xpcom/base/nsInterfaceRequestorAgg.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=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
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsInterfaceRequestorAgg.h"
   8 #include "nsIInterfaceRequestor.h"
   9 #include "nsCOMPtr.h"
  10 #include "mozilla/Attributes.h"
  11 #include "nsThreadUtils.h"
  12 #include "nsProxyRelease.h"
  13
  14 class nsInterfaceRequestorAgg final : public nsIInterfaceRequestor {
  15  public:
  16   // XXX This needs to support threadsafe refcounting until we fix bug 243591.
  17   NS_DECL_THREADSAFE_ISUPPORTS
  18   NS_DECL_NSIINTERFACEREQUESTOR
  19
  20   nsInterfaceRequestorAgg(nsIInterfaceRequestor* aFirst,
  21                           nsIInterfaceRequestor* aSecond,
  22                           nsIEventTarget* aConsumerTarget = nullptr)
  23       : mFirst(aFirst), mSecond(aSecond), mConsumerTarget(aConsumerTarget) {
  24     if (!mConsumerTarget) {
  25       mConsumerTarget = mozilla::GetCurrentSerialEventTarget();
  26     }
  27   }
  28
  29  private:
  30   ~nsInterfaceRequestorAgg();
  31
  32   nsCOMPtr<nsIInterfaceRequestor> mFirst, mSecond;
  33   nsCOMPtr<nsIEventTarget> mConsumerTarget;
  34 };
  35
  36 NS_IMPL_ISUPPORTS(nsInterfaceRequestorAgg, nsIInterfaceRequestor)
  37
  38 NS_IMETHODIMP
  39 nsInterfaceRequestorAgg::GetInterface(const nsIID& aIID, void** aResult) {
  40   nsresult rv = NS_ERROR_NO_INTERFACE;
  41   if (mFirst) {
  42     rv = mFirst->GetInterface(aIID, aResult);
  43   }
  44   if (mSecond && NS_FAILED(rv)) {
  45     rv = mSecond->GetInterface(aIID, aResult);
  46   }
  47   return rv;
  48 }
  49
  50 nsInterfaceRequestorAgg::~nsInterfaceRequestorAgg() {
  51   NS_ProxyRelease("nsInterfaceRequestorAgg::mFirst", mConsumerTarget,
  52                   mFirst.forget());
  53   NS_ProxyRelease("nsInterfaceRequestorAgg::mSecond", mConsumerTarget,
  54                   mSecond.forget());
  55 }
  56
  57 nsresult NS_NewInterfaceRequestorAggregation(nsIInterfaceRequestor* aFirst,
  58                                              nsIInterfaceRequestor* aSecond,
  59                                              nsIInterfaceRequestor** aResult) {
  60   *aResult = new nsInterfaceRequestorAgg(aFirst, aSecond);
  61
  62   NS_ADDREF(*aResult);
  63   return NS_OK;
  64 }
  65
  66 nsresult NS_NewInterfaceRequestorAggregation(nsIInterfaceRequestor* aFirst,
  67                                              nsIInterfaceRequestor* aSecond,
  68                                              nsIEventTarget* aTarget,
  69                                              nsIInterfaceRequestor** aResult) {
  70   *aResult = new nsInterfaceRequestorAgg(aFirst, aSecond, aTarget);
  71
  72   NS_ADDREF(*aResult);
  73   return NS_OK;
  74 }