Added a net::BidirectionalStream to expose a bidirectional streaming interface

net/spdy/bidirectional_stream_spdy_job.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/spdy/bidirectional_stream_spdy_job.h"
+
+#include "base/bind.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "net/base/request_priority.h"
+#include "net/spdy/spdy_buffer.h"
+#include "net/spdy/spdy_header_block.h"
+#include "net/spdy/spdy_http_utils.h"
+#include "net/spdy/spdy_stream.h"
+
+namespace net {
+
+const base::TimeDelta kBufferTime = base::TimeDelta::FromMilliseconds(1);
+
+BidirectionalStreamSpdyJob::BidirectionalStreamSpdyJob(
+    const base::WeakPtr<SpdySession>& spdy_session,
+    scoped_ptr<base::Timer> timer)
+    : spdy_session_(spdy_session),
+      timer_(timer.release()),
+      stream_closed_(false),
+      closed_stream_status_(ERR_FAILED),
+      more_read_data_pending_(false),
+      weak_factory_(this) {}
+
+BidirectionalStreamSpdyJob::BidirectionalStreamSpdyJob(
+    const base::WeakPtr<SpdySession>& spdy_session)
+    : BidirectionalStreamSpdyJob(
+          spdy_session,
+          make_scoped_ptr(new base::Timer(false, false))) {}
+
+BidirectionalStreamSpdyJob::~BidirectionalStreamSpdyJob() {
+  if (stream_.get()) {
+    stream_->DetachDelegate();
+    DCHECK(!stream_.get());
+  }
+}
+
+void BidirectionalStreamSpdyJob::Start(
+    const HttpRequestInfo& request_info,
+    RequestPriority priority,
+    const BoundNetLog& net_log,
+    BidirectionalStreamJob::Delegate* delegate) {
+  delegate_ = delegate;
+  DCHECK(!stream_);
+  if (!spdy_session_) {
+    delegate_->OnFailed(ERR_CONNECTION_CLOSED);
+    return;
+  }
+
+  request_info_ = request_info;
+
+  int rv = stream_request_.StartRequest(
+      SPDY_BIDIRECTIONAL_STREAM, spdy_session_, request_info_.url, priority,
+      net_log, base::Bind(&BidirectionalStreamSpdyJob::OnStreamInitialized,
+                          weak_factory_.GetWeakPtr()));
+  if (rv != ERR_IO_PENDING)
+    OnStreamInitialized(rv);
+}
+
+int BidirectionalStreamSpdyJob::ReadData(IOBuffer* buf, int buf_len) {
+  if (stream_.get())
+    CHECK(!stream_->IsIdle());
+
+  CHECK(buf);
+  CHECK(buf_len);
+  CHECK(!timer_->IsRunning()) << "There should be only one ReadData in flight";
+
+  if (!stream_closed_)
+    CHECK(stream_);
+
+  // If there is data buffered, complete the IO immediately.
+  if (!data_queue_.IsEmpty()) {
+    return data_queue_.Dequeue(buf->data(), buf_len);
+  } else if (stream_closed_) {
+    return closed_stream_status_;
+  }
+  // Read will complete asynchronously and Delegate::OnReadCompleted will be
+  // called upon completion.
+  user_buffer_ = buf;
+  user_buffer_len_ = buf_len;
+  return ERR_IO_PENDING;
+}
+
+void BidirectionalStreamSpdyJob::SendData(IOBuffer* data,
+                                          int length,
+                                          bool end_stream) {
+  CHECK(!stream_closed_);
+  CHECK(stream_);
+
+  stream_->SendData(data, length,
+                    end_stream ? NO_MORE_DATA_TO_SEND : MORE_DATA_TO_SEND);
+}
+
+void BidirectionalStreamSpdyJob::Cancel() {
+  if (!stream_)
+    return;
+  // Cancels the stream and detaches the delegate so it doesn't get called back.
+  stream_->DetachDelegate();
+  DCHECK(!stream_);
+}
+
+void BidirectionalStreamSpdyJob::OnRequestHeadersSent() {
+  delegate_->OnRequestHeadersSent();
+}
+
+SpdyResponseHeadersStatus BidirectionalStreamSpdyJob::OnResponseHeadersUpdated(
+    const SpdyHeaderBlock& response_headers) {
+  delegate_->OnHeaders(response_headers);
+  return RESPONSE_HEADERS_ARE_COMPLETE;
+}
+
+void BidirectionalStreamSpdyJob::OnDataReceived(scoped_ptr<SpdyBuffer> buffer) {
+  DCHECK(stream_);
+  DCHECK(!stream_closed_);
+
+  if (buffer) {
+    data_queue_.Enqueue(buffer.Pass());
+    if (user_buffer_) {
+      // Handing small chunks of data to the caller creates measurable overhead.
+      // So buffer data in short time-spans and send a single read notification.
+      ScheduleBufferedRead();
+    }
+  }
+  // If |buffer| is null, BidirectionalStreamSpdyJob::OnClose will be invoked by
+  // SpdyStream to indicate the end of stream.
+}
+
+void BidirectionalStreamSpdyJob::OnDataSent() {
+  DCHECK(stream_);
+  DCHECK(!stream_closed_);
+
+  delegate_->OnDataSent();
+}
+
+void BidirectionalStreamSpdyJob::OnTrailers(const SpdyHeaderBlock& trailers) {
+  DCHECK(stream_);
+  DCHECK(!stream_closed_);
+
+  delegate_->OnTrailers(trailers);
+}
+
+void BidirectionalStreamSpdyJob::OnClose(int status) {
+  DCHECK(stream_);
+
+  stream_closed_ = true;
+  closed_stream_status_ = status;
+  stream_.reset();
+
+  if (status != OK) {
+    delegate_->OnFailed(status);
+    return;
+  }
+  // Complete any remaining read, as all data has been buffered.
+  // If user has not called ReadData (i.e |user_buffer_| is nullptr), this will
+  // do nothing.
+  if (!data_queue_.IsEmpty()) {

[xunjieli, 2015/12/07 17:35:54]

BUG: If a former ReadData returned ERR_IO_PENDING, and then the server sends
END_STREAM without data, we won't ever complete the Read (since
data_queue_.IsEmpty() is true). This conditional should be removed. 

I will work on adding a test for this now.

[xunjieli, 2015/12/07 19:05:45]

Done.

+    DCHECK_EQ(OK, status);
+    timer_->Stop();
+    DoBufferedRead();
+  }
+}
+
+void BidirectionalStreamSpdyJob::SendRequestHeaders() {
+  scoped_ptr<SpdyHeaderBlock> headers(new SpdyHeaderBlock);
+  CreateSpdyHeadersFromHttpRequest(request_info_, request_info_.extra_headers,
+                                   stream_->GetProtocolVersion(), true,
+                                   headers.get());
+  bool end_stream = (request_info_.method == "GET");
+  stream_->SendRequestHeaders(
+      headers.Pass(), end_stream ? NO_MORE_DATA_TO_SEND : MORE_DATA_TO_SEND);
+}
+
+void BidirectionalStreamSpdyJob::OnStreamInitialized(int rv) {
+  DCHECK_NE(ERR_IO_PENDING, rv);
+  if (rv == OK) {
+    stream_ = stream_request_.ReleaseStream();
+    stream_->SetDelegate(this);
+    SendRequestHeaders();
+    return;
+  }
+  delegate_->OnFailed(static_cast<Error>(rv));
+}
+
+void BidirectionalStreamSpdyJob::ScheduleBufferedRead() {
+  // If there is already a scheduled DoBufferedRead, don't issue
+  // another one. Mark that we have received more data and return.
+  if (timer_->IsRunning()) {
+    more_read_data_pending_ = true;
+    return;
+  }
+
+  more_read_data_pending_ = false;
+  timer_->Start(FROM_HERE, kBufferTime,
+                base::Bind(&BidirectionalStreamSpdyJob::DoBufferedRead,
+                           weak_factory_.GetWeakPtr()));
+}
+
+void BidirectionalStreamSpdyJob::DoBufferedRead() {
+  DCHECK(!timer_->IsRunning());
+  // If the stream errored out, do not complete the read.
+  if (!stream_ && !stream_closed_)
+    return;
+  if (stream_closed_ && closed_stream_status_ != OK)
+    return;
+
+  // When |more_read_data_pending_| is true, it means that more data has arrived
+  // since started waiting. Wait a little longer and continue to buffer.
+  if (more_read_data_pending_ && ShouldWaitForMoreBufferedData()) {
+    ScheduleBufferedRead();
+    return;
+  }
+
+  int rv = 0;
+  if (user_buffer_) {
+    rv = ReadData(user_buffer_.get(), user_buffer_len_);
+    DCHECK_NE(ERR_IO_PENDING, rv);
+    user_buffer_ = nullptr;
+    user_buffer_len_ = 0;
+    delegate_->OnReadCompleted(rv);
+  }
+}
+
+bool BidirectionalStreamSpdyJob::ShouldWaitForMoreBufferedData() const {
+  if (stream_closed_)
+    return false;
+  DCHECK_GT(user_buffer_len_, 0);
+  return data_queue_.GetTotalSize() < static_cast<size_t>(user_buffer_len_);
+}
+
+}  // namespace net