Chromecast: adds class to help record complex histograms.

chromecast/media/cma/base/buffering_controller.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 "chromecast/media/cma/base/buffering_controller.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "chromecast/base/metrics/cast_metrics_helper.h"
 #include "chromecast/media/cma/base/buffering_state.h"
 #include "chromecast/media/cma/base/cma_logging.h"
 #include "media/base/buffers.h"
 
 namespace chromecast {
 namespace media {
 
 BufferingController::BufferingController(
     const scoped_refptr<BufferingConfig>& config,
     const BufferingNotificationCB& buffering_notification_cb)
     : config_(config),
       buffering_notification_cb_(buffering_notification_cb),
       is_buffering_(false),
       begin_buffering_time_(base::Time()),
+      initial_buffering_(true),
       weak_factory_(this) {
   weak_this_ = weak_factory_.GetWeakPtr();
   thread_checker_.DetachFromThread();
 }
 
 BufferingController::~BufferingController() {
   // Some weak pointers might possibly be invalidated here.
   DCHECK(thread_checker_.CalledOnValidThread());
 }
 
@@ skipping 65 matching lines @@
       max_rendering_time = max_stream_rendering_time;
     }
   }
   return max_rendering_time;
 }
 
 void BufferingController::Reset() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   is_buffering_ = false;
   stream_list_.clear();

[damienv1, 2014/10/16 00:00:13]

Should initial_buffering_ be reset here as well ?

[gunsch, 2014/10/20 21:36:48]

Done.

 }
 
 void BufferingController::OnBufferingStateChanged(
     bool force_notification, bool buffering_timeout) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // Log the state of each stream.
   DumpState();
 
   bool is_low_buffering = IsLowBufferLevel();
@@ skipping 20 matching lines @@
   }
 
   // End buffering.
   if (is_buffering_prv && !is_buffering_) {
     // TODO(damienv): |buffering_user_time| could be a UMA histogram.
     base::Time current_time = base::Time::Now();
     base::TimeDelta buffering_user_time = current_time - begin_buffering_time_;
     CMALOG(kLogControl)
         << "Buffering took: "
         << buffering_user_time.InMilliseconds() << "ms";
+    chromecast::metrics::CastMetricsHelper::BufferingType buffering_type =
+        initial_buffering_ ?
+            chromecast::metrics::CastMetricsHelper::kInitialBuffering :
+            chromecast::metrics::CastMetricsHelper::kBufferingAfterUnderrun;
+    chromecast::metrics::CastMetricsHelper::GetInstance()->LogTimeToBufferAv(
+        buffering_type, buffering_user_time);
+
+    // Only the first buffering report is considered "initial buffering".
+    initial_buffering_ = false;
   }
 
   if (is_buffering_prv != is_buffering_ || force_notification)
     buffering_notification_cb_.Run(is_buffering_);
 }
 
 bool BufferingController::IsHighBufferLevel() {
   if (stream_list_.empty())
     return true;
 
@@ skipping 25 matching lines @@
 void BufferingController::DumpState() const {
   CMALOG(kLogControl) << __FUNCTION__;
   for (StreamList::const_iterator it = stream_list_.begin();
        it != stream_list_.end(); ++it) {
     CMALOG(kLogControl) << (*it)->ToString();
   }
 }
 
 }  // namespace media
 }  // namespace chromecast