7ec91dfde7
This is copy-pasted from the gzip utility, along with its existing TODO. This is currently only needed by that utility, but this gives us API symmetry with GzipDecompressor, and helps ensure we won't end up in a situation where only one utility receives optimizations that should be received by all interested parties.
102 lines
2.9 KiB
C++
102 lines
2.9 KiB
C++
/*
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* Copyright (c) 2020-2022, the SerenityOS developers.
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* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/NonnullOwnPtr.h>
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#include <AK/OwnPtr.h>
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#include <AK/Stream.h>
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#include <LibCompress/Deflate.h>
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#include <LibCrypto/Checksum/CRC32.h>
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namespace Compress {
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constexpr u8 gzip_magic_1 = 0x1f;
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constexpr u8 gzip_magic_2 = 0x8b;
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struct [[gnu::packed]] BlockHeader {
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u8 identification_1;
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u8 identification_2;
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u8 compression_method;
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u8 flags;
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LittleEndian<u32> modification_time;
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u8 extra_flags;
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u8 operating_system;
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bool valid_magic_number() const;
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bool supported_by_implementation() const;
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};
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struct Flags {
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static constexpr u8 FTEXT = 1 << 0;
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static constexpr u8 FHCRC = 1 << 1;
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static constexpr u8 FEXTRA = 1 << 2;
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static constexpr u8 FNAME = 1 << 3;
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static constexpr u8 FCOMMENT = 1 << 4;
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static constexpr u8 MAX = FTEXT | FHCRC | FEXTRA | FNAME | FCOMMENT;
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};
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class GzipDecompressor final : public Stream {
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public:
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GzipDecompressor(NonnullOwnPtr<Stream>);
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~GzipDecompressor();
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virtual ErrorOr<Bytes> read_some(Bytes) override;
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virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
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virtual bool is_eof() const override;
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virtual bool is_open() const override { return true; }
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virtual void close() override {};
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static ErrorOr<ByteBuffer> decompress_all(ReadonlyBytes);
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static ErrorOr<void> decompress_file(StringView input_file, NonnullOwnPtr<Stream> output_stream);
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static Optional<DeprecatedString> describe_header(ReadonlyBytes);
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static bool is_likely_compressed(ReadonlyBytes bytes);
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private:
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class Member {
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public:
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static ErrorOr<NonnullOwnPtr<Member>> construct(BlockHeader header, LittleEndianInputBitStream&);
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BlockHeader m_header;
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NonnullOwnPtr<DeflateDecompressor> m_stream;
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Crypto::Checksum::CRC32 m_checksum;
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size_t m_nread { 0 };
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private:
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Member(BlockHeader, NonnullOwnPtr<DeflateDecompressor>);
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};
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Member const& current_member() const { return *m_current_member; }
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Member& current_member() { return *m_current_member; }
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NonnullOwnPtr<LittleEndianInputBitStream> m_input_stream;
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u8 m_partial_header[sizeof(BlockHeader)];
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size_t m_partial_header_offset { 0 };
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OwnPtr<Member> m_current_member {};
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bool m_eof { false };
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};
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class GzipCompressor final : public Stream {
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public:
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GzipCompressor(MaybeOwned<Stream>);
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virtual ErrorOr<Bytes> read_some(Bytes) override;
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virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
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virtual bool is_eof() const override;
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virtual bool is_open() const override;
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virtual void close() override;
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static ErrorOr<ByteBuffer> compress_all(ReadonlyBytes bytes);
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static ErrorOr<void> compress_file(StringView input_file, NonnullOwnPtr<Stream> output_stream);
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private:
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MaybeOwned<Stream> m_output_stream;
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};
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}
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