inftrees.h
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- /* inftrees.h -- header to use inftrees.c
- * Copyright (C) 1995-2003 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- /* WARNING: this file should *not* be used by applications. It is
- part of the implementation of the compression library and is
- subject to change. Applications should only use zlib.h.
- */
- /* Structure for decoding tables. Each entry provides either the
- information needed to do the operation requested by the code that
- indexed that table entry, or it provides a pointer to another
- table that indexes more bits of the code. op indicates whether
- the entry is a pointer to another table, a literal, a length or
- distance, an end-of-block, or an invalid code. For a table
- pointer, the low four bits of op is the number of index bits of
- that table. For a length or distance, the low four bits of op
- is the number of extra bits to get after the code. bits is
- the number of bits in this code or part of the code to drop off
- of the bit buffer. val is the actual byte to output in the case
- of a literal, the base length or distance, or the offset from
- the current table to the next table. Each entry is four bytes. */
- typedef struct {
- unsigned char op; /* operation, extra bits, table bits */
- unsigned char bits; /* bits in this part of the code */
- unsigned short val; /* offset in table or code value */
- } code;
- /* op values as set by inflate_table():
- 00000000 - literal
- 0000tttt - table link, tttt != 0 is the number of table index bits
- 0001eeee - length or distance, eeee is the number of extra bits
- 01100000 - end of block
- 01000000 - invalid code
- */
- /* Maximum size of dynamic tree. The maximum found in a long but non-
- exhaustive search was 1004 code structures (850 for length/literals
- and 154 for distances, the latter actually the result of an
- exhaustive search). The true maximum is not known, but the value
- below is more than safe. */
- #define ENOUGH 1440
- #define MAXD 154
- /* Type of code to build for inftable() */
- typedef enum {
- CODES,
- LENS,
- DISTS
- } codetype;
- extern int inflate_table OF((codetype type, unsigned short FAR *lens,
- unsigned codes, code FAR * FAR *table,
- unsigned FAR *bits, unsigned short FAR *work));