Include compact revision for cancelled watch response.

Signed-off-by: Tao He <sighingnow@gmail.com>

etcd/Response.hpp

@@ -130,6 +130,12 @@ namespace etcd
      */
     std::string const & key(int index) const;
 
+    /**
+     * Returns the compact_revision if the response is a watch-cancelled revision.
+     * `-1` means uninitialized (the response is not watch-cancelled)
+     */
+    int compact_revision() const;
+
     /**
      * Returns the lock key.
      */
@@ -162,6 +168,7 @@ namespace etcd
     Value       _prev_value;
     Values      _values;
     Keys        _keys;
+    int         _compact_revision = -1; // for watch
     std::string _lock_key; // for lock
     std::string _name;  // for campaign (in v3election)
     std::vector<Event> _events; // for watch

etcd/v3/V3Response.hpp

@@ -25,6 +25,7 @@ namespace etcdv3
     etcdv3::KeyValue const & get_value() const;
     etcdv3::KeyValue const & get_prev_value() const;
     bool has_values() const;
+    int get_compact_revision() const;
     void set_lock_key(std::string const &key);
     std::string const &get_lock_key() const;
     void set_name(std::string const &name);
@@ -39,6 +40,7 @@ namespace etcdv3
     etcdv3::KeyValue prev_value; 
     std::vector<etcdv3::KeyValue> values;
     std::vector<etcdv3::KeyValue> prev_values; 
+    int compact_revision = -1;
     std::string lock_key; // for lock
     std::string name;  // for campaign (in v3election)
     std::vector<mvccpb::Event> events; // for watch

src/Response.cpp

@@ -24,6 +24,7 @@ etcd::Response::Response(const etcdv3::V3Response& reply, std::chrono::microseco
   }
   _prev_value = Value(reply.get_prev_value());
 
+  _compact_revision = reply.get_compact_revision();
   _lock_key = reply.get_lock_key();
   _name = reply.get_name();
 
@@ -109,6 +110,11 @@ std::string const & etcd::Response::key(int index) const
   return _keys[index];
 }
 
+int etcd::Response::compact_revision() const
+{
+  return _compact_revision;
+}
+
 std::string const & etcd::Response::lock_key() const {
   return _lock_key;
 }

src/v3/AsyncWatchAction.cpp

@@ -149,8 +149,10 @@ void etcdv3::AsyncWatchAction::waitForResponse(std::function<void(etcd::Response
         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"));
+          auto resp = etcd::Response(grpc::StatusCode::OUT_OF_RANGE /* error code */,
+                                     "required revision has been compacted");
+          resp._compact_revision = reply.compact_revision();
+          callback(resp);
         }
         break;
       }

src/v3/AsyncWatchResponse.cpp

@@ -6,6 +6,7 @@ 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";
+    compact_revision = reply.compact_revision();
     return;
   }
   index = reply.header().revision();

src/v3/V3Response.cpp

@@ -61,6 +61,11 @@ bool etcdv3::V3Response::has_values() const
   return values.size() > 0;
 }
 
+int etcdv3::V3Response::get_compact_revision() const
+{
+  return compact_revision;
+}
+
 void etcdv3::V3Response::set_lock_key(std::string const &key) {
   this->lock_key = key;
 }