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Annotation of sys/lib/libz/inftrees.h, Revision 1.1

1.1     ! nbrk        1: /*     $OpenBSD: inftrees.h,v 1.8 2005/07/20 15:56:46 millert Exp $    */
        !             2: /* inftrees.h -- header to use inftrees.c
        !             3:  * Copyright (C) 1995-2005 Mark Adler
        !             4:  * For conditions of distribution and use, see copyright notice in zlib.h
        !             5:  */
        !             6:
        !             7: /* WARNING: this file should *not* be used by applications. It is
        !             8:    part of the implementation of the compression library and is
        !             9:    subject to change. Applications should only use zlib.h.
        !            10:  */
        !            11:
        !            12: /* Structure for decoding tables.  Each entry provides either the
        !            13:    information needed to do the operation requested by the code that
        !            14:    indexed that table entry, or it provides a pointer to another
        !            15:    table that indexes more bits of the code.  op indicates whether
        !            16:    the entry is a pointer to another table, a literal, a length or
        !            17:    distance, an end-of-block, or an invalid code.  For a table
        !            18:    pointer, the low four bits of op is the number of index bits of
        !            19:    that table.  For a length or distance, the low four bits of op
        !            20:    is the number of extra bits to get after the code.  bits is
        !            21:    the number of bits in this code or part of the code to drop off
        !            22:    of the bit buffer.  val is the actual byte to output in the case
        !            23:    of a literal, the base length or distance, or the offset from
        !            24:    the current table to the next table.  Each entry is four bytes. */
        !            25: typedef struct {
        !            26:     unsigned char op;           /* operation, extra bits, table bits */
        !            27:     unsigned char bits;         /* bits in this part of the code */
        !            28:     unsigned short val;         /* offset in table or code value */
        !            29: } code;
        !            30:
        !            31: /* op values as set by inflate_table():
        !            32:     00000000 - literal
        !            33:     0000tttt - table link, tttt != 0 is the number of table index bits
        !            34:     0001eeee - length or distance, eeee is the number of extra bits
        !            35:     01100000 - end of block
        !            36:     01000000 - invalid code
        !            37:  */
        !            38:
        !            39: /* Maximum size of dynamic tree.  The maximum found in a long but non-
        !            40:    exhaustive search was 1444 code structures (852 for length/literals
        !            41:    and 592 for distances, the latter actually the result of an
        !            42:    exhaustive search).  The true maximum is not known, but the value
        !            43:    below is more than safe. */
        !            44: #define ENOUGH 2048
        !            45: #define MAXD 592
        !            46:
        !            47: /* Type of code to build for inftable() */
        !            48: typedef enum {
        !            49:     CODES,
        !            50:     LENS,
        !            51:     DISTS
        !            52: } codetype;
        !            53:
        !            54: extern int inflate_table OF((codetype type, unsigned short FAR *lens,
        !            55:                              unsigned codes, code FAR * FAR *table,
        !            56:                              unsigned FAR *bits, unsigned short FAR *work));