103 lines
3.1 KiB
C++
103 lines
3.1 KiB
C++
/*
|
|
* Copyright (C) 2024 Emeric Poupon
|
|
*
|
|
* This file is part of LMS.
|
|
*
|
|
* LMS is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* LMS is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with LMS. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <cassert>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
#include <array>
|
|
#include <list>
|
|
|
|
namespace lms::api::subsonic
|
|
{
|
|
class TLSMonotonicMemoryResource
|
|
{
|
|
public:
|
|
static TLSMonotonicMemoryResource& getInstance()
|
|
{
|
|
static thread_local TLSMonotonicMemoryResource instance;
|
|
return instance;
|
|
}
|
|
|
|
TLSMonotonicMemoryResource()
|
|
{
|
|
allocateNewBlock();
|
|
}
|
|
|
|
[[nodiscard]] std::byte* allocate(std::size_t byteCount, std::size_t alignment)
|
|
{
|
|
std::byte* currentAddrAligned{ computeAlignedAddr(_currentAddr, alignment) };
|
|
|
|
if (currentAddrAligned + byteCount > &_currentBlock->back() + 1)
|
|
{
|
|
allocateNewBlock();
|
|
currentAddrAligned = computeAlignedAddr(_currentAddr, alignment);
|
|
}
|
|
|
|
// Requested too many bytes for blockSize!
|
|
if (currentAddrAligned + byteCount > &_currentBlock->back() + 1)
|
|
throw std::bad_alloc{};
|
|
|
|
assert(currentAddrAligned >= &_currentBlock->front());
|
|
|
|
std::byte* res{ currentAddrAligned };
|
|
_currentAddr = currentAddrAligned + byteCount;
|
|
|
|
return res;
|
|
}
|
|
|
|
void deallocate(std::byte*)
|
|
{
|
|
// nothing to do!
|
|
}
|
|
|
|
void reset()
|
|
{
|
|
// always keep at least one block
|
|
if (_blocks.size() > 1)
|
|
_blocks.erase(std::next(std::cbegin(_blocks), 1), std::cend(_blocks));
|
|
|
|
_currentBlock = &_blocks.front();
|
|
_currentAddr = _currentBlock->data();
|
|
}
|
|
|
|
private:
|
|
void allocateNewBlock()
|
|
{
|
|
_currentBlock = &_blocks.emplace_back();
|
|
_currentAddr = _currentBlock->data();
|
|
}
|
|
|
|
static std::byte* computeAlignedAddr(std::byte* addr, std::size_t alignment) noexcept
|
|
{
|
|
const std::uintptr_t addrValue{ reinterpret_cast<std::uintptr_t>(addr) };
|
|
|
|
const std::uintptr_t mask{ alignment - 1 };
|
|
const std::uintptr_t adjustment{ (alignment - (addrValue & mask)) & mask };
|
|
return reinterpret_cast<std::byte*>(addr + adjustment);
|
|
}
|
|
|
|
static constexpr std::size_t blockSize{ static_cast<std::size_t>(1 * 1024 * 1024) };
|
|
using BlockType = std::array<std::byte, blockSize>;
|
|
|
|
std::list<BlockType> _blocks;
|
|
BlockType* _currentBlock{};
|
|
std::byte* _currentAddr{};
|
|
};
|
|
} |