cosmopolitan/third_party/zlib/inflate.h

145 lines
6.5 KiB
C

#ifndef COSMOPOLITAN_THIRD_PARTY_ZLIB_INFLATE_H_
#define COSMOPOLITAN_THIRD_PARTY_ZLIB_INFLATE_H_
#include "third_party/zlib/inftrees.h"
#include "third_party/zlib/zlib.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
/* inflate.h -- internal inflate state definition
* Copyright (C) 1995-2016 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.
*/
/* define NO_GZIP when compiling if you want to disable gzip header and
trailer decoding by inflate(). NO_GZIP would be used to avoid linking in
the crc code when it is not needed. For shared libraries, gzip decoding
should be left enabled. */
#ifndef NO_GZIP
#define GUNZIP
#endif
/**
* Possible inflate modes between inflate() calls
*
* State transitions between modes -
*
* (most modes can go to BAD or MEM on error -- not shown for clarity)
*
* Process header:
* HEAD → (gzip) or (zlib) or (raw)
* (gzip) → FLAGS → TIME → OS → EXLEN → EXTRA → NAME → COMMENT →
* HCRC → TYPE
* (zlib) → DICTID or TYPE
* DICTID → DICT → TYPE
* (raw) → TYPEDO
* Read deflate blocks:
* TYPE → TYPEDO → STORED or TABLE or LEN_ or CHECK
* STORED → COPY_ → COPY → TYPE
* TABLE → LENLENS → CODELENS → LEN_
* LEN_ → LEN
* Read deflate codes in fixed or dynamic block:
* LEN → LENEXT or LIT or TYPE
* LENEXT → DIST → DISTEXT → MATCH → LEN
* LIT → LEN
* Process trailer:
* CHECK → LENGTH → DONE
*/
typedef enum {
HEAD = 16180, /* i: waiting for magic header */
FLAGS, /* i: waiting for method and flags (gzip) */
TIME, /* i: waiting for modification time (gzip) */
OS, /* i: waiting for extra flags and operating system (gzip) */
EXLEN, /* i: waiting for extra length (gzip) */
EXTRA, /* i: waiting for extra bytes (gzip) */
NAME, /* i: waiting for end of file name (gzip) */
COMMENT, /* i: waiting for end of comment (gzip) */
HCRC, /* i: waiting for header crc (gzip) */
DICTID, /* i: waiting for dictionary check value */
DICT, /* waiting for inflateSetDictionary() call */
TYPE, /* i: waiting for type bits, including last-flag bit */
TYPEDO, /* i: same, but skip check to exit inflate on new block */
STORED, /* i: waiting for stored size (length and complement) */
COPY_, /* i/o: same as COPY below, but only first time in */
COPY, /* i/o: waiting for input or output to copy stored block */
TABLE, /* i: waiting for dynamic block table lengths */
LENLENS, /* i: waiting for code length code lengths */
CODELENS, /* i: waiting for length/lit and distance code lengths */
LEN_, /* i: same as LEN below, but only first time in */
LEN, /* i: waiting for length/lit/eob code */
LENEXT, /* i: waiting for length extra bits */
DIST, /* i: waiting for distance code */
DISTEXT, /* i: waiting for distance extra bits */
MATCH, /* o: waiting for output space to copy string */
LIT, /* o: waiting for output space to write literal */
CHECK, /* i: waiting for 32-bit check value */
LENGTH, /* i: waiting for 32-bit length (gzip) */
DONE, /* finished check, done -- remain here until reset */
BAD, /* got a data error -- remain here until reset */
MEM, /* got an inflate() memory error -- remain here until reset */
SYNC /* looking for synchronization bytes to restart inflate() */
} inflate_mode;
/**
* State maintained between inflate() calls -- approximately 7K bytes,
* not including the allocated sliding window, which is up to 32K bytes.
*/
struct InflateState {
z_streamp strm; /* pointer back to this zlib stream */
inflate_mode mode; /* current inflate mode */
int last; /* true if processing last block */
int wrap; /* bit 0 true for zlib, bit 1 true for gzip,
bit 2 true to validate check value */
int havedict; /* true if dictionary provided */
int flags; /* gzip header method and flags (0 if zlib) */
unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */
unsigned long check; /* protected copy of check value */
unsigned long total; /* protected copy of output count */
gz_headerp head; /* where to save gzip header information */
/* sliding window */
unsigned wbits; /* log base 2 of requested window size */
unsigned wsize; /* window size or zero if not using window */
unsigned whave; /* valid bytes in the window */
unsigned wnext; /* window write index */
unsigned char *window; /* allocated sliding window, if needed */
/* bit accumulator */
unsigned long hold; /* input bit accumulator */
unsigned bits; /* number of bits in "in" */
/* for string and stored block copying */
unsigned length; /* literal or length of data to copy */
unsigned offset; /* distance back to copy string from */
/* for table and code decoding */
unsigned extra; /* extra bits needed */
/* fixed and dynamic code tables */
const struct zcode *lencode; /* starting table for length/literal codes */
const struct zcode *distcode; /* starting table for distance codes */
unsigned lenbits; /* index bits for lencode */
unsigned distbits; /* index bits for distcode */
/* dynamic table building */
unsigned ncode; /* number of code length code lengths */
unsigned nlen; /* number of length code lengths */
unsigned ndist; /* number of distance code lengths */
unsigned have; /* number of code lengths in lens[] */
struct zcode *next; /* next available space in codes[] */
unsigned short lens[320]; /* temporary storage for code lengths */
unsigned short work[288]; /* work area for code table building */
struct zcode codes[ENOUGH]; /* space for code tables */
int sane; /* if false, allow invalid distance too far */
int back; /* bits back of last unprocessed length/lit */
unsigned was; /* initial length of match */
};
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_THIRD_PARTY_ZLIB_INFLATE_H_ */