xzfile.h

[詳解]

/*==========================================================================*/
/* Lhaz xzfileインタフェース                                lhaz@chitora.jp */
/*==========================================================================*/
#pragma once
 
#include <vector>
#include "lzma.h"
#include "mybuf.h"
 
using namespace std;
 
class MYSTR;
class MYFILE;
 
class XZFILE {
 
public:
    static const uint8_t    HEADER_MAGIC[6];
    //
    XZFILE(void) :
        UnCompressedSize(0)
    {
    }
    //
    uint64_t    GetUnCompressedSize(void) const { return UnCompressedSize; }
    bool        Get(const MYSTR& name);
    bool        Test(const MYSTR& name);
 
private:
    enum STREAM_FLAGS {
        SF_CRC32 = 0x01,
        SF_CRC64 = 0x04,
        SF_SHA256 = 0x0A,
    };
    enum BLOCK_FLAGS {
        BF_NUMBER_OF_FILTERS_M = 0x03,
        BF_RESERVED_M = 0x3C,
        BF_COMPRESSED_SIZE_PRESENT = 0x40,
        BF_UNCOMPRESSED_SIZE_PRESENT = 0x80,
    };
    //
    static const uint8_t    FOOTER_MAGIC[2];
    //
    struct stream_header_t {
        uint8_t     header_magic_bytes[6];
        uint8_t     stream_flags[2];
        uint32_t    crc32;
    }               stream_header;
    struct block_t {
        struct block_header_t {
            uint8_t                 block_header_size;
            uint8_t                 block_flags;
            uint64_t                compressed_size;
            uint64_t                uncompressed_size;
            struct filter_flags_t {
                uint64_t    filter_id;
                uint64_t    size_of_properties;
                MYBUF       filter_properties;
            };
            vector<filter_flags_t>  filter_flags;
            MYBUF                   header_padding;
            uint32_t                crc32;
        }       block_header;
        MYBUF   compressed_data;
        MYBUF   block_padding;
        MYBUF   check;
    };
    vector<block_t> block;
    struct index_t {
        uint8_t             index_indicator;
        uint64_t            number_of_records;
        struct record_t {
            uint64_t    unpadded_size;
            uint64_t    uncompressed_size;
        };
        vector<record_t>    record;
        MYBUF               index_padding;
        uint32_t            crc32;
    }               index;
    struct stream_footer_t {
        uint32_t    crc32;
        int         backward_size;
        uint8_t     stream_flags[2];
        uint8_t     footer_magic_bytes[2];
    }               stream_footer;
    //
    uint64_t    UnCompressedSize;
    //
    bool        GetVli(MYFILE& fp, uint64_t& ret, uint64_t& read);
 
};