Refactor WebSocket throttling feature.

net/socket_stream/socket_stream_throttle.h

-// Copyright (c) 2009 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 NET_SOCKET_STREAM_SOCKET_STREAM_THROTTLE_H_
-#define NET_SOCKET_STREAM_SOCKET_STREAM_THROTTLE_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "net/base/completion_callback.h"
-#include "net/base/net_errors.h"
-
-namespace net {
-
-class SocketStream;
-
-// Abstract interface to throttle SocketStream per URL scheme.
-// Each URL scheme (protocol) could define own SocketStreamThrottle.
-// These methods will be called on IO thread.
-class SocketStreamThrottle {
- public:
-  // Called when |socket| is about to open connection.
-  // Returns net::OK if the connection can open now.
-  // Returns net::ERR_IO_PENDING if the connection should wait.  In this case,
-  // |callback| will be called when it's ready to open connection.
-  virtual int OnStartOpenConnection(SocketStream* socket,
-                                    CompletionCallback* callback) {
-    // No throttle by default.
-    return OK;
-  }
-
-  // Called when |socket| read |len| bytes of |data|.
-  // May wake up another waiting socket.
-  // Returns net::OK if |socket| can continue to run.
-  // Returns net::ERR_IO_PENDING if |socket| should suspend to run.  In this
-  // case, |callback| will be called when it's ready to resume running.
-  virtual int OnRead(SocketStream* socket, const char* data, int len,
-                     CompletionCallback* callback) {
-    // No throttle by default.
-    return OK;
-  }
-
-  // Called when |socket| wrote |len| bytes of |data|.
-  // May wake up another waiting socket.
-  // Returns net::OK if |socket| can continue to run.
-  // Returns net::ERR_IO_PENDING if |socket| should suspend to run.  In this
-  // case, |callback| will be called when it's ready to resume running.
-  virtual int OnWrite(SocketStream* socket, const char* data, int len,
-                      CompletionCallback* callback) {
-    // No throttle by default.
-    return OK;
-  }
-
-  // Called when |socket| is closed.
-  // May wake up another waiting socket.
-  virtual void OnClose(SocketStream* socket) {}
-
-  // Gets SocketStreamThrottle for URL |scheme|.
-  // Doesn't pass ownership of the SocketStreamThrottle.
-  static SocketStreamThrottle* GetSocketStreamThrottleForScheme(
-      const std::string& scheme);
-
-  // Registers |throttle| for URL |scheme|.
-  // Doesn't take ownership of |throttle|.  Typically |throttle| is
-  // singleton instance.
-  static void RegisterSocketStreamThrottle(
-      const std::string& scheme,
-      SocketStreamThrottle* throttle);
-
- protected:
-  SocketStreamThrottle() {}
-  virtual ~SocketStreamThrottle() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(SocketStreamThrottle);
-};
-
-}  // namespace net
-
-#endif  // NET_SOCKET_STREAM_SOCKET_STREAM_THROTTLE_H_