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