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/*
* Copyright (C) 2021 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 "ProcessIdentifier.h"
#include <wtf/Hasher.h>
#include <wtf/text/StringConcatenateNumbers.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
template <typename T>
class ProcessQualified {
public:
// This class is used when a single process retains objects representing things in multiple other processes.
// (E.g. resources in the GPU process.)
// Generally, objects are identified uniquely per process, but if multiple processes share them to a single
// process, the single process should distinguish between them by augmenting the objects with the
// ProcessIdentifier of the process which created them.
ProcessQualified() = default;
ProcessQualified(T&& object, ProcessIdentifier processIdentifier)
: m_object(WTFMove(object))
, m_processIdentifier(processIdentifier)
{
}
ProcessQualified(const T& object, ProcessIdentifier processIdentifier)
: m_object(object)
, m_processIdentifier(processIdentifier)
{
}
ProcessQualified(WTF::HashTableDeletedValueType)
: m_processIdentifier(WTF::HashTableDeletedValue)
{
}
operator bool() const
{
return static_cast<bool>(m_object);
}
const T& object() const
{
return m_object;
}
ProcessIdentifier processIdentifier() const
{
return m_processIdentifier;
}
bool isHashTableDeletedValue() const
{
return m_processIdentifier.isHashTableDeletedValue();
}
bool operator==(const ProcessQualified& other) const
{
return m_object == other.m_object
&& m_processIdentifier == other.m_processIdentifier;
}
bool operator!=(const ProcessQualified& other) const
{
return !(*this == other);
}
static ProcessQualified generateThreadSafe() { return { T::generateThreadSafe(), Process::identifier() }; }
static ProcessQualified generate() { return { T::generate(), Process::identifier() }; }
String toString() const { return makeString(m_processIdentifier.toUInt64(), '-', m_object.toUInt64()); }
template<typename Encoder> void encode(Encoder& encoder) const { encoder << m_object << m_processIdentifier; }
template<typename Decoder> static std::optional<ProcessQualified> decode(Decoder&);
private:
T m_object;
ProcessIdentifier m_processIdentifier;
};
template <typename T>
template<typename Decoder> std::optional<ProcessQualified<T>> ProcessQualified<T>::decode(Decoder& decoder)
{
std::optional<T> object;
decoder >> object;
if (!object)
return std::nullopt;
std::optional<ProcessIdentifier> processIdentifier;
decoder >> processIdentifier;
if (!processIdentifier)
return std::nullopt;
return { { *object, *processIdentifier } };
}
template <typename T>
inline TextStream& operator<<(TextStream& ts, const ProcessQualified<T>& processQualified)
{
ts << "ProcessQualified(" << processQualified.object() << ", " << processQualified.processIdentifier() << ')';
return ts;
}
template <typename T>
inline void add(Hasher& hasher, const ProcessQualified<T>& processQualified)
{
add(hasher, processQualified.object());
add(hasher, processQualified.processIdentifier());
}
} // namespace WebCore
namespace WTF {
template<typename T> struct DefaultHash;
template<typename T> struct DefaultHash<WebCore::ProcessQualified<T>> {
static unsigned hash(const WebCore::ProcessQualified<T>& processQualified)
{
return computeHash(processQualified);
}
static bool equal(const WebCore::ProcessQualified<T>& a, const WebCore::ProcessQualified<T>& b)
{
return a == b;
}
static const bool safeToCompareToEmptyOrDeleted = DefaultHash<T>::safeToCompareToEmptyOrDeleted;
};
template<typename T> struct HashTraits<WebCore::ProcessQualified<T>> : SimpleClassHashTraits<WebCore::ProcessQualified<T>> {
static constexpr bool emptyValueIsZero = HashTraits<T>::emptyValueIsZero;
};
} // namespace WTF