Slight reduction in string copying for WebRTC stats.

content/renderer/media/peer_connection_tracker.cc

 // Copyright (c) 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 "content/renderer/media/peer_connection_tracker.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/common/media/peer_connection_tracker_messages.h"
 #include "content/renderer/media/rtc_media_constraints.h"
 #include "content/renderer/media/rtc_peer_connection_handler.h"
 #include "content/renderer/render_thread_impl.h"
 #include "third_party/WebKit/public/platform/WebMediaConstraints.h"
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 #include "third_party/WebKit/public/platform/WebRTCICECandidate.h"
 #include "third_party/WebKit/public/platform/WebRTCPeerConnectionHandlerClient.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "third_party/WebKit/public/web/WebUserMediaRequest.h"
 
 using std::string;
 using webrtc::MediaConstraintsInterface;
+using webrtc::StatsReport;
+using webrtc::StatsReports;
 using blink::WebRTCPeerConnectionHandlerClient;
 
 namespace content {
 
 static string SerializeServers(
     const std::vector<webrtc::PeerConnectionInterface::IceServer>& servers) {
   string result = "[";
   for (size_t i = 0; i < servers.size(); ++i) {
     result += servers[i].uri;
     if (i != servers.size() - 1)
@@ skipping 162 matching lines @@
       break;
   }
   return result;
 }
 
 // Builds a DictionaryValue from the StatsReport.
 // The caller takes the ownership of the returned value.
 // Note:
 // The format must be consistent with what webrtc_internals.js expects.
 // If you change it here, you must change webrtc_internals.js as well.
-static base::DictionaryValue* GetDictValueStats(
-    const webrtc::StatsReport& report) {
+static base::DictionaryValue* GetDictValueStats(const StatsReport& report) {
   if (report.values().empty())
     return NULL;
 
   base::DictionaryValue* dict = new base::DictionaryValue();
   dict->SetDouble("timestamp", report.timestamp());
 
   base::ListValue* values = new base::ListValue();
   dict->Set("values", values);
 
   for (const auto& v : report.values()) {
-    values->AppendString(v.second->display_name());
-    values->AppendString(v.second->ToString());
+    const StatsReport::ValuePtr& value = v.second;
+    values->AppendString(value->display_name());
+    switch (value->type()) {
+      case StatsReport::Value::kInt:
+        values->AppendInteger(value->int_val());
+        break;
+      case StatsReport::Value::kFloat:
+        values->AppendDouble(value->float_val());
+        break;
+      case StatsReport::Value::kString:
+        values->AppendString(value->string_val());
+        break;
+      case StatsReport::Value::kStaticString:
+        values->AppendString(value->static_string_val());
+        break;
+      case StatsReport::Value::kBool:
+        values->AppendBoolean(value->bool_val());
+        break;
+      case StatsReport::Value::kInt64:  // int64 isn't supported, so use string.

[perkj_chrome, 2015/03/16 10:36:39]

todo:tommi fix int64 support?

[tommi (sloooow) - chröme, 2015/03/16 18:07:41]

It's not supported by base::ListValue and apparently it would be a spec
violation if it did:
https://code.google.com/p/chromium/codesearch#chromium/src/base/values.h&l=12

+      case StatsReport::Value::kId:
+      default:
+        values->AppendString(value->ToString());
+        break;
+    }
   }
 
   return dict;
 }
 
 // Builds a DictionaryValue from the StatsReport.
 // The caller takes the ownership of the returned value.
-static base::DictionaryValue* GetDictValue(const webrtc::StatsReport& report) {
+static base::DictionaryValue* GetDictValue(const StatsReport& report) {
   scoped_ptr<base::DictionaryValue> stats, result;
 
   stats.reset(GetDictValueStats(report));
   if (!stats)
     return NULL;
 
   result.reset(new base::DictionaryValue());
   // Note:
   // The format must be consistent with what webrtc_internals.js expects.
   // If you change it here, you must change webrtc_internals.js as well.
   result->Set("stats", stats.release());
   result->SetString("id", report.id()->ToString());
   result->SetString("type", report.TypeToString());
 
   return result.release();
 }
 
 class InternalStatsObserver : public webrtc::StatsObserver {
  public:
   InternalStatsObserver(int lid)
       : lid_(lid), main_thread_(base::ThreadTaskRunnerHandle::Get()) {}
 
-  void OnComplete(const webrtc::StatsReports& reports) override {
+  void OnComplete(const StatsReports& reports) override {
     scoped_ptr<base::ListValue> list(new base::ListValue());
 
     for (const auto* r : reports) {
       base::DictionaryValue* report = GetDictValue(*r);
       if (report)
         list->Append(report);
     }
 
     if (!list->empty()) {
       main_thread_->PostTask(FROM_HERE,
@@ skipping 312 matching lines @@
   DCHECK(main_thread_.CalledOnValidThread());
   if (peer_connection_id_map_.find(pc_handler) == peer_connection_id_map_.end())
     return;
 
   RenderThreadImpl::current()->Send(
       new PeerConnectionTrackerHost_UpdatePeerConnection(
           peer_connection_id_map_[pc_handler], type, value));
 }
 
 }  // namespace content