Introduce PoseGraphInterface::ToProto() (#813)

cartographer/mapping/pose_graph.h

@@ -109,8 +109,7 @@ class PoseGraph : public PoseGraphInterface {
   // not exist (anymore).
   virtual SubmapData GetSubmapData(const SubmapId& submap_id) = 0;
 
-  // Serializes the constraints and trajectories.
-  proto::PoseGraph ToProto();
+  proto::PoseGraph ToProto() override;
 
   // Returns the IMU data.
   virtual sensor::MapByTime<sensor::ImuData> GetImuData() = 0;

cartographer/mapping/pose_graph_interface.h

@@ -90,6 +90,9 @@ class PoseGraphInterface {
 
   // Returns the collection of constraints.
   virtual std::vector<Constraint> constraints() = 0;
+
+  // Serializes the constraints and trajectories.
+  virtual proto::PoseGraph ToProto() = 0;
 };
 
 }  // namespace mapping

cartographer_grpc/mapping/pose_graph_stub.cc

@@ -109,5 +109,9 @@ PoseGraphStub::constraints() {
   return cartographer::mapping::FromProto(response.constraints());
 }
 
+cartographer::mapping::proto::PoseGraph PoseGraphStub::ToProto() {
+  LOG(FATAL) << "Not implemented";
+}
+
 }  // namespace mapping
 }  // namespace cartographer_grpc

cartographer_grpc/mapping/pose_graph_stub.h

@@ -47,6 +47,7 @@ class PoseGraphStub : public cartographer::mapping::PoseGraphInterface {
   GetTrajectoryNodePoses() override;
   bool IsTrajectoryFinished(int trajectory_id) override;
   std::vector<Constraint> constraints() override;
+  cartographer::mapping::proto::PoseGraph ToProto() override;
 
  private:
   std::shared_ptr<grpc::Channel> client_channel_;