From fd7199f64ec05c46f6aebd8644bbcb78f2889898 Mon Sep 17 00:00:00 2001
From: Yang Gao <yangg@google.com>
Date: Wed, 11 Feb 2015 23:14:49 -0800
Subject: [PATCH] Add client side WaitForInitialMetadata for streaming.
---
include/grpc++/impl/call.h | 9 +++++++++
include/grpc++/stream.h | 29 +++++++++++++++++++++++++++++
src/cpp/common/call.cc | 6 ++++++
3 files changed, 44 insertions(+)
diff --git a/include/grpc++/impl/call.h b/include/grpc++/impl/call.h
index a1ef9268f0..5fafd0e890 100644
--- a/include/grpc++/impl/call.h
+++ b/include/grpc++/impl/call.h
@@ -134,7 +134,16 @@ class Call final {
grpc_call *call() { return call_; }
CompletionQueue *cq() { return cq_; }
+ // TODO(yangg) change it to a general state query function.
+ bool initial_metadata_received() {
+ return initial_metadata_received_;
+ }
+ void set_initial_metadata_received() {
+ initial_metadata_received_ = true;
+ }
+
private:
+ bool initial_metadata_received_ = false;
CallHook *call_hook_;
CompletionQueue *cq_;
grpc_call* call_;
diff --git a/include/grpc++/stream.h b/include/grpc++/stream.h
index a59ccd8c05..6da1be4e9f 100644
--- a/include/grpc++/stream.h
+++ b/include/grpc++/stream.h
@@ -98,7 +98,22 @@ class ClientReader final : public ClientStreamingInterface,
cq_.Pluck(&buf);
}
+ // Blocking wait for initial metadata from server. The received metadata
+ // can only be accessed after this call returns. Calling this method is
+ // optional as it will be called internally before the first Read.
+ void WaitForInitialMetadata() {
+ if (!call_.initial_metadata_received()) {
+ CallOpBuffer buf;
+ buf.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+ call_.PerformOps(&buf);
+ GPR_ASSERT(cq_.Pluck(&buf));
+ call_.set_initial_metadata_received();
+ }
+ }
+
+
virtual bool Read(R *msg) override {
+ WaitForInitialMetadata();
CallOpBuffer buf;
bool got_message;
buf.AddRecvMessage(msg, &got_message);
@@ -186,7 +201,21 @@ class ClientReaderWriter final : public ClientStreamingInterface,
GPR_ASSERT(cq_.Pluck(&buf));
}
+ // Blocking wait for initial metadata from server. The received metadata
+ // can only be accessed after this call returns. Calling this method is
+ // optional as it will be called internally before the first Read.
+ void WaitForInitialMetadata() {
+ if (!call_.initial_metadata_received()) {
+ CallOpBuffer buf;
+ buf.AddRecvInitialMetadata(&context_->recv_initial_metadata_);
+ call_.PerformOps(&buf);
+ GPR_ASSERT(cq_.Pluck(&buf));
+ call_.set_initial_metadata_received();
+ }
+ }
+
virtual bool Read(R *msg) override {
+ WaitForInitialMetadata();
CallOpBuffer buf;
bool got_message;
buf.AddRecvMessage(msg, &got_message);
diff --git a/src/cpp/common/call.cc b/src/cpp/common/call.cc
index a20d4a0d9a..aae69084eb 100644
--- a/src/cpp/common/call.cc
+++ b/src/cpp/common/call.cc
@@ -121,6 +121,12 @@ void CallOpBuffer::AddSendInitialMetadata(
initial_metadata_ = FillMetadataArray(metadata);
}
+void CallOpBuffer::AddRecvInitialMetadata(
+ std::multimap<grpc::string, grpc::string>* metadata) {
+ recv_initial_metadata_ = metadata;
+}
+
+
void CallOpBuffer::AddSendInitialMetadata(ClientContext *ctx) {
AddSendInitialMetadata(&ctx->send_initial_metadata_);
}
--
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