symbian-qemu-0.9.1-12/zlib-1.2.3/inflate.h
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0:ffa851df0825 1:2fb8b9db1c86
       
     1 /* inflate.h -- internal inflate state definition
       
     2  * Copyright (C) 1995-2004 Mark Adler
       
     3  * For conditions of distribution and use, see copyright notice in zlib.h
       
     4  */
       
     5 
       
     6 /* WARNING: this file should *not* be used by applications. It is
       
     7    part of the implementation of the compression library and is
       
     8    subject to change. Applications should only use zlib.h.
       
     9  */
       
    10 
       
    11 /* define NO_GZIP when compiling if you want to disable gzip header and
       
    12    trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
       
    13    the crc code when it is not needed.  For shared libraries, gzip decoding
       
    14    should be left enabled. */
       
    15 #ifndef NO_GZIP
       
    16 #  define GUNZIP
       
    17 #endif
       
    18 
       
    19 /* Possible inflate modes between inflate() calls */
       
    20 typedef enum {
       
    21     HEAD,       /* i: waiting for magic header */
       
    22     FLAGS,      /* i: waiting for method and flags (gzip) */
       
    23     TIME,       /* i: waiting for modification time (gzip) */
       
    24     OS,         /* i: waiting for extra flags and operating system (gzip) */
       
    25     EXLEN,      /* i: waiting for extra length (gzip) */
       
    26     EXTRA,      /* i: waiting for extra bytes (gzip) */
       
    27     NAME,       /* i: waiting for end of file name (gzip) */
       
    28     COMMENT,    /* i: waiting for end of comment (gzip) */
       
    29     HCRC,       /* i: waiting for header crc (gzip) */
       
    30     DICTID,     /* i: waiting for dictionary check value */
       
    31     DICT,       /* waiting for inflateSetDictionary() call */
       
    32         TYPE,       /* i: waiting for type bits, including last-flag bit */
       
    33         TYPEDO,     /* i: same, but skip check to exit inflate on new block */
       
    34         STORED,     /* i: waiting for stored size (length and complement) */
       
    35         COPY,       /* i/o: waiting for input or output to copy stored block */
       
    36         TABLE,      /* i: waiting for dynamic block table lengths */
       
    37         LENLENS,    /* i: waiting for code length code lengths */
       
    38         CODELENS,   /* i: waiting for length/lit and distance code lengths */
       
    39             LEN,        /* i: waiting for length/lit code */
       
    40             LENEXT,     /* i: waiting for length extra bits */
       
    41             DIST,       /* i: waiting for distance code */
       
    42             DISTEXT,    /* i: waiting for distance extra bits */
       
    43             MATCH,      /* o: waiting for output space to copy string */
       
    44             LIT,        /* o: waiting for output space to write literal */
       
    45     CHECK,      /* i: waiting for 32-bit check value */
       
    46     LENGTH,     /* i: waiting for 32-bit length (gzip) */
       
    47     DONE,       /* finished check, done -- remain here until reset */
       
    48     BAD,        /* got a data error -- remain here until reset */
       
    49     MEM,        /* got an inflate() memory error -- remain here until reset */
       
    50     SYNC        /* looking for synchronization bytes to restart inflate() */
       
    51 } inflate_mode;
       
    52 
       
    53 /*
       
    54     State transitions between above modes -
       
    55 
       
    56     (most modes can go to the BAD or MEM mode -- not shown for clarity)
       
    57 
       
    58     Process header:
       
    59         HEAD -> (gzip) or (zlib)
       
    60         (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
       
    61         NAME -> COMMENT -> HCRC -> TYPE
       
    62         (zlib) -> DICTID or TYPE
       
    63         DICTID -> DICT -> TYPE
       
    64     Read deflate blocks:
       
    65             TYPE -> STORED or TABLE or LEN or CHECK
       
    66             STORED -> COPY -> TYPE
       
    67             TABLE -> LENLENS -> CODELENS -> LEN
       
    68     Read deflate codes:
       
    69                 LEN -> LENEXT or LIT or TYPE
       
    70                 LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
       
    71                 LIT -> LEN
       
    72     Process trailer:
       
    73         CHECK -> LENGTH -> DONE
       
    74  */
       
    75 
       
    76 /* state maintained between inflate() calls.  Approximately 7K bytes. */
       
    77 struct inflate_state {
       
    78     inflate_mode mode;          /* current inflate mode */
       
    79     int last;                   /* true if processing last block */
       
    80     int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip */
       
    81     int havedict;               /* true if dictionary provided */
       
    82     int flags;                  /* gzip header method and flags (0 if zlib) */
       
    83     unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
       
    84     unsigned long check;        /* protected copy of check value */
       
    85     unsigned long total;        /* protected copy of output count */
       
    86     gz_headerp head;            /* where to save gzip header information */
       
    87         /* sliding window */
       
    88     unsigned wbits;             /* log base 2 of requested window size */
       
    89     unsigned wsize;             /* window size or zero if not using window */
       
    90     unsigned whave;             /* valid bytes in the window */
       
    91     unsigned write;             /* window write index */
       
    92     unsigned char FAR *window;  /* allocated sliding window, if needed */
       
    93         /* bit accumulator */
       
    94     unsigned long hold;         /* input bit accumulator */
       
    95     unsigned bits;              /* number of bits in "in" */
       
    96         /* for string and stored block copying */
       
    97     unsigned length;            /* literal or length of data to copy */
       
    98     unsigned offset;            /* distance back to copy string from */
       
    99         /* for table and code decoding */
       
   100     unsigned extra;             /* extra bits needed */
       
   101         /* fixed and dynamic code tables */
       
   102     code const FAR *lencode;    /* starting table for length/literal codes */
       
   103     code const FAR *distcode;   /* starting table for distance codes */
       
   104     unsigned lenbits;           /* index bits for lencode */
       
   105     unsigned distbits;          /* index bits for distcode */
       
   106         /* dynamic table building */
       
   107     unsigned ncode;             /* number of code length code lengths */
       
   108     unsigned nlen;              /* number of length code lengths */
       
   109     unsigned ndist;             /* number of distance code lengths */
       
   110     unsigned have;              /* number of code lengths in lens[] */
       
   111     code FAR *next;             /* next available space in codes[] */
       
   112     unsigned short lens[320];   /* temporary storage for code lengths */
       
   113     unsigned short work[288];   /* work area for code table building */
       
   114     code codes[ENOUGH];         /* space for code tables */
       
   115 };