Define Stable API for WebRTC/Quartc

net/quic/quartc/quartc_packet_writer.cc

+// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/quic/quartc/quartc_packet_writer.h"
+
+namespace net {
+
+QuartcPacketWriter::QuartcPacketWriter(
+    QuartcSessionInterface::Transport* transport)
+    : transport_(transport) {}
+
+WriteResult QuartcPacketWriter::WritePacket(const char* buffer,
+                                            size_t buf_len,
+                                            const IPAddress& self_address,
+                                            const IPEndPoint& peer_address,
+                                            PerPacketOptions* options) {
+  DCHECK(transport_);
+  int bytes_written = transport_->Write(buffer, buf_len);
+  if (bytes_written <= 0) {
+    return WriteResult(WRITE_STATUS_BLOCKED, EWOULDBLOCK);
+  }
+  return WriteResult(WRITE_STATUS_OK, bytes_written);
+}
+
+bool QuartcPacketWriter::IsWriteBlockedDataBuffered() const {
+  return false;
+}
+
+bool QuartcPacketWriter::IsWriteBlocked() const {
+  DCHECK(transport_);
+  return !transport_->CanWrite();
+}
+
+// TODO(zhihuang) To figure out what is the better value to return. The
+// transport in WebRTC network layer may become the bottleneck when determining
+// the MTU.
+QuicByteCount QuartcPacketWriter::GetMaxPacketSize(
+    const IPEndPoint& peer_address) const {
+  return kMaxPacketSize;

[pthatcher2, 2016/10/05 22:12:06]

We may want to drop it somewhat so that TURN encapsulation doesn't cause a UDP
packet to get too big.

[zhihuang1, 2016/10/13 06:22:40]

Make it half?

[pthatcher1, 2016/10/14 18:58:58]

No, that's way too drastic.  I looked into our current video and SCTP code, and
both use 1200:

https://cs.chromium.org/chromium/src/third_party/webrtc/media/engine/webrtcvi...

https://cs.chromium.org/chromium/src/third_party/webrtc/media/sctp/sctpdataen...


So we probably want to use that.  But I think passing it in via the config makes
sense.  

+}
+
+void QuartcPacketWriter::SetWritable() {}
+
+}  // namespace net