Cleanup channel dispatchers

remoting/protocol/protobuf_message_parser.h

+// Copyright 2014 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_PROTOBUF_MESSAGE_PARSER_H_
+#define REMOTING_PROTOCOL_PROTOBUF_MESSAGE_PARSER_H_
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "remoting/base/compound_buffer.h"
+#include "remoting/protocol/message_reader.h"
+
+namespace remoting {
+namespace protocol {
+
+// Version of MessageReader for protocol buffer messages, that parses
+// each incoming message.
+template <class T>
+class ProtobufMessageParser {
+ public:
+  // The callback that is called when a new message is received. |done_task|
+  // must be called by the callback when it's done processing the |message|.
+  typedef typename base::Callback<void(scoped_ptr<T> message,
+                                       const base::Closure& done_task)>
+      MessageReceivedCallback;
+
+  // |message_reader| must outlive ProtobufMessageParser.
+  ProtobufMessageParser(const MessageReceivedCallback& callback,
+                        MessageReader* message_reader)
+      : message_reader_(message_reader),
+        message_received_callback_(callback) {
+    message_reader->SetMessageReceivedCallback(base::Bind(
+        &ProtobufMessageParser<T>::OnNewData, base::Unretained(this)));
+  }
+  ~ProtobufMessageParser() {
+    message_reader_->SetMessageReceivedCallback(
+        MessageReader::MessageReceivedCallback());
+  }
+
+ private:
+  void OnNewData(scoped_ptr<CompoundBuffer> buffer,
+                 const base::Closure& done_task) {
+    scoped_ptr<T> message(new T());
+    CompoundBufferInputStream stream(buffer.get());
+    bool ret = message->ParseFromZeroCopyStream(&stream);
+    if (!ret) {
+      LOG(WARNING) << "Received message that is not a valid protocol buffer.";
+    } else {
+      DCHECK_EQ(stream.position(), buffer->total_bytes());
+      message_received_callback_.Run(message.Pass(), done_task);
+    }
+  }
+
+  MessageReader* message_reader_;
+  MessageReceivedCallback message_received_callback_;
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_PROTOBUF_MESSAGE_PARSER_H_