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/*
* Copyright (C) 2009, 2010 Google Inc. All rights reserved.
* Copyright (C) 2014-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <wtf/Assertions.h>
#include <wtf/Forward.h>
#include <wtf/HashSet.h>
#include <wtf/RefPtr.h>
#include <wtf/ThreadSafeRefCounted.h>
#include <wtf/text/WTFString.h>
namespace WTF {
struct CrossThreadCopierBaseHelper {
template<typename T> struct RemovePointer {
typedef T Type;
};
template<typename T> struct RemovePointer<T*> {
typedef T Type;
};
template<typename T> struct RemovePointer<RefPtr<T>> {
typedef T Type;
};
template<typename T> struct IsEnumOrConvertibleToInteger {
static const bool value = std::is_integral<T>::value || std::is_enum<T>::value || std::is_convertible<T, long double>::value;
};
template<typename T> struct IsThreadSafeRefCountedPointer {
static const bool value = std::is_convertible<typename RemovePointer<T>::Type*, ThreadSafeRefCounted<typename RemovePointer<T>::Type>*>::value;
};
};
template<typename T> struct CrossThreadCopierPassThrough {
typedef T Type;
static Type copy(const T& parameter)
{
return parameter;
}
};
template<bool isEnumOrConvertibleToInteger, bool isThreadSafeRefCounted, typename T> struct CrossThreadCopierBase;
// Integers get passed through without any changes.
template<typename T> struct CrossThreadCopierBase<true, false, T> : public CrossThreadCopierPassThrough<T> {
};
// Classes that have an isolatedCopy() method get a default specialization.
template<class T> struct CrossThreadCopierBase<false, false, T> {
static T copy(const T& value)
{
return value.isolatedCopy();
}
};
// Custom copy methods.
template<typename T> struct CrossThreadCopierBase<false, true, T> {
typedef typename CrossThreadCopierBaseHelper::RemovePointer<T>::Type RefCountedType;
static_assert(std::is_convertible<RefCountedType*, ThreadSafeRefCounted<RefCountedType>*>::value, "T is not convertible to ThreadSafeRefCounted!");
typedef RefPtr<RefCountedType> Type;
static Type copy(const T& refPtr)
{
return refPtr;
}
};
template<> struct CrossThreadCopierBase<false, false, WTF::ASCIILiteral> {
typedef WTF::ASCIILiteral Type;
static Type copy(const Type& source)
{
return source;
}
};
template<typename T>
struct CrossThreadCopier : public CrossThreadCopierBase<CrossThreadCopierBaseHelper::IsEnumOrConvertibleToInteger<T>::value, CrossThreadCopierBaseHelper::IsThreadSafeRefCountedPointer<T>::value, T> {
};
// Default specialization for Vectors of CrossThreadCopyable classes.
template<typename T> struct CrossThreadCopierBase<false, false, Vector<T>> {
typedef Vector<T> Type;
static Type copy(const Type& source)
{
Type destination;
destination.reserveInitialCapacity(source.size());
for (auto& object : source)
destination.uncheckedAppend(CrossThreadCopier<T>::copy(object));
return destination;
}
};
// Default specialization for HashSets of CrossThreadCopyable classes
template<typename T> struct CrossThreadCopierBase<false, false, HashSet<T> > {
typedef HashSet<T> Type;
static Type copy(const Type& source)
{
Type destination;
for (auto& object : source)
destination.add(CrossThreadCopier<T>::copy(object));
return destination;
}
};
// Default specialization for std::optional of CrossThreadCopyable class.
template<typename T> struct CrossThreadCopierBase<false, false, std::optional<T>> {
typedef std::optional<T> Type;
static Type copy(const Type& source)
{
if (!source)
return std::nullopt;
return CrossThreadCopier<T>::copy(*source);
}
};
template<typename T> T crossThreadCopy(const T& source)
{
return CrossThreadCopier<T>::copy(source);
}
} // namespace WTF
using WTF::CrossThreadCopierBaseHelper;
using WTF::CrossThreadCopierBase;
using WTF::CrossThreadCopier;
using WTF::crossThreadCopy;