| /* inftrees.h -- header to use inftrees.c | |
| * Copyright (C) 1995-2005 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 1444 code structures (852 for length/literals | |
| and 592 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 2048 | |
| #define MAXD 592 | |
| /* 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)); |