Add Socket::ReadIfReady()

net/spdy/spdy_session.cc

 // Copyright (c) 2012 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/spdy_session.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 11 matching lines @@
 #include "net/http/http_server_properties.h"
 #include "net/http/http_util.h"
 #include "net/http/transport_security_state.h"
 #include "net/log/net_log.h"
 #include "net/log/net_log_capture_mode.h"
 #include "net/log/net_log_event_type.h"
 #include "net/log/net_log_source.h"
 #include "net/log/net_log_source_type.h"
 #include "net/log/net_log_with_source.h"
 #include "net/proxy/proxy_server.h"
+#include "net/socket/socket.h"
 #include "net/socket/ssl_client_socket.h"
 #include "net/spdy/spdy_buffer_producer.h"
 #include "net/spdy/spdy_frame_builder.h"
 #include "net/spdy/spdy_http_utils.h"
 #include "net/spdy/spdy_protocol.h"
 #include "net/spdy/spdy_session_pool.h"
 #include "net/spdy/spdy_stream.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/ssl_cipher_suite_names.h"
 #include "net/ssl/ssl_connection_status_flags.h"
@@ skipping 1376 matching lines @@
 
   return result;
 }
 
 int SpdySession::DoRead() {
   CHECK(in_io_loop_);
 
   CHECK(connection_);
   CHECK(connection_->socket());
   read_state_ = READ_STATE_DO_READ_COMPLETE;
-  return connection_->socket()->Read(
-      read_buffer_.get(),
-      kReadBufferSize,
-      base::Bind(&SpdySession::PumpReadLoop,
-                 weak_factory_.GetWeakPtr(), READ_STATE_DO_READ_COMPLETE));
+  int rv = ERR_READ_IF_READY_NOT_IMPLEMENTED;
+  if (base::FieldTrialList::FindFullName(Socket::kReadIfReadyTrialName) ==
+      "enable") {
+    rv = connection_->socket()->ReadIfReady(
+        read_buffer_.get(), kReadBufferSize,
+        base::Bind(&SpdySession::PumpReadLoop, weak_factory_.GetWeakPtr(),
+                   READ_STATE_DO_READ));

[davidben, 2017/02/01 22:25:58]

Hah. That's much simpler than I expected!

[xunjieli, 2017/02/03 16:35:33]

Acknowledged :)

+    // TODO(xunjieli): Follow-up CL to release |read_buffer_|.
+  }
+  if (rv == ERR_READ_IF_READY_NOT_IMPLEMENTED) {
+    // Fallback to regular Read().
+    return connection_->socket()->Read(
+        read_buffer_.get(), kReadBufferSize,
+        base::Bind(&SpdySession::PumpReadLoop, weak_factory_.GetWeakPtr(),
+                   READ_STATE_DO_READ_COMPLETE));
+  }
+  if (rv == ERR_IO_PENDING)
+    read_state_ = READ_STATE_DO_READ;
+  return rv;
 }
 
 int SpdySession::DoReadComplete(int result) {
   CHECK(in_io_loop_);
 
   // Parse a frame.  For now this code requires that the frame fit into our
   // buffer (kReadBufferSize).
   // TODO(mbelshe): support arbitrarily large frames!
 
   if (result == 0) {
@@ skipping 1659 matching lines @@
     if (!queue->empty()) {
       SpdyStreamId stream_id = queue->front();
       queue->pop_front();
       return stream_id;
     }
   }
   return 0;
 }
 
 }  // namespace net