Modify PeerConnection for end-to-end QuicDataChannel usage

webrtc/api/quictransport.h

Index: webrtc/api/quictransport.h
diff --git a/webrtc/api/quictransport.h b/webrtc/api/quictransport.h
new file mode 100644
index 0000000000000000000000000000000000000000..06f814cfda8246a436638497d3424d7c11eb5373
--- /dev/null
+++ b/webrtc/api/quictransport.h
@@ -0,0 +1,77 @@
+/*
+ *  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_QUICTRANSPORT_H_
+#define WEBRTC_API_QUICTRANSPORT_H_
+
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+
+#include "webrtc/api/quicdatachannel.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/scoped_ref_ptr.h"

[pthatcher1, 2016/03/30 20:34:49]

If these aren't used in this file, please move them to the .cc.

[mikescarlett, 2016/04/05 19:58:51]

Done.

+#include "webrtc/base/sigslot.h"
+
+namespace net {
+typedef uint32_t QuicStreamId;
+}  // namespace net
+
+namespace cricket {
+class QuicTransportChannel;
+class ReliableQuicStream;
+}  // namepsace cricket
+
+namespace webrtc {
+
+// QuicTransport dispatches each ReliableQuicStream initiated by the
+// remote peer to its corresponding QuicDataChannel, and encapsulates a

[pthatcher1, 2016/03/30 20:34:49]

Might be more clear as "by reading the data channel ID from the stream and
looking it up in a map of id => QuicDataChannel."

[mikescarlett, 2016/04/05 19:58:51]

Done.

+// <data channel id, QuicDataChannel*> map. It reads the initial stream frame
+// sent by the remote peer's ReliableQuicStream to obtain the data channel id.
+// If the local peer has no existing QuicDataChannel with the given id, then a
+// new QuicDataChannel is created with the given id and remaining data from the
+// ReliableQuicStream. Otherwise the ReliableQuicStream is dispatched to an
+// existing QuicDataChannel, which reads the remaining data.

[pthatcher1, 2016/03/30 20:34:49]

Might be more clear as "if the QuicDataChannel exists, it sends the stream to
the QuicDataChannel.  Otherwise, it creates a QuicDataChannel with the given ID"

[mikescarlett, 2016/04/05 19:58:51]

Done.

+//
+// Each time the local peer creates a QuicDataChannel, the local peer should
+// call RegisterDataChannel() to register it to the map of QuicDataChannel ids.
+// The local peer should call UnregisterDataChannel() if the QuicDataChannel
+// should no longer be accessed.
+class QuicTransport : public sigslot::has_slots<> {
+ public:
+  explicit QuicTransport(cricket::QuicTransportChannel* quic_transport_channel);
+  // Adds a QUIC data channel to the map of existing QUIC data channels.
+  void RegisterDataChannel(QuicDataChannel* data_channel);
+  // Removes a QUIC data channel from the map of QUIC data channels.
+  void UnregisterDataChannel(int id);

[pthatcher1, 2016/03/30 20:34:49]

I think AddDataChannel and RemoveDataChannel would be slightly better names.

[mikescarlett, 2016/04/05 19:58:51]

Done.

+  bool has_data_channel(int id) const {

[pthatcher1, 2016/03/30 20:34:49]

HasDataChannel

[mikescarlett, 2016/04/05 19:58:51]

Done.

+    return data_channel_map_.find(id) != data_channel_map_.end();
+  }
+
+ private:
+  // Called by QuicTransportChannel when a QUIC stream is created for incoming
+  // data.
+  void OnIncomingStream(cricket::ReliableQuicStream* stream);
+  // Called by ReliableQuicStream when the first QUIC stream frame is received
+  // for incoming data.
+  void OnDataReceived(net::QuicStreamId stream_id,
+                      const char* data,
+                      size_t len);
+
+  // Map of <data channel id, QuicDataChannel*> values.

[pthatcher1, 2016/03/30 20:34:49]

Might be easier to read as "data channel ID => QuicDataChannel*"

[mikescarlett, 2016/04/05 19:58:51]

Done.

+  std::unordered_map<int, QuicDataChannel*> data_channel_map_;

[pthatcher1, 2016/03/30 20:34:49]

I think a better name would be data_channel_by_id_.

[mikescarlett, 2016/04/05 19:58:51]

Done.

+  // Map of <QUIC stream id, ReliableQuicStream*> values.

[pthatcher1, 2016/03/30 20:34:49]

Similarly, "QUIC stream ID => ReliableQuicStream"

[mikescarlett, 2016/04/05 19:58:51]

Done.

+  std::unordered_map<net::QuicStreamId, cricket::ReliableQuicStream*>
+      quic_stream_map_;

[pthatcher1, 2016/03/30 20:34:49]

quic_stream_by_id_

[mikescarlett, 2016/04/05 19:58:51]

Done.

+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_QUICTRANSPORT_H_