]>
Commit | Line | Data |
---|---|---|
c801d85f | 1 | /* inftrees.h -- header to use inftrees.c |
41faf807 | 2 | * Copyright (C) 1995-2005 Mark Adler |
51dbdf87 | 3 | * For conditions of distribution and use, see copyright notice in zlib.h |
c801d85f KB |
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 | ||
51dbdf87 VS |
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 | */ | |
c801d85f KB |
37 | |
38 | /* Maximum size of dynamic tree. The maximum found in a long but non- | |
41faf807 MW |
39 | exhaustive search was 1444 code structures (852 for length/literals |
40 | and 592 for distances, the latter actually the result of an | |
51dbdf87 VS |
41 | exhaustive search). The true maximum is not known, but the value |
42 | below is more than safe. */ | |
41faf807 MW |
43 | #define ENOUGH 2048 |
44 | #define MAXD 592 | |
51dbdf87 VS |
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)); |