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 media {
  16 namespace cast {
  17
  18 // A RawEventSubscriber implementation with the following properties:
  19 // - Only processes raw event types that are relevant for sending from cast
  20 //   receiver to cast sender via RTCP.
  21 // - Captures information to be sent over to RTCP from raw event logs into the
  22 //   more compact RtcpEvent struct.
  23 // - Orders events by RTP timestamp with a multimap.
  24 // - Internally, the map is capped at a maximum size configurable by the caller.
  25 //   The subscriber only keeps the most recent events (determined by RTP
  26 //   timestamp) up to the size limit.
  27 class ReceiverRtcpEventSubscriber : public RawEventSubscriber {
  28  public:
  29   typedef std::multimap<RtpTimestamp, RtcpEvent> RtcpEventMultiMap;
  30
  31   // |max_size_to_retain|: The object will keep up to |max_size_to_retain|
  32   // events
  33   // in the map. Once threshold has been reached, an event with the smallest
  34   // RTP timestamp will be removed.
  35   // |type|: Determines whether the subscriber will process only audio or video
  36   // events.
  37   ReceiverRtcpEventSubscriber(const size_t max_size_to_retain,
  38       EventMediaType type);
  39
  40   virtual ~ReceiverRtcpEventSubscriber();
  41
  42   // RawEventSubscriber implementation.
  43   virtual void OnReceiveFrameEvent(const FrameEvent& frame_event) OVERRIDE;
  44   virtual void OnReceivePacketEvent(const PacketEvent& packet_event) OVERRIDE;
  45
  46   // Assigns events collected to |rtcp_events| and clears them from this
  47   // object.
  48   void GetRtcpEventsAndReset(RtcpEventMultiMap* rtcp_events);
  49
  50  private:
  51   // If |rtcp_events_.size()| exceeds |max_size_to_retain_|, remove an oldest
  52   // entry (determined by RTP timestamp) so its size no greater than
  53   // |max_size_to_retain_|.
  54   void TruncateMapIfNeeded();
  55
  56   // Returns |true| if events of |event_type| and |media_type|
  57   // should be processed.
  58   bool ShouldProcessEvent(CastLoggingEvent event_type,
  59       EventMediaType media_type);
  60
  61   const size_t max_size_to_retain_;
  62   EventMediaType type_;
  63
  64   // The key should really be something more than just a RTP timestamp in order
  65   // to differentiate between video and audio frames, but since the
  66   // implementation doesn't mix audio and video frame events, RTP timestamp
  67   // only as key is fine.
  68   RtcpEventMultiMap rtcp_events_;
  69
  70   // Ensures methods are only called on the main thread.
  71   base::ThreadChecker thread_checker_;
  72
  73   DISALLOW_COPY_AND_ASSIGN(ReceiverRtcpEventSubscriber);
  74 };
  75
  76 }  // namespace cast
  77 }  // namespace media
  78
  79 #endif  // MEDIA_CAST_RTCP_RECEIVER_RTCP_EVENT_SUBSCRIBER_H_