Copy the (early prototype of) remoting in Chrome into the public tree....

remoting/base/protocol_decoder.h

+// Copyright (c) 2010 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_BASE_PROTOCOL_DECODER_H_
+#define REMOTING_BASE_PROTOCOL_DECODER_H_
+
+#include <deque>
+#include <vector>
+
+#include "base/ref_counted.h"
+#include "google/protobuf/message_lite.h"
+#include "media/base/data_buffer.h"
+#include "remoting/base/protocol/chromotocol.pb.h"
+
+namespace remoting {
+
+typedef std::vector<chromotocol_pb::HostMessage*> HostMessageList;
+typedef std::vector<chromotocol_pb::ClientMessage*> ClientMessageList;
+
+// A protocol decoder is used to decode data transmitted in the chromoting
+// network.
+// TODO(hclam): Defines the interface and implement methods.
+class ProtocolDecoder {
+ public:
+  ProtocolDecoder();
+
+  virtual ~ProtocolDecoder() {}
+
+  // Parse data received from network into ClientMessages. Ownership of |data|
+  // is passed to this object and output is written to |messages|.
+  virtual void ParseClientMessages(scoped_refptr<media::DataBuffer> data,
+                                   ClientMessageList* messages);
+
+  // Parse data received from network into HostMessages. Ownership of |data|
+  // is passed to this object and output is written to |messages|.
+  virtual void ParseHostMessages(scoped_refptr<media::DataBuffer> data,
+                                 HostMessageList* messages);
+
+ private:
+  // A private method used to parse data received from network into protocol
+  // buffers.
+  template <typename T>
+  void ParseMessages(scoped_refptr<media::DataBuffer> data,
+                     std::vector<T*>* messages);
+
+  // Parse one message from |data_list_|. Return true if sucessful.
+  template <typename T>
+  bool ParseOneMessage(T** messages);
+
+  // A utility method to read payload size of the protocol buffer from the
+  // data list. Return false if we don't have enough data.
+  bool GetPayloadSize(int* size);
+
+  typedef std::deque<scoped_refptr<media::DataBuffer> > DataList;
+  DataList data_list_;
+  int last_read_position_;
+
+  // Count the number of bytes in |data_list_| not read.
+  int available_bytes_;
+
+  // Stores the size of the next payload if known.
+  int next_payload_;
+
+  // True if the size of the next payload is known. After one payload is read,
+  // this is reset to false.
+  bool next_payload_known_;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_BASE_PROTOCOL_DECODER_H_