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Annotation of embedaddon/sudo/zlib/inflate.h, revision 1.1

1.1     ! misho       1: /* inflate.h -- internal inflate state definition
        !             2:  * Copyright (C) 1995-2009 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: same as COPY below, but only first time in */
        !            36:         COPY,       /* i/o: waiting for input or output to copy stored block */
        !            37:         TABLE,      /* i: waiting for dynamic block table lengths */
        !            38:         LENLENS,    /* i: waiting for code length code lengths */
        !            39:         CODELENS,   /* i: waiting for length/lit and distance code lengths */
        !            40:             LEN_,       /* i: same as LEN below, but only first time in */
        !            41:             LEN,        /* i: waiting for length/lit/eob code */
        !            42:             LENEXT,     /* i: waiting for length extra bits */
        !            43:             DIST,       /* i: waiting for distance code */
        !            44:             DISTEXT,    /* i: waiting for distance extra bits */
        !            45:             MATCH,      /* o: waiting for output space to copy string */
        !            46:             LIT,        /* o: waiting for output space to write literal */
        !            47:     CHECK,      /* i: waiting for 32-bit check value */
        !            48:     LENGTH,     /* i: waiting for 32-bit length (gzip) */
        !            49:     DONE,       /* finished check, done -- remain here until reset */
        !            50:     BAD,        /* got a data error -- remain here until reset */
        !            51:     MEM,        /* got an inflate() memory error -- remain here until reset */
        !            52:     SYNC        /* looking for synchronization bytes to restart inflate() */
        !            53: } inflate_mode;
        !            54: 
        !            55: /*
        !            56:     State transitions between above modes -
        !            57: 
        !            58:     (most modes can go to BAD or MEM on error -- not shown for clarity)
        !            59: 
        !            60:     Process header:
        !            61:         HEAD -> (gzip) or (zlib) or (raw)
        !            62:         (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT ->
        !            63:                   HCRC -> TYPE
        !            64:         (zlib) -> DICTID or TYPE
        !            65:         DICTID -> DICT -> TYPE
        !            66:         (raw) -> TYPEDO
        !            67:     Read deflate blocks:
        !            68:             TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK
        !            69:             STORED -> COPY_ -> COPY -> TYPE
        !            70:             TABLE -> LENLENS -> CODELENS -> LEN_
        !            71:             LEN_ -> LEN
        !            72:     Read deflate codes in fixed or dynamic block:
        !            73:                 LEN -> LENEXT or LIT or TYPE
        !            74:                 LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
        !            75:                 LIT -> LEN
        !            76:     Process trailer:
        !            77:         CHECK -> LENGTH -> DONE
        !            78:  */
        !            79: 
        !            80: /* state maintained between inflate() calls.  Approximately 10K bytes. */
        !            81: struct inflate_state {
        !            82:     inflate_mode mode;          /* current inflate mode */
        !            83:     int last;                   /* true if processing last block */
        !            84:     int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip */
        !            85:     int havedict;               /* true if dictionary provided */
        !            86:     int flags;                  /* gzip header method and flags (0 if zlib) */
        !            87:     unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
        !            88:     unsigned long check;        /* protected copy of check value */
        !            89:     unsigned long total;        /* protected copy of output count */
        !            90:     gz_headerp head;            /* where to save gzip header information */
        !            91:         /* sliding window */
        !            92:     unsigned wbits;             /* log base 2 of requested window size */
        !            93:     unsigned wsize;             /* window size or zero if not using window */
        !            94:     unsigned whave;             /* valid bytes in the window */
        !            95:     unsigned wnext;             /* window write index */
        !            96:     unsigned char FAR *window;  /* allocated sliding window, if needed */
        !            97:         /* bit accumulator */
        !            98:     unsigned long hold;         /* input bit accumulator */
        !            99:     unsigned bits;              /* number of bits in "in" */
        !           100:         /* for string and stored block copying */
        !           101:     unsigned length;            /* literal or length of data to copy */
        !           102:     unsigned offset;            /* distance back to copy string from */
        !           103:         /* for table and code decoding */
        !           104:     unsigned extra;             /* extra bits needed */
        !           105:         /* fixed and dynamic code tables */
        !           106:     code const FAR *lencode;    /* starting table for length/literal codes */
        !           107:     code const FAR *distcode;   /* starting table for distance codes */
        !           108:     unsigned lenbits;           /* index bits for lencode */
        !           109:     unsigned distbits;          /* index bits for distcode */
        !           110:         /* dynamic table building */
        !           111:     unsigned ncode;             /* number of code length code lengths */
        !           112:     unsigned nlen;              /* number of length code lengths */
        !           113:     unsigned ndist;             /* number of distance code lengths */
        !           114:     unsigned have;              /* number of code lengths in lens[] */
        !           115:     code FAR *next;             /* next available space in codes[] */
        !           116:     unsigned short lens[320];   /* temporary storage for code lengths */
        !           117:     unsigned short work[288];   /* work area for code table building */
        !           118:     code codes[ENOUGH];         /* space for code tables */
        !           119:     int sane;                   /* if false, allow invalid distance too far */
        !           120:     int back;                   /* bits back of last unprocessed length/lit */
        !           121:     unsigned was;               /* initial length of match */
        !           122: };