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   typedef std::multimap<RtpTimestamp, RtcpEvent> RtcpEventMultiMap;
  34
  35   // Identifies whether the subscriber will process audio or video related
  36   // frame events.
  37   enum Type {
  38     kAudioEventSubscriber,  // Only processes audio events
  39     kVideoEventSubscriber   // Only processes video events
  40   };
  41
  42   // |max_size_to_retain|: The object will keep up to |max_size_to_retain|
  43   // events
  44   // in the map. Once threshold has been reached, an event with the smallest
  45   // RTP timestamp will be removed.
  46   // |type|: Determines whether the subscriber will process only audio or video
  47   // events.
  48   ReceiverRtcpEventSubscriber(const size_t max_size_to_retain, Type type);
  49
  50   virtual ~ReceiverRtcpEventSubscriber();
  51
  52   // RawEventSubscriber implementation.
  53   virtual void OnReceiveFrameEvent(const FrameEvent& frame_event) OVERRIDE;
  54   virtual void OnReceivePacketEvent(const PacketEvent& packet_event) OVERRIDE;
  55   virtual void OnReceiveGenericEvent(const GenericEvent& generic_event)
  56       OVERRIDE;
  57
  58   const RtcpEventMultiMap& get_rtcp_events() const { return rtcp_events_; }
  59
  60  private:
  61   // If |rtcp_events_.size()| exceeds |max_size_to_retain_|, remove an oldest
  62   // entry (determined by RTP timestamp) so its size no greater than
  63   // |max_size_to_retain_|.
  64   void TruncateMapIfNeeded();
  65
  66   // Returns |true| if events of |event_type| should be processed.
  67   bool ShouldProcessEvent(CastLoggingEvent event_type);
  68
  69   const size_t max_size_to_retain_;
  70   Type type_;
  71
  72   // The key should really be something more than just a RTP timestamp in order
  73   // to differentiate between video and audio frames, but since the
  74   // implementation doesn't mix audio and video frame events, RTP timestamp
  75   // only as key is fine.
  76   RtcpEventMultiMap rtcp_events_;
  77
  78   // Ensures methods are only called on the main thread.
  79   base::ThreadChecker thread_checker_;
  80
  81   DISALLOW_COPY_AND_ASSIGN(ReceiverRtcpEventSubscriber);
  82 };
  83
  84 }  // namespace cast
  85 }  // namespace media
  86
  87 #endif  // MEDIA_CAST_RTCP_RECEIVER_RTCP_EVENT_SUBSCRIBER_H_