id = reply.get_watch_id();
   _lock_key = reply.get_lock_key();
-  _events = reply.get_events();
+  _name = reply.get_name();
+
+  for (auto const& ev : reply.get_events()) {
+    _events.emplace_back(etcd::Event(ev));
+  }
 
   // duration
   _duration = duration;
+
+  // etcd head
+  _cluster_id = reply.get_cluster_id();
+  _member_id = reply.get_member_id();
+  _raft_term = reply.get_raft_term();
+
+  // lease list
+  this->_leases = reply.get_leases();
+  // member list
+  this->_members = reply.get_members();
 }
 
+etcd::Response::Response(int error_code, std::string const& error_message)
+    : _error_code(error_code), _error_message(error_message), _index(0) {}
 
-etcd::Response::Response()
-  : _error_code(0),
-    _index(0)
-{
-}
+etcd::Response::Response(int error_code, char const* error_message)
+    : _error_code(error_code), _error_message(error_message), _index(0) {}
 
-etcd::Response::Response(int error_code, char const * error_message)
-  : _error_code(error_code),
-    _error_message(error_message),
-    _index(0)
-{
-}
+int etcd::Response::error_code() const { return _error_code; }
 
-int etcd::Response::error_code() const
-{
-  return _error_code;
-}
-
-std::string const & etcd::Response::error_message() const
-{
+std::string const& etcd::Response::error_message() const {
   return _error_message;
 }
 
-int etcd::Response::index() const
-{
-  return _index;
-}
+bool etcd::Response::is_ok() const { return error_code() == 0; }
 
-std::string const & etcd::Response::action() const
-{
-  return _action;
-}
-
-bool etcd::Response::is_ok() const
-{
-  return error_code() == 0;
-}
-
-bool etcd::Response::is_network_unavailable() const
-{
+bool etcd::Response::is_network_unavailable() const {
   return error_code() == ::grpc::StatusCode::UNAVAILABLE;
 }
 
-etcd::Value const & etcd::Response::value() const
-{
-  return _value;
+bool etcd::Response::is_grpc_timeout() const {
+  return _error_code == grpc::StatusCode::DEADLINE_EXCEEDED;
 }
 
-etcd::Value const & etcd::Response::prev_value() const
-{
-  return _prev_value;
-}
+std::string const& etcd::Response::action() const { return _action; }
 
-etcd::Values const & etcd::Response::values() const
-{
-  return _values;
-}
+int64_t etcd::Response::index() const { return _index; }
 
-etcd::Value const & etcd::Response::value(int index) const
-{
+etcd::Value const& etcd::Response::value() const { return _value; }
+
+etcd::Value const& etcd::Response::prev_value() const { return _prev_value; }
+
+etcd::Values const& etcd::Response::values() const { return _values; }
+
+etcd::Value const& etcd::Response::value(int index) const {
   return _values[index];
 }
 
-etcd::Keys const & etcd::Response::keys() const
-{
-  return _keys;
-}
+etcd::Keys const& etcd::Response::keys() const { return _keys; }
 
-std::string const & etcd::Response::key(int index) const
-{
-  return _keys[index];
-}
+std::string const& etcd::Response::key(int index) const { return _keys[index]; }
 
-std::string const & etcd::Response::lock_key() const {
-  return _lock_key;
-}
+int64_t etcd::Response::compact_revision() const { return _compact_revision; }
 
-std::vector<mvccpb::Event> const & etcd::Response::events() const {
+int64_t etcd::Response::watch_id() const { return _watch_id; }
+
+std::string const& etcd::Response::lock_key() const { return _lock_key; }
+
+std::string const& etcd::Response::name() const { return _name; }
+
+std::vector<etcd::Event> const& etcd::Response::events() const {
   return this->_events;
 }
 
 std::chrono::microseconds const& etcd::Response::duration() const {
   return this->_duration;
 }
+
+uint64_t etcd::Response::cluster_id() const { return this->_cluster_id; }
+
+uint64_t etcd::Response::member_id() const { return this->_member_id; }
+
+uint64_t etcd::Response::raft_term() const { return this->_raft_term; }
+
+std::vector<int64_t> const& etcd::Response::leases() const {
+  return this->_leases;
+}
+
+std::vector<etcdv3::Member> const& etcd::Response::members() const {
+  return this->_members;
+}

src/Value.cpp

@@ -1,60 +1,116 @@
+#include <cstdint>
 #include <iomanip>
 
 #include "etcd/Value.hpp"
 #include "etcd/v3/KeyValue.hpp"
 
 etcd::Value::Value()
-  : dir(false),
-    created(0),
-    modified(0),
-    _ttl(0),
-    leaseId(0)
-{
-}
+    : dir(false), created(0), modified(0), _version(0), _ttl(0), leaseId(0) {}
 
-
-etcd::Value::Value(etcdv3::KeyValue const & kv)
-{
-  dir=false;
-  _key=kv.kvs.key();
-  value=kv.kvs.value();
-  created=kv.kvs.create_revision();
-  modified=kv.kvs.mod_revision();
+etcd::Value::Value(etcdv3::KeyValue const& kv) {
+  dir = false;
+  _key = kv.kvs.key();
+  value = kv.kvs.value();
+  created = kv.kvs.create_revision();
+  modified = kv.kvs.mod_revision();
+  _version = kv.kvs.version();
   leaseId = kv.kvs.lease();
   _ttl = kv.get_ttl();
 }
 
-std::string const & etcd::Value::key() const
-{
-  return _key;
+etcd::Value::Value(mvccpb::KeyValue const& kv) {
+  dir = false;
+  _key = kv.key();
+  value = kv.value();
+  created = kv.create_revision();
+  modified = kv.mod_revision();
+  _version = kv.version();
+  leaseId = kv.lease();
+  _ttl = -1;
 }
 
-bool etcd::Value::is_dir() const
-{
-  return dir;
+std::string const& etcd::Value::key() const { return _key; }
+
+bool etcd::Value::is_dir() const { return dir; }
+
+std::string const& etcd::Value::as_string() const { return value; }
+
+int64_t etcd::Value::created_index() const { return created; }
+
+int64_t etcd::Value::modified_index() const { return modified; }
+
+int64_t etcd::Value::version() const { return _version; }
+
+int etcd::Value::ttl() const { return _ttl; }
+
+int64_t etcd::Value::lease() const { return leaseId; }
+
+std::ostream& etcd::operator<<(std::ostream& os, const etcd::Value& value) {
+  os << "Event: {";
+  os << "Key: " << value.key() << ", ";
+  os << "Value: " << value.as_string() << ", ";
+  os << "Created: " << value.created_index() << ", ";
+  os << "Modified: " << value.modified_index() << ", ";
+  os << "Version: " << value.version() << ", ";
+  os << "TTL: " << value.ttl() << ", ";
+  os << "Lease: " << value.lease() << ", ";
+  os << "}";
+  return os;
 }
 
-std::string const & etcd::Value::as_string() const
-{
-  return value;
+etcd::Event::Event(mvccpb::Event const& event) {
+  _has_kv = event.has_kv();
+  _has_prev_kv = event.has_prev_kv();
+  if (_has_kv) {
+    _kv = Value(event.kv());
+  }
+  if (_has_prev_kv) {
+    _prev_kv = Value(event.prev_kv());
+  }
+  if (event.type() == mvccpb::Event::PUT) {
+    event_type_ = EventType::PUT;
+  } else if (event.type() == mvccpb::Event::DELETE_) {
+    event_type_ = EventType::DELETE_;
+  } else {
+    event_type_ = EventType::INVALID;
+  }
 }
 
-int etcd::Value::created_index() const
-{
-  return created;
+enum etcd::Event::EventType etcd::Event::event_type() const {
+  return event_type_;
 }
 
-int etcd::Value::modified_index() const
-{
-  return modified;
+bool etcd::Event::has_kv() const { return _has_kv; }
+
+bool etcd::Event::has_prev_kv() const { return _has_prev_kv; }
+
+const etcd::Value& etcd::Event::kv() const { return _kv; }
+
+const etcd::Value& etcd::Event::prev_kv() const { return _prev_kv; }
+
+std::ostream& etcd::operator<<(std::ostream& os,
+                               const etcd::Event::EventType& value) {
+  switch (value) {
+  case etcd::Event::EventType::PUT:
+    os << "PUT";
+    break;
+  case etcd::Event::EventType::DELETE_:
+    os << "DELETE";
+    break;
+  case etcd::Event::EventType::INVALID:
+    os << "INVALID";
+    break;
+  }
+  return os;
 }
 
-int etcd::Value::ttl() const
-{
-  return _ttl;
-}
-
-int64_t etcd::Value::lease() const
-{
-  return leaseId;
+std::ostream& etcd::operator<<(std::ostream& os, const etcd::Event& event) {
+  os << "Event type: " << event.event_type();
+  if (event.has_kv()) {
+    os << ", KV: " << event.kv();
+  }
+  if (event.has_prev_kv()) {
+    os << ", Prev KV: " << event.prev_kv();
+  }
+  return os;
 }

src/Watcher.cpp

@@ -1,102 +1,226 @@
 #include "etcd/Watcher.hpp"
-#include "etcd/v3/AsyncWatchAction.hpp"
+
+#include "etcd/SyncClient.hpp"
+
+#include "etcd/v3/AsyncGRPC.hpp"
 
 struct etcd::Watcher::EtcdServerStubs {
   std::unique_ptr<Watch::Stub> watchServiceStub;
   std::unique_ptr<etcdv3::AsyncWatchAction> call;
 };
 
-void etcd::Watcher::EtcdServerStubsDeleter::operator()(etcd::Watcher::EtcdServerStubs *stubs) {
+void etcd::Watcher::EtcdServerStubsDeleter::operator()(
+    etcd::Watcher::EtcdServerStubs* stubs) {
   if (stubs) {
+    if (stubs->watchServiceStub) {
+      stubs->watchServiceStub.reset();
+    }
+    if (stubs->call) {
+      stubs->call.reset();
+    }
     delete stubs;
   }
 }
 
-etcd::Watcher::Watcher(Client const &client, std::string const & key,
-                       std::function<void(Response)> callback, bool recursive):
-    Watcher(client, key, -1, callback, recursive) {
-}
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive)
+    : Watcher(client, key, -1, callback, wait_callback, recursive) {}
 
-etcd::Watcher::Watcher(Client const &client, std::string const & key,
-                       std::string const &range_end,
-                       std::function<void(Response)> callback):
-    Watcher(client, key, range_end, -1, callback) {
-}
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback)
+    : Watcher(client, key, range_end, -1, callback, wait_callback) {}
 
-etcd::Watcher::Watcher(Client const &client, std::string const & key, int fromIndex,
-                       std::function<void(Response)> callback, bool recursive):
-    fromIndex(fromIndex), recursive(recursive) {
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive)
+    : wait_callback(wait_callback), fromIndex(fromIndex), recursive(recursive) {
   stubs.reset(new EtcdServerStubs{});
   stubs->watchServiceStub = Watch::NewStub(client.channel);
-  doWatch(key, "", client.auth_token, callback);
+  doWatch(key, "", client.current_auth_token(), callback);
 }
 
-etcd::Watcher::Watcher(Client const &client, std::string const & key,
-                       std::string const &range_end, int fromIndex,
-                       std::function<void(Response)> callback):
-    fromIndex(fromIndex), recursive(false) {
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback)
+    : wait_callback(wait_callback), fromIndex(fromIndex), recursive(false) {
   stubs.reset(new EtcdServerStubs{});
   stubs->watchServiceStub = Watch::NewStub(client.channel);
-  doWatch(key, range_end, client.auth_token, callback);
+  doWatch(key, range_end, client.current_auth_token(), callback);
 }
 
-etcd::Watcher::Watcher(std::string const & address, std::string const & key,
-                       std::function<void(Response)> callback, bool recursive):
-    Watcher(address, key, -1, callback, recursive) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive)
+    : Watcher(address, key, -1, callback, wait_callback, recursive) {}
 
-etcd::Watcher::Watcher(std::string const & address, std::string const & key,
-                       std::string const & range_end,
-                       std::function<void(Response)> callback):
-    Watcher(address, key, range_end, -1, callback) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback)
+    : Watcher(address, key, range_end, -1, callback, wait_callback) {}
 
-etcd::Watcher::Watcher(std::string const & address, std::string const & key, int fromIndex,
-                       std::function<void(Response)> callback, bool recursive):
-    Watcher(Client(address), key, fromIndex, callback, recursive) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive)
+    : Watcher(SyncClient(address), key, fromIndex, callback, wait_callback,
+              recursive) {}
 
-etcd::Watcher::Watcher(std::string const & address, std::string const & key,
-                       std::string const & range_end, int fromIndex,
-                       std::function<void(Response)> callback):
-    Watcher(Client(address), key, range_end, fromIndex, callback) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback)
+    : Watcher(SyncClient(address), key, range_end, fromIndex, callback,
+              wait_callback) {}
 
-etcd::Watcher::Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key,
-            std::function<void(Response)> callback, bool recursive):
-    Watcher(address, username, password, key, -1, callback, recursive) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, -1, callback, wait_callback,
+              recursive, auth_token_ttl) {}
 
-etcd::Watcher::Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, std::string const & range_end,
-            std::function<void(Response)> callback):
-    Watcher(address, username, password, key, range_end, -1, callback) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, range_end, -1, callback,
+              wait_callback, auth_token_ttl) {}
 
-etcd::Watcher::Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, int fromIndex,
-            std::function<void(Response)> callback, bool recursive):
-    Watcher(Client(address, username, password), key, fromIndex, callback, recursive) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive,
+                       int const auth_token_ttl)
+    : Watcher(SyncClient(address, username, password, auth_token_ttl), key,
+              fromIndex, callback, wait_callback, recursive) {}
 
-etcd::Watcher::Watcher(std::string const & address,
-            std::string const & username, std::string const & password,
-            std::string const & key, std::string const & range_end, int fromIndex,
-            std::function<void(Response)> callback):
-    Watcher(Client(address, username, password), key, range_end, fromIndex, callback) {
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback,
+                       int const auth_token_ttl)
+    : Watcher(SyncClient(address, username, password, auth_token_ttl), key,
+              range_end, fromIndex, callback, wait_callback) {}
 
-etcd::Watcher::~Watcher()
-{
-  this->Cancel();
-}
+etcd::Watcher::Watcher(std::string const& address, std::string const& ca,
+                       std::string const& cert, std::string const& privkey,
+                       std::string const& key, int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback, bool recursive,
+                       std::string const& target_name_override)
+    : Watcher(SyncClient(address, ca, cert, privkey, target_name_override), key,
+              fromIndex, callback, wait_callback, recursive) {}
 
-bool etcd::Watcher::Wait()
-{
+etcd::Watcher::Watcher(std::string const& address, std::string const& ca,
+                       std::string const& cert, std::string const& privkey,
+                       std::string const& key, std::string const& range_end,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::function<void(bool)> wait_callback,
+                       std::string const& target_name_override)
+    : Watcher(SyncClient(address, ca, cert, privkey, target_name_override), key,
+              range_end, fromIndex, callback, wait_callback) {}
+
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::function<void(Response)> callback, bool recursive)
+    : Watcher(client, key, callback, nullptr, recursive) {}
+
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback)
+    : Watcher(client, key, range_end, callback, nullptr) {}
+
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback, bool recursive)
+    : Watcher(client, key, fromIndex, callback, nullptr, recursive) {}
+
+etcd::Watcher::Watcher(SyncClient const& client, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback)
+    : Watcher(client, key, range_end, fromIndex, callback, nullptr) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::function<void(Response)> callback, bool recursive)
+    : Watcher(address, key, callback, nullptr, recursive) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback)
+    : Watcher(address, key, range_end, callback, nullptr) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback, bool recursive)
+    : Watcher(address, key, fromIndex, callback, nullptr, recursive) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback)
+    : Watcher(address, key, range_end, fromIndex, callback, nullptr) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::function<void(Response)> callback, bool recursive,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, callback, nullptr, recursive,
+              auth_token_ttl) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::string const& range_end,
+                       std::function<void(Response)> callback,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, range_end, callback, nullptr,
+              auth_token_ttl) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback, bool recursive,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, fromIndex, callback, nullptr,
+              recursive, auth_token_ttl) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& username,
+                       std::string const& password, std::string const& key,
+                       std::string const& range_end, int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       int const auth_token_ttl)
+    : Watcher(address, username, password, key, range_end, fromIndex, callback,
+              nullptr, auth_token_ttl) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& ca,
+                       std::string const& cert, std::string const& privkey,
+                       std::string const& key, int64_t fromIndex,
+                       std::function<void(Response)> callback, bool recursive,
+                       std::string const& target_name_override)
+    : Watcher(address, ca, cert, privkey, key, fromIndex, callback, nullptr,
+              recursive, target_name_override) {}
+
+etcd::Watcher::Watcher(std::string const& address, std::string const& ca,
+                       std::string const& cert, std::string const& privkey,
+                       std::string const& key, std::string const& range_end,
+                       int64_t fromIndex,
+                       std::function<void(Response)> callback,
+                       std::string const& target_name_override)
+    : Watcher(address, ca, cert, privkey, key, range_end, fromIndex, callback,
+              nullptr, target_name_override) {}
+
+etcd::Watcher::~Watcher() { this->Cancel(); }
+
+bool etcd::Watcher::Wait() {
   if (!cancelled.exchange(true)) {
     if (task_.joinable()) {
       task_.join();
@@ -105,28 +229,37 @@ bool etcd::Watcher::Wait()
   return stubs->call->Cancelled();
 }
 
-void etcd::Watcher::Wait(std::function<void(bool)> callback)
-{
+bool etcd::Watcher::Wait(std::function<void(bool)> callback) {
   if (wait_callback == nullptr) {
     wait_callback = callback;
+    return true;
   } else {
-    std::cerr << "Failed to set a asynchronous wait callback since it has already been set" << std::endl;
+#ifndef NDEBUG
+    std::cerr
+        << "[warn] failed to set a asynchronous wait callback since it has "
+           "already been set"
+        << std::endl;
+#endif
+    return false;
   }
 }
 
-void etcd::Watcher::Cancel()
-{
+bool etcd::Watcher::Cancel() {
   stubs->call->CancelWatch();
-  this->Wait();
+  return this->Wait();
 }
 
-void etcd::Watcher::doWatch(std::string const & key,
-                            std::string const & range_end,
-                            std::string const & auth_token,
-                            std::function<void(Response)> callback)
-{
+bool etcd::Watcher::Cancelled() const {
+  return cancelled.load() || stubs->call->Cancelled();
+}
+
+void etcd::Watcher::doWatch(std::string const& key,
+                            std::string const& range_end,
+                            std::string const& auth_token,
+                            std::function<void(Response)> callback) {
   etcdv3::ActionParameters params;
   params.auth_token.assign(auth_token);
+  // n.b.: watch: no need for timeout
   params.key.assign(key);
   params.range_end.assign(range_end);
   if (fromIndex >= 0) {
@@ -135,12 +268,19 @@ void etcd::Watcher::doWatch(std::string const & key,
   params.withPrefix = recursive;
   params.watch_stub = stubs->watchServiceStub.get();
 
-  stubs->call.reset(new etcdv3::AsyncWatchAction(params));
+  stubs->call.reset(new etcdv3::AsyncWatchAction(std::move(params)));
 
   task_ = std::thread([this, callback]() {
     stubs->call->waitForResponse(callback);
     if (wait_callback != nullptr) {
-      wait_callback(stubs->call->Cancelled());
+      // issue the callback in another thread (detached) to avoid deadlock,
+      // it is ok to detach a pplx::task, but we don't want to use the
+      // pplx::task in the core library
+      bool cancelled = stubs->call->Cancelled();
+      std::function<void(bool)> wait_callback = this->wait_callback;
+      std::thread canceller(
+          [wait_callback, cancelled]() { wait_callback(cancelled); });
+      canceller.detach();
     }
   });
   cancelled.store(false);

src/v3/Action.cpp

@@ -1,9 +1,35 @@
-#include <grpc/support/log.h>
 #include "etcd/v3/Action.hpp"
+#include <grpc/support/log.h>
+#include <grpcpp/support/status.h>
+#include "etcd/v3/action_constants.hpp"
+#include <cstdlib>
 
-etcdv3::Action::Action(etcdv3::ActionParameters params)
-{
+#ifndef GPR_ASSERT
+#define GPR_ASSERT(x)                                             \
+  if (!(x)) {                                                     \
+    fprintf(stderr, "%s:%d assert failed\n", __FILE__, __LINE__); \
+    abort();                                                      \
+}
+#endif
+
+etcdv3::Action::Action(etcdv3::ActionParameters const& params) {
   parameters = params;
+  this->InitAction();
+}
+
+etcdv3::Action::Action(etcdv3::ActionParameters&& params) {
+  parameters = std::move(params);
+  this->InitAction();
+}
+
+etcdv3::Action::~Action() {
+  cq_.Shutdown();
+
+  // cancel on-the-fly calls
+  context.TryCancel();
+}
+
+void etcdv3::Action::InitAction() {
   if (!parameters.auth_token.empty()) {
     // use `token` as the key, see:
     //
@@ -13,44 +39,97 @@ etcdv3::Action::Action(etcdv3::ActionParameters params)
   start_timepoint = std::chrono::high_resolution_clock::now();
 }
 
-etcdv3::ActionParameters::ActionParameters()
-{
+etcdv3::ActionParameters::ActionParameters() {
   withPrefix = false;
   revision = 0;
   old_revision = 0;
   lease_id = 0;
   ttl = 0;
+  keys_only = false;
+  count_only = false;
   kv_stub = NULL;
   watch_stub = NULL;
   lease_stub = NULL;
 }
 
-void etcdv3::Action::waitForResponse() 
-{
+bool etcdv3::ActionParameters::has_grpc_timeout() const {
+  return this->grpc_timeout != std::chrono::microseconds::zero();
+}
+
+std::chrono::system_clock::time_point etcdv3::ActionParameters::grpc_deadline()
+    const {
+  return std::chrono::system_clock::now() + this->grpc_timeout;
+}
+
+void etcdv3::ActionParameters::dump(std::ostream& os) const {
+  os << "ActionParameters:" << std::endl;
+  os << "  withPrefix:    " << withPrefix << std::endl;
+  os << "  revision:      " << revision << std::endl;
+  os << "  old_revision:  " << old_revision << std::endl;
+  os << "  lease_id:      " << lease_id << std::endl;
+  os << "  ttl:           " << ttl << std::endl;
+  os << "  limit:         " << limit << std::endl;
+  os << "  name:          " << name << std::endl;
+  os << "  key:           " << key << std::endl;
+  os << "  range_end:     " << range_end << std::endl;
+  os << "  keys_only:     " << keys_only << std::endl;
+  os << "  count_only:    " << count_only << std::endl;
+  os << "  value:         " << value << std::endl;
+  os << "  old_value:     " << old_value << std::endl;
+  os << "  auth_token:    " << auth_token << std::endl;
+  os << "  grpc_timeout:  " << grpc_timeout.count() << "(ms)" << std::endl;
+}
+
+void etcdv3::Action::waitForResponse() {
   void* got_tag;
   bool ok = false;
 
-  cq_.Next(&got_tag, &ok);
-  GPR_ASSERT(got_tag == (void*)this);
+  if (parameters.has_grpc_timeout()) {
+    switch (cq_.AsyncNext(&got_tag, &ok, parameters.grpc_deadline())) {
+    case CompletionQueue::NextStatus::TIMEOUT: {
+      status =
+          grpc::Status(grpc::StatusCode::DEADLINE_EXCEEDED, "gRPC timeout");
+      break;
+    }
+    case CompletionQueue::NextStatus::SHUTDOWN: {
+      status =
+          grpc::Status(grpc::StatusCode::UNAVAILABLE, "gRPC already shutdown");
+      break;
+    }
+    case CompletionQueue::NextStatus::GOT_EVENT: {
+      if (!ok) {
+        status =
+            grpc::Status(grpc::StatusCode::ABORTED,
+                         "Failed to execute the action: not ok or invalid tag");
+      }
+      break;
+    }
+    }
+  } else {
+    cq_.Next(&got_tag, &ok);
+    GPR_ASSERT(got_tag == (void*) this);
+  }
 }
 
-const std::chrono::high_resolution_clock::time_point etcdv3::Action::startTimepoint() {
+const std::chrono::high_resolution_clock::time_point
+etcdv3::Action::startTimepoint() {
   return this->start_timepoint;
 }
 
-std::string etcdv3::detail::string_plus_one(std::string const &value) {
-  // referred from the Go implementation in etcd.
-  char *s = static_cast<char *>(calloc(value.size() + 1, sizeof(char)));
-  std::memcpy(s, value.c_str(), value.size());
-  for (int i = value.size() - 1; i >= 0; --i) {
-    if (static_cast<unsigned char>(s[i]) < 0xff) {
+std::string etcdv3::detail::string_plus_one(std::string const& value) {
+  // Referred from the Go implementation in etcd.
+  for (int32_t i = value.size() - 1; i >= 0; --i) {
+    if (static_cast<unsigned char>(value[i]) < 0xff) {
+      std::string s = value.substr(0, i + 1);
       s[i] = s[i] + 1;
-      std::string ret = std::string(s, i + 1);
-      free(s);
-      return ret;
+      return s;
     }
   }
-  // see: noPrefixEnd in etcd, however c++ doesn't allows '\0' inside a string, thus we use
-  // the UTF-8 char U+0000 (i.e., "\xC0\x80").
-  return {"\xC0\x80"};
+  return {etcdv3::NUL};
+}
+
+std::string etcdv3::detail::resolve_etcd_endpoints(
+    std::string const& default_endpoints) {
+  const char* ep = std::getenv("ETCD_ENDPOINTS");
+  return ep ? ep : default_endpoints;
 }

src/v3/AsyncCompareAndDeleteAction.cpp

@@ -1,55 +0,0 @@
-#include "etcd/v3/AsyncCompareAndDeleteAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-using etcdserverpb::Compare;
-using etcdserverpb::RangeRequest;
-using etcdserverpb::PutRequest;
-using etcdserverpb::RequestOp;
-using etcdserverpb::ResponseOp;
-using etcdserverpb::TxnRequest;
-
-etcdv3::AsyncCompareAndDeleteAction::AsyncCompareAndDeleteAction(etcdv3::ActionParameters param, etcdv3::Atomicity_Type type) 
-  :etcdv3::Action(param)
-{
-  etcdv3::Transaction transaction(parameters.key);
-  if(type == etcdv3::Atomicity_Type::PREV_VALUE)
-  {
-    transaction.init_compare(parameters.old_value, Compare::CompareResult::Compare_CompareResult_EQUAL,
-		    Compare::CompareTarget::Compare_CompareTarget_VALUE);
-  }
-  else if (type == etcdv3::Atomicity_Type::PREV_INDEX)
-  {
-    transaction.init_compare(parameters.old_revision, Compare::CompareResult::Compare_CompareResult_EQUAL,
-								  Compare::CompareTarget::Compare_CompareTarget_MOD);
-  }
-
-  transaction.setup_compare_and_delete_operation(parameters.key);
-  transaction.setup_basic_failure_operation(parameters.key);
-
-  response_reader = parameters.kv_stub->AsyncTxn(&context, *transaction.txn_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncTxnResponse etcdv3::AsyncCompareAndDeleteAction::ParseResponse()
-{
-  AsyncTxnResponse txn_resp;
-  if(!status.ok())
-  {
-    txn_resp.set_error_code(status.error_code());
-    txn_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    txn_resp.ParseResponse(parameters.key, parameters.withPrefix, reply);
-    txn_resp.set_action(etcdv3::COMPAREDELETE_ACTION);
-
-    if(!reply.succeeded())
-    {
-      txn_resp.set_error_code(101);
-      txn_resp.set_error_message("Compare failed");
-    } 
-  }
-    
-  return txn_resp;
-}

src/v3/AsyncCompareAndSwapAction.cpp

@@ -1,58 +0,0 @@
-#include "etcd/v3/AsyncCompareAndSwapAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-using etcdserverpb::Compare;
-using etcdserverpb::RangeRequest;
-using etcdserverpb::PutRequest;
-using etcdserverpb::RequestOp;
-using etcdserverpb::ResponseOp;
-using etcdserverpb::TxnRequest;
-
-etcdv3::AsyncCompareAndSwapAction::AsyncCompareAndSwapAction(etcdv3::ActionParameters param, etcdv3::Atomicity_Type type)
-  : etcdv3::Action(param)  
-{
-  etcdv3::Transaction transaction(parameters.key);
-  if(type == etcdv3::Atomicity_Type::PREV_VALUE)
-  {
-    transaction.init_compare(parameters.old_value, Compare::CompareResult::Compare_CompareResult_EQUAL,
-		  	  	  	  	  	  	  	    Compare::CompareTarget::Compare_CompareTarget_VALUE);
-  }
-  else if (type == etcdv3::Atomicity_Type::PREV_INDEX)
-  {
-    transaction.init_compare(parameters.old_revision, Compare::CompareResult::Compare_CompareResult_EQUAL,
-		  	  	  	  	  	  	  	  Compare::CompareTarget::Compare_CompareTarget_MOD);    
-  }
-
-  transaction.setup_basic_failure_operation(parameters.key);
-  transaction.setup_compare_and_swap_sequence(parameters.value, parameters.lease_id);
-
-  response_reader = parameters.kv_stub->AsyncTxn(&context, *transaction.txn_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncTxnResponse etcdv3::AsyncCompareAndSwapAction::ParseResponse()
-{
-  AsyncTxnResponse txn_resp;
-  
-  if(!status.ok())
-  {
-    txn_resp.set_error_code(status.error_code());
-    txn_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    txn_resp.ParseResponse(parameters.key, parameters.withPrefix, reply);
-    txn_resp.set_action(etcdv3::COMPARESWAP_ACTION);
-
-    //if there is an error code returned by parseResponse, we must 
-    //not overwrite it.
-    if(!reply.succeeded() && !txn_resp.get_error_code())
-    {
-      txn_resp.set_error_code(101);
-      txn_resp.set_error_message("Compare failed");
-    } 
-  }
-    
-  return txn_resp;
-}

src/v3/AsyncDeleteAction.cpp

@@ -1,43 +0,0 @@
-#include "etcd/v3/AsyncDeleteAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-using etcdserverpb::DeleteRangeRequest;
-
-etcdv3::AsyncDeleteAction::AsyncDeleteAction(ActionParameters param)
-  : etcdv3::Action(param) 
-{
-  DeleteRangeRequest del_request;
-  del_request.set_key(parameters.key);
-  del_request.set_prev_kv(true);
-  if(parameters.withPrefix)
-  {
-    if (parameters.key.empty()) {
-      del_request.set_range_end(detail::string_plus_one("\0"));
-    } else {
-      del_request.set_range_end(detail::string_plus_one(parameters.key));
-    }
-  }
-  if(!parameters.range_end.empty()) {
-    del_request.set_range_end(parameters.range_end);
-  }
-
-  response_reader = parameters.kv_stub->AsyncDeleteRange(&context, del_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncDeleteRangeResponse etcdv3::AsyncDeleteAction::ParseResponse()
-{
-  AsyncDeleteRangeResponse del_resp;
-  
-  if(!status.ok())
-  {
-    del_resp.set_error_code(status.error_code());
-    del_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    del_resp.ParseResponse(parameters.key, parameters.withPrefix || !parameters.range_end.empty(), reply); 
-  }
-    
-  return del_resp;
-}

src/v3/AsyncDeleteRangeResponse.cpp

@@ -1,34 +0,0 @@
-#include "etcd/v3/AsyncDeleteRangeResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-
-void etcdv3::AsyncDeleteRangeResponse::ParseResponse(std::string const& key, bool prefix, DeleteRangeResponse& resp)
-{
-  index = resp.header().revision();
-
-  if(resp.prev_kvs_size() == 0)
-  {
-    error_code=100;
-    error_message="Key not found";
-  }
-  else
-  {
-    action = etcdv3::DELETE_ACTION;
-    //get all previous values
-    for(int cnt=0; cnt < resp.prev_kvs_size(); cnt++)
-    {
-      etcdv3::KeyValue kv; 
-      kv.kvs.CopyFrom(resp.prev_kvs(cnt));
-      values.push_back(kv);
-    }
-
-    if(!prefix)
-    {
-      prev_value = values[0];
-      value = values[0];
-      value.kvs.clear_value();
-      values.clear();
-    }
-
-  }
-}

src/v3/AsyncGetAction.cpp

@@ -1,49 +0,0 @@
-#include "etcd/v3/AsyncGetAction.hpp"
-
-#include <cstdlib>
-
-#include "etcd/v3/action_constants.hpp"
-
-using etcdserverpb::RangeRequest;
-
-etcdv3::AsyncGetAction::AsyncGetAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-  RangeRequest get_request;
-  if (parameters.key.empty()) {
-    get_request.set_key("\0");
-  } else {
-    get_request.set_key(parameters.key);
-  }
-  get_request.set_limit(param.limit);
-  if(parameters.withPrefix)
-  {
-    if (parameters.key.empty()) {
-      get_request.set_range_end(detail::string_plus_one("\0"));
-    } else {
-      get_request.set_range_end(detail::string_plus_one(parameters.key));
-    }
-  }
-  if(!parameters.range_end.empty()) {
-    get_request.set_range_end(parameters.range_end);
-  }
-  get_request.set_sort_order(RangeRequest::SortOrder::RangeRequest_SortOrder_NONE);
-
-  response_reader = parameters.kv_stub->AsyncRange(&context,get_request,&cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncRangeResponse etcdv3::AsyncGetAction::ParseResponse()
-{
-  AsyncRangeResponse range_resp;
-  if(!status.ok())
-  {
-    range_resp.set_error_code(status.error_code());
-    range_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    range_resp.ParseResponse(reply, parameters.withPrefix || !parameters.range_end.empty());
-  }
-  return range_resp;
-}

src/v3/AsyncLeaseAction.cpp

@@ -1,179 +0,0 @@
-#include "etcd/v3/AsyncLeaseAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-using etcdserverpb::LeaseGrantRequest;
-using etcdserverpb::LeaseRevokeRequest;
-using etcdserverpb::LeaseCheckpointRequest;
-using etcdserverpb::LeaseKeepAliveRequest;
-using etcdserverpb::LeaseTimeToLiveRequest;
-using etcdserverpb::LeaseLeasesRequest;
-
-etcdv3::AsyncLeaseGrantAction::AsyncLeaseGrantAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-	LeaseGrantRequest leasegrant_request;
-  leasegrant_request.set_ttl(parameters.ttl);
-  // If ID is set to 0, etcd will choose an ID.
-  leasegrant_request.set_id(parameters.lease_id);
-
-  response_reader = parameters.lease_stub->AsyncLeaseGrant(&context, leasegrant_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncLeaseGrantResponse etcdv3::AsyncLeaseGrantAction::ParseResponse()
-{
-  AsyncLeaseGrantResponse lease_resp;
-  if (!status.ok()) {
-    lease_resp.set_error_code(status.error_code());
-    lease_resp.set_error_message(status.error_message());
-  } else { 
-    lease_resp.ParseResponse(reply);
-  }
-  return lease_resp;
-}
-
-etcdv3::AsyncLeaseRevokeAction::AsyncLeaseRevokeAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-	LeaseRevokeRequest leaserevoke_request;
-  leaserevoke_request.set_id(parameters.lease_id);
-
-  response_reader = parameters.lease_stub->AsyncLeaseRevoke(&context, leaserevoke_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncLeaseRevokeResponse etcdv3::AsyncLeaseRevokeAction::ParseResponse()
-{
-  AsyncLeaseRevokeResponse lease_resp;
-  if (!status.ok()) {
-    lease_resp.set_error_code(status.error_code());
-    lease_resp.set_error_message(status.error_message());
-  } else { 
-    lease_resp.ParseResponse(reply);
-  }
-  return lease_resp;
-}
-
-etcdv3::AsyncLeaseKeepAliveAction::AsyncLeaseKeepAliveAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-  isCancelled = false;
-  stream = parameters.lease_stub->AsyncLeaseKeepAlive(&context, &cq_, (void*)"keepalive create");
-
-  void *got_tag = nullptr;
-  bool ok = false;
-  if (cq_.Next(&got_tag, &ok) && ok && got_tag == (void *)"keepalive create") {
-    // ok
-  } else {
-    throw std::runtime_error("Failed to create a lease keep-alive connection");
-  }
-}
-
-etcdv3::AsyncLeaseKeepAliveResponse etcdv3::AsyncLeaseKeepAliveAction::ParseResponse()
-{
-  AsyncLeaseKeepAliveResponse lease_resp;
-  if (!status.ok()) {
-    lease_resp.set_error_code(status.error_code());
-    lease_resp.set_error_message(status.error_message());
-  } else { 
-    lease_resp.ParseResponse(reply);
-  }
-  return lease_resp;
-}
-
-etcd::Response etcdv3::AsyncLeaseKeepAliveAction::Refresh()
-{
-  std::lock_guard<std::mutex> scope_lock(this->protect_is_cancelled);
-
-  auto start_timepoint = std::chrono::high_resolution_clock::now();
-  if (isCancelled) {
-    auto resp = ParseResponse();
-    auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-            std::chrono::high_resolution_clock::now() - start_timepoint);
-    return etcd::Response(resp, duration);
-  }
-
-  LeaseKeepAliveRequest leasekeepalive_request;
-  leasekeepalive_request.set_id(parameters.lease_id);
-
-  void *got_tag = nullptr;
-  bool ok = false;
-
-  stream->Write(leasekeepalive_request, (void *)"keepalive write");
-  // wait write finish
-  if (cq_.Next(&got_tag, &ok) && ok && got_tag == (void *)"keepalive write") {
-    stream->Read(&reply, (void*)"keepalive read");
-    // wait read finish
-    if (cq_.Next(&got_tag, &ok) && ok && got_tag == (void *)"keepalive read") {
-      auto resp = ParseResponse();
-      auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-            std::chrono::high_resolution_clock::now() - start_timepoint);
-      return etcd::Response(resp, duration);
-    }
-  }
-  return etcd::Response(grpc::StatusCode::ABORTED, "Failed to create a lease keep-alive connection");
-}
-
-void etcdv3::AsyncLeaseKeepAliveAction::CancelKeepAlive()
-{
-  std::lock_guard<std::mutex> scope_lock(this->protect_is_cancelled);
-  if(isCancelled == false)
-  {
-    isCancelled = true;
-    stream->WritesDone((void*)"keepalive done");
-    grpc::Status status;
-    stream->Finish(&status, (void *)this);
-    cq_.Shutdown();
-  }
-}
-
-bool etcdv3::AsyncLeaseKeepAliveAction::Cancelled() const
-{
-  return isCancelled;
-}
-
-etcdv3::AsyncLeaseTimeToLiveAction::AsyncLeaseTimeToLiveAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-	LeaseTimeToLiveRequest leasetimetolive_request;
-  leasetimetolive_request.set_id(parameters.lease_id);
-  // FIXME: unsupported parameters: "keys"
-  // leasetimetolive_request.set_keys(parameters.keys);
-
-  response_reader = parameters.lease_stub->AsyncLeaseTimeToLive(&context, leasetimetolive_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncLeaseTimeToLiveResponse etcdv3::AsyncLeaseTimeToLiveAction::ParseResponse()
-{
-  AsyncLeaseTimeToLiveResponse lease_resp;
-  if (!status.ok()) {
-    lease_resp.set_error_code(status.error_code());
-    lease_resp.set_error_message(status.error_message());
-  } else { 
-    lease_resp.ParseResponse(reply);
-  }
-  return lease_resp;
-}
-
-etcdv3::AsyncLeaseLeasesAction::AsyncLeaseLeasesAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param)
-{
-	LeaseLeasesRequest leaseleases_request;
-
-  response_reader = parameters.lease_stub->AsyncLeaseLeases(&context, leaseleases_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncLeaseLeasesResponse etcdv3::AsyncLeaseLeasesAction::ParseResponse()
-{
-  AsyncLeaseLeasesResponse lease_resp;
-  if (!status.ok()) {
-    lease_resp.set_error_code(status.error_code());
-    lease_resp.set_error_message(status.error_message());
-  } else { 
-    lease_resp.ParseResponse(reply);
-  }
-  return lease_resp;
-}

src/v3/AsyncLeaseResponse.cpp

@@ -1,35 +0,0 @@
-#include "etcd/v3/AsyncLeaseResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-
-void etcdv3::AsyncLeaseGrantResponse::ParseResponse(LeaseGrantResponse& resp) {
-  index = resp.header().revision();
-  value.kvs.set_lease(resp.id());
-  value.set_ttl(resp.ttl());
-  error_message = resp.error();
-}
-
-void etcdv3::AsyncLeaseRevokeResponse::ParseResponse(LeaseRevokeResponse& resp) {
-  index = resp.header().revision();
-}
-
-void etcdv3::AsyncLeaseKeepAliveResponse::ParseResponse(LeaseKeepAliveResponse& resp) {
-  index = resp.header().revision();
-  value.kvs.set_lease(resp.id());
-  value.set_ttl(resp.ttl());
-}
-
-void etcdv3::AsyncLeaseTimeToLiveResponse::ParseResponse(LeaseTimeToLiveResponse& resp) {
-  index = resp.header().revision();
-  value.kvs.set_lease(resp.id());
-  value.set_ttl(resp.ttl());
-  // FIXME: unsupported: fields "grantedTTL" and "keys"
-}
-
-void etcdv3::AsyncLeaseLeasesResponse::ParseResponse(LeaseLeasesResponse& resp) {
-  index = resp.header().revision();
-  // FIXME: only the first leases is recorded.
-  if (resp.leases_size() > 0) {
-    value.kvs.set_lease(resp.leases(0).id());
-  }
-}

src/v3/AsyncLockAction.cpp

@@ -1,62 +0,0 @@
-#include "etcd/v3/AsyncLockAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-using v3lockpb::LockRequest;
-using v3lockpb::UnlockRequest;
-
-etcdv3::AsyncLockAction::AsyncLockAction(ActionParameters param)
-  : etcdv3::Action(param) 
-{
-  LockRequest lock_request;
-  lock_request.set_name(parameters.key);
-  lock_request.set_lease(parameters.lease_id);
-
-  response_reader = parameters.lock_stub->AsyncLock(&context, lock_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncLockResponse etcdv3::AsyncLockAction::ParseResponse()
-{
-  AsyncLockResponse lock_resp;
-  
-  if(!status.ok())
-  {
-    lock_resp.set_error_code(status.error_code());
-    lock_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    lock_resp.ParseResponse(reply);
-    lock_resp.set_action(etcdv3::LOCK_ACTION);
-  }
-
-  return lock_resp;
-}
-
-etcdv3::AsyncUnlockAction::AsyncUnlockAction(ActionParameters param)
-  : etcdv3::Action(param) 
-{
-  UnlockRequest unlock_request;
-  unlock_request.set_key(parameters.key);
-
-  response_reader = parameters.lock_stub->AsyncUnlock(&context, unlock_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncUnlockResponse etcdv3::AsyncUnlockAction::ParseResponse()
-{
-  AsyncUnlockResponse unlock_resp;
-  
-  if(!status.ok())
-  {
-    unlock_resp.set_error_code(status.error_code());
-    unlock_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    unlock_resp.ParseResponse(reply);
-    unlock_resp.set_action(etcdv3::UNLOCK_ACTION);
-  }
-    
-  return unlock_resp;
-}

src/v3/AsyncLockResponse.cpp

@@ -1,14 +0,0 @@
-#include "etcd/v3/AsyncLockResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-
-void etcdv3::AsyncLockResponse::ParseResponse(LockResponse& resp)
-{
-  index = resp.header().revision();
-  lock_key = resp.key();
-}
-
-void etcdv3::AsyncUnlockResponse::ParseResponse(UnlockResponse& resp)
-{
-  index = resp.header().revision();
-}

src/v3/AsyncRangeResponse.cpp

@@ -1,30 +0,0 @@
-#include "etcd/v3/AsyncRangeResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-
-void etcdv3::AsyncRangeResponse::ParseResponse(RangeResponse& resp, bool prefix)
-{
-  action = etcdv3::GET_ACTION;
-  index = resp.header().revision();
-  if(resp.kvs_size() == 0 && !prefix)
-  {
-    error_code=100;
-    error_message="Key not found";
-    return;
-  }
-  else
-  {
-    for(int index=0; index < resp.kvs_size(); index++)
-    {
-      etcdv3::KeyValue kv;
-      kv.kvs.CopyFrom(resp.kvs(index));
-      values.push_back(kv); 
-    }
-
-    if(!prefix)
-    {
-      value = values[0];
-      values.clear();
-    }
-  }
-}

src/v3/AsyncSetAction.cpp

@@ -1,52 +0,0 @@
-#include "etcd/v3/AsyncSetAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-using etcdserverpb::Compare;
-
-etcdv3::AsyncSetAction::AsyncSetAction(etcdv3::ActionParameters param, bool create)
-  : etcdv3::Action(param) 
-{
-  etcdv3::Transaction transaction(parameters.key);
-  isCreate = create;
-  transaction.init_compare(Compare::CompareResult::Compare_CompareResult_EQUAL,
-                           Compare::CompareTarget::Compare_CompareTarget_VERSION);
-
-  transaction.setup_basic_create_sequence(parameters.key, parameters.value, parameters.lease_id);
-
-  if(isCreate)
-  {
-    transaction.setup_basic_failure_operation(parameters.key);
-  }
-  else
-  {
-    transaction.setup_set_failure_operation(parameters.key, parameters.value, parameters.lease_id);
-  }
-  response_reader = parameters.kv_stub->AsyncTxn(&context, *transaction.txn_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncTxnResponse etcdv3::AsyncSetAction::ParseResponse()
-{
-
-  AsyncTxnResponse txn_resp;
-  
-  if(!status.ok())
-  {
-    txn_resp.set_error_code(status.error_code());
-    txn_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    txn_resp.ParseResponse(parameters.key, parameters.withPrefix, reply);
-    std::string action = isCreate? etcdv3::CREATE_ACTION:etcdv3::SET_ACTION;
-    txn_resp.set_action(action);
-
-    if(!reply.succeeded() && action == etcdv3::CREATE_ACTION)
-    {
-      txn_resp.set_error_code(105);
-      txn_resp.set_error_message("Key already exists");
-    } 
-  }
-  return txn_resp;
-}

src/v3/AsyncTxnAction.cpp

@@ -1,37 +0,0 @@
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/AsyncTxnAction.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-
-etcdv3::AsyncTxnAction::AsyncTxnAction(etcdv3::ActionParameters param, etcdv3::Transaction const &tx)
-  : etcdv3::Action(param)
-{
-    response_reader = parameters.kv_stub->AsyncTxn(&context, *tx.txn_request, &cq_);
-    response_reader->Finish(&reply, &status, (void *)this);
-}
-
-etcdv3::AsyncTxnResponse etcdv3::AsyncTxnAction::ParseResponse()
-{
-  AsyncTxnResponse txn_resp;
-  
-  if(!status.ok())
-  {
-    txn_resp.set_error_code(status.error_code());
-    txn_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    txn_resp.ParseResponse(parameters.key, parameters.withPrefix, reply);
-    txn_resp.set_action(etcdv3::TXN_ACTION);
-
-    //if there is an error code returned by parseResponse, we must 
-    //not overwrite it.
-    if(!reply.succeeded() && !txn_resp.get_error_code())
-    {
-      txn_resp.set_error_code(101);
-      txn_resp.set_error_message("compare failed");
-    } 
-  }
-    
-  return txn_resp;
-}

src/v3/AsyncTxnResponse.cpp

@@ -1,48 +0,0 @@
-#include "etcd/v3/AsyncTxnResponse.hpp"
-#include "etcd/v3/AsyncRangeResponse.hpp"
-#include "etcd/v3/AsyncDeleteRangeResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-using etcdserverpb::ResponseOp;
-
-void etcdv3::AsyncTxnResponse::ParseResponse(TxnResponse& reply) {
-  index = reply.header().revision();
-}
-
-void etcdv3::AsyncTxnResponse::ParseResponse(std::string const& key, bool prefix, TxnResponse& reply)
-{
-  index = reply.header().revision();
-  for(int index=0; index < reply.responses_size(); index++)
-  {
-    auto resp = reply.responses(index);
-    if(ResponseOp::ResponseCase::kResponseRange == resp.response_case())
-    {
-      AsyncRangeResponse response;
-      response.ParseResponse(*(resp.mutable_response_range()),prefix);
-     
-      error_code = response.get_error_code();
-      error_message = response.get_error_message();
-      
-      values = response.get_values();
-      value = response.get_value();
-    }
-    else if(ResponseOp::ResponseCase::kResponsePut == resp.response_case())
-    {
-      auto put_resp = resp.response_put();
-      if(put_resp.has_prev_kv())
-      {
-        prev_value.kvs.CopyFrom(put_resp.prev_kv());
-      }
-    }
-    else if(ResponseOp::ResponseCase::kResponseDeleteRange == resp.response_case())
-    {
-      AsyncDeleteRangeResponse response;
-      response.ParseResponse(key,prefix,*(resp.mutable_response_delete_range()));
-
-      prev_value.kvs.CopyFrom(response.get_prev_value().kvs);
-     
-      values = response.get_values();
-      value = response.get_value();
-    }
-  }
-}

src/v3/AsyncUpdateAction.cpp

@@ -1,50 +0,0 @@
-#include "etcd/v3/AsyncUpdateAction.hpp"
-#include "etcd/v3/AsyncRangeResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-#include "etcd/v3/Transaction.hpp"
-
-using etcdserverpb::Compare;
-using etcdserverpb::RangeRequest;
-using etcdserverpb::PutRequest;
-using etcdserverpb::RequestOp;
-using etcdserverpb::ResponseOp;
-using etcdserverpb::TxnRequest;
-
-etcdv3::AsyncUpdateAction::AsyncUpdateAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param) 
-{
-  etcdv3::Transaction transaction(parameters.key);
-  transaction.init_compare(Compare::CompareResult::Compare_CompareResult_GREATER,
-                           Compare::CompareTarget::Compare_CompareTarget_VERSION);
-
-  transaction.setup_compare_and_swap_sequence(parameters.value, parameters.lease_id);
-
-  response_reader = parameters.kv_stub->AsyncTxn(&context, *transaction.txn_request, &cq_);
-  response_reader->Finish(&reply, &status, (void*)this);
-}
-
-etcdv3::AsyncTxnResponse etcdv3::AsyncUpdateAction::ParseResponse()
-{
-  AsyncTxnResponse txn_resp;
-  
-  if(!status.ok())
-  {
-    txn_resp.set_error_code(status.error_code());
-    txn_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    if(reply.succeeded())
-    {
-      txn_resp.ParseResponse(parameters.key, parameters.withPrefix, reply);
-      txn_resp.set_action(etcdv3::UPDATE_ACTION);
-    }
-    else
-    {
-      txn_resp.set_error_code(100);
-      txn_resp.set_error_message("Key not found");
-    }
-
-  }
-  return txn_resp;
-}

src/v3/AsyncWatchAction.cpp

@@ -1,171 +0,0 @@
-#include "etcd/v3/AsyncWatchAction.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-
-using etcdserverpb::RangeRequest;
-using etcdserverpb::RangeResponse;
-using etcdserverpb::WatchCreateRequest;
-
-etcdv3::AsyncWatchAction::AsyncWatchAction(etcdv3::ActionParameters param)
-  : etcdv3::Action(param) 
-{
-  isCancelled.store(false);
-  stream = parameters.watch_stub->AsyncWatch(&context,&cq_,(void*)"create");
-
-  WatchRequest watch_req;
-  WatchCreateRequest watch_create_req;
-  watch_create_req.set_key(parameters.key);
-  watch_create_req.set_prev_kv(true);
-  watch_create_req.set_start_revision(parameters.revision);
-
-  if(parameters.withPrefix)
-  {
-    if (parameters.key.empty()) {
-      watch_create_req.set_range_end(detail::string_plus_one("\0"));
-    } else {
-      watch_create_req.set_range_end(detail::string_plus_one(parameters.key));
-    }
-  }
-  if(!parameters.range_end.empty()) {
-    watch_create_req.set_range_end(parameters.range_end);
-  }
-
-  watch_req.mutable_create_request()->CopyFrom(watch_create_req);
-
-  // wait "create" success (the stream becomes ready)
-  void *got_tag;
-  bool ok = false;
-  if (cq_.Next(&got_tag, &ok) && ok && got_tag == (void *)"create") {
-    stream->Write(watch_req, (void *)"write");
-  } else {
-    throw std::runtime_error("failed to create a watch connection");
-  }
-
-  // wait "write" (WatchCreateRequest) success, and start to read the first reply
-  if (cq_.Next(&got_tag, &ok) && ok && got_tag == (void *)"write") {
-    stream->Read(&reply, (void*)this);
-  } else {
-    throw std::runtime_error("failed to write WatchCreateRequest to server");
-  }
-}
-
-void etcdv3::AsyncWatchAction::waitForResponse() 
-{
-  void* got_tag;
-  bool ok = false;
-
-  while(cq_.Next(&got_tag, &ok))
-  {
-    if(ok == false)
-    {
-      break;
-    }
-    if(got_tag == (void*)"writes done") {
-      isCancelled.store(true);
-      cq_.Shutdown();
-      break;
-    }
-    if(got_tag == (void*)this) // read tag
-    {
-      if (reply.canceled()) {
-        isCancelled.store(true);
-        cq_.Shutdown();
-      }
-      else if ((reply.created() && reply.header().revision() < parameters.revision) ||
-          reply.events_size() > 0) {
-        // we stop watch under two conditions:
-        //
-        // 1. watch for a future revision, return immediately with empty events set
-        // 2. receive any effective events.
-        isCancelled.store(true);
-        stream->WritesDone((void*)"writes done");
-        grpc::Status status;
-        stream->Finish(&status, (void *)this);
-        cq_.Shutdown();
-
-        // leave a warning if the response is too large and been fragmented
-        if (reply.fragment()) {
-          std::cerr << "WARN: The response hasn't been fully received and parsed" << std::endl;
-        }
-      }
-      else
-      {
-        // otherwise, start next round read-reply
-        stream->Read(&reply, (void*)this);
-      } 
-    }  
-  }
-}
-
-void etcdv3::AsyncWatchAction::CancelWatch()
-{
-  std::lock_guard<std::mutex> scope_lock(this->protect_is_cancalled);
-  if (!isCancelled.exchange(true)) {
-    stream->WritesDone((void*)"writes done");
-    grpc::Status status;
-    stream->Finish(&status, (void *)this);
-    cq_.Shutdown();
-  }
-}
-
-bool etcdv3::AsyncWatchAction::Cancelled() const {
-  return isCancelled.load();
-}
-
-void etcdv3::AsyncWatchAction::waitForResponse(std::function<void(etcd::Response)> callback) 
-{
-  void* got_tag;
-  bool ok = false;    
-
-  while(cq_.Next(&got_tag, &ok))
-  {
-    if(ok == false)
-    {
-      break;
-    }
-    if(got_tag == (void*)"writes done")
-    {
-      isCancelled.store(true);
-      cq_.Shutdown();
-      break;
-    }
-    else if(got_tag == (void*)this) // read tag
-    {
-      if (reply.canceled()) {
-        isCancelled.store(true);
-        cq_.Shutdown();
-        if (reply.compact_revision() != 0) {
-          callback(etcd::Response(grpc::StatusCode::OUT_OF_RANGE /* error code */,
-                                  "required revision has been compacted"));
-        }
-        break;
-      }
-      if(reply.events_size())
-      {
-        // for the callback case, we don't stop immediately if watching for a future revison,
-        // we wait until there are some expected events.
-        auto resp = ParseResponse();
-        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
-            std::chrono::high_resolution_clock::now() - start_timepoint);
-        callback(etcd::Response(resp, duration)); 
-        start_timepoint = std::chrono::high_resolution_clock::now();
-      }
-      stream->Read(&reply, (void*)this);
-    }
-  }
-}
-
-etcdv3::AsyncWatchResponse etcdv3::AsyncWatchAction::ParseResponse()
-{
-  AsyncWatchResponse watch_resp;
-  if(!status.ok())
-  {
-    watch_resp.set_error_code(status.error_code());
-    watch_resp.set_error_message(status.error_message());
-  }
-  else
-  { 
-    watch_resp.ParseResponse(reply);
-  }
-  return watch_resp;
-}

src/v3/AsyncWatchResponse.cpp

@@ -1,45 +0,0 @@
-#include "etcd/v3/AsyncWatchResponse.hpp"
-#include "etcd/v3/action_constants.hpp"
-
-void etcdv3::AsyncWatchResponse::ParseResponse(WatchResponse& reply)
-{
-  if (reply.canceled() && reply.compact_revision() != 0) {
-    error_code=grpc::StatusCode::OUT_OF_RANGE;
-    error_message="required revision has been compacted";
-    return;
-  }
-  index = reply.header().revision();
-  for (auto const &e: reply.events()) {
-    events.emplace_back(e);
-  }
-  for(int cnt =0; cnt < reply.events_size(); cnt++)
-  {
-    auto event = reply.events(cnt);
-    if(mvccpb::Event::EventType::Event_EventType_PUT == event.type())
-    {
-      if(event.kv().version() == 1)
-      {
-        action = etcdv3::CREATE_ACTION;
-      }
-      else
-      {
-        action = etcdv3::SET_ACTION;
-      }
-      value.kvs = event.kv();       
-
-    }
-    else if(mvccpb::Event::EventType::Event_EventType_DELETE_ == event.type())
-    {
-      action = etcdv3::DELETE_ACTION;
-      value.kvs = event.kv();
-    } 
-    if(event.has_prev_kv())
-    {
-      prev_value.kvs = event.prev_kv();   
-    }
-    // just store the first occurence of the key in values.
-    // this is done so tas client will not need to change their behaviour.
-    // break immediately
-    break;
-  }
-}

src/v3/KeyValue.cpp

@@ -1,16 +1,7 @@
 #include "etcd/v3/KeyValue.hpp"
 
-etcdv3::KeyValue::KeyValue()
-{
-  ttl = 0;
-}
+etcdv3::KeyValue::KeyValue() { ttl = 0; }
 
-void etcdv3::KeyValue::set_ttl(int ttl) 
-{
-  this->ttl = ttl;
-}
+void etcdv3::KeyValue::set_ttl(int ttl) { this->ttl = ttl; }
 
-int etcdv3::KeyValue::get_ttl() const
-{
-  return ttl;
-}
+int etcdv3::KeyValue::get_ttl() const { return ttl; }

src/v3/Member.cpp

@@ -0,0 +1,40 @@
+#include "etcd/v3/Member.hpp"
+
+etcdv3::Member::Member() {
+  id = 0;
+  name = "";
+  peerURLs = {};
+  clientURLs = {};
+  isLearner = false;
+}
+
+void etcdv3::Member::set_id(uint64_t const& id) { this->id = id; }
+
+void etcdv3::Member::set_name(std::string const& name) { this->name = name; }
+
+void etcdv3::Member::set_peerURLs(std::vector<std::string> const& peerURLs) {
+  this->peerURLs = peerURLs;
+}
+
+void etcdv3::Member::set_clientURLs(
+    std::vector<std::string> const& clientURLs) {
+  this->clientURLs = clientURLs;
+}
+
+void etcdv3::Member::set_learner(bool isLearner) {
+  this->isLearner = isLearner;
+}
+
+uint64_t const& etcdv3::Member::get_id() const { return id; }
+
+std::string const& etcdv3::Member::get_name() const { return name; }
+
+std::vector<std::string> const& etcdv3::Member::get_peerURLs() const {
+  return peerURLs;
+}
+
+std::vector<std::string> const& etcdv3::Member::get_clientURLs() const {
+  return clientURLs;
+}
+
+bool etcdv3::Member::get_learner() const { return isLearner; }

src/v3/Transaction.cpp

@@ -2,180 +2,359 @@
 
 #include "proto/rpc.grpc.pb.h"
 
-using etcdserverpb::Compare;
-using etcdserverpb::RangeRequest;
-using etcdserverpb::PutRequest;
-using etcdserverpb::RequestOp;
-using etcdserverpb::DeleteRangeRequest;
+#include "etcd/v3/Action.hpp"
+
+namespace etcdv3 {
+
+namespace detail {
+
+static etcdserverpb::Compare::CompareResult to_compare_result(CompareResult r) {
+  return static_cast<etcdserverpb::Compare::CompareResult>(static_cast<int>(r));
+}
+
+static etcdserverpb::Compare::CompareTarget to_compare_target(CompareTarget t) {
+  return static_cast<etcdserverpb::Compare::CompareTarget>(static_cast<int>(t));
+}
+
+}  // namespace detail
+
+}  // namespace etcdv3
 
 etcdv3::Transaction::Transaction() {
-	txn_request.reset(new etcdserverpb::TxnRequest{});
+  txn_request.reset(new etcdserverpb::TxnRequest{});
 }
 
-etcdv3::Transaction::Transaction(const std::string& key) : key(key) {
-	txn_request.reset(new etcdserverpb::TxnRequest{});
+etcdv3::Transaction::~Transaction() {}
+
+void etcdv3::Transaction::add_compare(std::string const& key,
+                                      CompareTarget const& target,
+                                      CompareResult const& result,
+                                      Value const& target_value,
+                                      std::string const& range_end) {
+  switch (target) {
+  case CompareTarget::VERSION:
+    add_compare_version(key, result, target_value.version, range_end);
+    break;
+  case CompareTarget::CREATE:
+    add_compare_create(key, result, target_value.create_revision, range_end);
+    break;
+  case CompareTarget::MOD:
+    add_compare_mod(key, result, target_value.mod_revision, range_end);
+    break;
+  case CompareTarget::VALUE:
+    add_compare_value(key, result, target_value.value, range_end);
+    break;
+  case CompareTarget::LEASE:
+    add_compare_lease(key, result, target_value.lease, range_end);
+    break;
+  default:
+    // ignore invalid compare target
+    break;
+  }
 }
 
-void etcdv3::Transaction::init_compare(Compare::CompareResult result, Compare::CompareTarget target){
-	Compare* compare = txn_request->add_compare();
-	compare->set_result(result);
-	compare->set_target(target);
-	compare->set_key(key);
-
-	compare->set_version(0);
+void etcdv3::Transaction::add_compare_version(std::string const& key,
+                                              int64_t const& version,
+                                              std::string const& range_end) {
+  this->add_compare_version(key, CompareResult::EQUAL, version, range_end);
 }
 
-void etcdv3::Transaction::init_compare(std::string const& old_value, Compare::CompareResult result, Compare::CompareTarget target){
-	Compare* compare = txn_request->add_compare();
-	compare->set_result(result);
-	compare->set_target(target);
-	compare->set_key(key);
-
-	compare->set_value(old_value);
+void etcdv3::Transaction::add_compare_version(std::string const& key,
+                                              CompareResult const& result,
+                                              int64_t const& version,
+                                              std::string const& range_end) {
+  auto compare = txn_request->add_compare();
+  compare->set_result(detail::to_compare_result(result));
+  compare->set_target(detail::to_compare_target(CompareTarget::VERSION));
+  compare->set_key(key);
+  compare->set_version(version);
+  compare->set_range_end(range_end);
 }
 
-void etcdv3::Transaction::init_compare(int old_index, Compare::CompareResult result, Compare::CompareTarget target){
-	Compare* compare = txn_request->add_compare();
-	compare->set_result(result);
-	compare->set_target(target);
-	compare->set_key(key);
-
-	compare->set_mod_revision(old_index);
+void etcdv3::Transaction::add_compare_create(std::string const& key,
+                                             int64_t const& create_revision,
+                                             std::string const& range_end) {
+  this->add_compare_create(key, CompareResult::EQUAL, create_revision,
+                           range_end);
 }
 
-/**
- * get key on failure
- */
-void etcdv3::Transaction::setup_basic_failure_operation(std::string const& key) {
-	std::unique_ptr<RangeRequest> get_request(new RangeRequest());
-	get_request->set_key(key);
-	RequestOp* req_failure = txn_request->add_failure();
-	req_failure->set_allocated_request_range(get_request.release());
+void etcdv3::Transaction::add_compare_create(std::string const& key,
+                                             CompareResult const& result,
+                                             int64_t const& create_revision,
+                                             std::string const& range_end) {
+  auto compare = txn_request->add_compare();
+  compare->set_result(detail::to_compare_result(result));
+  compare->set_target(detail::to_compare_target(CompareTarget::CREATE));
+  compare->set_key(key);
+  compare->set_create_revision(create_revision);
+  compare->set_range_end(range_end);
 }
 
-/**
- * get key on failure, get key before put, modify and then get updated key
- */
-void etcdv3::Transaction::setup_set_failure_operation(std::string const &key, std::string const &value, int64_t leaseid) {
-	std::unique_ptr<PutRequest> put_request(new PutRequest());
-	put_request->set_key(key);
-	put_request->set_value(value);
-    put_request->set_prev_kv(true);
-    put_request->set_lease(leaseid);
-	RequestOp* req_failure = txn_request->add_failure();
-	req_failure->set_allocated_request_put(put_request.release());
-
-	std::unique_ptr<RangeRequest> get_request(new RangeRequest());
-	get_request->set_key(key);
-	req_failure = txn_request->add_failure();
-	req_failure->set_allocated_request_range(get_request.release());
+void etcdv3::Transaction::add_compare_mod(std::string const& key,
+                                          int64_t const& mod_revision,
+                                          std::string const& range_end) {
+  this->add_compare_mod(key, CompareResult::EQUAL, mod_revision, range_end);
 }
 
-/**
- * add key and then get new value of key
- */
-void etcdv3::Transaction::setup_basic_create_sequence(std::string const& key, std::string const& value, int64_t leaseid) {
-	std::unique_ptr<PutRequest> put_request(new PutRequest());
-	put_request->set_key(key);
-	put_request->set_value(value);
-    put_request->set_prev_kv(true);
-    put_request->set_lease(leaseid);
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_put(put_request.release());
-
-    std::unique_ptr<RangeRequest> get_request(new RangeRequest());
-	get_request->set_key(key);
-	req_success = txn_request->add_success();
-	req_success->set_allocated_request_range(get_request.release());
+void etcdv3::Transaction::add_compare_mod(std::string const& key,
+                                          CompareResult const& result,
+                                          int64_t const& mod_revision,
+                                          std::string const& range_end) {
+  auto compare = txn_request->add_compare();
+  compare->set_result(detail::to_compare_result(result));
+  compare->set_target(detail::to_compare_target(CompareTarget::MOD));
+  compare->set_key(key);
+  compare->set_mod_revision(mod_revision);
+  compare->set_range_end(range_end);
 }
 
-/**
- * get key value then modify and get new value
- */
-void etcdv3::Transaction::setup_compare_and_swap_sequence(std::string const& value, int64_t leaseid) {
-	std::unique_ptr<PutRequest> put_request(new PutRequest());
-	put_request->set_key(key);
-	put_request->set_value(value);
-    put_request->set_prev_kv(true);
-    put_request->set_lease(leaseid);
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_put(put_request.release());
-
-	std::unique_ptr<RangeRequest> get_request(new RangeRequest());
-	get_request->set_key(key);
-	req_success = txn_request->add_success();
-	req_success->set_allocated_request_range(get_request.release());
+void etcdv3::Transaction::add_compare_value(std::string const& key,
+                                            std::string const& value,
+                                            std::string const& range_end) {
+  this->add_compare_value(key, CompareResult::EQUAL, value, range_end);
 }
 
-/**
- * get key, delete
- */
-void etcdv3::Transaction::setup_delete_sequence(std::string const &key, std::string const &range_end, bool recursive) {
-	std::unique_ptr<DeleteRangeRequest> del_request(new DeleteRangeRequest());
-	del_request->set_key(key);
-    del_request->set_prev_kv(true);
-	if(recursive)
-	{
-          del_request->set_range_end(range_end);
-	}
-
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_delete_range(del_request.release());
+void etcdv3::Transaction::add_compare_value(std::string const& key,
+                                            CompareResult const& result,
+                                            std::string const& value,
+                                            std::string const& range_end) {
+  auto compare = txn_request->add_compare();
+  compare->set_result(detail::to_compare_result(result));
+  compare->set_target(detail::to_compare_target(CompareTarget::VALUE));
+  compare->set_key(key);
+  compare->set_value(value);
+  compare->set_range_end(range_end);
 }
 
-/**
- * get key, delete
- */
-void etcdv3::Transaction::setup_delete_failure_operation(std::string const &key, std::string const &range_end, bool recursive) {
-	std::unique_ptr<RangeRequest> get_request(new RangeRequest());
-	std::unique_ptr<DeleteRangeRequest> del_request(new DeleteRangeRequest());
-	get_request.reset(new RangeRequest());
-	get_request->set_key(key);
-	if(recursive)
-	{
-		get_request->set_range_end(range_end);
-		get_request->set_sort_target(RangeRequest::SortTarget::RangeRequest_SortTarget_KEY);
-		get_request->set_sort_order(RangeRequest::SortOrder::RangeRequest_SortOrder_ASCEND);
-	}
-	RequestOp* req_failure = txn_request->add_failure();
-	req_failure->set_allocated_request_range(get_request.release());
-
-	del_request.reset(new DeleteRangeRequest());
-	del_request->set_key(key);
-	if(recursive)
-	{
-		del_request->set_range_end(range_end);
-	}
-
-	req_failure = txn_request->add_failure();
-	req_failure->set_allocated_request_delete_range(del_request.release());
+void etcdv3::Transaction::add_compare_lease(std::string const& key,
+                                            int64_t const& lease,
+                                            std::string const& range_end) {
+  this->add_compare_lease(key, CompareResult::EQUAL, lease, range_end);
 }
 
-void etcdv3::Transaction::setup_compare_and_delete_operation(std::string const& key) {
-	std::unique_ptr<DeleteRangeRequest> del_request(new DeleteRangeRequest());
-	del_request->set_key(key);
-    del_request->set_prev_kv(true);
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_delete_range(del_request.release());
+void etcdv3::Transaction::add_compare_lease(std::string const& key,
+                                            CompareResult const& result,
+                                            int64_t const& lease,
+                                            std::string const& range_end) {
+  auto compare = txn_request->add_compare();
+  compare->set_result(detail::to_compare_result(result));
+  compare->set_target(detail::to_compare_target(CompareTarget::LEASE));
+  compare->set_key(key);
+  compare->set_lease(lease);
+  compare->set_range_end(range_end);
 }
 
-void etcdv3::Transaction::setup_put(std::string const &key, std::string const &value) {
-	std::unique_ptr<PutRequest> put_request(new PutRequest());
-	put_request->set_key(key);
-	put_request->set_value(value);
-    put_request->set_prev_kv(false);
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_put(put_request.release());
+void etcdv3::Transaction::add_success_range(std::string const& key,
+                                            std::string const& range_end,
+                                            bool const recursive,
+                                            const int64_t limit) {
+  auto succ = txn_request->add_success();
+  auto get_request = succ->mutable_request_range();
+  etcdv3::detail::make_request_with_ranges(*get_request, key, range_end,
+                                           recursive);
+  get_request->set_limit(limit);
 }
 
-void etcdv3::Transaction::setup_delete(std::string const &key) {
-	std::unique_ptr<DeleteRangeRequest> del_request(new DeleteRangeRequest());
-	del_request->set_key(key);
-    del_request->set_prev_kv(false);
-
-	RequestOp* req_success = txn_request->add_success();
-	req_success->set_allocated_request_delete_range(del_request.release());
+void etcdv3::Transaction::add_success_put(std::string const& key,
+                                          std::string const& value,
+                                          int64_t const leaseid,
+                                          const bool prev_kv) {
+  auto succ = txn_request->add_success();
+  auto put_request = succ->mutable_request_put();
+  put_request->set_key(key);
+  put_request->set_value(value);
+  put_request->set_prev_kv(prev_kv);
+  put_request->set_lease(leaseid);
 }
 
-etcdv3::Transaction::~Transaction() {
+void etcdv3::Transaction::add_success_delete(std::string const& key,
+                                             std::string const& range_end,
+                                             bool const recursive,
+                                             const bool prev_kv) {
+  auto succ = txn_request->add_success();
+  auto del_request = succ->mutable_request_delete_range();
+  etcdv3::detail::make_request_with_ranges(*del_request, key, range_end,
+                                           recursive);
+  del_request->set_prev_kv(prev_kv);
+}
+
+void etcdv3::Transaction::add_success_txn(
+    const std::shared_ptr<Transaction> txn) {
+  auto succ = txn_request->add_success();
+  auto txn_request = succ->mutable_request_txn();
+  txn_request->CopyFrom(*txn->txn_request);
+}
+
+void etcdv3::Transaction::add_failure_range(std::string const& key,
+                                            std::string const& range_end,
+                                            bool const recursive,
+                                            const int64_t limit) {
+  auto fail = txn_request->add_failure();
+  auto get_request = fail->mutable_request_range();
+  etcdv3::detail::make_request_with_ranges(*get_request, key, range_end,
+                                           recursive);
+  get_request->set_limit(limit);
+}
+
+void etcdv3::Transaction::add_failure_put(std::string const& key,
+                                          std::string const& value,
+                                          int64_t const leaseid,
+                                          const bool prev_kv) {
+  auto fail = txn_request->add_failure();
+  auto put_request = fail->mutable_request_put();
+  put_request->set_key(key);
+  put_request->set_value(value);
+  put_request->set_prev_kv(prev_kv);
+  put_request->set_lease(leaseid);
+}
+
+void etcdv3::Transaction::add_failure_delete(std::string const& key,
+                                             std::string const& range_end,
+                                             bool const recursive,
+                                             const bool prev_kv) {
+  auto fail = txn_request->add_failure();
+  auto del_request = fail->mutable_request_delete_range();
+  etcdv3::detail::make_request_with_ranges(*del_request, key, range_end,
+                                           recursive);
+  del_request->set_prev_kv(prev_kv);
+}
+
+void etcdv3::Transaction::add_failure_txn(
+    const std::shared_ptr<Transaction> txn) {
+  auto fail = txn_request->add_failure();
+  auto txn_request = fail->mutable_request_txn();
+  txn_request->CopyFrom(*txn->txn_request);
+}
+
+void etcdv3::Transaction::setup_compare_and_create(
+    std::string const& key, std::string const& prev_value,
+    std::string const& create_key, std::string const& value,
+    int64_t const leaseid) {
+  this->add_compare_value(key, CompareResult::EQUAL, prev_value);
+  this->add_success_put(create_key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_create(std::string const& key,
+                                                  std::string const& prev_value,
+                                                  std::string const& create_key,
+                                                  std::string const& value,
+                                                  int64_t const leaseid) {
+  this->add_compare_value(key, CompareResult::NOT_EQUAL, prev_value);
+  this->add_success_put(create_key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_and_swap(std::string const& key,
+                                                 std::string const& prev_value,
+                                                 std::string const& value,
+                                                 int64_t const leaseid) {
+  this->add_compare_value(key, CompareResult::EQUAL, prev_value);
+  this->add_success_put(key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_swap(std::string const& key,
+                                                std::string const& prev_value,
+                                                std::string const& value,
+                                                int64_t const leaseid) {
+  this->add_compare_value(key, CompareResult::NOT_EQUAL, prev_value);
+  this->add_success_put(key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_and_delete(
+    std::string const& key, std::string const& prev_value,
+    std::string const& delete_key, std::string const& range_end,
+    const bool recursive) {
+  this->add_compare_value(key, CompareResult::EQUAL, prev_value);
+  this->add_success_delete(delete_key, range_end, recursive,
+                           true /* for backwards compatibility */);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_delete(std::string const& key,
+                                                  std::string const& prev_value,
+                                                  std::string const& delete_key,
+                                                  std::string const& range_end,
+                                                  const bool recursive) {
+  this->add_compare_value(key, CompareResult::NOT_EQUAL, prev_value);
+  this->add_success_delete(delete_key, range_end, recursive,
+                           true /* for backwards compatibility */);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_and_create(
+    std::string const& key, const int64_t prev_revision,
+    std::string const& create_key, std::string const& value,
+    int64_t const leaseid) {
+  this->add_compare_mod(key, CompareResult::EQUAL, prev_revision);
+  this->add_success_put(create_key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_create(std::string const& key,
+                                                  const int64_t prev_revision,
+                                                  std::string const& create_key,
+                                                  std::string const& value,
+                                                  int64_t const leaseid) {
+  this->add_compare_mod(key, CompareResult::NOT_EQUAL, prev_revision);
+  this->add_success_put(create_key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_and_swap(std::string const& key,
+                                                 const int64_t prev_revision,
+                                                 std::string const& value,
+                                                 int64_t const leaseid) {
+  this->add_compare_mod(key, CompareResult::EQUAL, prev_revision);
+  this->add_success_put(key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_swap(std::string const& key,
+                                                const int64_t prev_revision,
+                                                std::string const& value,
+                                                int64_t const leaseid) {
+  this->add_compare_mod(key, CompareResult::NOT_EQUAL, prev_revision);
+  this->add_success_put(key, value, leaseid);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_and_delete(
+    std::string const& key, const int64_t prev_revision,
+    std::string const& delete_key, std::string const& range_end,
+    const bool recursive) {
+  this->add_compare_mod(key, CompareResult::EQUAL, prev_revision);
+  this->add_success_delete(delete_key, range_end, recursive,
+                           true /* for backwards compatibility */);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_compare_or_delete(std::string const& key,
+                                                  const int64_t prev_revision,
+                                                  std::string const& delete_key,
+                                                  std::string const& range_end,
+                                                  const bool recursive) {
+  this->add_compare_mod(key, CompareResult::NOT_EQUAL, prev_revision);
+  this->add_success_delete(delete_key, range_end, recursive,
+                           true /* for backwards compatibility */);
+  this->add_failure_range(key);
+}
+
+void etcdv3::Transaction::setup_put(std::string const& key,
+                                    std::string const& value) {
+  this->add_success_put(key, value);
+}
+
+void etcdv3::Transaction::setup_delete(std::string const& key) {
+  this->add_success_delete(key, "", false,
+                           true /* for backwards compatibility */);
+}
+
+void etcdv3::Transaction::setup_delete(std::string const& key,
+                                       std::string const& range_end,
+                                       const bool recursive) {
+  this->add_success_delete(key, range_end, recursive,
+                           true /* for backwards compatibility */);
 }

src/v3/V3Response.cpp

@@ -1,74 +1,86 @@
 #include "etcd/v3/V3Response.hpp"
+#include "etcd/v3/Member.hpp"
 #include "etcd/v3/action_constants.hpp"
 
-void etcdv3::V3Response::set_error_code(int code) 
-{
-  error_code = code;
-}
+void etcdv3::V3Response::set_error_code(int code) { error_code = code; }
 
-void etcdv3::V3Response::set_error_message(std::string msg)
-{
+void etcdv3::V3Response::set_error_message(std::string msg) {
   error_message = msg;
 }
 
-int etcdv3::V3Response::get_index() const
-{
-  return index;
-}
+int64_t etcdv3::V3Response::get_index() const { return index; }
 
-std::string const & etcdv3::V3Response::get_action() const
-{
-  return action;
-}
+std::string const& etcdv3::V3Response::get_action() const { return action; }
 
-int etcdv3::V3Response::get_error_code() const
-{
-  return error_code;
-}
+int etcdv3::V3Response::get_error_code() const { return error_code; }
 
-std::string const & etcdv3::V3Response::get_error_message() const
-{
+std::string const& etcdv3::V3Response::get_error_message() const {
   return error_message;
 }
 
-void etcdv3::V3Response::set_action(std::string action)
-{
+void etcdv3::V3Response::set_action(std::string action) {
   this->action = action;
 }
 
-std::vector<etcdv3::KeyValue> const & etcdv3::V3Response::get_values() const
-{
+std::vector<etcdv3::KeyValue> const& etcdv3::V3Response::get_values() const {
   return values;
 }
 
-std::vector<etcdv3::KeyValue> const & etcdv3::V3Response::get_prev_values() const
-{
+std::vector<etcdv3::KeyValue> const& etcdv3::V3Response::get_prev_values()
+    const {
   return prev_values;
 }
 
-etcdv3::KeyValue const & etcdv3::V3Response::get_value() const
-{
-  return value;
-}
+etcdv3::KeyValue const& etcdv3::V3Response::get_value() const { return value; }
 
-etcdv3::KeyValue const & etcdv3::V3Response::get_prev_value() const
-{
+etcdv3::KeyValue const& etcdv3::V3Response::get_prev_value() const {
   return prev_value;
 }
 
-bool etcdv3::V3Response::has_values() const
-{
-  return values.size() > 0;
+bool etcdv3::V3Response::has_values() const { return values.size() > 0; }
+
+int64_t etcdv3::V3Response::get_compact_revision() const {
+  return compact_revision;
 }
 
-void etcdv3::V3Response::set_lock_key(std::string const &key) {
+void etcdv3::V3Response::set_compact_revision(const int64_t compact_revision) {
+  this->compact_revision = compact_revision;
+}
+
+int64_t etcdv3::V3Response::get_watch_id() const { return watch_id; }
+
+void etcdv3::V3Response::set_watch_id(const int64_t watch_id) {
+  this->watch_id = watch_id;
+}
+
+void etcdv3::V3Response::set_lock_key(std::string const& key) {
   this->lock_key = key;
 }
 
-std::string const & etcdv3::V3Response::get_lock_key() const {
+std::string const& etcdv3::V3Response::get_lock_key() const {
   return this->lock_key;
 }
 
-std::vector<mvccpb::Event> const & etcdv3::V3Response::get_events() const {
+void etcdv3::V3Response::set_name(std::string const& name) {
+  this->name = name;
+}
+
+std::string const& etcdv3::V3Response::get_name() const { return this->name; }
+
+std::vector<mvccpb::Event> const& etcdv3::V3Response::get_events() const {
   return this->events;
 }
+
+uint64_t etcdv3::V3Response::get_cluster_id() const { return this->cluster_id; }
+
+uint64_t etcdv3::V3Response::get_member_id() const { return this->member_id; }
+
+uint64_t etcdv3::V3Response::get_raft_term() const { return this->raft_term; }
+
+std::vector<int64_t> const& etcdv3::V3Response::get_leases() const {
+  return this->leases;
+}
+
+std::vector<etcdv3::Member> const& etcdv3::V3Response::get_members() const {
+  return this->members;
+}

src/v3/action_constants.cpp

@@ -1,12 +1,72 @@
 #include "etcd/v3/action_constants.hpp"
 
-char const * etcdv3::CREATE_ACTION = "create";
-char const * etcdv3::COMPARESWAP_ACTION = "compareAndSwap";
-char const * etcdv3::UPDATE_ACTION = "update";
-char const * etcdv3::SET_ACTION = "set";
-char const * etcdv3::GET_ACTION = "get";
-char const * etcdv3::DELETE_ACTION = "delete";
-char const * etcdv3::COMPAREDELETE_ACTION = "compareAndDelete";
-char const * etcdv3::LOCK_ACTION = "lock";
-char const * etcdv3::UNLOCK_ACTION = "unlock";
-char const * etcdv3::TXN_ACTION = "txn";
+char const* etcdv3::CREATE_ACTION = "create";
+char const* etcdv3::COMPARESWAP_ACTION = "compareAndSwap";
+char const* etcdv3::UPDATE_ACTION = "update";
+char const* etcdv3::SET_ACTION = "set";
+char const* etcdv3::GET_ACTION = "get";
+char const* etcdv3::PUT_ACTION = "set";  // alias
+char const* etcdv3::DELETE_ACTION = "delete";
+char const* etcdv3::COMPAREDELETE_ACTION = "compareAndDelete";
+char const* etcdv3::LOCK_ACTION = "lock";
+char const* etcdv3::UNLOCK_ACTION = "unlock";
+char const* etcdv3::TXN_ACTION = "txn";
+char const* etcdv3::WATCH_ACTION = "watch";
+
+char const* etcdv3::LEASEGRANT = "leasegrant";
+char const* etcdv3::LEASEREVOKE = "leaserevoke";
+char const* etcdv3::LEASEKEEPALIVE = "leasekeepalive";
+char const* etcdv3::LEASETIMETOLIVE = "leasetimetolive";
+char const* etcdv3::LEASELEASES = "leaseleases";
+
+char const* etcdv3::ADDMEMBER = "addmember";
+char const* etcdv3::LISTMEMBER = "listmember";
+char const* etcdv3::REMOVEMEMBER = "removemember";
+
+char const* etcdv3::CAMPAIGN_ACTION = "campaign";
+char const* etcdv3::PROCLAIM_ACTION = "preclaim";
+char const* etcdv3::LEADER_ACTION = "leader";
+char const* etcdv3::OBSERVE_ACTION = "obverse";
+char const* etcdv3::RESIGN_ACTION = "resign";
+
+// see: noPrefixEnd in etcd, however c++ doesn't allows naive '\0' inside
+// a string, thus we use std::string(1, '\x00') as the constructor.
+std::string const etcdv3::NUL = std::string(1, '\x00');
+
+char const* etcdv3::KEEPALIVE_CREATE = "keepalive create";
+char const* etcdv3::KEEPALIVE_WRITE = "keepalive write";
+char const* etcdv3::KEEPALIVE_READ = "keepalive read";
+char const* etcdv3::KEEPALIVE_DONE = "keepalive done";
+char const* etcdv3::KEEPALIVE_FINISH = "keepalive finish";
+
+char const* etcdv3::WATCH_CREATE = "watch create";
+char const* etcdv3::WATCH_WRITE = "watch write";
+char const* etcdv3::WATCH_WRITE_CANCEL = "watch write cancel";
+char const* etcdv3::WATCH_WRITES_DONE = "watch writes done";
+char const* etcdv3::WATCH_FINISH = "watch finish";
+
+char const* etcdv3::ELECTION_OBSERVE_CREATE = "observe create";
+char const* etcdv3::ELECTION_OBSERVE_FINISH = "observe finish";
+
+const int etcdv3::ERROR_GRPC_OK = 0;
+const int etcdv3::ERROR_GRPC_CANCELLED = 1;
+const int etcdv3::ERROR_GRPC_UNKNOWN = 2;
+const int etcdv3::ERROR_GRPC_INVALID_ARGUMENT = 3;
+const int etcdv3::ERROR_GRPC_DEADLINE_EXCEEDED = 4;
+const int etcdv3::ERROR_GRPC_NOT_FOUND = 5;
+const int etcdv3::ERROR_GRPC_ALREADY_EXISTS = 6;
+const int etcdv3::ERROR_GRPC_PERMISSION_DENIED = 7;
+const int etcdv3::ERROR_GRPC_UNAUTHENTICATED = 16;
+const int etcdv3::ERROR_GRPC_RESOURCE_EXHAUSTED = 8;
+const int etcdv3::ERROR_GRPC_FAILED_PRECONDITION = 9;
+const int etcdv3::ERROR_GRPC_ABORTED = 10;
+const int etcdv3::ERROR_GRPC_OUT_OF_RANGE = 11;
+const int etcdv3::ERROR_GRPC_UNIMPLEMENTED = 12;
+const int etcdv3::ERROR_GRPC_INTERNAL = 13;
+const int etcdv3::ERROR_GRPC_UNAVAILABLE = 14;
+const int etcdv3::ERROR_GRPC_DATA_LOSS = 15;
+
+const int etcdv3::ERROR_KEY_NOT_FOUND = 100;
+const int etcdv3::ERROR_COMPARE_FAILED = 101;
+const int etcdv3::ERROR_KEY_ALREADY_EXISTS = 105;
+const int etcdv3::ERROR_ACTION_CANCELLED = 106;

tst/AuthTest.cpp

@@ -5,45 +5,50 @@
 
 #include "etcd/Client.hpp"
 
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
 
-TEST_CASE("setup with auth")
-{
-  etcd::Client *etcd = etcd::Client::WithUser("http://127.0.0.1:2379", "root", "root");
+TEST_CASE("setup with auth") {
+  etcd::Client* etcd = etcd::Client::WithUser(etcd_url, "root", "root");
   etcd->rmdir("/test", true).wait();
 }
 
-TEST_CASE("add a new key after authenticate")
-{
-  etcd::Client *etcd = etcd::Client::WithUser("http://127.0.0.1:2379", "root", "root");
+TEST_CASE("add a new key after authenticate") {
+  etcd::Client* etcd = etcd::Client::WithUser(etcd_url, "root", "root");
   etcd->rmdir("/test", true).wait();
   etcd::Response resp = etcd->add("/test/key1", "42").get();
   REQUIRE(0 == resp.error_code());
   CHECK("create" == resp.action());
-  etcd::Value const & val = resp.value();
+  etcd::Value const& val = resp.value();
   CHECK("42" == val.as_string());
   CHECK("/test/key1" == val.key());
   CHECK(!val.is_dir());
   CHECK(0 < val.created_index());
   CHECK(0 < val.modified_index());
+  CHECK(1 == val.version());
   CHECK(0 < resp.index());
-  CHECK(105 == etcd->add("/test/key1", "43").get().error_code()); // Key already exists
-  CHECK(105 == etcd->add("/test/key1", "42").get().error_code()); // Key already exists
-  CHECK("Key already exists" == etcd->add("/test/key1", "42").get().error_message());
+  CHECK(
+      etcd::ERROR_KEY_ALREADY_EXISTS ==
+      etcd->add("/test/key1", "43").get().error_code());  // Key already exists
+  CHECK(
+      etcd::ERROR_KEY_ALREADY_EXISTS ==
+      etcd->add("/test/key1", "42").get().error_code());  // Key already exists
+  CHECK("etcd-cpp-apiv3: key already exists" ==
+        etcd->add("/test/key1", "42").get().error_message());
 }
 
-TEST_CASE("read a value from etcd")
-{
-  etcd::Client *etcd = etcd::Client::WithUser("http://127.0.0.1:2379", "root", "root");
+TEST_CASE("read a value from etcd") {
+  etcd::Client* etcd = etcd::Client::WithUser(etcd_url, "root", "root");
   etcd::Response resp = etcd->get("/test/key1").get();
   CHECK("get" == resp.action());
   REQUIRE(resp.is_ok());
   REQUIRE(0 == resp.error_code());
   CHECK("42" == resp.value().as_string());
-  CHECK("" == etcd->get("/test").get().value().as_string()); // key points to a directory
+  CHECK("" == etcd->get("/test").get().value().as_string());  // key points to a
+                                                              // directory
 }
 
-TEST_CASE("cleanup")
-{
-  etcd::Client *etcd = etcd::Client::WithUser("http://127.0.0.1:2379", "root", "root");
+TEST_CASE("cleanup") {
+  etcd::Client* etcd = etcd::Client::WithUser(etcd_url, "root", "root");
   REQUIRE(0 == etcd->rmdir("/test", true).get().error_code());
 }

tst/CMakeLists.txt

@@ -5,18 +5,34 @@ add_custom_target(check ${CMAKE_COMMAND} -E env CTEST_OUTPUT_ON_FAILURE=1
                         ${CMAKE_CTEST_COMMAND} -C $<CONFIG> --verbose
                         WORKING_DIRECTORY ${PROJECT_BINARY_DIR})
 
+add_custom_target(etcd_tests)
+add_dependencies(check etcd_tests)
+
 file(GLOB TEST_FILES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}/*.cpp")
 foreach(testfile ${TEST_FILES})
     string(REGEX MATCH "^(.*)\\.[^.]*$" dummy ${testfile})
     set(test_name ${CMAKE_MATCH_1})
     message(STATUS "Found unit_test - " ${test_name})
-    add_executable(${test_name} ${CMAKE_CURRENT_SOURCE_DIR}/${testfile})
+    if(BUILD_ETCD_TESTS)
+        add_executable(${test_name} ${CMAKE_CURRENT_SOURCE_DIR}/${testfile})
+    else()
+        add_executable(${test_name} EXCLUDE_FROM_ALL ${CMAKE_CURRENT_SOURCE_DIR}/${testfile})
+    endif()
+    use_cxx(${test_name})
+    set_exceptions(${test_name})
     add_test(NAME ${test_name} COMMAND $<TARGET_FILE:${test_name}>)
 
-    set_property(TARGET ${test_name} PROPERTY CXX_STANDARD 11)
     target_include_directories(${test_name} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen)
     target_include_directories(${test_name} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen/proto)
-    target_link_libraries(${test_name} etcd-cpp-api)
+    target_link_libraries(${test_name} PRIVATE etcd-cpp-api)
 
-    add_dependencies(check ${test_name})
+    if(UNIX AND NOT APPLE)
+        if(CMAKE_VERSION VERSION_LESS 3.13)
+            target_link_libraries(${test_name} PRIVATE -Wl,--no-as-needed -lSegFault -Wl,--as-needed)
+        else()
+            target_link_options(${test_name} PRIVATE -Wl,--no-as-needed -lSegFault -Wl,--as-needed)
+        endif()
+    endif()
+
+    add_dependencies(etcd_tests ${test_name})
 endforeach()

tst/CampaignTest.cpp

@@ -0,0 +1,109 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <chrono>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+#include "etcd/Response.hpp"
+#include "etcd/SyncClient.hpp"
+#include "etcd/Value.hpp"
+
+static std::string etcd_uri = etcdv3::detail::resolve_etcd_endpoints(
+    "http://127.0.0.1:2379,http://127.0.0.1:2479,http://127.0.0.1:2579");
+
+TEST_CASE("campaign and leadership using keepalive") {
+  etcd::Client etcd(etcd_uri);
+  auto keepalive = etcd.leasekeepalive(5).get();
+  auto lease_id = keepalive->Lease();
+
+  std::cout << lease_id << std::endl;
+  std::string value = std::string("192.168.1.6:1880");
+  auto resp1 = etcd.campaign("/leader", lease_id, value).get();
+  if (0 == resp1.error_code()) {
+    std::cout << "became leader: " << resp1.index() << std::endl;
+  } else {
+    std::cout << "error code: " << resp1.error_code()
+              << "error message: " << resp1.error_message() << std::endl;
+    assert(false);
+  }
+
+  std::cout << "finish campaign" << std::endl;
+
+  auto resp2 = etcd.leader("/leader").get();
+  CHECK(0 == resp2.error_code());
+  CHECK(value == resp2.value().as_string());
+  CHECK(resp1.value().key() == resp2.value().key());
+  std::cout << resp2.value().key() << std::endl;
+
+  std::cout << "finish leader" << std::endl;
+
+  auto resp3 = etcd.resign("/leader", resp1.value().lease(),
+                           resp1.value().key(), resp1.value().created_index())
+                   .get();
+  CHECK(0 == resp3.error_code());
+
+  std::cout << "finish resign" << std::endl;
+}
+
+TEST_CASE("concurrent campaign with grpc timeout") {
+  std::string value1 = std::string("192.168.1.6:1880");
+  std::string value2 = std::string("192.168.1.6:1890");
+
+  auto fn1 = [&]() {
+    etcd::Client etcd(etcd_uri);
+    auto keepalive = etcd.leasekeepalive(5).get();
+    auto lease_id = keepalive->Lease();
+    auto resp1 = etcd.campaign("/leader", lease_id, value1).get();
+    CHECK(0 == resp1.error_code());
+
+    std::this_thread::sleep_for(std::chrono::seconds(10));
+
+    // resign
+    auto resp2 = etcd.resign("/leader", resp1.value().lease(),
+                             resp1.value().key(), resp1.value().created_index())
+                     .get();
+    CHECK(0 == resp2.error_code());
+  };
+
+  auto fn2 = [&]() {
+    etcd::Client etcd(etcd_uri);
+    auto keepalive = etcd.leasekeepalive(5).get();
+    auto lease_id = keepalive->Lease();
+
+    // set client timeout
+    etcd.set_grpc_timeout(std::chrono::seconds(3));
+
+    std::this_thread::sleep_for(std::chrono::seconds(3));
+    auto resp1 = etcd.campaign("/leader", lease_id, value2).get();
+    std::cout << resp1.error_code() << resp1.error_message() << std::endl;
+    CHECK(0 != resp1.error_code());
+
+    // wait until success
+    while (true) {
+      resp1 = etcd.campaign("/leader", lease_id, value2).get();
+      if (resp1.error_code() == 0) {
+        // check value
+        auto resp2 = etcd.leader("/leader").get();
+        CHECK(0 == resp2.error_code());
+        CHECK(value2 == resp2.value().as_string());
+        CHECK(resp1.value().key() == resp2.value().key());
+
+        // break the loop
+        break;
+      }
+    }
+
+    auto resp2 = etcd.resign("/leader", resp1.value().lease(),
+                             resp1.value().key(), resp1.value().created_index())
+                     .get();
+    CHECK(0 == resp2.error_code());
+  };
+
+  std::thread t1(fn1);
+  std::thread t2(fn2);
+
+  t1.join();
+  t2.join();
+}

tst/ElectionTest.cpp

@@ -0,0 +1,115 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+TEST_CASE("setup") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+}
+
+TEST_CASE("campaign and resign") {
+  etcd::Client etcd(etcd_url);
+
+  auto keepalive = etcd.leasekeepalive(60).get();
+  auto lease_id = keepalive->Lease();
+
+  // campaign
+  auto resp1 = etcd.campaign("test", lease_id, "xxxx").get();
+  REQUIRE(0 == resp1.error_code());
+
+  // leader
+  {
+    auto resp2 = etcd.leader("test").get();
+    REQUIRE(0 == resp2.error_code());
+    REQUIRE(resp1.value().key() == resp2.value().key());
+    REQUIRE("xxxx" == resp2.value().as_string());
+  }
+
+  // proclaim
+  auto resp3 = etcd.proclaim("test", lease_id, resp1.value().key(),
+                             resp1.value().created_index(), "tttt")
+                   .get();
+  REQUIRE(0 == resp3.error_code());
+
+  // leader
+  {
+    auto resp4 = etcd.leader("test").get();
+    REQUIRE(0 == resp4.error_code());
+    REQUIRE(resp1.value().key() == resp4.value().key());
+    REQUIRE("tttt" == resp4.value().as_string());
+  }
+
+  // resign
+  auto resp5 = etcd.resign("test", lease_id, resp1.value().key(),
+                           resp1.value().created_index())
+                   .get();
+  REQUIRE(0 == resp5.error_code());
+}
+
+TEST_CASE("campaign and observe") {
+  etcd::Client etcd(etcd_url);
+
+  auto keepalive = etcd.leasekeepalive(60).get();
+  auto lease_id = keepalive->Lease();
+
+  auto observer_thread = std::thread([&etcd]() {
+    std::unique_ptr<etcd::SyncClient::Observer> observer = etcd.observe("test");
+    // wait many change events, blocked execution
+    for (size_t i = 0; i < 10; ++i) {
+      etcd::Response resp = observer->WaitOnce();
+      std::cout << "observe " << resp.value().key()
+                << " as the leader: " << resp.value().as_string() << std::endl;
+    }
+    std::cout << "finish the observe" << std::endl;
+    // cancel the observers
+    observer.reset(nullptr);
+  });
+
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+
+  for (int i = 0; i < 5; ++i) {
+    // campaign
+    auto resp1 = etcd.campaign("test", lease_id, "xxxx").get();
+    REQUIRE(0 == resp1.error_code());
+    std::cout << "key " << resp1.value().key() << " becomes the leader"
+              << std::endl;
+
+    // proclaim
+    auto resp3 = etcd.proclaim("test", lease_id, resp1.value().key(),
+                               resp1.value().created_index(),
+                               "tttt - " + std::to_string(i))
+                     .get();
+    REQUIRE(0 == resp3.error_code());
+
+    // leader
+    {
+      auto resp4 = etcd.leader("test").get();
+      REQUIRE(0 == resp4.error_code());
+      REQUIRE(resp1.value().key() == resp4.value().key());
+      REQUIRE("tttt - " + std::to_string(i) == resp4.value().as_string());
+    }
+
+    // resign
+    auto resp5 = etcd.resign("test", lease_id, resp1.value().key(),
+                             resp1.value().created_index())
+                     .get();
+    REQUIRE(0 == resp5.error_code());
+    std::this_thread::sleep_for(std::chrono::seconds(1));
+  }
+
+  observer_thread.join();
+}
+
+TEST_CASE("cleanup") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).get();
+}

tst/EtcdMemberTest.cpp

@@ -0,0 +1,136 @@
+#include <cmath>
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <chrono>
+#include <cstring>
+#include <iostream>
+#include <thread>
+#include <vector>
+
+#include "etcd/Client.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+pid_t new_etcd_pid = 0;
+
+pid_t start_etcd_server(const std::string& etcd_path,
+                        const std::vector<std::string>& args) {
+  pid_t pid = fork();
+  if (pid == -1) {
+    std::cout << "Failed to fork process" << std::endl;
+    exit(EXIT_FAILURE);
+  } else if (pid == 0) {
+    std::vector<char*> c_args;
+    c_args.push_back(const_cast<char*>(etcd_path.c_str()));
+    for (const auto& arg : args) {
+      c_args.push_back(const_cast<char*>(arg.c_str()));
+    }
+    c_args.push_back(nullptr);
+
+    if (execvp(etcd_path.c_str(), c_args.data()) == -1) {
+      std::cout << "Failed to exec etcd process: " << std::strerror(errno)
+                << std::endl;
+      exit(EXIT_FAILURE);
+    }
+  }
+
+  return pid;
+}
+
+TEST_CASE("add member") {
+  etcd::Client etcd(etcd_url);
+  etcd::Response res = etcd.list_member().get();
+  REQUIRE(res.is_ok());
+  CHECK(1 == res.members().size());
+
+  std::string member_name = res.members()[0].get_name();
+  std::string prev_peer_urls = res.members()[0].get_peerURLs()[0];
+
+  // Add a new member
+  std::string peer_urls = "http://127.0.0.1:33691";
+  std::string client_urls = "http://127.0.0.1:33690";
+  bool is_learner = false;
+  res = etcd.add_member(peer_urls, is_learner).get();
+  REQUIRE(res.is_ok());
+
+  // Create the directory for the new etcd server
+  std::string cmd = "mkdir -p /tmp/new_etcd_member";
+  system(cmd.c_str());
+
+  // Start a new etcd server
+  std::vector<std::string> args = {
+      "--name",
+      "new_etcd_member",
+      "--initial-advertise-peer-urls",
+      peer_urls,
+      "--listen-peer-urls",
+      peer_urls,
+      "--initial-cluster",
+      member_name + "=" + prev_peer_urls + ",new_etcd_member=" + peer_urls,
+      "--initial-cluster-state",
+      "existing",
+      "--listen-client-urls",
+      client_urls,
+      "--advertise-client-urls",
+      client_urls,
+      "--data-dir",
+      "/tmp/new_etcd_member",
+  };
+
+  new_etcd_pid = start_etcd_server("/usr/local/bin/etcd", args);
+
+  std::this_thread::sleep_for(std::chrono::seconds(30));
+
+  // Check the member's number
+  {
+    etcd::Response res = etcd.list_member().get();
+    REQUIRE(res.is_ok());
+    CHECK(2 == res.members().size());
+  }
+}
+
+TEST_CASE("member remove") {
+  etcd::Client etcd(etcd_url);
+  etcd::Response res = etcd.list_member().get();
+  REQUIRE(res.is_ok());
+  CHECK(2 == res.members().size());
+
+  uint64_t member_id = 0;
+  for (const auto& member : res.members()) {
+    if (member.get_name() == "new_etcd_member") {
+      member_id = member.get_id();
+      break;
+    }
+  }
+
+  REQUIRE(member_id != 0);
+  // Remove the new member
+  res = etcd.remove_member(member_id).get();
+
+  std::this_thread::sleep_for(std::chrono::seconds(30));
+
+  // Check whether the new etcd server is quited
+  {
+    int status;
+    pid_t wpid = waitpid(new_etcd_pid, &status, WNOHANG);
+    REQUIRE(wpid == new_etcd_pid);
+    REQUIRE(WIFEXITED(status));
+    REQUIRE(WEXITSTATUS(status) == 0);
+  }
+
+  // Remove the directory for the new etcd server
+  std::string cmd = "rm -rf /tmp/new_etcd_member";
+  system(cmd.c_str());
+
+  // Check the member's number
+  {
+    etcd::Response res = etcd.list_member().get();
+    REQUIRE(res.is_ok());
+    CHECK(1 == res.members().size());
+  }
+}

tst/EtcdResolverTest.cpp

@@ -0,0 +1,30 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <iostream>
+
+#include "etcd/Client.hpp"
+
+static const std::string etcd_v4_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+static const std::string etcd_v6_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://::1:2379");
+// http://[ipv6]:port url
+static const std::string etcd_ipv6_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://[::1]:2379");
+
+TEST_CASE("test ipv4 connection") {
+  std::cout << "ipv4 endpoints: " << etcd_v4_url << std::endl;
+  etcd::Client etcd(etcd_v4_url);
+  REQUIRE(etcd.head().get().is_ok());
+}
+
+TEST_CASE("test ipv6 connection") {
+  std::cout << "ipv6 endpoints: " << etcd_v6_url << std::endl;
+  etcd::Client etcd(etcd_v6_url);
+  REQUIRE(etcd.head().get().is_ok());
+
+  std::cout << "ipv6 endpoints: " << etcd_ipv6_url << std::endl;
+  etcd::Client etcd1(etcd_ipv6_url);
+  REQUIRE(etcd1.head().get().is_ok());
+}

tst/EtcdSyncTest.cpp

@@ -5,38 +5,46 @@
 
 #include "etcd/SyncClient.hpp"
 
-static std::string etcd_uri("http://127.0.0.1:2379");
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
 
-TEST_CASE("sync operations")
-{
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("sync operations") {
+  etcd::SyncClient etcd(etcd_url);
   etcd.rmdir("/test", true);
 
+  etcd::Response res;
+  int64_t index;
+
   // add
   CHECK(0 == etcd.add("/test/key1", "42").error_code());
-  CHECK(105 == etcd.add("/test/key1", "42").error_code()); // Key already exists
+  CHECK(etcd::ERROR_KEY_ALREADY_EXISTS ==
+        etcd.add("/test/key1", "41").error_code());  // Key already exists
   CHECK("42" == etcd.get("/test/key1").value().as_string());
 
   // modify
   CHECK(0 == etcd.modify("/test/key1", "43").error_code());
-  CHECK(100 == etcd.modify("/test/key2", "43").error_code()); // Key not found
-  CHECK("43" == etcd.modify("/test/key1", "42").prev_value().as_string());
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.modify("/test/key2", "43").error_code());  // Key not found
+  res = etcd.modify("/test/key1", "42");
+  CHECK(0 == res.error_code());
+  CHECK("43" == res.prev_value().as_string());
 
   // set
-  CHECK(0  == etcd.set("/test/key1", "43").error_code()); // overwrite
-  CHECK(0  == etcd.set("/test/key2", "43").error_code()); // create new
+  CHECK(0 == etcd.set("/test/key1", "43").error_code());  // overwrite
+  CHECK(0 == etcd.set("/test/key2", "43").error_code());  // create new
   CHECK("43" == etcd.set("/test/key2", "44").prev_value().as_string());
-  CHECK(""   == etcd.set("/test/key3", "44").prev_value().as_string());
+  CHECK("" == etcd.set("/test/key3", "44").prev_value().as_string());
 
   // get
   CHECK("43" == etcd.get("/test/key1").value().as_string());
   CHECK("44" == etcd.get("/test/key2").value().as_string());
   CHECK("44" == etcd.get("/test/key3").value().as_string());
-  CHECK(100 == etcd.get("/test/key4").error_code()); // key not found
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.get("/test/key4").error_code());  // key not found
 
   // rm
   CHECK(3 == etcd.ls("/test").keys().size());
-  CHECK(0  == etcd.rm("/test/key1").error_code());
+  CHECK(0 == etcd.rm("/test/key1").error_code());
   CHECK(2 == etcd.ls("/test").keys().size());
 
   // ls
@@ -45,73 +53,87 @@ TEST_CASE("sync operations")
   etcd.set("/test/new_dir/key2", "value2");
   CHECK(2 == etcd.ls("/test/new_dir").keys().size());
 
+  // keys
+  etcd.set("/test/new_dir/key1", "value1");
+  etcd.set("/test/new_dir/key2", "value2");
+  CHECK(2 == etcd.keys("/test/new_dir").keys().size());
+
   // rmdir
-  CHECK(100 == etcd.rmdir("/test/new_dir").error_code()); // key not found
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.rmdir("/test/new_dir").error_code());  // key not found
   CHECK(0 == etcd.rmdir("/test/new_dir", true).error_code());
 
   // compare and swap
   etcd.set("/test/key1", "42");
-  int index = etcd.modify_if("/test/key1", "43", "42").index();
-  CHECK(101 == etcd.modify_if("/test/key1", "44", "42").error_code());
+  index = etcd.modify_if("/test/key1", "43", "42").index();
+  CHECK(etcd::ERROR_COMPARE_FAILED ==
+        etcd.modify_if("/test/key1", "44", "42").error_code());
   REQUIRE(etcd.modify_if("/test/key1", "44", index).is_ok());
-  CHECK(101 == etcd.modify_if("/test/key1", "45", index).error_code());
+  CHECK(etcd::ERROR_COMPARE_FAILED ==
+        etcd.modify_if("/test/key1", "45", index).error_code());
 
   // atomic compare-and-delete based on prevValue
   etcd.set("/test/key1", "42");
-  CHECK(101 == etcd.rm_if("/test/key1", "43").error_code());
-  CHECK(0   == etcd.rm_if("/test/key1", "42").error_code());
+  CHECK(etcd::ERROR_COMPARE_FAILED ==
+        etcd.rm_if("/test/key1", "43").error_code());
+  res = etcd.rm_if("/test/key1", "42");
+  CHECK(
+      (0 == res.error_code() || etcd::ERROR_KEY_NOT_FOUND == res.error_code()));
 
   // atomic compare-and-delete based on prevIndex
   index = etcd.set("/test/key1", "42").index();
-  CHECK(101 == etcd.rm_if("/test/key1", index - 1).error_code());
-  CHECK(0   == etcd.rm_if("/test/key1", index).error_code());
+  CHECK(etcd::ERROR_COMPARE_FAILED ==
+        etcd.rm_if("/test/key1", index - 1).error_code());
+  res = etcd.rm_if("/test/key1", index);
+  CHECK(
+      (0 == res.error_code() || etcd::ERROR_KEY_NOT_FOUND == res.error_code()));
 
-  //leasegrant
-  etcd::Response res = etcd.leasegrant(60);
+  // leasegrant
+  res = etcd.leasegrant(60);
   REQUIRE(res.is_ok());
   CHECK(60 == res.value().ttl());
-  CHECK(0 <  res.value().lease());
+  CHECK(0 < res.value().lease());
   int64_t leaseid = res.value().lease();
 
-  //add with lease
+  // add with lease
   res = etcd.add("/test/key1111", "43", leaseid);
-  REQUIRE(0  == res.error_code()); // overwrite
+  REQUIRE(0 == res.error_code());  // overwrite
   CHECK("create" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  CHECK(leaseid == res.value().lease());
 
-  //set with lease
+  // set with lease
   res = etcd.set("/test/key1", "43", leaseid);
-  REQUIRE(0  == res.error_code());
+  REQUIRE(0 == res.error_code());
   CHECK("set" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  res = etcd.get("/test/key1");
+  CHECK(leaseid == res.value().lease());
 
-  //modify with lease
+  // modify with lease
   res = etcd.modify("/test/key1", "44", leaseid);
-  REQUIRE(0  == res.error_code()); 
+  REQUIRE(0 == res.error_code());
   CHECK("update" == res.action());
-  CHECK(leaseid ==  res.value().lease());
-  CHECK("44" ==  res.value().as_string());
+  CHECK(leaseid == res.value().lease());
+  CHECK("44" == res.value().as_string());
 
   res = etcd.modify_if("/test/key1", "45", "44", leaseid);
   index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  CHECK(leaseid == res.value().lease());
   CHECK("45" == res.value().as_string());
 
   res = etcd.modify_if("/test/key1", "44", index, leaseid);
   index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  CHECK(leaseid == res.value().lease());
   CHECK("44" == res.value().as_string());
 
   REQUIRE(0 == etcd.rmdir("/test", true).error_code());
 }
 
-TEST_CASE("wait for a value change")
-{
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("wait for a value change") {
+  etcd::SyncClient etcd(etcd_url);
   etcd.set("/test/key1", "42");
 
   std::thread watch_thrd([&]() {
@@ -127,9 +149,8 @@ TEST_CASE("wait for a value change")
   REQUIRE(0 == etcd.rmdir("/test", true).error_code());
 }
 
-TEST_CASE("wait for a directory change")
-{
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("wait for a directory change") {
+  etcd::SyncClient etcd(etcd_url);
 
   std::thread watch_thrd1([&]() {
     etcd::Response res = etcd.watch("/test", true);
@@ -154,11 +175,10 @@ TEST_CASE("wait for a directory change")
   REQUIRE(0 == etcd.rmdir("/test", true).error_code());
 }
 
-TEST_CASE("watch changes in the past")
-{
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("watch changes in the past") {
+  etcd::SyncClient etcd(etcd_url);
 
-  int index = etcd.set("/test/key1", "42").index();
+  int64_t index = etcd.set("/test/key1", "42").index();
 
   etcd.set("/test/key1", "43");
   etcd.set("/test/key1", "44");
@@ -181,7 +201,7 @@ TEST_CASE("watch changes in the past")
 
 // TEST_CASE("request cancellation")
 // {
-//   etcd::Client etcd(etcd_uri);
+//   etcd::Client etcd(etcd_url);
 //   etcd.set("/test/key1", "42").wait();
 
 //   pplx::task<etcd::Response> res = etcd.watch("/test/key1");

tst/EtcdTest.cpp

@@ -7,89 +7,105 @@
 
 #include "etcd/Client.hpp"
 
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
 
-TEST_CASE("setup")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("setup") {
+  etcd::Client etcd(etcd_url);
   etcd.rmdir("/test", true).wait();
 }
 
-TEST_CASE("add a new key")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("add a new key") {
+  etcd::Client etcd(etcd_url);
   etcd.rmdir("/test", true).wait();
   etcd::Response resp = etcd.add("/test/key1", "42").get();
   REQUIRE(0 == resp.error_code());
   CHECK("create" == resp.action());
-  etcd::Value const & val = resp.value();
+  etcd::Value const& val = resp.value();
   CHECK("42" == val.as_string());
   CHECK("/test/key1" == val.key());
   CHECK(!val.is_dir());
   CHECK(0 < val.created_index());
   CHECK(0 < val.modified_index());
+  CHECK(1 == val.version());
   CHECK(0 < resp.index());
-  CHECK(105 == etcd.add("/test/key1", "43").get().error_code()); // Key already exists
-  CHECK(105 == etcd.add("/test/key1", "42").get().error_code()); // Key already exists
-  CHECK("Key already exists" == etcd.add("/test/key1", "42").get().error_message());
+  CHECK(etcd::ERROR_KEY_ALREADY_EXISTS ==
+        etcd.add("/test/key1", "43").get().error_code());  // Key already exists
+  CHECK(etcd::ERROR_KEY_ALREADY_EXISTS ==
+        etcd.add("/test/key1", "42").get().error_code());  // Key already exists
+  CHECK("etcd-cpp-apiv3: key already exists" ==
+        etcd.add("/test/key1", "42").get().error_message());
 }
 
-TEST_CASE("read a value from etcd")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("read a value from etcd") {
+  etcd::Client etcd(etcd_url);
   etcd::Response resp = etcd.get("/test/key1").get();
   CHECK("get" == resp.action());
   REQUIRE(resp.is_ok());
   REQUIRE(0 == resp.error_code());
   CHECK("42" == resp.value().as_string());
-  CHECK("" == etcd.get("/test").get().value().as_string()); // key points to a directory
+  CHECK("" == etcd.get("/test").get().value().as_string());  // key points to a
+                                                             // directory
 }
 
-TEST_CASE("simplified read")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("simplified read") {
+  etcd::Client etcd(etcd_url);
   CHECK("42" == etcd.get("/test/key1").get().value().as_string());
-  CHECK(100  == etcd.get("/test/key2").get().error_code()); // Key not found
-  CHECK(""  == etcd.get("/test/key2").get().value().as_string()); // Key not found
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.get("/test/key2").get().error_code());  // Key not found
+  CHECK("" ==
+        etcd.get("/test/key2").get().value().as_string());  // Key not found
 }
 
-TEST_CASE("modify a key")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
-  etcd::Response resp = etcd.modify("/test/key1", "43").get();
-  REQUIRE(0 == resp.error_code()); // overwrite
+TEST_CASE("modify a key") {
+  etcd::Client etcd(etcd_url);
+
+  // get
+  etcd::Response resp = etcd.get("/test/key1").get();
+  REQUIRE(resp.is_ok());
+  int64_t revision = resp.value().modified_index();
+  CHECK("42" == resp.value().as_string());
+
+  // modify
+  resp = etcd.modify("/test/key1", "43").get();
+  REQUIRE(0 == resp.error_code());  // overwrite
   CHECK("update" == resp.action());
-  CHECK(100 == etcd.modify("/test/key2", "43").get().error_code()); // Key not found
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.modify("/test/key2", "43").get().error_code());  // Key not found
   CHECK("43" == etcd.modify("/test/key1", "42").get().prev_value().as_string());
+
+  // check previous
+  resp = etcd.get("/test/key1", revision).get();
+  REQUIRE(resp.is_ok());
+  CHECK("42" == resp.value().as_string());
 }
 
-TEST_CASE("set a key")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("set a key") {
+  etcd::Client etcd(etcd_url);
   etcd::Response resp = etcd.set("/test/key1", "43").get();
-  REQUIRE(0  == resp.error_code()); // overwrite
+  REQUIRE(0 == resp.error_code());  // overwrite
   CHECK("set" == resp.action());
-  CHECK(0  == etcd.set("/test/key2", "43").get().error_code()); // create new
+  CHECK(0 == etcd.set("/test/key2", "43").get().error_code());  // create new
   CHECK("43" == etcd.set("/test/key2", "44").get().prev_value().as_string());
-  CHECK(""   == etcd.set("/test/key3", "44").get().prev_value().as_string());
-  CHECK(0  == etcd.set("/test",      "42").get().error_code()); // Not a file
+  CHECK("" == etcd.set("/test/key3", "44").get().prev_value().as_string());
+  CHECK(0 == etcd.set("/test", "42").get().error_code());  // Not a file
 
-  //set with ttl
-  resp = etcd.set("/test/key1", "50", 10).get();
-  REQUIRE(0  == resp.error_code()); // overwrite
+  // set with ttl
+  resp = etcd.set("/test/key1", "50").get();
+  REQUIRE(0 == resp.error_code());  // overwrite
   CHECK("set" == resp.action());
   CHECK("43" == resp.prev_value().as_string());
+  resp = etcd.get("/test/key1").get();
   CHECK("50" == resp.value().as_string());
-  CHECK( 0 < resp.value().lease());
+  CHECK(0 == resp.value().lease());
 }
 
-TEST_CASE("atomic compare-and-swap")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("atomic compare-and-swap") {
+  etcd::Client etcd(etcd_url);
   etcd.set("/test/key1", "42").wait();
 
   // modify success
   etcd::Response res = etcd.modify_if("/test/key1", "43", "42").get();
-  int index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
   CHECK("43" == res.value().as_string());
@@ -97,48 +113,53 @@ TEST_CASE("atomic compare-and-swap")
   // modify fails the second time
   res = etcd.modify_if("/test/key1", "44", "42").get();
   CHECK(!res.is_ok());
-  CHECK(101 == res.error_code());
-  CHECK("Compare failed" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 
-  // modify fails the second time
+  // modify fails on non-existing keys
   res = etcd.modify_if("/test/key222", "44", "42").get();
   CHECK(!res.is_ok());
-  CHECK(100 == res.error_code());
-  CHECK("Key not found" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 }
 
-TEST_CASE("delete a value")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("delete a value") {
+  etcd::Client etcd(etcd_url);
   etcd::Response resp = etcd.rm("/test/key11111").get();
   CHECK(!resp.is_ok());
-  CHECK(100 == resp.error_code());
-  CHECK("Key not found" == resp.error_message());
+  CHECK(etcd::ERROR_KEY_NOT_FOUND == resp.error_code());
+  CHECK("etcd-cpp-apiv3: key not found" == resp.error_message());
+
+  int64_t index = etcd.get("/test/key1").get().index();
+  int64_t create_index = etcd.get("/test/key1").get().value().created_index();
+  int64_t modify_index = etcd.get("/test/key1").get().value().modified_index();
+  int64_t version = etcd.get("/test/key1").get().value().version();
+
+  int head_index = etcd.head().get().index();
+  CHECK(index == head_index);
 
-  int index = etcd.get("/test/key1").get().index();
-  int create_index = etcd.get("/test/key1").get().value().created_index();
-  int modify_index = etcd.get("/test/key1").get().value().modified_index();
   resp = etcd.rm("/test/key1").get();
   CHECK("43" == resp.prev_value().as_string());
-  CHECK( "/test/key1" == resp.prev_value().key());
-  CHECK( create_index == resp.prev_value().created_index());
-  CHECK( modify_index == resp.prev_value().modified_index());
+  CHECK("/test/key1" == resp.prev_value().key());
+  CHECK(create_index == resp.prev_value().created_index());
+  CHECK(modify_index == resp.prev_value().modified_index());
+  CHECK(version == resp.prev_value().version());
   CHECK("delete" == resp.action());
-  CHECK( modify_index == resp.value().modified_index());
-  CHECK( create_index == resp.value().created_index());
-  CHECK("" == resp.value().as_string());
-  CHECK( "/test/key1" == resp.value().key());
+  CHECK(create_index == resp.value().created_index());
+  CHECK(modify_index == resp.value().modified_index());
+  CHECK(version == resp.value().version());
+  CHECK("43" == resp.value().as_string());
+  CHECK("/test/key1" == resp.value().key());
 }
 
-TEST_CASE("atomic compare-and-delete based on prevValue")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("atomic compare-and-delete based on prevValue") {
+  etcd::Client etcd(etcd_url);
   etcd.set("/test/key1", "42").wait();
 
   etcd::Response res = etcd.rm_if("/test/key1", "43").get();
   CHECK(!res.is_ok());
-  CHECK(101 == res.error_code());
-  CHECK("Compare failed" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 
   res = etcd.rm_if("/test/key1", "42").get();
   REQUIRE(res.is_ok());
@@ -146,15 +167,14 @@ TEST_CASE("atomic compare-and-delete based on prevValue")
   CHECK("42" == res.prev_value().as_string());
 }
 
-TEST_CASE("atomic compare-and-delete based on prevIndex")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
-  int index = etcd.set("/test/key1", "42").get().index();
+TEST_CASE("atomic compare-and-delete based on prevIndex") {
+  etcd::Client etcd(etcd_url);
+  int64_t index = etcd.set("/test/key1", "42").get().index();
 
   etcd::Response res = etcd.rm_if("/test/key1", index - 1).get();
   CHECK(!res.is_ok());
-  CHECK(101 == res.error_code());
-  CHECK("Compare failed" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 
   res = etcd.rm_if("/test/key1", index).get();
   REQUIRE(res.is_ok());
@@ -162,15 +182,13 @@ TEST_CASE("atomic compare-and-delete based on prevIndex")
   CHECK("42" == res.prev_value().as_string());
 }
 
-
-TEST_CASE("deep atomic compare-and-swap")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("deep atomic compare-and-swap") {
+  etcd::Client etcd(etcd_url);
   etcd.set("/test/key1", "42").wait();
 
   // modify success
   etcd::Response res = etcd.modify_if("/test/key1", "43", "42").get();
-  int index = res.index();
+  int64_t index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
   CHECK("43" == res.value().as_string());
@@ -178,8 +196,8 @@ TEST_CASE("deep atomic compare-and-swap")
   // modify fails the second time
   res = etcd.modify_if("/test/key1", "44", "42").get();
   CHECK(!res.is_ok());
-  CHECK(101 == res.error_code());
-  CHECK("Compare failed" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 
   // succes with the correct index
   res = etcd.modify_if("/test/key1", "44", index).get();
@@ -190,13 +208,65 @@ TEST_CASE("deep atomic compare-and-swap")
   // index changes so second modify fails
   res = etcd.modify_if("/test/key1", "45", index).get();
   CHECK(!res.is_ok());
-  CHECK(101 == res.error_code());
-  CHECK("Compare failed" == res.error_message());
+  CHECK(etcd::ERROR_COMPARE_FAILED == res.error_code());
+  CHECK("etcd-cpp-apiv3: compare failed" == res.error_message());
 }
 
-TEST_CASE("list a directory")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("using binary keys and values, raw char pointer doesn't work") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+  {
+    etcd::Response resp = etcd.put("/test/key1\0xyz", "42\0foo").get();
+    REQUIRE(resp.is_ok());
+  }
+  {
+    // should not exist
+    etcd::Response resp = etcd.get(std::string("/test/key1\0xyz", 14)).get();
+    CHECK(!resp.is_ok());
+    CHECK(etcd::ERROR_KEY_NOT_FOUND == resp.error_code());
+  }
+  {
+    // should exist
+    etcd::Response resp = etcd.get(std::string("/test/key1", 10)).get();
+    REQUIRE(resp.is_ok());
+    CHECK(std::string("42") == resp.value().as_string());
+    CHECK(std::string("42\0foo", 6) != resp.value().as_string());
+  }
+  {
+    // should exist, but different value
+    etcd::Response resp = etcd.get("/test/key1\0xyz").get();
+    REQUIRE(resp.is_ok());
+    CHECK(std::string("42") == resp.value().as_string());
+    CHECK(std::string("42\0foo", 6) != resp.value().as_string());
+  }
+}
+
+TEST_CASE("using binary keys and values, std::string is ok for \\0") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+  {
+    etcd::Response resp =
+        etcd.put(std::string("/test/key1\0xyz", 14), std::string("42\0foo", 6))
+            .get();
+    REQUIRE(resp.is_ok());
+  }
+  {
+    // should not exist
+    etcd::Response resp = etcd.get("/test/key1").get();
+    CHECK(!resp.is_ok());
+    CHECK(etcd::ERROR_KEY_NOT_FOUND == resp.error_code());
+  }
+  {
+    // should exist
+    etcd::Response resp = etcd.get(std::string("/test/key1\0xyz", 14)).get();
+    REQUIRE(resp.is_ok());
+    CHECK(std::string("42") != resp.value().as_string());
+    CHECK(std::string("42\0foo", 6) == resp.value().as_string());
+  }
+}
+
+TEST_CASE("list a directory") {
+  etcd::Client etcd(etcd_url);
   CHECK(0 == etcd.ls("/test/new_dir").get().keys().size());
 
   etcd.set("/test/new_dir/key1", "value1").wait();
@@ -223,12 +293,16 @@ TEST_CASE("list a directory")
 
   CHECK(0 == etcd.ls("/test/new_dir/key1").get().error_code());
 
+  // list with empty prefix
+  resp = etcd.ls("").get();
+  CHECK(0 == resp.error_code());
+  CHECK(0 < resp.keys().size());
+
   CHECK(etcd.rmdir("/test/new_dir", true).get().is_ok());
 }
 
-TEST_CASE("list by range")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("list by range") {
+  etcd::Client etcd(etcd_url);
   CHECK(0 == etcd.ls("/test/new_dir").get().keys().size());
 
   etcd.set("/test/new_dir/key0", "value0").wait();
@@ -237,13 +311,15 @@ TEST_CASE("list by range")
   etcd.set("/test/new_dir/key3", "value3").wait();
   etcd.set("/test/new_dir/key4", "value4").wait();
 
-  etcd::Response resp1 = etcd.ls("/test/new_dir/key1", "/test/new_dir/key3").get();
+  etcd::Response resp1 =
+      etcd.ls("/test/new_dir/key1", "/test/new_dir/key3").get();
   REQUIRE(resp1.is_ok());
   CHECK("get" == resp1.action());
   REQUIRE(2 == resp1.keys().size());
   REQUIRE(2 == resp1.values().size());
 
-  etcd::Response resp2 = etcd.ls("/test/new_dir/key1", "/test/new_dir/key4").get();
+  etcd::Response resp2 =
+      etcd.ls("/test/new_dir/key1", "/test/new_dir/key4").get();
   REQUIRE(resp2.is_ok());
   CHECK("get" == resp2.action());
   REQUIRE(3 == resp2.keys().size());
@@ -255,7 +331,10 @@ TEST_CASE("list by range")
   REQUIRE(4 == resp3.keys().size());
   REQUIRE(4 == resp3.values().size());
 
-  etcd::Response resp4 = etcd.ls("/test/new_dir/key1", etcdv3::detail::string_plus_one("/test/new_dir/key")).get();
+  etcd::Response resp4 =
+      etcd.ls("/test/new_dir/key1",
+              etcdv3::detail::string_plus_one("/test/new_dir/key"))
+          .get();
   REQUIRE(resp4.is_ok());
   CHECK("get" == resp4.action());
   REQUIRE(4 == resp4.keys().size());
@@ -266,19 +345,47 @@ TEST_CASE("list by range")
   CHECK(etcd.rmdir("/test/new_dir", true).get().is_ok());
 }
 
-TEST_CASE("delete a directory")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("list by range, w/o values") {
+  etcd::Client etcd(etcd_url);
+  CHECK(0 == etcd.ls("/test/new_dir").get().keys().size());
+
+  etcd.set("/test/new_dir/key0", "value0").wait();
+  etcd.set("/test/new_dir/key1", "value1").wait();
+  etcd.set("/test/new_dir/key2", "value2").wait();
+  etcd.set("/test/new_dir/key3", "value3").wait();
+  etcd.set("/test/new_dir/key4", "value4").wait();
+
+  etcd::Response resp1 =
+      etcd.ls("/test/new_dir/key1", "/test/new_dir/key2").get();
+  REQUIRE(resp1.is_ok());
+  CHECK("get" == resp1.action());
+  REQUIRE(1 == resp1.keys().size());
+  REQUIRE(1 == resp1.values().size());
+  REQUIRE(resp1.values()[0].as_string() == "value1");
+
+  etcd::Response resp2 =
+      etcd.keys("/test/new_dir/key1", "/test/new_dir/key2").get();
+  REQUIRE(resp1.is_ok());
+  CHECK("get" == resp2.action());
+  REQUIRE(1 == resp2.keys().size());
+  REQUIRE(1 == resp2.values().size());
+  REQUIRE(resp2.values()[0].as_string() == "");
+
+  CHECK(etcd.rmdir("/test/new_dir", true).get().is_ok());
+}
+
+TEST_CASE("delete a directory") {
+  etcd::Client etcd(etcd_url);
 
   etcd.set("/test/new_dir/key1", "value1").wait();
   etcd.set("/test/new_dir/key2", "value2").wait();
   etcd.set("/test/new_dir/key3", "value3").wait();
 
-  CHECK(100 == etcd.rmdir("/test/new_dir").get().error_code()); // key not found
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.rmdir("/test/new_dir").get().error_code());  // key not found
   etcd::Response resp = etcd.ls("/test/new_dir").get();
 
   resp = etcd.rmdir("/test/new_dir", true).get();
-  int index = resp.index();
   CHECK("delete" == resp.action());
   REQUIRE(3 == resp.keys().size());
   CHECK("/test/new_dir/key1" == resp.key(0));
@@ -286,23 +393,35 @@ TEST_CASE("delete a directory")
   CHECK("value1" == resp.value(0).as_string());
   CHECK("value2" == resp.value(1).as_string());
 
-
   resp = etcd.rmdir("/test/dirnotfound", true).get();
   CHECK(!resp.is_ok());
-  CHECK(100 == resp.error_code());
-  CHECK("Key not found" == resp.error_message());
+  CHECK(etcd::ERROR_KEY_NOT_FOUND == resp.error_code());
+  CHECK("etcd-cpp-apiv3: key not found" == resp.error_message());
 
   resp = etcd.rmdir("/test/new_dir", false).get();
   CHECK(!resp.is_ok());
-  CHECK(100 == resp.error_code());
-  CHECK("Key not found" == resp.error_message());
+  CHECK(etcd::ERROR_KEY_NOT_FOUND == resp.error_code());
+  CHECK("etcd-cpp-apiv3: key not found" == resp.error_message());
 }
 
-TEST_CASE("delete by range")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("delete all keys with rmdir(\"\", true)") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("", true).wait();
 
-  CHECK(100 == etcd.rmdir("/test/new_dir").get().error_code()); // key not found
+  etcd.set("/test/new_dir/key1", "value1").wait();
+  etcd.set("/test/new_dir/key2", "value2").wait();
+  etcd.set("/test/new_dir/key3", "value3").wait();
+
+  auto resp = etcd.rmdir("", true).get();
+  CHECK(resp.is_ok());
+  CHECK(resp.values().size() == 3);
+}
+
+TEST_CASE("delete by range") {
+  etcd::Client etcd(etcd_url);
+
+  CHECK(etcd::ERROR_KEY_NOT_FOUND ==
+        etcd.rmdir("/test/new_dir").get().error_code());  // key not found
   etcd::Response resp = etcd.ls("/test/new_dir").get();
 
   etcd.set("/test/new_dir/key1", "value1").wait();
@@ -319,9 +438,8 @@ TEST_CASE("delete by range")
   CHECK("value2" == resp.value(1).as_string());
 }
 
-TEST_CASE("wait for a value change")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("wait for a value change") {
+  etcd::Client etcd(etcd_url);
   etcd.set("/test/key1", "42").wait();
 
   pplx::task<etcd::Response> res = etcd.watch("/test/key1");
@@ -337,9 +455,8 @@ TEST_CASE("wait for a value change")
   CHECK("42" == res.get().prev_value().as_string());
 }
 
-TEST_CASE("wait for a directory change")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("wait for a directory change") {
+  etcd::Client etcd(etcd_url);
 
   pplx::task<etcd::Response> res = etcd.watch("/test", true);
   CHECK(!res.is_done());
@@ -364,16 +481,18 @@ TEST_CASE("wait for a directory change")
   CHECK("45" == res2.get().value().as_string());
 }
 
-TEST_CASE("watch changes in the past")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("watch changes in the past") {
+  etcd::Client etcd(etcd_url);
   REQUIRE(0 == etcd.rmdir("/test", true).get().error_code());
-  int index = etcd.set("/test/key1", "42").get().index();
+  int64_t index = etcd.set("/test/key1", "42").get().index();
 
   etcd.set("/test/key1", "43").wait();
   etcd.set("/test/key1", "44").wait();
   etcd.set("/test/key1", "45").wait();
 
+  int64_t head_index = etcd.head().get().index();
+  CHECK(index + 3 == head_index);
+
   etcd::Response res = etcd.watch("/test/key1", ++index).get();
   CHECK("set" == res.action());
   CHECK("43" == res.value().as_string());
@@ -388,17 +507,19 @@ TEST_CASE("watch changes in the past")
   CHECK("45" == res.value().as_string());
 }
 
-TEST_CASE("watch range changes in the past")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("watch range changes in the past") {
+  etcd::Client etcd(etcd_url);
   REQUIRE(0 == etcd.rmdir("/test", true).get().error_code());
-  int index = etcd.set("/test/key1", "42").get().index();
+  int64_t index = etcd.set("/test/key1", "42").get().index();
 
   etcd.set("/test/key1", "43").wait();
   etcd.set("/test/key2", "44").wait();
   etcd.set("/test/key3", "45").wait();
   etcd.set("/test/key4", "45").wait();
 
+  int64_t head_index = etcd.head().get().index();
+  CHECK(index + 4 == head_index);
+
   etcd::Response res;
 
   res = etcd.watch("/test/key1", "/test/key4", index).get();
@@ -412,98 +533,120 @@ TEST_CASE("watch range changes in the past")
 }
 
 TEST_CASE("watch multiple keys and use promise") {
-  etcd::Client etcd("http://127.0.0.1:2379");
+  etcd::Client etcd(etcd_url);
 
-  int start_index = etcd.set("/test/key1", "value1").get().index();
+  int64_t start_index = etcd.set("/test/key1", "value1").get().index();
   etcd.set("/test/key2", "value2").get();
 
-  pplx::task<size_t> res = etcd.watch("/test", start_index, true)
-    .then([](pplx::task<etcd::Response> const &resp_task) -> size_t {
-      auto const &resp = resp_task.get();
-      return resp.events().size();
-    });
+  pplx::task<size_t> res =
+      etcd.watch("/test", start_index, true)
+          .then([](pplx::task<etcd::Response> const& resp_task) -> size_t {
+            auto const& resp = resp_task.get();
+            return resp.events().size();
+          });
   size_t event_size = res.get();
   CHECK(2 == event_size);
 }
 
-TEST_CASE("lease grant")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("lease grant") {
+  etcd::Client etcd(etcd_url);
   etcd::Response res = etcd.leasegrant(60).get();
   REQUIRE(res.is_ok());
   CHECK(60 == res.value().ttl());
-  CHECK(0 <  res.value().lease());
+  CHECK(0 < res.value().lease());
   int64_t leaseid = res.value().lease();
 
   res = etcd.set("/test/key1", "43", leaseid).get();
-  REQUIRE(0  == res.error_code()); // overwrite
+  REQUIRE(0 == res.error_code());  // overwrite
   CHECK("set" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  res = etcd.get("/test/key1").get();
+  REQUIRE(0 == res.error_code());  // overwrite
+  CHECK(leaseid == res.value().lease());
 
-  //change leaseid
+  // change with lease id
   res = etcd.leasegrant(10).get();
   leaseid = res.value().lease();
   res = etcd.set("/test/key1", "43", leaseid).get();
-  REQUIRE(0  == res.error_code()); // overwrite
+  REQUIRE(0 == res.error_code());  // overwrite
   CHECK("set" == res.action());
+  res = etcd.get("/test/key1").get();
+  REQUIRE(0 == res.error_code());  // overwrite
   CHECK(leaseid == res.value().lease());
 
-  //failure to attach lease id
-  res = etcd.set("/test/key1", "43", leaseid+1).get();
+  // failure to attach lease id
+  res = etcd.set("/test/key1", "43", leaseid + 1).get();
   REQUIRE(!res.is_ok());
-  REQUIRE(5  == res.error_code()); 
+  REQUIRE(5 == res.error_code());
   CHECK("etcdserver: requested lease not found" == res.error_message());
 
   res = etcd.modify("/test/key1", "44", leaseid).get();
-  REQUIRE(0  == res.error_code()); // overwrite
+  REQUIRE(0 == res.error_code());  // overwrite
   CHECK("update" == res.action());
-  CHECK(leaseid ==  res.value().lease());
-  CHECK("44" ==  res.value().as_string());
+  CHECK(leaseid == res.value().lease());
+  CHECK("44" == res.value().as_string());
 
-  //failure to attach lease id
-  res = etcd.modify("/test/key1", "45", leaseid+1).get();
+  // failure to attach invalid lease id
+  res = etcd.modify("/test/key1", "45", leaseid + 1).get();
   REQUIRE(!res.is_ok());
-  REQUIRE(5  == res.error_code()); 
+  REQUIRE(5 == res.error_code());
   CHECK("etcdserver: requested lease not found" == res.error_message());
 
   res = etcd.modify_if("/test/key1", "45", "44", leaseid).get();
-  int index = res.index();
+  int64_t index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
   CHECK("45" == res.value().as_string());
 
-  //failure to attach lease id
-  res = etcd.modify_if("/test/key1", "46", "45", leaseid+1).get();
+  // failure to attach invalid lease id
+  res = etcd.modify_if("/test/key1", "46", "45", leaseid + 1).get();
   REQUIRE(!res.is_ok());
-  REQUIRE(5  == res.error_code()); 
+  REQUIRE(5 == res.error_code());
   CHECK("etcdserver: requested lease not found" == res.error_message());
 
-  // succes with the correct index
+  // succes with the correct index & lease id
   res = etcd.modify_if("/test/key1", "44", index, leaseid).get();
   index = res.index();
   REQUIRE(res.is_ok());
   CHECK("compareAndSwap" == res.action());
   CHECK("44" == res.value().as_string());
 
-  res = etcd.modify_if("/test/key1", "44", index, leaseid+1).get();
+  res = etcd.modify_if("/test/key1", "44", index, leaseid + 1).get();
   REQUIRE(!res.is_ok());
-  REQUIRE(5  == res.error_code()); 
+  REQUIRE(5 == res.error_code());
   CHECK("etcdserver: requested lease not found" == res.error_message());
 
   res = etcd.add("/test/key11111", "43", leaseid).get();
-  REQUIRE(0  == res.error_code()); 
+  REQUIRE(0 == res.error_code());
   CHECK("create" == res.action());
-  CHECK(leaseid ==  res.value().lease());
+  CHECK(leaseid == res.value().lease());
 
-  //failure to attach lease id
-  res = etcd.set("/test/key11111", "43", leaseid+1).get();
+  // failure to attach invalid lease id
+  res = etcd.set("/test/key11111", "43", leaseid + 1).get();
   REQUIRE(!res.is_ok());
-  REQUIRE(5  == res.error_code()); 
+  REQUIRE(5 == res.error_code());
   CHECK("etcdserver: requested lease not found" == res.error_message());
 }
 
-TEST_CASE("cleanup")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("lease list") {
+  etcd::Client etcd(etcd_url);
+  etcd::Response res = etcd.leasegrant(60).get();
+  REQUIRE(res.is_ok());
+  CHECK(60 == res.value().ttl());
+  CHECK(0 < res.value().lease());
+  int64_t leaseid = res.value().lease();
+
+  etcd::Response leasesresp = etcd.leases().get();
+  if (leasesresp.is_ok()) {
+    REQUIRE(leasesresp.is_ok());
+    auto const& leases = leasesresp.leases();
+    REQUIRE(leases.size() > 0);
+    CHECK(std::find(leases.begin(), leases.end(), leaseid) != leases.end());
+  } else {
+    REQUIRE(leasesresp.error_code() == etcdv3::ERROR_GRPC_UNIMPLEMENTED);
+  }
+}
+
+TEST_CASE("cleanup") {
+  etcd::Client etcd(etcd_url);
   REQUIRE(0 == etcd.rmdir("/test", true).get().error_code());
 }

tst/ForkTest.cpp

@@ -0,0 +1,44 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <unistd.h>
+
+#include <atomic>
+#include <chrono>
+#include <cstdlib>
+#include <iostream>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+TEST_CASE("fork: set in child and get from self") {
+  pid_t pid = fork();
+  REQUIRE(pid >= 0);
+
+  if (pid == 0) {
+    // child
+    etcd::Client etcd(etcd_url);
+    etcd.set("/test/fork-key1", "fork: abcdefgh").wait();
+    std::cout << "child: set finished ..." << std::endl;
+  } else {
+    // self
+    etcd::Client etcd(etcd_url);
+    size_t check = 0;
+    while (check < 10) {
+      auto resp = etcd.get("/test/fork-key1").get();
+      if (!resp.is_ok()) {
+        check += 1;
+        std::this_thread::sleep_for(std::chrono::seconds(1));
+        continue;
+      } else {
+        CHECK(resp.value().as_string() == "fork: abcdefgh");
+        break;
+      }
+    }
+    std::cout << "self: get finished ..." << std::endl;
+  }
+}

tst/KeepAliveTest.cpp

@@ -0,0 +1,81 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <chrono>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+#include "etcd/Response.hpp"
+#include "etcd/SyncClient.hpp"
+#include "etcd/Value.hpp"
+
+static std::string etcd_uri =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+TEST_CASE("keepalive revoke and check if alive") {
+  etcd::Client etcd(etcd_uri);
+
+  // create a lease with 30 seconds TTL
+  auto keepalive = etcd.leasekeepalive(30).get();
+  auto lease_id = keepalive->Lease();
+
+  // revoke the lease before it reaches its TTL
+  etcd.leaserevoke(lease_id).wait();
+
+  // retrieves its TTL again, and it is now -1
+  auto response = etcd.leasetimetolive(lease_id).get();
+  REQUIRE(response.value().ttl() == -1);
+
+  // shorter than the TLL, or no sleep
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+
+  // expect keep_alive->Check() to throw exception
+#ifndef _ETCD_NO_EXCEPTIONS
+  REQUIRE_THROWS(keepalive->Check());
+#endif
+}
+
+TEST_CASE("keepalive won't expire") {
+  etcd::Client etcd(etcd_uri);
+
+  const int64_t ttl = 3;
+  const std::string key = "key";
+  const std::string meta_str = "meta ....";
+
+  etcd::Response resp = etcd.leasegrant(ttl).get();
+  auto lease_id = resp.value().lease();
+  etcd.add(key, meta_str, lease_id);
+
+#ifndef _ETCD_NO_EXCEPTIONS
+  std::function<void(std::exception_ptr)> handler =
+      [](std::exception_ptr eptr) {
+        try {
+          if (eptr) {
+            std::rethrow_exception(eptr);
+          }
+        } catch (const std::runtime_error& e) {
+          std::cerr << "Connection failure \"" << e.what() << "\"\n";
+        } catch (const std::out_of_range& e) {
+          std::cerr << "Lease expiry \"" << e.what() << "\"\n";
+        }
+      };
+#else
+  std::function<void(std::exception_ptr)> handler;
+#endif
+  etcd::KeepAlive keepalive(etcd, handler, ttl, lease_id);
+  std::this_thread::sleep_for(std::chrono::seconds(5));
+}
+
+TEST_CASE("keepalive auto-grant") {
+  etcd::Client etcd(etcd_uri);
+
+  // create a lease without pre-granted lease id
+  auto keepalive = std::make_shared<etcd::KeepAlive>(etcd, 10 /* ttl */);
+  auto lease_id = keepalive->Lease();
+  REQUIRE(lease_id != 0);
+
+  // sleep for a while, and cancel
+  std::this_thread::sleep_for(std::chrono::seconds(5));
+  keepalive->Cancel();
+}

tst/LockTest.cpp

@@ -10,10 +10,11 @@
 #include "etcd/Client.hpp"
 #include "etcd/KeepAlive.hpp"
 
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
 
-TEST_CASE("lock and unlock")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("lock and unlock") {
+  etcd::Client etcd(etcd_url);
 
   // lock
   etcd::Response resp1 = etcd.lock("/test/abcd").get();
@@ -28,9 +29,8 @@ TEST_CASE("lock and unlock")
   REQUIRE(0 == resp2.error_code());
 }
 
-TEST_CASE("double lock will fail")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("double lock will fail") {
+  etcd::Client etcd(etcd_url);
 
   // lock
   etcd::Response resp1 = etcd.lock("/test/abcd").get();
@@ -41,7 +41,7 @@ TEST_CASE("double lock will fail")
   bool first_lock_release = false;
   std::string lock_key = resp1.lock_key();
 
-  auto second_lock_thr = std::thread([&](){
+  auto second_lock_thr = std::thread([&]() {
     // lock again
     etcd::Response resp2 = etcd.lock("/test/abcd").get();
     CHECK("lock" == resp2.action());
@@ -61,11 +61,13 @@ TEST_CASE("double lock will fail")
     REQUIRE(0 == resp3.error_code());
 
     // create a duration
-    first_lock_release = true;
-    // using a duration longer than default lease TTL for lock (see: DEFAULT_LEASE_TTL_FOR_LOCK)
+    // using a duration longer than default lease TTL for lock (see:
+    // DEFAULT_LEASE_TTL_FOR_LOCK)
     std::this_thread::sleep_for(std::chrono::seconds(15));
 
     // unlock the first lock
+    first_lock_release = true;
+
     etcd::Response resp4 = etcd.unlock(lock_key).get();
     CHECK("unlock" == resp4.action());
     REQUIRE(resp4.is_ok());
@@ -82,22 +84,54 @@ TEST_CASE("double lock will fail")
   REQUIRE(0 == resp5.error_code());
 }
 
-TEST_CASE("lock using lease")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("lock could be timeout") {
+  etcd::Client etcd(etcd_url);
+
+  // setup the timeout
+  etcd.set_grpc_timeout(std::chrono::seconds(5));
+
+  // lock
+  etcd::Response resp1 = etcd.lock("/test/abcd").get();
+  CHECK("lock" == resp1.action());
+  REQUIRE(resp1.is_ok());
+  REQUIRE(0 == resp1.error_code());
+
+  auto lock_in_another_thread = std::thread([&]() {
+    // lock again
+    etcd::Response resp2 = etcd.lock("/test/abcd").get();
+    CHECK("lock" == resp2.action());
+    REQUIRE(resp2.is_grpc_timeout());
+  });
+
+  lock_in_another_thread.join();
+
+  // cleanup: unlock the second lock
+  etcd::Response resp5 = etcd.unlock(resp1.lock_key()).get();
+  CHECK("unlock" == resp5.action());
+  REQUIRE(resp5.is_ok());
+  REQUIRE(0 == resp5.error_code());
+}
+
+TEST_CASE("lock using lease") {
+  etcd::Client etcd(etcd_url);
 
   bool failed = false;
 
-  std::function<void (std::exception_ptr)> handler = [&failed](std::exception_ptr eptr) {
-    try {
-        if (eptr) {
+#ifndef _ETCD_NO_EXCEPTIONS
+  std::function<void(std::exception_ptr)> handler =
+      [&failed](std::exception_ptr eptr) {
+        try {
+          if (eptr) {
             std::rethrow_exception(eptr);
+          }
+        } catch (const std::exception& e) {
+          std::cerr << "Caught exception \"" << e.what() << "\"\n";
+          failed = true;
         }
-    } catch(const std::exception& e) {
-        std::cerr << "Caught exception \"" << e.what() << "\"\n";
-        failed = true;
-    }
-  };
+      };
+#else
+  std::function<void(std::exception_ptr)> handler;
+#endif
 
   // with handler
   {
@@ -166,24 +200,61 @@ TEST_CASE("lock using lease")
   }
 }
 
-TEST_CASE("concurrent lock & unlock")
-{
-  etcd::Client etcd("http://127.0.0.1:2379");
+TEST_CASE("concurrent lock & unlock") {
+  etcd::Client etcd(etcd_url);
   std::string const lock_key = "/test/test_key";
 
-  constexpr size_t trials = 128;
+  constexpr size_t trials = 192;
 
-  std::function<void(std::string const &, const size_t)> locker = [&etcd](std::string const &key, const size_t index) {
-    std::cout << "start lock for " << index << std::endl;
-    auto resp = etcd.lock(key).get();
-    std::cout << "lock for " << index << " is ok, start sleep: ..." << resp.error_message() << std::endl;
-    REQUIRE(resp.is_ok());
-    std::srand(index);
-    size_t time_to_sleep = 1;
-    std::this_thread::sleep_for(std::chrono::seconds(time_to_sleep));
-    REQUIRE(etcd.unlock(resp.lock_key()).get().is_ok());
-    std::cout << "thread " << index << " been unlocked" << std::endl;
-  };
+  std::function<void(std::string const&, const size_t)> locker =
+      [&etcd](std::string const& key, const size_t index) {
+        std::cout << "start lock for " << key << ", index is " << index
+                  << std::endl;
+        auto resp = etcd.lock(key).get();
+        std::cout << "lock for " << index << " is ok, starts sleeping: ..."
+                  << resp.error_message() << std::endl
+                  << std::flush;
+        REQUIRE(resp.is_ok());
+        std::srand(index);
+        size_t time_to_sleep = 1;
+        std::this_thread::sleep_for(std::chrono::seconds(time_to_sleep));
+        std::cout << "lock for " << index << " resumes from sleep: ..."
+                  << resp.error_message() << std::endl
+                  << std::flush;
+        REQUIRE(etcd.unlock(resp.lock_key()).get().is_ok());
+        std::cout << "thread " << index << " been unlocked" << std::endl
+                  << std::flush;
+      };
+
+  std::vector<std::thread> locks(trials);
+  for (size_t index = 0; index < trials; ++index) {
+    locks[index] = std::thread(locker, lock_key, index);
+  }
+
+  for (size_t index = 0; index < trials; ++index) {
+    locks[index].join();
+  }
+}
+
+TEST_CASE("concurrent lock & unlock with a put in between") {
+  etcd::Client etcd(etcd_url);
+  std::string const lock_key = "/test/test_key";
+
+  constexpr size_t trials = 128;
+
+  std::function<void(std::string const&, const size_t)> locker =
+      [&etcd](std::string const& key, const size_t index) {
+        std::cout << "start lock for " << index << std::endl;
+        auto resp = etcd.lock(key, true).get();
+        std::cout << "lock for " << index << " is ok, start put and unlock: ..."
+                  << resp.error_message() << std::endl;
+        REQUIRE(resp.is_ok());
+        auto put_resp =
+            etcd.put("/test/test_put", "hello" + std::to_string(index)).get();
+        REQUIRE(put_resp.is_ok());
+        REQUIRE(etcd.unlock(resp.lock_key()).get().is_ok());
+        std::cout << "thread " << index << " been unlocked" << std::endl;
+      };
 
   std::vector<std::thread> locks(trials);
   for (size_t index = 0; index < trials; ++index) {

tst/MemLeakTest.cpp

@@ -0,0 +1,85 @@
+// See also: https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3/issues/86
+
+#include <future>
+#include <memory>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+class DistributedLock {
+ public:
+  DistributedLock(const std::string& lock_name, uint timeout = 0);
+  ~DistributedLock() noexcept;
+  inline bool lock_acquired() { return _acquired; }
+
+ private:
+  bool _acquired = false;
+  std::string _lock_key;
+  std::unique_ptr<::etcd::Client> _etcd_client;
+};
+
+DistributedLock::DistributedLock(const std::string& lock_name, uint timeout) {
+  _etcd_client = std::unique_ptr<etcd::Client>(new etcd::Client(etcd_url));
+
+  if (timeout == 0) {
+    etcd::Response resp = _etcd_client->lock(lock_name).get();
+    if (resp.is_ok()) {
+      _lock_key = resp.lock_key();
+      _acquired = true;
+    }
+  } else {
+    std::future<etcd::Response> future = std::async(std::launch::async, [&]() {
+      etcd::Response resp = _etcd_client->lock(lock_name).get();
+      return resp;
+    });
+
+    std::future_status status = future.wait_for(std::chrono::seconds(timeout));
+    if (status == std::future_status::ready) {
+      auto resp = future.get();
+      if (resp.is_ok()) {
+        _lock_key = resp.lock_key();
+        _acquired = true;
+      }
+    } else if (status == std::future_status::timeout) {
+      std::cerr << "failed to acquire distributed because of lock timeout"
+                << std::endl;
+    } else {
+      std::cerr << "failed to acquire distributed lock" << std::endl;
+    }
+  }
+}
+
+DistributedLock::~DistributedLock() noexcept {
+  if (!_acquired) {
+    return;
+  }
+
+  auto resp = _etcd_client->unlock(_lock_key).get();
+  if (!resp.is_ok()) {
+    std::cout << resp.error_code() << std::endl;
+  }
+}
+
+int main() {
+  int i = 0, t = 0;
+  while (t < 100 /* update this value to make it run for longer */) {
+    {
+      DistributedLock lock(std::to_string(i), 0);
+      if (!lock.lock_acquired()) {
+        std::cerr << "failed to acquire lock" << std::endl;
+      }
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    }
+    ++i;
+    ++t;
+    if (i == 10) {
+      i = 0;
+    }
+    if (t % 10 == 0) {
+      std::cout << "round: i = " << i << ", t = " << t << std::endl;
+    }
+  }
+}

tst/MemLeakWatcherTest.cpp

@@ -0,0 +1,60 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <future>
+#include <memory>
+
+#include "etcd/Client.hpp"
+#include "etcd/KeepAlive.hpp"
+#include "etcd/Watcher.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+static std::atomic_int watcher_called;
+
+void print_response(etcd::Response const& resp) { watcher_called.fetch_add(1); }
+
+/**
+ * @brief emulate the behavior of creating watcher many times:
+ *
+ * 1. create a watcher
+ * 2. change a value
+ * 3. cancel the watcher
+ */
+void watch_once(etcd::Client& client, std::unique_ptr<etcd::Watcher>& watcher,
+                const size_t round) {
+  const std::string my_prefix = "/test";
+  const std::string my_key = my_prefix + "/foo";
+  watcher.reset(new etcd::Watcher(client, my_prefix, print_response, true));
+
+  int k = watcher_called.load();
+  client.set(my_key, "bar-" + std::to_string(round)).wait();
+  while (true) {
+    if (watcher_called.load() > k) {
+      break;
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+
+  // cancel the watcher
+  watcher->Cancel();
+}
+
+TEST_CASE("watch shouldn't leak memory") {
+  watcher_called.store(0);
+
+  // issue some changes to see if the watcher works
+  etcd::Client client(etcd_url);
+  std::unique_ptr<etcd::Watcher> watcher;
+  for (int round = 0;
+       round < 10 /* update this value to make it run for longer */; ++round) {
+    if (round % 50 == 0) {
+      std::cout << "starting round " << round << std::endl;
+    }
+    watch_once(client, watcher, round);
+  }
+
+  std::cout << "watcher been called for " << watcher_called.load() << " times"
+            << std::endl;
+}

tst/RewatchTest.cpp

@@ -0,0 +1,133 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <chrono>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/SyncClient.hpp"
+#include "etcd/Watcher.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+static int watcher_called = 0;
+
+void print_response(etcd::Response const& resp) {
+  ++watcher_called;
+  std::cout << "print response called" << std::endl;
+  if (resp.error_code()) {
+    std::cout << resp.error_code() << ": " << resp.error_message() << std::endl;
+  } else {
+    std::cout << resp.action() << " " << resp.value().as_string() << std::endl;
+    std::cout << "Previous value: " << resp.prev_value().as_string()
+              << std::endl;
+
+    std::cout << "Events size: " << resp.events().size() << std::endl;
+    for (auto const& ev : resp.events()) {
+      std::cout << "Value change in events: "
+                << static_cast<int>(ev.event_type())
+                << ", prev kv = " << ev.prev_kv().key() << " -> "
+                << ev.prev_kv().as_string() << ", kv = " << ev.kv().key()
+                << " -> " << ev.kv().as_string() << std::endl;
+    }
+  }
+}
+
+void wait_for_connection(std::string endpoints) {
+  // wait until the client connects to etcd server
+  while (true) {
+#ifndef _ETCD_NO_EXCEPTIONS
+    try {
+      etcd::Client client(endpoints);
+      if (client.head().get().is_ok()) {
+        break;
+      }
+    } catch (...) {
+      // pass
+    }
+#else
+    etcd::Client client(endpoints);
+    if (client.head().get().is_ok()) {
+      break;
+    }
+#endif
+    sleep(1);
+  }
+}
+
+void initialize_watcher(const std::string& endpoints, const std::string& prefix,
+                        std::function<void(etcd::Response)> callback,
+                        std::shared_ptr<etcd::Watcher>& watcher) {
+  // wait until the endpoints turn to be available
+  wait_for_connection(endpoints);
+  etcd::Client client(endpoints);
+
+  // Check if the failed one has been cancelled first
+  if (watcher && watcher->Cancelled()) {
+    std::cout << "watcher's reconnect loop been cancelled" << std::endl;
+    return;
+  }
+  watcher.reset(new etcd::Watcher(client, prefix, callback, true));
+
+  // Note that lambda requires `mutable`qualifier.
+  watcher->Wait(
+      [endpoints, prefix, callback,
+       /* By reference for renewing */ &watcher](bool cancelled) mutable {
+        if (cancelled) {
+          std::cout << "watcher's reconnect loop stopped as been cancelled"
+                    << std::endl;
+          return;
+        }
+        initialize_watcher(endpoints, prefix, callback, watcher);
+      });
+}
+
+TEST_CASE("watch should can be re-established") {
+  const std::string my_prefix = "/test";
+
+  // the watcher initialized in this way will auto re-connect to etcd
+  std::shared_ptr<etcd::Watcher> watcher;
+  initialize_watcher(etcd_url, my_prefix, print_response, watcher);
+
+  // issue some changes to see if the watcher works
+  for (int round = 0; round < 100000; ++round) {
+#ifndef _ETCD_NO_EXCEPTIONS
+    try {
+      etcd::Client client(etcd_url);
+      auto response =
+          client.set(my_prefix + "/foo", "bar-" + std::to_string(round)).get();
+    } catch (...) {
+      // pass
+    }
+#else
+    etcd::Client client(etcd_url);
+    auto response =
+        client.set(my_prefix + "/foo", "bar-" + std::to_string(round)).get();
+#endif
+
+    std::this_thread::sleep_for(std::chrono::seconds(2));
+  }
+
+  // cancel the worker
+  watcher->Cancel();
+
+  // the watcher has been cancelled and shouldn't work anymore
+  for (int round = 10; round < 20; ++round) {
+#ifndef _ETCD_NO_EXCEPTIONS
+    try {
+      etcd::Client client(etcd_url);
+      auto response =
+          client.set(my_prefix + "/foo", "bar-" + std::to_string(round)).get();
+    } catch (...) {
+      // pass
+    }
+#else
+    etcd::Client client(etcd_url);
+    auto response =
+        client.set(my_prefix + "/foo", "bar-" + std::to_string(round)).get();
+#endif
+
+    std::this_thread::sleep_for(std::chrono::seconds(2));
+  }
+}

tst/SecurityChannelTest.cpp

@@ -9,44 +9,50 @@ static std::string ca = "security-config/certs/ca.crt";
 static std::string cert = "security-config/certs/etcd0.example.com.crt";
 static std::string key = "security-config/private/etcd0.example.com.key";
 
-TEST_CASE("setup with auth")
-{
-  etcd::Client *etcd = etcd::Client::WithSSL("https://127.0.0.1:2379", ca, cert, key);
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("https://127.0.0.1:2379");
+
+TEST_CASE("setup with auth") {
+  etcd::Client* etcd = etcd::Client::WithSSL(etcd_url, ca, cert, key);
   etcd->rmdir("/test", true).wait();
 }
 
-TEST_CASE("add a new key after authenticate")
-{
-  etcd::Client *etcd = etcd::Client::WithSSL("https://127.0.0.1:2379", ca, cert, key);
+TEST_CASE("add a new key after authenticate") {
+  etcd::Client* etcd = etcd::Client::WithSSL(etcd_url, ca, cert, key);
   etcd->rmdir("/test", true).wait();
   etcd::Response resp = etcd->add("/test/key1", "42").get();
   REQUIRE(0 == resp.error_code());
   CHECK("create" == resp.action());
-  etcd::Value const & val = resp.value();
+  etcd::Value const& val = resp.value();
   CHECK("42" == val.as_string());
   CHECK("/test/key1" == val.key());
   CHECK(!val.is_dir());
   CHECK(0 < val.created_index());
   CHECK(0 < val.modified_index());
+  CHECK(1 == val.version());
   CHECK(0 < resp.index());
-  CHECK(105 == etcd->add("/test/key1", "43").get().error_code()); // Key already exists
-  CHECK(105 == etcd->add("/test/key1", "42").get().error_code()); // Key already exists
-  CHECK("Key already exists" == etcd->add("/test/key1", "42").get().error_message());
+  CHECK(
+      etcd::ERROR_KEY_ALREADY_EXISTS ==
+      etcd->add("/test/key1", "43").get().error_code());  // Key already exists
+  CHECK(
+      etcd::ERROR_KEY_ALREADY_EXISTS ==
+      etcd->add("/test/key1", "42").get().error_code());  // Key already exists
+  CHECK("etcd-cpp-apiv3: key already exists" ==
+        etcd->add("/test/key1", "42").get().error_message());
 }
 
-TEST_CASE("read a value from etcd")
-{
-  etcd::Client *etcd = etcd::Client::WithSSL("https://127.0.0.1:2379", ca, cert, key);
+TEST_CASE("read a value from etcd") {
+  etcd::Client* etcd = etcd::Client::WithSSL(etcd_url, ca, cert, key);
   etcd::Response resp = etcd->get("/test/key1").get();
   CHECK("get" == resp.action());
   REQUIRE(resp.is_ok());
   REQUIRE(0 == resp.error_code());
   CHECK("42" == resp.value().as_string());
-  CHECK("" == etcd->get("/test").get().value().as_string()); // key points to a directory
+  CHECK("" == etcd->get("/test").get().value().as_string());  // key points to a
+                                                              // directory
 }
 
-TEST_CASE("cleanup")
-{
-  etcd::Client *etcd = etcd::Client::WithSSL("https://127.0.0.1:2379", ca, cert, key);
+TEST_CASE("cleanup") {
+  etcd::Client* etcd = etcd::Client::WithSSL(etcd_url, ca, cert, key);
   REQUIRE(0 == etcd->rmdir("/test", true).get().error_code());
 }

tst/TransactionTest.cpp

@@ -0,0 +1,130 @@
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+#include "etcd/Client.hpp"
+#include "etcd/v3/Transaction.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
+
+TEST_CASE("setup") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+}
+
+TEST_CASE("add a new key") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+
+  // do some put using txn
+  {
+    etcdv3::Transaction txn;
+    txn.setup_put("/test/x1", "1");
+    txn.setup_put("/test/x2", "2");
+    txn.setup_put("/test/x3", "3");
+    etcd::Response resp = etcd.txn(txn).get();
+    REQUIRE(0 == resp.error_code());
+  }
+
+  // check the value
+  {
+    etcd::Response resp = etcd.get("/test/x1").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == "1");
+
+    resp = etcd.get("/test/x2").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == "2");
+
+    resp = etcd.get("/test/x3").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == "3");
+  }
+
+  // do some put and delete using txn
+  {
+    etcdv3::Transaction txn;
+
+    // setup the conditions
+    txn.add_compare_value("/test/x1", "1");
+    txn.add_compare_value("/test/x2", "2");
+
+    txn.setup_put("/test/x1", "111");
+    txn.setup_delete("/test/x2");
+    txn.setup_delete("/test/x3");
+    txn.setup_put("/test/x4", "4");
+    etcd::Response resp = etcd.txn(txn).get();
+    REQUIRE(0 == resp.error_code());
+  }
+
+  // check the value
+  {
+    etcd::Response resp = etcd.get("/test/x1").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == "111");
+
+    resp = etcd.get("/test/x2").get();
+    REQUIRE(etcdv3::ERROR_KEY_NOT_FOUND == resp.error_code());
+
+    resp = etcd.get("/test/x3").get();
+    REQUIRE(etcdv3::ERROR_KEY_NOT_FOUND == resp.error_code());
+
+    resp = etcd.get("/test/x4").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == "4");
+  }
+}
+
+TEST_CASE("fetch & add") {
+  etcd::Client etcd(etcd_url);
+  etcd.rmdir("/test", true).wait();
+
+  etcd.set("/test/key", "0").wait();
+
+  auto fetch_and_add = [](etcd::Client& client,
+                          std::string const& key) -> void {
+    auto value = stoi(client.get(key).get().value().as_string());
+    while (true) {
+      auto txn = etcdv3::Transaction();
+      txn.setup_compare_and_swap(key, std::to_string(value),
+                                 std::to_string(value + 1));
+      etcd::Response resp = client.txn(txn).get();
+      if (resp.is_ok()) {
+        break;
+      }
+      value = stoi(resp.value().as_string());
+    }
+  };
+
+  // run 1000 times
+  const size_t rounds = 100;
+  std::atomic_size_t counter(0);
+
+  std::vector<std::thread> threads;
+  for (size_t i = 0; i < 10; ++i) {
+    threads.emplace_back([&]() {
+      while (counter.fetch_add(1) < rounds) {
+        fetch_and_add(etcd, "/test/key");
+      }
+    });
+  }
+  for (auto& thr : threads) {
+    thr.join();
+  }
+
+  // check the value
+  {
+    etcd::Response resp = etcd.get("/test/key").get();
+    REQUIRE(0 == resp.error_code());
+    CHECK(resp.value().as_string() == std::to_string(rounds));
+  }
+}
+
+TEST_CASE("cleanup") {
+  etcd::Client etcd(etcd_url);
+  REQUIRE(0 == etcd.rmdir("/test", true).get().error_code());
+}

tst/WatcherTest.cpp

@@ -4,116 +4,231 @@
 #include <chrono>
 #include <thread>
 
-#include "etcd/Watcher.hpp"
 #include "etcd/SyncClient.hpp"
+#include "etcd/Watcher.hpp"
+
+static const std::string etcd_url =
+    etcdv3::detail::resolve_etcd_endpoints("http://127.0.0.1:2379");
 
-static std::string etcd_uri("http://127.0.0.1:2379");
 static int watcher_called = 0;
 
-void printResponse(etcd::Response const & resp)
-{
-  ++watcher_called;
-  std::cout << "print response called" << std::endl;
+void printResponse(etcd::Response const& resp) {
   if (resp.error_code()) {
-    std::cout << resp.error_code() << ": " << resp.error_message() << std::endl;
-  }
-  else
-  {
-    std::cout << resp.action() << " " << resp.value().as_string() << std::endl;
-    std::cout << "Previous value: " << resp.prev_value().as_string() << std::endl;
+    std::cout << "Watcher " << resp.watch_id() << " fails with "
+              << resp.error_code() << ": " << resp.error_message() << std::endl;
+  } else {
+    std::cout << "Watcher " << resp.watch_id() << " responses with "
+              << resp.action() << " " << resp.value().as_string() << std::endl;
+    std::cout << "Previous value: " << resp.prev_value().as_string()
+              << std::endl;
+
+    std::cout << "Events size: " << resp.events().size() << std::endl;
+    for (auto const& ev : resp.events()) {
+      if (ev.prev_kv().key().find("/leader") == 0 ||
+          ev.kv().key().find("/leader") == 0) {
+        return;
+      }
+      std::cout << "Value change in events: "
+                << static_cast<int>(ev.event_type())
+                << ", prev kv = " << ev.prev_kv().key() << " -> "
+                << ev.prev_kv().as_string() << ", kv = " << ev.kv().key()
+                << " -> " << ev.kv().as_string() << std::endl;
+    }
   }
+  std::cout << "print response called" << std::endl;
+  ++watcher_called;
 }
 
-TEST_CASE("create watcher with cancel")
-{
-  
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("create watcher") {
+  etcd::SyncClient etcd(etcd_url);
   etcd.rmdir("/test", true);
 
   watcher_called = 0;
-  etcd::Watcher watcher(etcd_uri, "/test", printResponse, true);
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  {
+    etcd::Watcher watcher(etcd_url, "/test", printResponse, true);
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    etcd.set("/test/key", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    etcd.set("/test/key", "43");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+  }
+  CHECK(2 == watcher_called);
+  etcd.rmdir("/test", true);
+}
+
+TEST_CASE("watch with correct prefix") {
+  etcd::SyncClient etcd(etcd_url);
+  etcd.rmdir("/test", true);
+
+  watcher_called = 0;
+  etcd::Watcher watcher(etcd_url, "/test/key_prefix", printResponse, true);
+
+  {
+    etcd.set("/test/key1", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    CHECK(0 == watcher_called);
+  }
+  {
+    etcd.set("/test/key_prefix", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    CHECK(1 == watcher_called);
+  }
+  {
+    etcd.set("/test/key_prefix1", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    CHECK(2 == watcher_called);
+  }
+  {
+    etcd.set("/test/key_prefiy", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    CHECK(2 == watcher_called);
+  }
+  {
+    etcd.set("/test/key1", "42");
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    CHECK(2 == watcher_called);
+  }
+
+  etcd.rmdir("/test", true);
+}
+
+TEST_CASE("create watcher with cancel") {
+  etcd::SyncClient etcd(etcd_url);
+  etcd.rmdir("/test", true);
+
+  watcher_called = 0;
+  etcd::Watcher watcher(etcd_url, "/test", printResponse, true);
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   etcd.set("/test/key", "42");
   etcd.set("/test/key", "43");
   etcd.rm("/test/key");
   etcd.set("/test/key", "44");
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   CHECK(4 == watcher_called);
   watcher.Cancel();
   etcd.set("/test/key", "50");
   etcd.set("/test/key", "51");
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   CHECK(4 == watcher_called);
 
   etcd.rmdir("/test", true);
 }
 
-TEST_CASE("create watcher on ranges with cancel")
-{
-  etcd::SyncClient etcd(etcd_uri);
+TEST_CASE("create watcher on ranges with cancel") {
+  etcd::SyncClient etcd(etcd_url);
   etcd.rmdir("/test", true);
 
   watcher_called = 0;
-  etcd::Watcher watcher(etcd_uri, "/test/key1", "/test/key5", printResponse);
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  etcd::Watcher watcher(etcd_url, "/test/key1", "/test/key5", printResponse);
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   etcd.set("/test/key1", "42");
   etcd.set("/test/key2", "43");
   etcd.rm("/test/key1");
   etcd.set("/test/key5", "44");
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   CHECK(3 == watcher_called);
   watcher.Cancel();
   etcd.set("/test/key3", "50");
   etcd.set("/test/key4", "51");
-  std::this_thread::sleep_for(std::chrono::seconds(3));
+  std::this_thread::sleep_for(std::chrono::seconds(5));
   CHECK(3 == watcher_called);
 
   etcd.rmdir("/test", true);
 }
 
-TEST_CASE("create watcher")
-{
-  etcd::SyncClient etcd(etcd_uri);
-  etcd.rmdir("/test", true);
-
-  watcher_called = 0;
-  {
-    etcd::Watcher watcher(etcd_uri, "/test", printResponse, true);
-    std::this_thread::sleep_for(std::chrono::seconds(3));
-    etcd.set("/test/key", "42");
-    std::this_thread::sleep_for(std::chrono::seconds(3));
-    etcd.set("/test/key", "43");
-    std::this_thread::sleep_for(std::chrono::seconds(3));
-  }
-  CHECK(2 == watcher_called);
-  etcd.rmdir("/test", true).error_code();
-}
-
-TEST_CASE("watch should exit normally")
-{
-  // cancal immediately after start watch.
-  etcd::Watcher watcher(etcd_uri, "/test", printResponse, true);
+TEST_CASE("watch should exit normally") {
+  // cancel immediately after start watch.
+  etcd::Watcher watcher(etcd_url, "/test", printResponse, true);
   watcher.Cancel();
 }
 
-TEST_CASE("watch should can be cancelled repeatedly")
-{
-  // cancal immediately after start watch.
-  etcd::Watcher watcher(etcd_uri, "/test", printResponse, true);
+TEST_CASE("watch should can be cancelled repeatedly") {
+  etcd::Watcher watcher(etcd_url, "/test", printResponse, true);
   std::vector<std::thread> threads(10);
   for (size_t i = 0; i < 10; ++i) {
-    threads[i] = std::thread([&]() {
-      watcher.Cancel();
-    });
+    threads[i] = std::thread([&]() { watcher.Cancel(); });
   }
   for (size_t i = 0; i < 10; ++i) {
     threads[i].join();
   }
 }
 
+TEST_CASE("watch changes on the same key (#212)") {
+  std::string key_watch = "key watch";
+  etcd::SyncClient client(etcd_url);
+  client.put(key_watch, "inittt");
+
+  auto current_index = client.head().index();
+  std::cout << "Current index " << current_index << std::endl;
+  auto internal_cb = [&](etcd::Response resp) -> void {
+    if (!resp.is_ok()) {
+      std::cout << "Error: " << resp.error_message() << std::endl;
+      return;
+    }
+    for (auto const& event : resp.events()) {
+      std::cout << "Watch '" << event.kv().key()
+                << "'. ModifedRevision : " << event.kv().modified_index()
+                << "', Vision : " << event.kv().version()
+                << ", value = " << event.kv().as_string() << std::endl;
+    }
+  };
+  auto wait_cb = [&](bool) {};
+  etcd::Watcher w(client, key_watch, current_index, std::move(internal_cb),
+                  std::move(wait_cb), false);
+
+  std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  for (int i = 0; i < 10; ++i) {
+    std::string value = "watch_" + std::to_string(i);
+    client.put(key_watch, value);
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  }
+}
+
+TEST_CASE("create two watcher") {
+  etcd::Watcher w1(etcd_url, "/test", printResponse, true);
+  etcd::Watcher w2(etcd_url, "/test", printResponse, true);
+
+  std::this_thread::sleep_for(std::chrono::seconds(5));
+}
+
+TEST_CASE("using two watcher") {
+  etcd::SyncClient etcd(etcd_url);
+
+  int watched1 = 0;
+  int watched2 = 0;
+
+  etcd::Watcher w1(
+      etcd, "/test/def",
+      [&](etcd::Response const& resp) {
+        std::cout << "w1 called: " << resp.events().at(0).event_type() << " on "
+                  << resp.events().at(0).kv().key() << std::endl;
+        ++watched1;
+      },
+      true);
+  etcd::Watcher w2(
+      etcd, "/test",
+      [&](etcd::Response const& resp) {
+        std::cout << "w2 called: " << resp.events().at(0).event_type() << " on "
+                  << resp.events().at(0).kv().key() << std::endl;
+        ++watched2;
+      },
+      true);
+
+  std::this_thread::sleep_for(std::chrono::seconds(5));
+
+  etcd.put("/test/def/xxx", "42");
+  etcd.put("/test/abc", "42");
+  etcd.rm("/test/def/xxx");
+  etcd.rm("/test/abc");
+
+  std::this_thread::sleep_for(std::chrono::seconds(5));
+  CHECK(2 == watched1);
+  CHECK(4 == watched2);
+}
+
 // TEST_CASE("request cancellation")
 // {
-//   etcd::Client etcd(etcd_uri);
+//   etcd::Client etcd(etcd_url);
 //   etcd.set("/test/key1", "42").wait();
 
 //   pplx::task<etcd::Response> res = etcd.watch("/test/key1");

vcpkg/etcd-cpp-apiv3/CONTROL

@@ -1,6 +0,0 @@
-Source: etcd-cpp-apiv3
-Version: etcd-cpp-apiv3-7e280ec
-Homepage: https://github.com/etcd-cpp-apiv3/etcd-cpp-apiv3
-Description: The etcd-cpp-apiv3 is a C++ API for etcd's v3 client API, i.e., ETCDCTL_API=3.
-Build-Depends: boost-system, boost-thread, boost-random,
-               cpprestsdk, grpc, openssl, protobuf

vcpkg/etcd-cpp-apiv3/portfile.cmake

@@ -1,25 +0,0 @@
-vcpkg_from_github(
-    OUT_SOURCE_PATH SOURCE_PATH
-    REPO etcd-cpp-apiv3/etcd-cpp-apiv3
-    REF 7e280ec8a49aaf26976d72a4080f2e2c6756f2b7
-    SHA512 1e1d525f79840731102e6400ff2582807e0626b58fa60726e49bea6ca51868a6b8bf3a34c7bf1d1266e156daa1e741bbfa2acce42b54680a23426bc00192dc6d
-    HEAD_REF master
-)
-
-vcpkg_configure_cmake(
-    SOURCE_PATH ${SOURCE_PATH}
-    PREFER_NINJA
-    OPTIONS
-        -DBUILD_ETCD_TESTS=OFF
-)
-set(VCPKG_POLICY_DLLS_WITHOUT_LIBS enabled)
-set(VCPKG_POLICY_DLLS_WITHOUT_EXPORTS enabled)
-
-vcpkg_install_cmake()
-
-file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)
-
-vcpkg_copy_pdbs()
-
-# Handle copyright
-file(INSTALL ${SOURCE_PATH}/LICENSE.txt DESTINATION ${CURRENT_PACKAGES_DIR}/share/etcd-cpp-apiv3 RENAME copyright)