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