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/*
* Copyright (c) 2020, the SerenityOS developers
* 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 <AK/BitStream.h>
#include <AK/ByteBuffer.h>
#include <AK/CircularDuplexStream.h>
#include <AK/Endian.h>
#include <AK/Vector.h>
namespace Compress {
class CanonicalCode {
public:
CanonicalCode() = default;
u32 read_symbol(InputBitStream&) const;
static const CanonicalCode& fixed_literal_codes();
static const CanonicalCode& fixed_distance_codes();
static Optional<CanonicalCode> from_bytes(ReadonlyBytes);
private:
Vector<u32> m_symbol_codes;
Vector<u32> m_symbol_values;
};
class DeflateDecompressor final : public InputStream {
private:
class CompressedBlock {
public:
CompressedBlock(DeflateDecompressor&, CanonicalCode literal_codes, Optional<CanonicalCode> distance_codes);
bool try_read_more();
private:
bool m_eof { false };
DeflateDecompressor& m_decompressor;
CanonicalCode m_literal_codes;
Optional<CanonicalCode> m_distance_codes;
};
class UncompressedBlock {
public:
UncompressedBlock(DeflateDecompressor&, size_t);
bool try_read_more();
private:
DeflateDecompressor& m_decompressor;
size_t m_bytes_remaining;
};
enum class State {
Idle,
ReadingCompressedBlock,
ReadingUncompressedBlock
};
public:
friend CompressedBlock;
friend UncompressedBlock;
DeflateDecompressor(InputStream&);
~DeflateDecompressor();
size_t read(Bytes) override;
bool read_or_error(Bytes) override;
bool discard_or_error(size_t) override;
bool unreliable_eof() const override;
static Optional<ByteBuffer> decompress_all(ReadonlyBytes);
private:
u32 decode_length(u32);
u32 decode_distance(u32);
void decode_codes(CanonicalCode& literal_code, Optional<CanonicalCode>& distance_code);
bool m_read_final_bock { false };
State m_state { State::Idle };
union {
CompressedBlock m_compressed_block;
UncompressedBlock m_uncompressed_block;
};
InputBitStream m_input_stream;
CircularDuplexStream<32 * 1024> m_output_stream;
};
}
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