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ZConstants.h

Go to the documentation of this file.

#ifndef CLASSLIB_Z_CONSTANTS_H
# define CLASSLIB_Z_CONSTANTS_H

//<<<<<< INCLUDES                                                       >>>>>>

# include "classlib/zip/ZipUtils.h"

namespace lat {
//<<<<<< PUBLIC DEFINES                                                 >>>>>>
//<<<<<< PUBLIC CONSTANTS                                               >>>>>>
//<<<<<< PUBLIC TYPES                                                   >>>>>>
//<<<<<< PUBLIC VARIABLES                                               >>>>>>
//<<<<<< PUBLIC FUNCTIONS                                               >>>>>>
//<<<<<< CLASS DECLARATIONS                                             >>>>>>

struct ZConstants : ZipUtils
{
    // ZLIB constants
    // - Compression method and strategy (FIXME: data type: ascii/binary?)
    enum Method {
        STORED                          = 0, //< Stored as is
        DEFLATED                        = 8  //< Stored using deflate
    };
    enum Strategy {
        DEFAULT                         = 0, //< Default compression strategy
        FILTERED                        = 1, //< FIXME
        HUFFMAN_ONLY                    = 2  //< FIXME
    };

    // - Compression levels
    enum { BEST_COMPRESSION             = 9 }; //< Best compression level
    enum { DEFAULT_COMPRESSION          = 6 }; //< Default compression level
    enum { BEST_SPEED                   = 1 }; //< Fastest compression level

    // - Other settings
    enum { DEFAULT_WINDOW_BITS          = 15 };
    enum { DEFAULT_MEM_LEVEL            = 8 };

    // ZIP archive constants
    // - Archive version required (and made)
    enum { ARCHIVE_VERSION              = 20 };

    // - Magic header constants
    enum { DIR_HEADER_MAGIC             = 0x02014b50 };
    enum { ENTRY_HEADER_MAGIC           = 0x04034b50 };
    enum { END_HEADER_MAGIC             = 0x06054b50 };
    enum { ZIP_MAGIC_LEN                = 4 };
    enum { MAX_VAR_LEN                  = 0xffff };     //< Max variable-width field length
    enum { MAX_SIZE                     = 0xffffffff }; //< Max size of things


    // - Offsets into the central directory headers
    enum {
        DIR_MAGIC_OFF           = 0,
        DIR_VMADE_OFF           = 4,    DIR_VMADE_LEN           = 2,
        DIR_VREQD_OFF           = 6,    DIR_VREQD_LEN           = 2,
        DIR_FLAG_OFF            = 8,    DIR_FLAG_LEN            = 2,
        DIR_METHOD_OFF          = 10,   DIR_METHOD_LEN          = 2,
        DIR_DATE_OFF            = 12,   DIR_DATE_LEN            = 4,
        DIR_CRC32_OFF           = 16,   DIR_CRC32_LEN           = 4,
        DIR_CSIZE_OFF           = 20,   DIR_CSIZE_LEN           = 4,
        DIR_USIZE_OFF           = 24,   DIR_USIZE_LEN           = 4,
        DIR_NAMELEN_OFF         = 28,   DIR_NAMELEN_LEN         = 2,
        DIR_EXTRALEN_OFF        = 30,   DIR_EXTRALEN_LEN        = 2,
        DIR_COMMENTLEN_OFF      = 32,   DIR_COMMENTLEN_LEN      = 2,
        DIR_DISK_START_OFF      = 34,   DIR_DISK_START_LEN      = 2,
        DIR_INT_ATTR_OFF        = 36,   DIR_INT_ATTR_LEN        = 2,
        DIR_EXT_ATTR_OFF        = 38,   DIR_EXT_ATTR_LEN        = 4,
        DIR_ENTRY_POS_OFF       = 42,   DIR_ENTRY_POS_LEN       = 4,
        DIR_HEADER_SIZE         = 46
    };

    // - Offsets into the end-of-archive header
    enum{
        END_MAGIC_OFF           = 0,
        END_DISK_OFF            = 4,    END_DISK_LEN            = 2,
        END_DIR_DISK_OFF        = 6,    END_DIR_DISK_LEN        = 2,
        END_DISK_HDRS_OFF       = 8,    END_DISK_HDRS_LEN       = 2,
        END_TOTAL_HDRS_OFF      = 10,   END_TOTAL_HDRS_LEN      = 2,
        END_DIR_SIZE_OFF        = 12,   END_DIR_SIZE_LEN        = 4,
        END_DIR_OFFSET_OFF      = 16,   END_DIR_OFFSET_LEN      = 4,
        END_COMMENTLEN_OFF      = 20,   END_COMMENTLEN_LEN      = 2,
        END_HEADER_SIZE         = 22
    };

    // - Offsets into the local entry headers
    enum {
        ENTRY_MAGIC_OFF         = 0,
        ENTRY_VREQD_OFF         = 4,    ENTRY_VREQD_LEN         = 2,
        ENTRY_FLAG_OFF          = 6,    ENTRY_FLAG_LEN          = 2,
        ENTRY_METHOD_OFF        = 8,    ENTRY_METHOD_LEN        = 2,
        ENTRY_DATE_OFF          = 10,   ENTRY_DATE_LEN          = 4,
        ENTRY_CRC32_OFF         = 14,   ENTRY_CRC32_LEN         = 4,
        ENTRY_CSIZE_OFF         = 18,   ENTRY_CSIZE_LEN         = 4,
        ENTRY_USIZE_OFF         = 22,   ENTRY_USIZE_LEN         = 4,
        ENTRY_NAMELEN_OFF       = 26,   ENTRY_NAMELEN_LEN       = 2,
        ENTRY_EXTRALEN_OFF      = 28,   ENTRY_EXTRALEN_LEN      = 2,
        ENTRY_HEADER_SIZE       = 30
    };

    // GZIP file format constants
    enum { GZIP_MAGIC = 0x8b1f };
    enum {
        GZHDR_MAGIC_OFF  = 0, GZHDR_MAGIC_LEN  = 2,
        GZHDR_METHOD_OFF = 2, GZHDR_METHOD_LEN = 1,
        GZHDR_FLAGS_OFF  = 3, GZHDR_FLAGS_LEN  = 1,
        GZHDR_TIME_OFF   = 4, GZHDR_TIME_LEN   = 4,
        GZHDR_XFLAGS_OFF = 8, GZHDR_XFLAGS_LEN = 1,
        GZHDR_OS_OFF     = 9, GZHDR_OS_LEN     = 1,
        GZHDR_SIZE       = 10,

        // The standard header can be followed by:
        //   - extra field: 2-byte len + data (flags & EXTRA_FIELD)
        //   - original file name: EOF-terminated string (flags & ORIG_NAME)
        //   - comment: EOF-terminaed string (flags & COMMENT)
        //   - header crc: 2-byte value (flags & HEAD_CRC)
        //
        // This is followed by data, and finally 4-byte CRC-32 and a
        // 4-byte original uncompressed data length (FIXME: .gz files
        // can be concatenated back-to-back, need to reset total_out
        // in z_stream and reinit crc32).

        GZHDR_FLAG_ASCII        = 1,  // bit 0: file is probably ascii text
        GZHDR_FLAG_HEAD_CRC     = 2,  // bit 1: header crc16 present
        GZHDR_FLAG_EXTRA_FIELD  = 4,  // bit 2: extra field present
        GZHDR_FLAG_ORIG_NAME    = 8,  // bit 3: original file name present
        GZHDR_FLAG_COMMENT      = 16, // bit 4: file comment present
        GZHDR_FLAG_RESERVED     = 0xe0 // bits 5-7: reserved
    };
};

//<<<<<< INLINE PUBLIC FUNCTIONS                                        >>>>>>
//<<<<<< INLINE MEMBER FUNCTIONS                                        >>>>>>

} // namespace lat
#endif // CLASSLIB_Z_CONSTANTS_H

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