nuclear@1: /* inftrees.h -- header to use inftrees.c
nuclear@1:  * Copyright (C) 1995-2005 Mark Adler
nuclear@1:  * For conditions of distribution and use, see copyright notice in zlib.h
nuclear@1:  */
nuclear@1: 
nuclear@1: /* WARNING: this file should *not* be used by applications. It is
nuclear@1:    part of the implementation of the compression library and is
nuclear@1:    subject to change. Applications should only use zlib.h.
nuclear@1:  */
nuclear@1: 
nuclear@1: /* Structure for decoding tables.  Each entry provides either the
nuclear@1:    information needed to do the operation requested by the code that
nuclear@1:    indexed that table entry, or it provides a pointer to another
nuclear@1:    table that indexes more bits of the code.  op indicates whether
nuclear@1:    the entry is a pointer to another table, a literal, a length or
nuclear@1:    distance, an end-of-block, or an invalid code.  For a table
nuclear@1:    pointer, the low four bits of op is the number of index bits of
nuclear@1:    that table.  For a length or distance, the low four bits of op
nuclear@1:    is the number of extra bits to get after the code.  bits is
nuclear@1:    the number of bits in this code or part of the code to drop off
nuclear@1:    of the bit buffer.  val is the actual byte to output in the case
nuclear@1:    of a literal, the base length or distance, or the offset from
nuclear@1:    the current table to the next table.  Each entry is four bytes. */
nuclear@1: typedef struct {
nuclear@1:     unsigned char op;           /* operation, extra bits, table bits */
nuclear@1:     unsigned char bits;         /* bits in this part of the code */
nuclear@1:     unsigned short val;         /* offset in table or code value */
nuclear@1: } code;
nuclear@1: 
nuclear@1: /* op values as set by inflate_table():
nuclear@1:     00000000 - literal
nuclear@1:     0000tttt - table link, tttt != 0 is the number of table index bits
nuclear@1:     0001eeee - length or distance, eeee is the number of extra bits
nuclear@1:     01100000 - end of block
nuclear@1:     01000000 - invalid code
nuclear@1:  */
nuclear@1: 
nuclear@1: /* Maximum size of dynamic tree.  The maximum found in a long but non-
nuclear@1:    exhaustive search was 1444 code structures (852 for length/literals
nuclear@1:    and 592 for distances, the latter actually the result of an
nuclear@1:    exhaustive search).  The true maximum is not known, but the value
nuclear@1:    below is more than safe. */
nuclear@1: #define ENOUGH 2048
nuclear@1: #define MAXD 592
nuclear@1: 
nuclear@1: /* Type of code to build for inftable() */
nuclear@1: typedef enum {
nuclear@1:     CODES,
nuclear@1:     LENS,
nuclear@1:     DISTS
nuclear@1: } codetype;
nuclear@1: 
nuclear@1: extern int inflate_table OF((codetype type, unsigned short FAR *lens,
nuclear@1:                              unsigned codes, code FAR * FAR *table,
nuclear@1:                              unsigned FAR *bits, unsigned short FAR *work));