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