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/*
* Copyright (C) 2024 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 <utility>
#include <wtf/FastMalloc.h>
#include <wtf/MallocCommon.h>
#include <wtf/Noncopyable.h>
#include <wtf/StdLibExtras.h>
#include <wtf/TypeTraits.h>
// MallocSpan is a smart pointer class that wraps a std::span and calls fastFree in its destructor.
namespace WTF {
template<typename T, typename Malloc = FastMalloc> class MallocSpan {
WTF_MAKE_NONCOPYABLE(MallocSpan);
public:
MallocSpan() = default;
MallocSpan(MallocSpan&& other)
: m_span(other.leakSpan())
{
}
template<typename U>
MallocSpan(MallocSpan<U, Malloc>&& other) requires (std::is_same_v<T, uint8_t>)
: m_span(asWritableBytes(other.leakSpan()))
{
}
~MallocSpan()
{
if constexpr (parameterCount(Malloc::free) == 2)
Malloc::free(m_span.data(), m_span.size());
else
Malloc::free(m_span.data());
}
MallocSpan& operator=(MallocSpan&& other)
{
MallocSpan ptr = WTFMove(other);
swap(ptr);
return *this;
}
void swap(MallocSpan& other)
{
std::swap(m_span, other.m_span);
}
size_t sizeInBytes() const { return m_span.size_bytes(); }
std::span<const T> span() const LIFETIME_BOUND { return spanConstCast<const T>(m_span); }
std::span<T> mutableSpan() LIFETIME_BOUND { return m_span; }
std::span<T> leakSpan() WARN_UNUSED_RETURN { return std::exchange(m_span, std::span<T>()); }
T& operator[](size_t i) LIFETIME_BOUND { return m_span[i]; }
const T& operator[](size_t i) const LIFETIME_BOUND { return m_span[i]; }
explicit operator bool() const
{
return !!m_span.data();
}
bool operator!() const
{
return !m_span.data();
}
static MallocSpan malloc(size_t sizeInBytes)
{
return MallocSpan { static_cast<T*>(Malloc::malloc(sizeInBytes)), sizeInBytes };
}
static MallocSpan zeroedMalloc(size_t sizeInBytes)
{
return MallocSpan { static_cast<T*>(Malloc::zeroedMalloc(sizeInBytes)), sizeInBytes };
}
static MallocSpan alignedMalloc(size_t alignment, size_t sizeInBytes)
{
return MallocSpan { static_cast<T*>(Malloc::alignedMalloc(alignment, sizeInBytes)), sizeInBytes };
}
#if HAVE(MMAP)
static MallocSpan mmap(size_t sizeInBytes, int pageProtection, int options, int fileDescriptor)
{
return MallocSpan { static_cast<T*>(Malloc::mmap(sizeInBytes, pageProtection, options, fileDescriptor)), sizeInBytes };
}
#endif
static MallocSpan tryMalloc(size_t sizeInBytes)
{
auto* ptr = Malloc::tryMalloc(sizeInBytes);
if (!ptr)
return { };
return MallocSpan { static_cast<T*>(ptr), sizeInBytes };
}
static MallocSpan tryZeroedMalloc(size_t sizeInBytes)
{
auto* ptr = Malloc::tryZeroedMalloc(sizeInBytes);
if (!ptr)
return { };
return MallocSpan { static_cast<T*>(ptr), sizeInBytes };
}
static MallocSpan tryAlignedMalloc(size_t alignment, size_t sizeInBytes)
{
auto* ptr = Malloc::tryAlignedMalloc(alignment, sizeInBytes);
if (!ptr)
return { };
return MallocSpan { static_cast<T*>(ptr), sizeInBytes };
}
void realloc(size_t newSizeInBytes)
{
RELEASE_ASSERT(!(newSizeInBytes % sizeof(T)));
m_span = unsafeMakeSpan(static_cast<T*>(Malloc::realloc(m_span.data(), newSizeInBytes)), newSizeInBytes / sizeof(T));
}
private:
template<typename U, typename OtherMalloc> friend MallocSpan<U, OtherMalloc> adoptMallocSpan(std::span<U>);
explicit MallocSpan(T* ptr, size_t sizeInBytes)
: m_span(unsafeMakeSpan(ptr, sizeInBytes / sizeof(T)))
{
RELEASE_ASSERT(!(sizeInBytes % sizeof(T)));
}
std::span<T> m_span;
};
template<typename U, typename OtherMalloc> MallocSpan<U, OtherMalloc> adoptMallocSpan(std::span<U> span)
{
return MallocSpan<U, OtherMalloc>(span.data(), span.size_bytes());
}
} // namespace WTF
using WTF::MallocSpan;
using WTF::adoptMallocSpan;
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