Cast: Increase UDP socket send buffer size

media/cast/net/cast_transport_sender_impl.cc

 // Copyright 2014 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 "media/cast/net/cast_transport_sender_impl.h"
 
 #include "base/single_thread_task_runner.h"
 #include "base/values.h"
 #include "media/cast/net/cast_transport_config.h"
 #include "media/cast/net/cast_transport_defines.h"
 #include "media/cast/net/udp_transport.h"
+#include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 
 namespace media {
 namespace cast {
 
 namespace {
+
+// See header file for what these mean.
+const char kOptionPacerTargetBurstSize[] = "pacer_target_burst_size";
+const char kOptionPacerMaxBurstSize[] = "pacer_max_burst_size";
+const char kOptionSendBufferMinSize[] = "send_buffer_min_size";
+const char kOptionDscp[] = "DSCP";
+const char kOptionWifiDisableScan[] = "disable_wifi_scan";
+const char kOptionWifiMediaStreamingMode[] = "media_streaming_mode";
+
 int LookupOptionWithDefault(const base::DictionaryValue& options,
                             const std::string& path,
                             int default_value) {
   int ret;
   if (options.GetInteger(path, &ret)) {
     return ret;
   } else {
     return default_value;
   }
 };
 
+int32 GetTransportSendBufferSize(const base::DictionaryValue& options) {

[miu, 2014/10/16 18:31:57]

s/int32/int/ and throughout.  There's no good reason to require a specific
number of bits.

[Alpha Left Google, 2014/10/16 18:41:27]

Reason I chose int32 is because udp socket's SetSendBufferSize(int32 size)
already takes a int32. I wanted to make the API consistent throughout.

+  // Socket send buffer size needs to be at least greater than one burst
+  // size.
+  int32 max_burst_size =
+      LookupOptionWithDefault(options, kOptionPacerMaxBurstSize,
+                              kMaxBurstSize) * kMaxIpPacketSize;
+  int32 min_send_buffer_size =
+      LookupOptionWithDefault(options, kOptionSendBufferMinSize, 0);
+  return std::max(max_burst_size, min_send_buffer_size);
+}
+
 }  // namespace
 
 scoped_ptr<CastTransportSender> CastTransportSender::Create(
     net::NetLog* net_log,
     base::TickClock* clock,
     const net::IPEndPoint& remote_end_point,
     scoped_ptr<base::DictionaryValue> options,
     const CastTransportStatusCallback& status_callback,
     const BulkRawEventsCallback& raw_events_callback,
     base::TimeDelta raw_events_callback_interval,
@@ skipping 20 matching lines @@
     const net::IPEndPoint& remote_end_point,
     scoped_ptr<base::DictionaryValue> options,
     const CastTransportStatusCallback& status_callback,
     const BulkRawEventsCallback& raw_events_callback,
     base::TimeDelta raw_events_callback_interval,
     const scoped_refptr<base::SingleThreadTaskRunner>& transport_task_runner,
     PacketSender* external_transport)
     : clock_(clock),
       status_callback_(status_callback),
       transport_task_runner_(transport_task_runner),
-      transport_(external_transport ? NULL
-                                    : new UdpTransport(net_log,
-                                                       transport_task_runner,
-                                                       net::IPEndPoint(),
-                                                       remote_end_point,
-                                                       status_callback)),
+      transport_(
+          external_transport ?
+              NULL :
+              new UdpTransport(net_log,
+                               transport_task_runner,
+                               net::IPEndPoint(),
+                               remote_end_point,
+                               GetTransportSendBufferSize(*options.get()),

[miu, 2014/10/16 18:31:57]

Don't need the .get().  Just *options will work.

[Alpha Left Google, 2014/10/16 18:41:27]

Done.

+                               status_callback)),
       pacer_(LookupOptionWithDefault(*options.get(),
-                                     "pacer_target_burst_size",
+                                     kOptionPacerTargetBurstSize,
                                      kTargetBurstSize),
              LookupOptionWithDefault(*options.get(),
-                                     "pacer_max_burst_size",
+                                     kOptionPacerMaxBurstSize,
                                      kMaxBurstSize),
              clock,
              &logging_,
              external_transport ? external_transport : transport_.get(),
              transport_task_runner),
       raw_events_callback_(raw_events_callback),
       raw_events_callback_interval_(raw_events_callback_interval),
       last_byte_acked_for_audio_(0),
       weak_factory_(this) {
   DCHECK(clock_);
   if (!raw_events_callback_.is_null()) {
     DCHECK(raw_events_callback_interval > base::TimeDelta());
     event_subscriber_.reset(new SimpleEventSubscriber);
     logging_.AddRawEventSubscriber(event_subscriber_.get());
     transport_task_runner->PostDelayedTask(
         FROM_HERE,
         base::Bind(&CastTransportSenderImpl::SendRawEvents,
                    weak_factory_.GetWeakPtr()),
         raw_events_callback_interval);
   }
   if (transport_) {
-    if (options->HasKey("DSCP")) {
+    if (options->HasKey(kOptionDscp)) {
       // The default DSCP value for cast is AF41. Which gives it a higher
       // priority over other traffic.
       transport_->SetDscp(net::DSCP_AF41);
     }
     transport_->StartReceiving(
         base::Bind(&CastTransportSenderImpl::OnReceivedPacket,
                    weak_factory_.GetWeakPtr()));
     int wifi_options = 0;
-    if (options->HasKey("disable_wifi_scan")) {
+    if (options->HasKey(kOptionWifiDisableScan)) {
       wifi_options |= net::WIFI_OPTIONS_DISABLE_SCAN;
     }
-    if (options->HasKey("media_streaming_mode")) {
+    if (options->HasKey(kOptionWifiMediaStreamingMode)) {
       wifi_options |= net::WIFI_OPTIONS_MEDIA_STREAMING_MODE;
     }
     if (wifi_options) {
       wifi_options_autoreset_ = net::SetWifiOptions(wifi_options);
     }
   }
 }
 
 CastTransportSenderImpl::~CastTransportSenderImpl() {
   if (event_subscriber_.get())
@@ skipping 269 matching lines @@
   // 2. Specifies a deduplication window. For video this would be the most
   //    recent RTT. For audio there is no deduplication.
   ResendPackets(ssrc,
                 cast_message.missing_frames_and_packets,
                 true,
                 dedup_info);
 }
 
 }  // namespace cast
 }  // namespace media