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 MOZ_FINAL : public nsIInterfaceRequestor
  15 {
  16 public:
  17   // XXX This needs to support threadsafe refcounting until we fix bug 243591.
  18   NS_DECL_THREADSAFE_ISUPPORTS
  19   NS_DECL_NSIINTERFACEREQUESTOR
  20
  21   nsInterfaceRequestorAgg(nsIInterfaceRequestor* aFirst,
  22                           nsIInterfaceRequestor* aSecond,
  23                           nsIEventTarget* aConsumerTarget = nullptr)
  24     : mFirst(aFirst)
  25     , mSecond(aSecond)
  26     , mConsumerTarget(aConsumerTarget)
  27   {
  28     if (!mConsumerTarget) {
  29       mConsumerTarget = NS_GetCurrentThread();
  30     }
  31   }
  32
  33 private:
  34   ~nsInterfaceRequestorAgg();
  35
  36   nsCOMPtr<nsIInterfaceRequestor> mFirst, mSecond;
  37   nsCOMPtr<nsIEventTarget> mConsumerTarget;
  38 };
  39
  40 NS_IMPL_ISUPPORTS(nsInterfaceRequestorAgg, nsIInterfaceRequestor)
  41
  42 NS_IMETHODIMP
  43 nsInterfaceRequestorAgg::GetInterface(const nsIID& aIID, void** aResult)
  44 {
  45   nsresult rv = NS_ERROR_NO_INTERFACE;
  46   if (mFirst) {
  47     rv = mFirst->GetInterface(aIID, aResult);
  48   }
  49   if (mSecond && NS_FAILED(rv)) {
  50     rv = mSecond->GetInterface(aIID, aResult);
  51   }
  52   return rv;
  53 }
  54
  55 nsInterfaceRequestorAgg::~nsInterfaceRequestorAgg()
  56 {
  57   nsIInterfaceRequestor* iir = nullptr;
  58   mFirst.swap(iir);
  59   if (iir) {
  60     NS_ProxyRelease(mConsumerTarget, iir);
  61   }
  62   iir = nullptr;
  63   mSecond.swap(iir);
  64   if (iir) {
  65     NS_ProxyRelease(mConsumerTarget, iir);
  66   }
  67 }
  68
  69 nsresult
  70 NS_NewInterfaceRequestorAggregation(nsIInterfaceRequestor* aFirst,
  71                                     nsIInterfaceRequestor* aSecond,
  72                                     nsIInterfaceRequestor** aResult)
  73 {
  74   *aResult = new nsInterfaceRequestorAgg(aFirst, aSecond);
  75   if (!*aResult) {
  76     return NS_ERROR_OUT_OF_MEMORY;
  77   }
  78   NS_ADDREF(*aResult);
  79   return NS_OK;
  80 }
  81
  82 nsresult
  83 NS_NewInterfaceRequestorAggregation(nsIInterfaceRequestor* aFirst,
  84                                     nsIInterfaceRequestor* aSecond,
  85                                     nsIEventTarget* aTarget,
  86                                     nsIInterfaceRequestor** aResult)
  87 {
  88   *aResult = new nsInterfaceRequestorAgg(aFirst, aSecond, aTarget);
  89   if (!*aResult) {
  90     return NS_ERROR_OUT_OF_MEMORY;
  91   }
  92   NS_ADDREF(*aResult);
  93   return NS_OK;
  94 }