ladybird/Libraries/LibCompress/Lzma2.h

46 lines
1.5 KiB
C++

/*
* Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/CircularBuffer.h>
#include <AK/MaybeOwned.h>
#include <AK/Stream.h>
#include <LibCompress/Lzma.h>
namespace Compress {
// This is based on the human-language description of the LZMA2 format on the English Wikipedia.
// https://en.wikipedia.org/wiki/Lempel%E2%80%93Ziv%E2%80%93Markov_chain_algorithm#LZMA2_format
class Lzma2Decompressor : public Stream {
public:
/// Creates a decompressor that does not require the leading byte indicating the dictionary size.
static ErrorOr<NonnullOwnPtr<Lzma2Decompressor>> create_from_raw_stream(MaybeOwned<Stream>, u32 dictionary_size);
virtual ErrorOr<Bytes> read_some(Bytes) override;
virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
virtual bool is_eof() const override;
virtual bool is_open() const override;
virtual void close() override;
private:
Lzma2Decompressor(MaybeOwned<Stream>, CircularBuffer dictionary);
MaybeOwned<Stream> m_stream;
CircularBuffer m_dictionary;
// Our dictionary is always initialized, but LZMA2 requires that the first chunk resets the dictionary.
bool m_dictionary_initialized { false };
bool m_found_end_of_stream { false };
Optional<MaybeOwned<Stream>> m_current_chunk_stream;
bool m_in_uncompressed_chunk { false };
Optional<NonnullOwnPtr<LzmaDecompressor>> m_last_lzma_stream;
Optional<LzmaDecompressorOptions> m_last_lzma_options;
};
}