BinaryObjectScanner/BinaryObjectScanner.Models/Compression/LZX/Constants.cs

namespace BinaryObjectScanner.Models.Compression.LZX
{
    public static class Constants
    {
        /* some constants defined by the LZX specification */
        public const int LZX_MIN_MATCH = (2);
        public const int LZX_MAX_MATCH = (257);
        public const int LZX_NUM_CHARS = (256);

        /// <summary>
        /// also blocktypes 4-7 invalid
        /// </summary>
        public const int LZX_BLOCKTYPE_INVALID = (0);
        public const int LZX_BLOCKTYPE_VERBATIM = (1);
        public const int LZX_BLOCKTYPE_ALIGNED = (2);
        public const int LZX_BLOCKTYPE_UNCOMPRESSED = (3);
        public const int LZX_PRETREE_NUM_ELEMENTS = (20);

        /// <summary>
        /// aligned offset tree #elements
        /// </summary>
        public const int LZX_ALIGNED_NUM_ELEMENTS = (8);

        /// <summary>
        /// this one missing from spec!
        /// </summary>
        public const int LZX_NUM_PRIMARY_LENGTHS = (7);

        /// <summary>
        /// length tree #elements
        /// </summary>
        public const int LZX_NUM_SECONDARY_LENGTHS = (249);

        /* LZX huffman defines: tweak tablebits as desired */
        public const int LZX_PRETREE_MAXSYMBOLS = (LZX_PRETREE_NUM_ELEMENTS);
        public const int LZX_PRETREE_TABLEBITS = (6);
        public const int LZX_MAINTREE_MAXSYMBOLS = (LZX_NUM_CHARS + 50 * 8);
        public const int LZX_MAINTREE_TABLEBITS = (12);
        public const int LZX_LENGTH_MAXSYMBOLS = (LZX_NUM_SECONDARY_LENGTHS + 1);
        public const int LZX_LENGTH_TABLEBITS = (12);
        public const int LZX_ALIGNED_MAXSYMBOLS = (LZX_ALIGNED_NUM_ELEMENTS);
        public const int LZX_ALIGNED_TABLEBITS = (7);

        public const int LZX_LENTABLE_SAFETY = (64); /* we allow length table decoding overruns */
    }
}