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/*
* Copyright (C) 2014 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/EnumTraits.h>
#include <wtf/SHA1.h>
#include <wtf/persistence/PersistentCoder.h>
namespace WTF {
namespace Persistence {
class Decoder {
WTF_MAKE_FAST_ALLOCATED;
public:
WTF_EXPORT_PRIVATE Decoder(const uint8_t* buffer, size_t bufferSize);
WTF_EXPORT_PRIVATE ~Decoder();
size_t length() const { return m_bufferEnd - m_buffer; }
size_t currentOffset() const { return m_bufferPosition - m_buffer; }
WTF_EXPORT_PRIVATE bool verifyChecksum();
WTF_EXPORT_PRIVATE bool decodeFixedLengthData(uint8_t*, size_t);
WTF_EXPORT_PRIVATE bool decode(bool&);
WTF_EXPORT_PRIVATE bool decode(uint8_t&);
WTF_EXPORT_PRIVATE bool decode(uint16_t&);
WTF_EXPORT_PRIVATE bool decode(uint32_t&);
WTF_EXPORT_PRIVATE bool decode(uint64_t&);
WTF_EXPORT_PRIVATE bool decode(int32_t&);
WTF_EXPORT_PRIVATE bool decode(int64_t&);
WTF_EXPORT_PRIVATE bool decode(float&);
WTF_EXPORT_PRIVATE bool decode(double&);
template<typename E> auto decode(E& e) -> std::enable_if_t<std::is_enum<E>::value, bool>
{
uint64_t value;
if (!decode(value))
return false;
if (!isValidEnum<E>(value))
return false;
e = static_cast<E>(value);
return true;
}
template<typename T> bool decodeEnum(T& result)
{
static_assert(sizeof(T) <= 8, "Enum type T must not be larger than 64 bits!");
uint64_t value;
if (!decode(value))
return false;
result = static_cast<T>(value);
return true;
}
template<typename T> auto decode(T& t) -> std::enable_if_t<!std::is_enum<T>::value, bool>
{
return Coder<T>::decode(*this, t);
}
template<typename T>
bool bufferIsLargeEnoughToContain(size_t numElements) const
{
static_assert(std::is_arithmetic<T>::value, "Type T must have a fixed, known encoded size!");
if (numElements > std::numeric_limits<size_t>::max() / sizeof(T))
return false;
return bufferIsLargeEnoughToContain(numElements * sizeof(T));
}
static const bool isIPCDecoder = false;
private:
WTF_EXPORT_PRIVATE bool bufferIsLargeEnoughToContain(size_t) const;
template<typename Type> bool decodeNumber(Type&);
const uint8_t* m_buffer;
const uint8_t* m_bufferPosition;
const uint8_t* m_bufferEnd;
SHA1 m_sha1;
};
}
}