Separates ipc code from common (http://crbug.com/16829)

ipc/ipc_channel.h

Index: ipc/ipc_channel.h
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
new file mode 100644
index 0000000000000000000000000000000000000000..a7a9a347b3c664133d8bffd3586a07592ae91a1d
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+++ b/ipc/ipc_channel.h
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+// Copyright (c) 2006-2008 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 IPC_IPC_CHANNEL_H_
+#define IPC_IPC_CHANNEL_H_
+
+#include "ipc/ipc_message.h"
+
+namespace IPC {
+
+//------------------------------------------------------------------------------
+
+class Channel : public Message::Sender {
+  // Security tests need access to the pipe handle.
+  friend class ChannelTest;
+
+ public:
+  // Implemented by consumers of a Channel to receive messages.
+  class Listener {
+   public:
+    virtual ~Listener() {}
+
+    // Called when a message is received.
+    virtual void OnMessageReceived(const Message& message) = 0;
+
+    // Called when the channel is connected and we have received the internal
+    // Hello message from the peer.
+    virtual void OnChannelConnected(int32 peer_pid) {}
+
+    // Called when an error is detected that causes the channel to close.
+    // This method is not called when a channel is closed normally.
+    virtual void OnChannelError() {}
+  };
+
+  enum Mode {
+    MODE_SERVER,
+    MODE_CLIENT
+  };
+
+  enum {
+    // The maximum message size in bytes. Attempting to receive a
+    // message of this size or bigger results in a channel error.
+    kMaximumMessageSize = 256 * 1024 * 1024,
+
+    // Ammount of data to read at once from the pipe.
+    kReadBufferSize = 4 * 1024
+  };
+
+  // Initialize a Channel.
+  //
+  // |channel_id| identifies the communication Channel.
+  // |mode| specifies whether this Channel is to operate in server mode or
+  // client mode.  In server mode, the Channel is responsible for setting up the
+  // IPC object, whereas in client mode, the Channel merely connects to the
+  // already established IPC object.
+  // |listener| receives a callback on the current thread for each newly
+  // received message.
+  //
+  Channel(const std::string& channel_id, Mode mode, Listener* listener);
+
+  ~Channel();
+
+  // Connect the pipe.  On the server side, this will initiate
+  // waiting for connections.  On the client, it attempts to
+  // connect to a pre-existing pipe.  Note, calling Connect()
+  // will not block the calling thread and may complete
+  // asynchronously.
+  bool Connect();
+
+  // Close this Channel explicitly.  May be called multiple times.
+  void Close();
+
+  // Modify the Channel's listener.
+  void set_listener(Listener* listener);
+
+  // Send a message over the Channel to the listener on the other end.
+  //
+  // |message| must be allocated using operator new.  This object will be
+  // deleted once the contents of the Message have been sent.
+  //
+  //  FIXME bug 551500: the channel does not notice failures, so if the
+  //    renderer crashes, it will silently succeed, leaking the parameter.
+  //    At least the leak will be fixed by...
+  //
+  virtual bool Send(Message* message);
+
+#if defined(OS_POSIX)
+  // On POSIX an IPC::Channel wraps a socketpair(), this method returns the
+  // FD # for the client end of the socket.
+  // This method may only be called on the server side of a channel.
+  //
+  // If the kTestingChannelID flag is specified on the command line then
+  // a named FIFO is used as the channel transport mechanism rather than a
+  // socketpair() in which case this method returns -1.
+  int GetClientFileDescriptor() const;
+#endif  // defined(OS_POSIX)
+
+ private:
+  // PIMPL to which all channel calls are delegated.
+  class ChannelImpl;
+  ChannelImpl *channel_impl_;
+
+  // The Hello message is internal to the Channel class.  It is sent
+  // by the peer when the channel is connected.  The message contains
+  // just the process id (pid).  The message has a special routing_id
+  // (MSG_ROUTING_NONE) and type (HELLO_MESSAGE_TYPE).
+  enum {
+    HELLO_MESSAGE_TYPE = kuint16max  // Maximum value of message type (uint16),
+                                     // to avoid conflicting with normal
+                                     // message types, which are enumeration
+                                     // constants starting from 0.
+  };
+};
+
+}  // namespace IPC
+
+#endif  // IPC_IPC_CHANNEL_H_