ladybird/Kernel/FileSystem/BlockBasedFileSystem.h

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C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT HOLDER OR 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 <Kernel/FileSystem/FileBackedFileSystem.h>
namespace Kernel {
class BlockBasedFS : public FileBackedFS {
public:
TYPEDEF_DISTINCT_ORDERED_ID(unsigned, BlockIndex);
virtual ~BlockBasedFS() override;
size_t logical_block_size() const { return m_logical_block_size; };
virtual void flush_writes() override;
void flush_writes_impl();
protected:
explicit BlockBasedFS(FileDescription&);
KResult read_block(BlockIndex, UserOrKernelBuffer*, size_t count, size_t offset = 0, bool allow_cache = true) const;
KResult read_blocks(BlockIndex, unsigned count, UserOrKernelBuffer&, bool allow_cache = true) const;
bool raw_read(BlockIndex, UserOrKernelBuffer&);
bool raw_write(BlockIndex, const UserOrKernelBuffer&);
bool raw_read_blocks(BlockIndex index, size_t count, UserOrKernelBuffer&);
bool raw_write_blocks(BlockIndex index, size_t count, const UserOrKernelBuffer&);
KResult write_block(BlockIndex, const UserOrKernelBuffer&, size_t count, size_t offset = 0, bool allow_cache = true);
KResult write_blocks(BlockIndex, unsigned count, const UserOrKernelBuffer&, bool allow_cache = true);
size_t m_logical_block_size { 512 };
private:
DiskCache& cache() const;
void flush_specific_block_if_needed(BlockIndex index);
mutable OwnPtr<DiskCache> m_cache;
};
}
template<>
struct AK::Formatter<Kernel::BlockBasedFS::BlockIndex> : AK::Formatter<FormatString> {
void format(FormatBuilder& builder, Kernel::BlockBasedFS::BlockIndex value)
{
return AK::Formatter<FormatString>::format(builder, "{}", value.value());
}
};