TrackMediaInfoMap added.

webrtc/api/trackmediainfomap.h

Index: webrtc/api/trackmediainfomap.h
diff --git a/webrtc/api/trackmediainfomap.h b/webrtc/api/trackmediainfomap.h
new file mode 100644
index 0000000000000000000000000000000000000000..dc86288c7e292902e2a0d99133fd75fe499f9d46
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+++ b/webrtc/api/trackmediainfomap.h
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+/*
+ *  Copyright 2016 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_API_TRACKMEDIAINFOMAP_H_
+#define WEBRTC_API_TRACKMEDIAINFOMAP_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "webrtc/api/mediastreaminterface.h"
+#include "webrtc/api/rtpreceiverinterface.h"
+#include "webrtc/api/rtpsenderinterface.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/media/base/mediachannel.h"
+
+namespace webrtc {
+
+// Audio/video tracks and sender/receiver statistical information are associated
+// with each other based on attachments to RTP senders/receivers. This class
+// maps that relationship, in both directions, so that stats about a track can
+// be retrieved on a per-attachment basis.
+//
+// An RTP sender/receiver sends or receives media for a set of SSRCs. The media
+// comes from an audio/video track that is attached to it.
+// |[Voice/Video][Sender/Receiver]Info| has statistical information for a set of
+// SSRCs. Looking at the RTP senders and receivers uncovers the track <-> info
+// relationships, which this class does.
+class TrackMediaInfoMap {
+ public:
+  TrackMediaInfoMap(
+      std::unique_ptr<cricket::VoiceMediaInfo> voice_media_info,
+      std::unique_ptr<cricket::VideoMediaInfo> video_media_info,
+      const std::vector<rtc::scoped_refptr<RtpSenderInterface>>& rtp_senders,
+      const std::vector<rtc::scoped_refptr<RtpReceiverInterface>>&
+          rtp_receivers);
+
+  const cricket::VoiceMediaInfo* voice_media_info() const {
+    return voice_media_info_.get();
+  }
+  const cricket::VideoMediaInfo* video_media_info() const {
+    return video_media_info_.get();
+  }
+
+  const std::vector<cricket::VoiceSenderInfo*>* GetVoiceSenderInfos(
+      const AudioTrackInterface& local_audio_track) const;
+  const cricket::VoiceReceiverInfo* GetVoiceReceiverInfo(
+      const AudioTrackInterface& remote_audio_track) const;
+  const std::vector<cricket::VideoSenderInfo*>* GetVideoSenderInfos(
+      const VideoTrackInterface& local_video_track) const;
+  const cricket::VideoReceiverInfo* GetVideoReceiverInfo(
+      const VideoTrackInterface& remote_video_track) const;
+
+  rtc::scoped_refptr<AudioTrackInterface> GetAudioTrack(
+      const cricket::VoiceSenderInfo& voice_sender_info) const;
+  rtc::scoped_refptr<AudioTrackInterface> GetAudioTrack(
+      const cricket::VoiceReceiverInfo& voice_receiver_info) const;
+  rtc::scoped_refptr<VideoTrackInterface> GetVideoTrack(
+      const cricket::VideoSenderInfo& video_sender_info) const;
+  rtc::scoped_refptr<VideoTrackInterface> GetVideoTrack(
+      const cricket::VideoReceiverInfo& video_receiver_info) const;
+
+ private:
+  std::unique_ptr<cricket::VoiceMediaInfo> voice_media_info_;
+  std::unique_ptr<cricket::VideoMediaInfo> video_media_info_;
+  // These maps map tracks (identified by a pointer) to their corresponding info
+  // object of the correct kind. One track can map to multiple info objects.
+  std::map<const AudioTrackInterface*, std::vector<cricket::VoiceSenderInfo*>>
+      local_audio_track_to_infos_;

[pthatcher1, 2017/01/13 00:10:29]

Would std::multimap make sense?  We use it in call.cc for things like this.

[hbos, 2017/01/13 13:58:24]

That works but then I'd have to make Get[Voice/Video]SenderInfos return a pair
of iterators, and expose the map's end() iterator or rely on std::distance == 0
or rtc::Optional. std::equal, std::distance, etc I find more messy than working
with std::vector. Or if I'm constructing a vector for the return value I might
as well map it like I do.

I'm keeping std::vector unless there is a good reason to switch.

+  std::map<const AudioTrackInterface*, cricket::VoiceReceiverInfo*>
+      remote_audio_track_to_info_;
+  std::map<const VideoTrackInterface*, std::vector<cricket::VideoSenderInfo*>>
+      local_video_track_to_infos_;
+  std::map<const VideoTrackInterface*, cricket::VideoReceiverInfo*>
+      remote_video_track_to_info_;
+  // These maps map info objects to their corresponding tracks. They are always
+  // the inverse of the maps above. One info object always maps to only one
+  // track.
+  std::map<const cricket::VoiceSenderInfo*,
+      rtc::scoped_refptr<AudioTrackInterface>> voice_sender_info_to_track_;

[pthatcher1, 2017/01/13 00:10:29]

I prefer, and usually see in our code y_by_x instead of x_to_y.   

[hbos, 2017/01/13 13:58:24]

Done.

+  std::map<const cricket::VoiceReceiverInfo*,
+      rtc::scoped_refptr<AudioTrackInterface>> voice_receiver_info_to_track_;
+  std::map<const cricket::VideoSenderInfo*,
+      rtc::scoped_refptr<VideoTrackInterface>> video_sender_info_to_track_;
+  std::map<const cricket::VideoReceiverInfo*,
+      rtc::scoped_refptr<VideoTrackInterface>> video_receiver_info_to_track_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_TRACKMEDIAINFOMAP_H_