blob: 092011cfcd1f0916c93d689eebb62fef66755c1a [file] [log] [blame]
/*
* Copyright (C) 2017, 2019 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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/Algorithms.h>
#include <wtf/HashSet.h>
#include <wtf/HashTraits.h>
#include <wtf/WeakPtr.h>
namespace WTF {
template <typename T>
class WeakHashSet {
public:
typedef HashSet<Ref<WeakReference<T>>> WeakReferenceSet;
class WeakHashSetConstIterator : public std::iterator<std::forward_iterator_tag, T, std::ptrdiff_t, const T*, const T&> {
private:
WeakHashSetConstIterator(const WeakReferenceSet& set, typename WeakReferenceSet::const_iterator position)
: m_position(position), m_endPosition(set.end())
{
skipEmptyBuckets();
}
public:
T* get() const { return m_position->get().get(); }
T& operator*() const { return *get(); }
T* operator->() const { return get(); }
WeakHashSetConstIterator& operator++()
{
ASSERT(m_position != m_endPosition);
++m_position;
skipEmptyBuckets();
return *this;
}
void skipEmptyBuckets()
{
while (m_position != m_endPosition && !m_position->get().get())
++m_position;
}
bool operator==(const WeakHashSetConstIterator& other) const
{
return m_position == other.m_position;
}
bool operator!=(const WeakHashSetConstIterator& other) const
{
return m_position != other.m_position;
}
private:
template <typename> friend class WeakHashSet;
typename WeakReferenceSet::const_iterator m_position;
typename WeakReferenceSet::const_iterator m_endPosition;
};
typedef WeakHashSetConstIterator const_iterator;
WeakHashSet() { }
const_iterator begin() const { return WeakHashSetConstIterator(m_set, m_set.begin()); }
const_iterator end() const { return WeakHashSetConstIterator(m_set, m_set.end()); }
template <typename U>
void add(const U& value)
{
m_set.add(*makeWeakPtr<T>(const_cast<U&>(value)).m_ref);
}
template <typename U>
bool remove(const U& value)
{
auto* weakReference = weak_reference_downcast<T>(value.weakPtrFactory().m_ref.get());
if (!weakReference)
return false;
return m_set.remove(weakReference);
}
template <typename U>
bool contains(const U& value) const
{
auto* weakReference = weak_reference_downcast<T>(value.weakPtrFactory().m_ref.get());
if (!weakReference)
return false;
return m_set.contains(weakReference);
}
unsigned capacity() const { return m_set.capacity(); }
bool computesEmpty() const
{
if (m_set.isEmpty())
return true;
for (auto& value : m_set) {
if (value->get())
return false;
}
return true;
}
bool hasNullReferences() const
{
return WTF::anyOf(m_set, [] (auto& value) { return !value->get(); });
}
unsigned computeSize() const
{
const_cast<WeakReferenceSet&>(m_set).removeIf([] (auto& value) { return !value->get(); });
return m_set.size();
}
#if ASSERT_DISABLED
void checkConsistency() const { }
#else
void checkConsistency() const { m_set.checkConsistency(); }
#endif
private:
WeakReferenceSet m_set;
};
template<typename T> struct HashTraits<Ref<WeakReference<T>>> : RefHashTraits<WeakReference<T>> {
static const bool hasIsReleasedWeakValueFunction = true;
static bool isReleasedWeakValue(const Ref<WeakReference<T>>& value)
{
return !value.isHashTableDeletedValue() && !value.isHashTableEmptyValue() && !value.get().get();
}
};
} // namespace WTF
using WTF::WeakHashSet;