implement ClientAsyncX api

include/grpc++/stream.h

@@ -365,6 +365,8 @@ class ClientAsyncStreamingInterface {
  public:
   virtual ~ClientAsyncStreamingInterface() {}
 
+  virtual void ReadInitialMetadata(void* tag) = 0;
+
   virtual void Finish(Status* status, void* tag) = 0;
 };
 
@@ -390,30 +392,50 @@ template <class R>
 class ClientAsyncReader final : public ClientAsyncStreamingInterface,
                            public AsyncReaderInterface<R> {
  public:
-  // Blocking create a stream and write the first request out.
+  // Create a stream and write the first request out.
   ClientAsyncReader(ChannelInterface *channel, const RpcMethod &method,
                ClientContext *context,
                const google::protobuf::Message &request, void* tag)
-      : call_(channel->CreateCall(method, context, &cq_)) {
+      : context_(context), call_(channel->CreateCall(method, context, &cq_)) {
     init_buf_.Reset(tag);
+    init_buf_.AddSendInitialMetadata(&context->send_initial_metadata_);
     init_buf_.AddSendMessage(request);
     init_buf_.AddClientSendClose();
     call_.PerformOps(&init_buf_);
   }
 
-  virtual void Read(R *msg, void* tag) override {
+  void ReadInitialMetadata(void* tag) override {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    CallOpBuffer buf;
+    buf.Reset(tag);
+    buf.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+    call_.PerformOps(&buf);
+    context_->initial_metadata_received_ = true;
+  }
+
+  void Read(R *msg, void* tag) override {
     read_buf_.Reset(tag);
+    if (!context_->initial_metadata_received_) {
+      read_buf_.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+      context_->initial_metadata_received_ = true;
+    }
     read_buf_.AddRecvMessage(msg);
     call_.PerformOps(&read_buf_);
   }
 
-  virtual void Finish(Status* status, void* tag) override {
+  void Finish(Status* status, void* tag) override {
     finish_buf_.Reset(tag);
-    finish_buf_.AddClientRecvStatus(nullptr, status);  // TODO metadata
+    if (!context_->initial_metadata_received_) {
+      finish_buf_.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+      context_->initial_metadata_received_ = true;
+    }
+    finish_buf_.AddClientRecvStatus(&context_->trailing_metadata_, status);
     call_.PerformOps(&finish_buf_);
   }
 
  private:
+  ClientContext* context_ = nullptr;
   CompletionQueue cq_;
   Call call_;
   CallOpBuffer init_buf_;
@@ -425,37 +447,56 @@ template <class W>
 class ClientAsyncWriter final : public ClientAsyncStreamingInterface,
                            public WriterInterface<W> {
  public:
-  // Blocking create a stream.
   ClientAsyncWriter(ChannelInterface *channel, const RpcMethod &method,
                ClientContext *context,
-               google::protobuf::Message *response)
-      : response_(response),
-        call_(channel->CreateCall(method, context, &cq_)) {}
+               google::protobuf::Message *response, void* tag)
+      : context_(context), response_(response),
+        call_(channel->CreateCall(method, context, &cq_)) {
+    init_buf_.Reset(tag);
+    init_buf_.AddSendInitialMetadata(&context->send_initial_metadata_);
+    call_.PerformOps(&init_buf_);
+  }
 
-  virtual void Write(const W& msg, void* tag) override {
+  void ReadInitialMetadata(void* tag) override {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    CallOpBuffer buf;
+    buf.Reset(tag);
+    buf.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+    call_.PerformOps(&buf);
+    context_->initial_metadata_received_ = true;
+  }
+
+  void Write(const W& msg, void* tag) override {
     write_buf_.Reset(tag);
     write_buf_.AddSendMessage(msg);
     call_.PerformOps(&write_buf_);
   }
 
-  virtual void WritesDone(void* tag) override {
+  void WritesDone(void* tag) override {
     writes_done_buf_.Reset(tag);
     writes_done_buf_.AddClientSendClose();
     call_.PerformOps(&writes_done_buf_);
   }
 
-  virtual void Finish(Status* status, void* tag) override {
+  void Finish(Status* status, void* tag) override {
     finish_buf_.Reset(tag);
+    if (!context_->initial_metadata_received_) {
+      finish_buf_.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+      context_->initial_metadata_received_ = true;
+    }
     finish_buf_.AddRecvMessage(response_, &got_message_);
-    finish_buf_.AddClientRecvStatus(nullptr, status);  // TODO metadata
+    finish_buf_.AddClientRecvStatus(&context_->trailing_metadata_, status);
     call_.PerformOps(&finish_buf_);
   }
 
  private:
+  ClientContext* context_ = nullptr;
   google::protobuf::Message *const response_;
   bool got_message_;
   CompletionQueue cq_;
   Call call_;
+  CallOpBuffer init_buf_;
   CallOpBuffer write_buf_;
   CallOpBuffer writes_done_buf_;
   CallOpBuffer finish_buf_;
@@ -468,36 +509,60 @@ class ClientAsyncReaderWriter final : public ClientAsyncStreamingInterface,
                                  public AsyncReaderInterface<R> {
  public:
   ClientAsyncReaderWriter(ChannelInterface *channel,
-                     const RpcMethod &method, ClientContext *context)
-      : call_(channel->CreateCall(method, context, &cq_)) {}
+                     const RpcMethod &method, ClientContext *context, void* tag)
+      : context_(context), call_(channel->CreateCall(method, context, &cq_)) {
+    init_buf_.Reset(tag);
+    init_buf_.AddSendInitialMetadata(&context->send_initial_metadata_);
+    call_.PerformOps(&init_buf_);
+  }
+
+  void ReadInitialMetadata(void* tag) override {
+    GPR_ASSERT(!context_->initial_metadata_received_);
 
-  virtual void Read(R *msg, void* tag) override {
+    CallOpBuffer buf;
+    buf.Reset(tag);
+    buf.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+    call_.PerformOps(&buf);
+    context_->initial_metadata_received_ = true;
+  }
+
+  void Read(R *msg, void* tag) override {
     read_buf_.Reset(tag);
+    if (!context_->initial_metadata_received_) {
+      read_buf_.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+      context_->initial_metadata_received_ = true;
+    }
     read_buf_.AddRecvMessage(msg);
     call_.PerformOps(&read_buf_);
   }
 
-  virtual void Write(const W& msg, void* tag) override {
+  void Write(const W& msg, void* tag) override {
     write_buf_.Reset(tag);
     write_buf_.AddSendMessage(msg);
     call_.PerformOps(&write_buf_);
   }
 
-  virtual void WritesDone(void* tag) override {
+  void WritesDone(void* tag) override {
     writes_done_buf_.Reset(tag);
     writes_done_buf_.AddClientSendClose();
     call_.PerformOps(&writes_done_buf_);
   }
 
-  virtual void Finish(Status* status, void* tag) override {
+  void Finish(Status* status, void* tag) override {
     finish_buf_.Reset(tag);
-    finish_buf_.AddClientRecvStatus(nullptr, status);  // TODO metadata
+    if (!context_->initial_metadata_received_) {
+      finish_buf_.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+      context_->initial_metadata_received_ = true;
+    }
+    finish_buf_.AddClientRecvStatus(&context_->trailing_metadata_, status);
     call_.PerformOps(&finish_buf_);
   }
 
  private:
+  ClientContext* context_ = nullptr;
   CompletionQueue cq_;
   Call call_;
+  CallOpBuffer init_buf_;
   CallOpBuffer read_buf_;
   CallOpBuffer write_buf_;
   CallOpBuffer writes_done_buf_;