ladybird/Libraries/LibCompress/Gzip.h

100 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 <AK/NonnullOwnPtr.h>
#include <AK/OwnPtr.h>
#include <AK/Stream.h>
#include <LibCompress/Deflate.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 Stream {
public:
GzipDecompressor(MaybeOwned<Stream>);
~GzipDecompressor();
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 { return true; }
virtual void close() override {};
static ErrorOr<ByteBuffer> decompress_all(ReadonlyBytes);
static ErrorOr<Optional<String>> describe_header(ReadonlyBytes);
static bool is_likely_compressed(ReadonlyBytes bytes);
private:
class Member {
public:
static ErrorOr<NonnullOwnPtr<Member>> construct(BlockHeader header, LittleEndianInputBitStream&);
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<LittleEndianInputBitStream> 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 Stream {
public:
GzipCompressor(MaybeOwned<Stream>);
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;
static ErrorOr<ByteBuffer> compress_all(ReadonlyBytes bytes);
private:
MaybeOwned<Stream> m_output_stream;
};
}