netwerk/base/src/AutoClose.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_net_AutoClose_h
   8 #define mozilla_net_AutoClose_h
   9
  10 #include "nsCOMPtr.h"
  11
  12 namespace mozilla { namespace net {
  13
  14 // Like an nsAutoPtr for XPCOM streams (e.g. nsIAsyncInputStream) and other
  15 // refcounted classes that need to have the Close() method called explicitly
  16 // before they are destroyed.
  17 template <typename T>
  18 class AutoClose
  19 {
  20 public:
  21   AutoClose() { }
  22   ~AutoClose(){
  23     Close();
  24   }
  25
  26   operator bool() const
  27   {
  28     return mPtr;
  29   }
  30
  31   already_AddRefed<T> forget()
  32   {
  33     return mPtr.forget();
  34   }
  35
  36   void takeOver(nsCOMPtr<T> & rhs)
  37   {
  38     Close();
  39     mPtr = rhs.forget();
  40   }
  41
  42   void takeOver(AutoClose<T> & rhs)
  43   {
  44     Close();
  45     mPtr = rhs.mPtr.forget();
  46   }
  47
  48   void CloseAndRelease()
  49   {
  50     Close();
  51     mPtr = nullptr;
  52   }
  53
  54   T* operator->() const
  55   {
  56     return mPtr.operator->();
  57   }
  58
  59 private:
  60   void Close()
  61   {
  62     if (mPtr) {
  63       mPtr->Close();
  64     }
  65   }
  66
  67   void operator=(const AutoClose<T> &) MOZ_DELETE;
  68   AutoClose(const AutoClose<T> &) MOZ_DELETE;
  69
  70   nsCOMPtr<T> mPtr;
  71 };
  72
  73 } } // namespace mozilla::net
  74
  75 #endif // mozilla_net_AutoClose_h