Lz4Decompressor.h

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/*
 * Copyright (C) 2020 Niek Linnenbank
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef __LIB_LIBEXEC_LZ4DECOMPRESSOR_H
#define __LIB_LIBEXEC_LZ4DECOMPRESSOR_H
 
#include <Types.h>
#include <Index.h>
 
class Lz4Decompressor
{
  private:
 
    static const u32 FrameMagic = 0x184D2204;
 
    enum FrameFlgFields
    {
        FrameDictIdShift     = 0,
        FrameContentChkShift = 2,
        FrameContentSzShift  = 3,
        FrameBlockChkShift   = 4,
        FrameBlockIndShift   = 5,
        FrameVersionShift    = 6,
    };
 
    static const u8 FrameVersion = 0x01;
 
    static const u32 EndMark = 0x00000000;
 
  public:
 
    enum Result
    {
        Success,
        IOError,
        InvalidArgument,
        NotSupported
    };
 
  public:
 
    Lz4Decompressor(const void *data, const Size size);
 
    Result initialize();
 
    u64 getUncompressedSize() const;
 
    Result read(void *buffer, const Size size) const;
 
  private:
 
    const u32 decompress(const u8 *input,
                         const Size inputSize,
                         u8 *output,
                         const Size outputSize) const;
 
    inline const u32 integerDecode(const u32 initial,
                                   const u8 *next,
                                   Size &byteCount) const;
 
  private:
 
    const u8 *m_inputData;
 
    const Size m_inputSize;
 
    Size m_frameDescSize;
 
    bool m_blockChecksums;
 
    bool m_contentChecksum;
 
    u64 m_contentSize;
 
    Size m_blockMaximumSize;
};
 
#endif /* __LIB_LIBEXEC_LZ4DECOMPRESSOR_H */