chrome.bluetooth API improvements.

device/bluetooth/bluetooth_socket.h

 // 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 DEVICE_BLUETOOTH_BLUETOOTH_SOCKET_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_SOCKET_H_
 
 #include <string>
 
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 
 namespace net {
-
-class DrainableIOBuffer;
-class GrowableIOBuffer;
-
+class IOBuffer;
 }  // namespace net
 
 namespace device {
 
 // BluetoothSocket represents a socket to a specific service on a
 // BluetoothDevice.  BluetoothSocket objects are ref counted and may outlive
 // both the BluetoothDevice and BluetoothAdapter that were involved in their
-// creation.
-class BluetoothSocket : public base::RefCounted<BluetoothSocket> {
+// creation.  In terms of threading, platform specific implementations may
+// differ slightly, but platform independent consumers must guarantee calling
+// various instances methods on the same thread as the thread used at
+// construction time -- platform specific implementation are resonsible for
+// marshalling calls to a different thread if required.
+class BluetoothSocket : public base::RefCountedThreadSafe<BluetoothSocket> {
  public:
-  // Receives data from the socket and stores it in |buffer|. It returns whether
-  // the reception has been successful. If it fails, the caller can get the
-  // error message through |GetLastErrorMessage()|.
-  virtual bool Receive(net::GrowableIOBuffer* buffer) = 0;
+  enum ErrorReason { kSystemError, kIOPending, kDisconnected };
 
-  // Sends |buffer| to the socket. It returns whether the sending has been
-  // successful. If it fails, the caller can get the error message through
-  // |GetLastErrorMessage()|.
-  virtual bool Send(net::DrainableIOBuffer* buffer) = 0;
+  typedef base::Callback<void(int)> SendCompletionCallback;
+  typedef base::Callback<void(int, scoped_refptr<net::IOBuffer> io_buffer)>
+      ReceiveCompletionCallback;
+  typedef base::Callback<void(const std::string& error_message)>
+      ErrorCompletionCallback;
+  typedef base::Callback<void(ErrorReason, const std::string& error_message)>
+      ReceiveErrorCompletionCallback;
 
-  virtual std::string GetLastErrorMessage() const = 0;
+  // Destroys resources associated with the socket. After calling this method,
+  // it is illegal to call any method on this socket instance (except for the
+  // desctrutor via Release).
+  virtual void Close() = 0;
+
+  // Gracefully disconnects the socket and calls |callback| upon completion.
+  // There is no failure case, as this is a best effort operation.
+  virtual void Disconnect(const base::Closure& callback) = 0;
+
+  // Receives data from the socket and calls |success_callback| when data is
+  // available. |count| is maximum amount of bytes received. If an error occurs,
+  // calls |error_callback| with a reason and an error message.
+  virtual void Receive(
+      int count,
+      const ReceiveCompletionCallback& success_callback,
+      const ReceiveErrorCompletionCallback& error_callback) = 0;
+
+  // Sends |buffer| to the socket and calls |success_callback| when data has
+  // been successfully sent. |buffer_size| is the number of bytes contained in
+  // |buffer|. If an error occurs, calls |error_callback| with an error message.
+  virtual void Send(scoped_refptr<net::IOBuffer> buffer,
+                    int buffer_size,
+                    const SendCompletionCallback& success_callback,
+                    const ErrorCompletionCallback& error_callback) = 0;
 
  protected:
-  friend class base::RefCounted<BluetoothSocket>;
-  virtual ~BluetoothSocket() {}
+  friend class base::RefCountedThreadSafe<BluetoothSocket>;
+  virtual ~BluetoothSocket();
 };
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_SOCKET_H_