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Diffstat (limited to 'src/zlib/inflate.h')
| -rw-r--r-- | src/zlib/inflate.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/zlib/inflate.h b/src/zlib/inflate.h new file mode 100644 index 000000000..b6965127b --- /dev/null +++ b/src/zlib/inflate.h @@ -0,0 +1,117 @@ +/* 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 */
+};
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