ladybird/Userland/Libraries/LibCompress/Gzip.h
Tim Schumacher 8464da1439 AK: Move Stream and SeekableStream from LibCore
`Stream` will be qualified as `AK::Stream` until we remove the
`Core::Stream` namespace. `IODevice` now reuses the `SeekMode` that is
defined by `SeekableStream`, since defining its own would require us to
qualify it with `AK::SeekMode` everywhere.
2023-01-29 19:16:44 -07:00

97 lines
2.7 KiB
C++

/*
* Copyright (c) 2020-2022, the SerenityOS developers.
* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibCompress/Deflate.h>
#include <LibCore/Stream.h>
#include <LibCrypto/Checksum/CRC32.h>
namespace Compress {
constexpr u8 gzip_magic_1 = 0x1f;
constexpr u8 gzip_magic_2 = 0x8b;
struct [[gnu::packed]] BlockHeader {
u8 identification_1;
u8 identification_2;
u8 compression_method;
u8 flags;
LittleEndian<u32> modification_time;
u8 extra_flags;
u8 operating_system;
bool valid_magic_number() const;
bool supported_by_implementation() const;
};
struct Flags {
static constexpr u8 FTEXT = 1 << 0;
static constexpr u8 FHCRC = 1 << 1;
static constexpr u8 FEXTRA = 1 << 2;
static constexpr u8 FNAME = 1 << 3;
static constexpr u8 FCOMMENT = 1 << 4;
static constexpr u8 MAX = FTEXT | FHCRC | FEXTRA | FNAME | FCOMMENT;
};
class GzipDecompressor final : public AK::Stream {
public:
GzipDecompressor(NonnullOwnPtr<AK::Stream>);
~GzipDecompressor();
virtual ErrorOr<Bytes> read(Bytes) override;
virtual ErrorOr<size_t> write(ReadonlyBytes) override;
virtual bool is_eof() const override;
virtual bool is_open() const override { return true; }
virtual void close() override {};
static ErrorOr<ByteBuffer> decompress_all(ReadonlyBytes);
static Optional<DeprecatedString> describe_header(ReadonlyBytes);
static bool is_likely_compressed(ReadonlyBytes bytes);
private:
class Member {
public:
static ErrorOr<NonnullOwnPtr<Member>> construct(BlockHeader header, AK::Stream&);
BlockHeader m_header;
NonnullOwnPtr<DeflateDecompressor> m_stream;
Crypto::Checksum::CRC32 m_checksum;
size_t m_nread { 0 };
private:
Member(BlockHeader, NonnullOwnPtr<DeflateDecompressor>);
};
Member const& current_member() const { return *m_current_member; }
Member& current_member() { return *m_current_member; }
NonnullOwnPtr<AK::Stream> m_input_stream;
u8 m_partial_header[sizeof(BlockHeader)];
size_t m_partial_header_offset { 0 };
OwnPtr<Member> m_current_member {};
bool m_eof { false };
};
class GzipCompressor final : public AK::Stream {
public:
GzipCompressor(MaybeOwned<AK::Stream>);
virtual ErrorOr<Bytes> read(Bytes) override;
virtual ErrorOr<size_t> write(ReadonlyBytes) override;
virtual bool is_eof() const override;
virtual bool is_open() const override;
virtual void close() override;
static ErrorOr<ByteBuffer> compress_all(ReadonlyBytes bytes);
private:
MaybeOwned<AK::Stream> m_output_stream;
};
}