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Diffstat (limited to 'parser/html/nsHtml5RefPtr.h')
| -rw-r--r-- | parser/html/nsHtml5RefPtr.h | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/parser/html/nsHtml5RefPtr.h b/parser/html/nsHtml5RefPtr.h new file mode 100644 index 0000000000..bc0477ba60 --- /dev/null +++ b/parser/html/nsHtml5RefPtr.h @@ -0,0 +1,449 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsHtml5RefPtr_h +#define nsHtml5RefPtr_h + +#include "nsThreadUtils.h" + +template <class T> +class nsHtml5RefPtrReleaser : public mozilla::Runnable + { + private: + T* mPtr; + public: + explicit nsHtml5RefPtrReleaser(T* aPtr) + : mPtr(aPtr) + {} + NS_IMETHOD Run() override + { + mPtr->Release(); + return NS_OK; + } + }; + +// template <class T> class nsHtml5RefPtrGetterAddRefs; + +/** + * Like nsRefPtr except release is proxied to the main thread. Mostly copied + * from nsRefPtr. + */ +template <class T> +class nsHtml5RefPtr + { + private: + + void + assign_with_AddRef( T* rawPtr ) + { + if ( rawPtr ) + rawPtr->AddRef(); + assign_assuming_AddRef(rawPtr); + } + + void** + begin_assignment() + { + assign_assuming_AddRef(0); + return reinterpret_cast<void**>(&mRawPtr); + } + + void + assign_assuming_AddRef( T* newPtr ) + { + T* oldPtr = mRawPtr; + mRawPtr = newPtr; + if ( oldPtr ) + release(oldPtr); + } + + void + release( T* aPtr ) + { + nsCOMPtr<nsIRunnable> releaser = new nsHtml5RefPtrReleaser<T>(aPtr); + if (NS_FAILED(NS_DispatchToMainThread(releaser))) + { + NS_WARNING("Failed to dispatch releaser event."); + } + } + + private: + T* mRawPtr; + + public: + typedef T element_type; + + ~nsHtml5RefPtr() + { + if ( mRawPtr ) + release(mRawPtr); + } + + // Constructors + + nsHtml5RefPtr() + : mRawPtr(0) + // default constructor + { + } + + nsHtml5RefPtr( const nsHtml5RefPtr<T>& aSmartPtr ) + : mRawPtr(aSmartPtr.mRawPtr) + // copy-constructor + { + if ( mRawPtr ) + mRawPtr->AddRef(); + } + + explicit nsHtml5RefPtr( T* aRawPtr ) + : mRawPtr(aRawPtr) + // construct from a raw pointer (of the right type) + { + if ( mRawPtr ) + mRawPtr->AddRef(); + } + + explicit nsHtml5RefPtr( const already_AddRefed<T>& aSmartPtr ) + : mRawPtr(aSmartPtr.mRawPtr) + // construct from |dont_AddRef(expr)| + { + } + + // Assignment operators + + nsHtml5RefPtr<T>& + operator=( const nsHtml5RefPtr<T>& rhs ) + // copy assignment operator + { + assign_with_AddRef(rhs.mRawPtr); + return *this; + } + + nsHtml5RefPtr<T>& + operator=( T* rhs ) + // assign from a raw pointer (of the right type) + { + assign_with_AddRef(rhs); + return *this; + } + + nsHtml5RefPtr<T>& + operator=( const already_AddRefed<T>& rhs ) + // assign from |dont_AddRef(expr)| + { + assign_assuming_AddRef(rhs.mRawPtr); + return *this; + } + + // Other pointer operators + + void + swap( nsHtml5RefPtr<T>& rhs ) + // ...exchange ownership with |rhs|; can save a pair of refcount operations + { + T* temp = rhs.mRawPtr; + rhs.mRawPtr = mRawPtr; + mRawPtr = temp; + } + + void + swap( T*& rhs ) + // ...exchange ownership with |rhs|; can save a pair of refcount operations + { + T* temp = rhs; + rhs = mRawPtr; + mRawPtr = temp; + } + + already_AddRefed<T> + forget() + // return the value of mRawPtr and null out mRawPtr. Useful for + // already_AddRefed return values. + { + T* temp = 0; + swap(temp); + return temp; + } + + template <typename I> + void + forget( I** rhs) + // Set the target of rhs to the value of mRawPtr and null out mRawPtr. + // Useful to avoid unnecessary AddRef/Release pairs with "out" + // parameters where rhs bay be a T** or an I** where I is a base class + // of T. + { + NS_ASSERTION(rhs, "Null pointer passed to forget!"); + *rhs = mRawPtr; + mRawPtr = 0; + } + + T* + get() const + /* + Prefer the implicit conversion provided automatically by |operator T*() const|. + Use |get()| to resolve ambiguity or to get a castable pointer. + */ + { + return const_cast<T*>(mRawPtr); + } + + operator T*() const + /* + ...makes an |nsHtml5RefPtr| act like its underlying raw pointer type whenever it + is used in a context where a raw pointer is expected. It is this operator + that makes an |nsHtml5RefPtr| substitutable for a raw pointer. + + Prefer the implicit use of this operator to calling |get()|, except where + necessary to resolve ambiguity. + */ + { + return get(); + } + + T* + operator->() const MOZ_NO_ADDREF_RELEASE_ON_RETURN + { + NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsHtml5RefPtr with operator->()."); + return get(); + } + + nsHtml5RefPtr<T>* + get_address() + // This is not intended to be used by clients. See |address_of| + // below. + { + return this; + } + + const nsHtml5RefPtr<T>* + get_address() const + // This is not intended to be used by clients. See |address_of| + // below. + { + return this; + } + + public: + T& + operator*() const + { + NS_PRECONDITION(mRawPtr != 0, "You can't dereference a NULL nsHtml5RefPtr with operator*()."); + return *get(); + } + + T** + StartAssignment() + { +#ifndef NSCAP_FEATURE_INLINE_STARTASSIGNMENT + return reinterpret_cast<T**>(begin_assignment()); +#else + assign_assuming_AddRef(0); + return reinterpret_cast<T**>(&mRawPtr); +#endif + } + }; + +template <class T> +inline +nsHtml5RefPtr<T>* +address_of( nsHtml5RefPtr<T>& aPtr ) + { + return aPtr.get_address(); + } + +template <class T> +inline +const nsHtml5RefPtr<T>* +address_of( const nsHtml5RefPtr<T>& aPtr ) + { + return aPtr.get_address(); + } + +template <class T> +class nsHtml5RefPtrGetterAddRefs + /* + ... + + This class is designed to be used for anonymous temporary objects in the + argument list of calls that return COM interface pointers, e.g., + + nsHtml5RefPtr<IFoo> fooP; + ...->GetAddRefedPointer(getter_AddRefs(fooP)) + + DO NOT USE THIS TYPE DIRECTLY IN YOUR CODE. Use |getter_AddRefs()| instead. + + When initialized with a |nsHtml5RefPtr|, as in the example above, it returns + a |void**|, a |T**|, or an |nsISupports**| as needed, that the + outer call (|GetAddRefedPointer| in this case) can fill in. + + This type should be a nested class inside |nsHtml5RefPtr<T>|. + */ + { + public: + explicit + nsHtml5RefPtrGetterAddRefs( nsHtml5RefPtr<T>& aSmartPtr ) + : mTargetSmartPtr(aSmartPtr) + { + // nothing else to do + } + + operator void**() + { + return reinterpret_cast<void**>(mTargetSmartPtr.StartAssignment()); + } + + operator T**() + { + return mTargetSmartPtr.StartAssignment(); + } + + T*& + operator*() + { + return *(mTargetSmartPtr.StartAssignment()); + } + + private: + nsHtml5RefPtr<T>& mTargetSmartPtr; + }; + +template <class T> +inline +nsHtml5RefPtrGetterAddRefs<T> +getter_AddRefs( nsHtml5RefPtr<T>& aSmartPtr ) + /* + Used around a |nsHtml5RefPtr| when + ...makes the class |nsHtml5RefPtrGetterAddRefs<T>| invisible. + */ + { + return nsHtml5RefPtrGetterAddRefs<T>(aSmartPtr); + } + + + + // Comparing two |nsHtml5RefPtr|s + +template <class T, class U> +inline +bool +operator==( const nsHtml5RefPtr<T>& lhs, const nsHtml5RefPtr<U>& rhs ) + { + return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs.get()); + } + + +template <class T, class U> +inline +bool +operator!=( const nsHtml5RefPtr<T>& lhs, const nsHtml5RefPtr<U>& rhs ) + { + return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs.get()); + } + + + // Comparing an |nsHtml5RefPtr| to a raw pointer + +template <class T, class U> +inline +bool +operator==( const nsHtml5RefPtr<T>& lhs, const U* rhs ) + { + return static_cast<const T*>(lhs.get()) == static_cast<const U*>(rhs); + } + +template <class T, class U> +inline +bool +operator==( const U* lhs, const nsHtml5RefPtr<T>& rhs ) + { + return static_cast<const U*>(lhs) == static_cast<const T*>(rhs.get()); + } + +template <class T, class U> +inline +bool +operator!=( const nsHtml5RefPtr<T>& lhs, const U* rhs ) + { + return static_cast<const T*>(lhs.get()) != static_cast<const U*>(rhs); + } + +template <class T, class U> +inline +bool +operator!=( const U* lhs, const nsHtml5RefPtr<T>& rhs ) + { + return static_cast<const U*>(lhs) != static_cast<const T*>(rhs.get()); + } + +template <class T, class U> +inline +bool +operator==( const nsHtml5RefPtr<T>& lhs, U* rhs ) + { + return static_cast<const T*>(lhs.get()) == const_cast<const U*>(rhs); + } + +template <class T, class U> +inline +bool +operator==( U* lhs, const nsHtml5RefPtr<T>& rhs ) + { + return const_cast<const U*>(lhs) == static_cast<const T*>(rhs.get()); + } + +template <class T, class U> +inline +bool +operator!=( const nsHtml5RefPtr<T>& lhs, U* rhs ) + { + return static_cast<const T*>(lhs.get()) != const_cast<const U*>(rhs); + } + +template <class T, class U> +inline +bool +operator!=( U* lhs, const nsHtml5RefPtr<T>& rhs ) + { + return const_cast<const U*>(lhs) != static_cast<const T*>(rhs.get()); + } + + + + // Comparing an |nsHtml5RefPtr| to |0| + +template <class T> +inline +bool +operator==( const nsHtml5RefPtr<T>& lhs, decltype(nullptr) ) + { + return lhs.get() == nullptr; + } + +template <class T> +inline +bool +operator==( decltype(nullptr), const nsHtml5RefPtr<T>& rhs ) + { + return nullptr == rhs.get(); + } + +template <class T> +inline +bool +operator!=( const nsHtml5RefPtr<T>& lhs, decltype(nullptr) ) + { + return lhs.get() != nullptr; + } + +template <class T> +inline +bool +operator!=( decltype(nullptr), const nsHtml5RefPtr<T>& rhs ) + { + return nullptr != rhs.get(); + } + +#endif // !defined(nsHtml5RefPtr_h) |