1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_BASE_COMPLETION_CALLBACK_H__ 6 #define NET_BASE_COMPLETION_CALLBACK_H__ 7 #pragma once 8 9 #include "base/callback.h" 10 11 namespace net { 12 13 // A callback specialization that takes a single int parameter. Usually this 14 // is used to report a byte count or network error code. 15 typedef Callback1<int>::Type CompletionCallback; 16 17 // Used to implement a CompletionCallback. 18 template <class T> 19 class CompletionCallbackImpl : 20 public CallbackImpl< T, void (T::*)(int), Tuple1<int> > { 21 public: CompletionCallbackImpl(T * obj,void (T::* meth)(int))22 CompletionCallbackImpl(T* obj, void (T::* meth)(int)) 23 : CallbackImpl< T, void (T::*)(int), 24 Tuple1<int> >::CallbackImpl(obj, meth) { 25 } 26 }; 27 28 // CancelableCompletionCallback is used for completion callbacks 29 // which may outlive the target for the method dispatch. In such a case, the 30 // provider of the callback calls Cancel() to mark the callback as 31 // "canceled". When the canceled callback is eventually run it does nothing 32 // other than to decrement the refcount to 0 and free the memory. 33 template <class T> 34 class CancelableCompletionCallback : 35 public CompletionCallbackImpl<T>, 36 public base::RefCounted<CancelableCompletionCallback<T> > { 37 public: CancelableCompletionCallback(T * obj,void (T::* meth)(int))38 CancelableCompletionCallback(T* obj, void (T::* meth)(int)) 39 : CompletionCallbackImpl<T>(obj, meth), is_canceled_(false) { 40 } 41 Cancel()42 void Cancel() { 43 is_canceled_ = true; 44 } 45 RunWithParams(const Tuple1<int> & params)46 virtual void RunWithParams(const Tuple1<int>& params) { 47 if (is_canceled_) { 48 base::RefCounted<CancelableCompletionCallback<T> >::Release(); 49 } else { 50 CompletionCallbackImpl<T>::RunWithParams(params); 51 } 52 } 53 54 private: 55 bool is_canceled_; 56 }; 57 58 } // namespace net 59 60 #endif // NET_BASE_COMPLETION_CALLBACK_H__ 61