Implement ChannelMultiplexer.

ChannelMultiplexer allows multiple logical channels to share a 
single underlying transport channel.

BUG=137135

Review URL: https://chromiumcodereview.appspot.com/10830046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150484 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 88 insertions, 0 deletions

diff --git a/remoting/protocol/channel_multiplexer.h b/remoting/protocol/channel_multiplexer.h
new file mode 100644
index 0000000..0f16fb1
--- /dev/null
+++ b/remoting/protocol/channel_multiplexer.h
@@ -0,0 +1,88 @@
+// Copyright (c) 2012 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.
+
+#ifndef REMOTING_PROTOCOL_CHANNEL_MULTIPLEXER_H_
+#define REMOTING_PROTOCOL_CHANNEL_MULTIPLEXER_H_
+
+#include "remoting/proto/mux.pb.h"
+#include "remoting/protocol/buffered_socket_writer.h"
+#include "remoting/protocol/channel_factory.h"
+#include "remoting/protocol/message_reader.h"
+
+namespace remoting {
+namespace protocol {
+
+class ChannelMultiplexer : public ChannelFactory {
+ public:
+  static const char kMuxChannelName[];
+
+  // |factory| is used to create the channel upon which to multiplex.
+  ChannelMultiplexer(ChannelFactory* factory,
+                     const std::string& base_channel_name);
+  virtual ~ChannelMultiplexer();
+
+  // ChannelFactory interface.
+  virtual void CreateStreamChannel(
+      const std::string& name,
+      const StreamChannelCallback& callback) OVERRIDE;
+  virtual void CreateDatagramChannel(
+      const std::string& name,
+      const DatagramChannelCallback& callback) OVERRIDE;
+  virtual void CancelChannelCreation(const std::string& name) OVERRIDE;
+
+ private:
+  struct PendingChannel;
+  class MuxChannel;
+  class MuxSocket;
+  friend class MuxChannel;
+
+  // Callback for |base_channel_| creation.
+  void OnBaseChannelReady(scoped_ptr<net::StreamSocket> socket);
+
+  // Helper method used to create channels.
+  MuxChannel* GetOrCreateChannel(const std::string& name);
+
+  // Callbacks for |writer_| and |reader_|.
+  void OnWriteFailed(int error);
+  void OnIncomingPacket(scoped_ptr<MultiplexPacket> packet,
+                        const base::Closure& done_task);
+
+  // Called by MuxChannel.
+  bool DoWrite(scoped_ptr<MultiplexPacket> packet,
+               const base::Closure& done_task);
+
+  // Factory used to create |base_channel_|. Set to NULL once creation is
+  // finished or failed.
+  ChannelFactory* base_channel_factory_;
+
+  // Name of the underlying channel.
+  std::string base_channel_name_;
+
+  // The channel over which to multiplex.
+  scoped_ptr<net::StreamSocket> base_channel_;
+
+  // List of requested channels while we are waiting for |base_channel_|.
+  std::list<PendingChannel> pending_channels_;
+
+  int next_channel_id_;
+  std::map<std::string, MuxChannel*> channels_;
+
+  // Channels are added to |channels_by_receive_id_| only after we receive
+  // receive_id from the remote peer.
+  std::map<int, MuxChannel*> channels_by_receive_id_;
+
+  BufferedSocketWriter writer_;
+  ProtobufMessageReader<MultiplexPacket> reader_;
+
+  // Flag used by OnWriteFailed() to detect when the multiplexer is destroyed.
+  bool* destroyed_flag_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChannelMultiplexer);
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+
+#endif  // REMOTING_PROTOCOL_CHANNEL_MULTIPLEXER_H_