зеркало из https://github.com/mozilla/gecko-dev.git
131 строка
3.0 KiB
C++
131 строка
3.0 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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// nsWeakReference.cpp
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#include "mozilla/Attributes.h"
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#include "nsWeakReference.h"
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#include "nsCOMPtr.h"
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class nsWeakReference MOZ_FINAL : public nsIWeakReference
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{
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public:
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// nsISupports...
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NS_DECL_ISUPPORTS
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// nsIWeakReference...
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NS_DECL_NSIWEAKREFERENCE
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private:
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friend class nsSupportsWeakReference;
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nsWeakReference( nsSupportsWeakReference* referent )
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: mReferent(referent)
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// ...I can only be constructed by an |nsSupportsWeakReference|
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{
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// nothing else to do here
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}
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~nsWeakReference()
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// ...I will only be destroyed by calling |delete| myself.
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{
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if ( mReferent )
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mReferent->NoticeProxyDestruction();
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}
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void
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NoticeReferentDestruction()
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// ...called (only) by an |nsSupportsWeakReference| from _its_ dtor.
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{
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mReferent = 0;
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}
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nsSupportsWeakReference* mReferent;
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};
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nsresult
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nsQueryReferent::operator()( const nsIID& aIID, void** answer ) const
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{
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nsresult status;
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if ( mWeakPtr )
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{
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if ( NS_FAILED(status = mWeakPtr->QueryReferent(aIID, answer)) )
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*answer = 0;
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}
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else
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status = NS_ERROR_NULL_POINTER;
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if ( mErrorPtr )
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*mErrorPtr = status;
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return status;
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}
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NS_COM_GLUE nsIWeakReference* // or else |already_AddRefed<nsIWeakReference>|
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NS_GetWeakReference( nsISupports* aInstancePtr, nsresult* aErrorPtr )
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{
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nsresult status;
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nsIWeakReference* result = nullptr;
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if ( aInstancePtr )
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{
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nsCOMPtr<nsISupportsWeakReference> factoryPtr = do_QueryInterface(aInstancePtr, &status);
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if ( factoryPtr )
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{
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status = factoryPtr->GetWeakReference(&result);
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}
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// else, |status| has already been set by |do_QueryInterface|
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}
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else
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status = NS_ERROR_NULL_POINTER;
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if ( aErrorPtr )
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*aErrorPtr = status;
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return result;
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}
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NS_COM_GLUE nsresult
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nsSupportsWeakReference::GetWeakReference( nsIWeakReference** aInstancePtr )
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{
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if ( !aInstancePtr )
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return NS_ERROR_NULL_POINTER;
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if ( !mProxy )
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mProxy = new nsWeakReference(this);
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*aInstancePtr = mProxy;
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nsresult status;
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if ( !*aInstancePtr )
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status = NS_ERROR_OUT_OF_MEMORY;
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else
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{
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NS_ADDREF(*aInstancePtr);
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status = NS_OK;
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}
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return status;
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}
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NS_IMPL_ISUPPORTS(nsWeakReference, nsIWeakReference)
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NS_IMETHODIMP
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nsWeakReference::QueryReferent( const nsIID& aIID, void** aInstancePtr )
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{
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return mReferent ? mReferent->QueryInterface(aIID, aInstancePtr) : NS_ERROR_NULL_POINTER;
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}
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void
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nsSupportsWeakReference::ClearWeakReferences()
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{
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if ( mProxy )
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{
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mProxy->NoticeReferentDestruction();
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mProxy = 0;
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}
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}
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