diff options
Diffstat (limited to 'zlib/inflate.h')
| -rw-r--r-- | zlib/inflate.h | 242 |
1 files changed, 125 insertions, 117 deletions
diff --git a/zlib/inflate.h b/zlib/inflate.h index b696512..a46cce6 100644 --- a/zlib/inflate.h +++ b/zlib/inflate.h @@ -1,117 +1,125 @@ -/* inflate.h -- internal inflate state definition
- * Copyright (C) 1995-2003 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 */
-typedef enum {
- HEAD, /* i: waiting for magic header */
-#ifdef GUNZIP
- 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) */
-#endif
- 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: 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: waiting for length/lit 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 */
-#ifdef GUNZIP
- LENGTH, /* i: waiting for 32-bit length (gzip) */
-#endif
- 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 transitions between above modes -
-
- (most modes can go to the BAD or MEM mode -- not shown for clarity)
-
- Process header:
- HEAD -> (gzip) or (zlib)
- (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
- NAME -> COMMENT -> HCRC -> TYPE
- (zlib) -> DICTID or TYPE
- DICTID -> DICT -> TYPE
- Read deflate blocks:
- TYPE -> STORED or TABLE or LEN or CHECK
- STORED -> COPY -> TYPE
- TABLE -> LENLENS -> CODELENS -> LEN
- Read deflate codes:
- LEN -> LENEXT or LIT or TYPE
- LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
- LIT -> LEN
- Process trailer:
- CHECK -> LENGTH -> DONE
- */
-
-/* state maintained between inflate() calls. Approximately 7K bytes. */
-struct inflate_state {
- 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 */
- int havedict; /* true if dictionary provided */
- int flags; /* gzip header method and flags (0 if zlib) */
- unsigned long check; /* protected copy of check value */
- unsigned long total; /* protected copy of output count */
- /* 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 write; /* window write index */
- unsigned char FAR *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 */
- code const FAR *lencode; /* starting table for length/literal codes */
- code const FAR *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[] */
- code FAR *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 */
- code codes[ENOUGH]; /* space for code tables */
-};
+/* 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 */ +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 transitions between above 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 + */ + +/* State maintained between inflate() calls -- approximately 7K bytes, not + including the allocated sliding window, which is up to 32K bytes. */ +struct inflate_state { + 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 FAR *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 */ + code const FAR *lencode; /* starting table for length/literal codes */ + code const FAR *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[] */ + code FAR *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 */ + code 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 */ +}; |