media/cast/rtcp/receiver_rtcp_event_subscriber.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_CAST_RTCP_RECEIVER_RTCP_EVENT_SUBSCRIBER_H_
   6 #define MEDIA_CAST_RTCP_RECEIVER_RTCP_EVENT_SUBSCRIBER_H_
   7
   8 #include <map>
   9
  10 #include "base/threading/thread_checker.h"
  11 #include "media/cast/logging/logging_defines.h"
  12 #include "media/cast/logging/raw_event_subscriber.h"
  13 #include "media/cast/rtcp/rtcp_defines.h"
  14
  15 namespace base {
  16 class SingleThreadTaskRunner;
  17 }
  18
  19 namespace media {
  20 namespace cast {
  21
  22 // A RawEventSubscriber implementation with the following properties:
  23 // - Only processes raw event types that are relevant for sending from cast
  24 //   receiver to cast sender via RTCP.
  25 // - Captures information to be sent over to RTCP from raw event logs into the
  26 //   more compact RtcpEvent struct.
  27 // - Orders events by RTP timestamp with a multimap.
  28 // - Internally, the map is capped at a maximum size configurable by the caller.
  29 //   The subscriber only keeps the most recent events (determined by RTP
  30 //   timestamp) up to the size limit.
  31 class ReceiverRtcpEventSubscriber : public RawEventSubscriber {
  32  public:
  33   // Identifies whether the subscriber will process audio or video related
  34   // frame events.
  35   enum Type {
  36     kAudioEventSubscriber,  // Only processes audio events
  37     kVideoEventSubscriber   // Only processes video events
  38   };
  39
  40   // |max_size_to_retain|: The object will keep up to |max_size_to_retain|
  41   // events
  42   // in the map. Once threshold has been reached, an event with the smallest
  43   // RTP timestamp will be removed.
  44   // |type|: Determines whether the subscriber will process only audio or video
  45   // events.
  46   ReceiverRtcpEventSubscriber(const size_t max_size_to_retain, Type type);
  47
  48   virtual ~ReceiverRtcpEventSubscriber();
  49
  50   // RawEventSubscriber implementation.
  51   virtual void OnReceiveFrameEvent(const FrameEvent& frame_event) OVERRIDE;
  52   virtual void OnReceivePacketEvent(const PacketEvent& packet_event) OVERRIDE;
  53   virtual void OnReceiveGenericEvent(const GenericEvent& generic_event)
  54       OVERRIDE;
  55
  56   // Converts all collected events since last invocation into
  57   // a RtcpReceiverFrameLogMessage, assigns it to |receiver_log|, and clears
  58   // |rtcp_events_|.
  59   void GetReceiverLogMessageAndReset(RtcpReceiverLogMessage* receiver_log);
  60
  61  private:
  62   // If |rtcp_events_.size()| exceeds |max_size_to_retain_|, remove an oldest
  63   // entry (determined by RTP timestamp) so its size no greater than
  64   // |max_size_to_retain_|.
  65   void TruncateMapIfNeeded();
  66
  67   // Returns |true| if events of |event_type| should be processed.
  68   bool ShouldProcessEvent(CastLoggingEvent event_type);
  69
  70   const size_t max_size_to_retain_;
  71   Type type_;
  72
  73   // The key should really be something more than just a RTP timestamp in order
  74   // to differentiate between video and audio frames, but since the
  75   // implementation doesn't mix audio and video frame events, RTP timestamp
  76   // only as key is fine.
  77   std::multimap<RtpTimestamp, RtcpEvent> rtcp_events_;
  78
  79   // Ensures methods are only called on the main thread.
  80   base::ThreadChecker thread_checker_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(ReceiverRtcpEventSubscriber);
  83 };
  84
  85 }  // namespace cast
  86 }  // namespace media
  87
  88 #endif  // MEDIA_CAST_RTCP_RECEIVER_RTCP_EVENT_SUBSCRIBER_H_