Adding ViE CallStats to keep track of call statistics. As a start, only rtt is handled.

This CL will be followed by another CL connecting the dots.

BUG=769
TEST=New unittest added.

Review URL: https://webrtc-codereview.appspot.com/968006

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3117 4adac7df-926f-26a2-2b94-8c16560cd09d

1 files changed, 84 insertions, 0 deletions

diff --git a/video_engine/call_stats.h b/video_engine/call_stats.h
new file mode 100644
index 00000000..14619f1e
--- /dev/null
+++ b/video_engine/call_stats.h
@@ -0,0 +1,84 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_VIDEO_ENGINE_CALL_STATS_H_
+#define WEBRTC_VIDEO_ENGINE_CALL_STATS_H_
+
+#include <list>
+
+#include "webrtc/modules/interface/module.h"
+#include "webrtc/system_wrappers/interface/constructor_magic.h"
+#include "webrtc/system_wrappers/interface/scoped_ptr.h"
+
+namespace webrtc {
+
+class CriticalSectionWrapper;
+class RtcpRttObserver;
+
+// Interface used to distribute call statistics. Callbacks will be triggered as
+// soon as the class has been registered using RegisterStatsObserver.
+class StatsObserver {
+ public:
+  virtual void OnRttUpdate(uint32_t rtt) = 0;
+
+  virtual ~StatsObserver() {}
+};
+
+// CallStats keeps track of statistics for a call.
+class CallStats : public Module {
+ public:
+  friend class RtcpObserver;
+
+  CallStats();
+  ~CallStats();
+
+  // Implements Module, to use the process thread.
+  virtual int32_t TimeUntilNextProcess();
+  virtual int32_t Process();
+
+  // Returns a RtcpRttObserver to register at a statistics provider. The object
+  // has the same lifetime as the CallStats instance.
+  RtcpRttObserver* rtcp_rtt_observer() const;
+
+  // Registers/deregisters a new observer to receive statistics updates.
+  void RegisterStatsObserver(StatsObserver* observer);
+  void DeregisterStatsObserver(StatsObserver* observer);
+
+ protected:
+  void OnRttUpdate(uint32_t rtt);
+
+ private:
+  // Helper struct keeping track of the time a rtt value is reported.
+  struct RttTime {
+    RttTime(uint32_t new_rtt, int64_t rtt_time)
+        : rtt(new_rtt), time(rtt_time) {}
+    const uint32_t rtt;
+    const int64_t time;
+  };
+
+  // Protecting all members.
+  scoped_ptr<CriticalSectionWrapper> crit_;
+  // Observer receiving statistics updates.
+  scoped_ptr<RtcpRttObserver> rtcp_rtt_observer_;
+  // The last time 'Process' resulted in statistic update.
+  int64_t last_process_time_;
+
+  // All Rtt reports within valid time interval, oldest first.
+  std::list<RttTime> reports_;
+
+  // Observers getting stats reports.
+  std::list<StatsObserver*> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(CallStats);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_VIDEO_ENGINE_CALL_STATS_H_