Cast: Add GetStats() extensions API.

chrome/renderer/extensions/cast_streaming_native_handler.cc

 // Copyright 2013 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 "chrome/renderer/extensions/cast_streaming_native_handler.h"
 
 #include <functional>
 
 #include "base/base64.h"
 #include "base/logging.h"
@@ skipping 441 matching lines @@
       base::Bind(&CastStreamingNativeHandler::CallGetRawEventsCallback,
                  weak_factory_.GetWeakPtr(),
                  transport_id));
 }
 
 void CastStreamingNativeHandler::GetStats(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(2, args.Length());
   CHECK(args[0]->IsInt32());
   CHECK(args[1]->IsFunction());
+  const int transport_id = args[0]->ToInt32()->Value();
+  CastRtpStream* transport = GetRtpStreamOrThrow(transport_id);
+  if (!transport)
+    return;
 
-  // TODO(imcheng): Implement this.
+  linked_ptr<extensions::ScopedPersistent<v8::Function> > callback(
+      new extensions::ScopedPersistent<v8::Function>);
+  callback->reset(args[1].As<v8::Function>());
+  get_stats_callbacks_.insert(std::make_pair(transport_id, callback));
+
+  transport->GetStats(
+      base::Bind(&CastStreamingNativeHandler::CallGetStatsCallback,
+                 weak_factory_.GetWeakPtr(),
+                 transport_id));
 }
 
 void CastStreamingNativeHandler::CallGetRawEventsCallback(
     int transport_id,
     scoped_ptr<std::string> raw_events) {
   v8::Isolate* isolate = context()->isolate();
   v8::HandleScope handle_scope(isolate);
   v8::Context::Scope context_scope(context()->v8_context());
 
   RtpStreamCallbackMap::iterator it =
       get_raw_events_callbacks_.find(transport_id);
   if (it != get_raw_events_callbacks_.end()) {

[Alpha Left Google, 2014/03/03 07:11:39]

nit: Early return if it is not found. This the following code doesn't need to be
indented.

[imcheng, 2014/03/04 02:06:24]

Done.

     v8::Handle<v8::Value> callback_args[1];
     callback_args[0] = v8::String::NewFromUtf8(isolate,
                                                raw_events->data(),
                                                v8::String::kNormalString,
                                                raw_events->size());
     context()->CallFunction(it->second->NewHandle(isolate), 1, callback_args);
     get_raw_events_callbacks_.erase(it);
   }
 }
 
+void CastStreamingNativeHandler::CallGetStatsCallback(
+    int transport_id,
+    scoped_ptr<std::string> stats) {
+  v8::Isolate* isolate = context()->isolate();
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(context()->v8_context());
+
+  RtpStreamCallbackMap::iterator it = get_stats_callbacks_.find(transport_id);
+  if (it != get_stats_callbacks_.end()) {

[Alpha Left Google, 2014/03/03 07:11:39]

nit: Early return if it is not found. This the following code doesn't need to be
indented.

[imcheng, 2014/03/04 02:06:24]

Done.

+    v8::Handle<v8::Value> callback_args[1];
+    callback_args[0] = v8::String::NewFromUtf8(

[Alpha Left Google, 2014/03/03 07:11:39]

I think it's odd that we pass the javascript API with a JSON string. Can we give
it a javascript object? 

The stats we got from CastRtpStream can be a base::DictionaryValue. And then we
use a V8ValueConverter to convert it.

[imcheng, 2014/03/04 02:06:24]

Per offline chat discussion, this api will return an object converted from
DictionaryValue.

+        isolate, stats->data(), v8::String::kNormalString, stats->size());
+    context()->CallFunction(it->second->NewHandle(isolate), 1, callback_args);
+    get_stats_callbacks_.erase(it);
+  }
+}
+
 CastRtpStream* CastStreamingNativeHandler::GetRtpStreamOrThrow(
     int transport_id) const {
   RtpStreamMap::const_iterator iter = rtp_stream_map_.find(
       transport_id);
   if (iter != rtp_stream_map_.end())
     return iter->second.get();
   v8::Isolate* isolate = context()->v8_context()->GetIsolate();
   isolate->ThrowException(v8::Exception::RangeError(v8::String::NewFromUtf8(
       isolate, kRtpStreamNotFound)));
   return NULL;
 }
 
 CastUdpTransport* CastStreamingNativeHandler::GetUdpTransportOrThrow(
     int transport_id) const {
   UdpTransportMap::const_iterator iter = udp_transport_map_.find(
       transport_id);
   if (iter != udp_transport_map_.end())
     return iter->second.get();
   v8::Isolate* isolate = context()->v8_context()->GetIsolate();
   isolate->ThrowException(v8::Exception::RangeError(
       v8::String::NewFromUtf8(isolate, kUdpTransportNotFound)));
   return NULL;
 }
 
 }  // namespace extensions