zlib123/inflate.h
author Ryan C. Gordon <icculus@icculus.org>
Wed, 03 Oct 2018 22:45:05 -0400
branchstable-1.0
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Fixed Win10's GetUserProfileDirectory() bug in stable-1.0 branch.
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/* inflate.h -- internal inflate state definition
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 * Copyright (C) 1995-2004 Mark Adler
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 * For conditions of distribution and use, see copyright notice in zlib.h
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 */
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/* WARNING: this file should *not* be used by applications. It is
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   part of the implementation of the compression library and is
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   subject to change. Applications should only use zlib.h.
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 */
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/* define NO_GZIP when compiling if you want to disable gzip header and
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   trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
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   the crc code when it is not needed.  For shared libraries, gzip decoding
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   should be left enabled. */
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#ifndef NO_GZIP
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#  define GUNZIP
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#endif
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/* Possible inflate modes between inflate() calls */
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typedef enum {
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    HEAD,       /* i: waiting for magic header */
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    FLAGS,      /* i: waiting for method and flags (gzip) */
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    TIME,       /* i: waiting for modification time (gzip) */
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    OS,         /* i: waiting for extra flags and operating system (gzip) */
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    EXLEN,      /* i: waiting for extra length (gzip) */
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    EXTRA,      /* i: waiting for extra bytes (gzip) */
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    NAME,       /* i: waiting for end of file name (gzip) */
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    COMMENT,    /* i: waiting for end of comment (gzip) */
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    HCRC,       /* i: waiting for header crc (gzip) */
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    DICTID,     /* i: waiting for dictionary check value */
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    DICT,       /* waiting for inflateSetDictionary() call */
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        TYPE,       /* i: waiting for type bits, including last-flag bit */
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        TYPEDO,     /* i: same, but skip check to exit inflate on new block */
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        STORED,     /* i: waiting for stored size (length and complement) */
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        COPY,       /* i/o: waiting for input or output to copy stored block */
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        TABLE,      /* i: waiting for dynamic block table lengths */
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        LENLENS,    /* i: waiting for code length code lengths */
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        CODELENS,   /* i: waiting for length/lit and distance code lengths */
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            LEN,        /* i: waiting for length/lit code */
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            LENEXT,     /* i: waiting for length extra bits */
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            DIST,       /* i: waiting for distance code */
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            DISTEXT,    /* i: waiting for distance extra bits */
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            MATCH,      /* o: waiting for output space to copy string */
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            LIT,        /* o: waiting for output space to write literal */
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    CHECK,      /* i: waiting for 32-bit check value */
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    LENGTH,     /* i: waiting for 32-bit length (gzip) */
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    DONE,       /* finished check, done -- remain here until reset */
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    BAD,        /* got a data error -- remain here until reset */
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    MEM,        /* got an inflate() memory error -- remain here until reset */
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    SYNC        /* looking for synchronization bytes to restart inflate() */
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} inflate_mode;
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/*
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    State transitions between above modes -
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    (most modes can go to the BAD or MEM mode -- not shown for clarity)
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    Process header:
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        HEAD -> (gzip) or (zlib)
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        (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
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        NAME -> COMMENT -> HCRC -> TYPE
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        (zlib) -> DICTID or TYPE
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        DICTID -> DICT -> TYPE
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    Read deflate blocks:
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            TYPE -> STORED or TABLE or LEN or CHECK
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            STORED -> COPY -> TYPE
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            TABLE -> LENLENS -> CODELENS -> LEN
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    Read deflate codes:
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                LEN -> LENEXT or LIT or TYPE
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                LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
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                LIT -> LEN
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    Process trailer:
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        CHECK -> LENGTH -> DONE
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 */
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/* state maintained between inflate() calls.  Approximately 7K bytes. */
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struct inflate_state {
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    inflate_mode mode;          /* current inflate mode */
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    int last;                   /* true if processing last block */
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    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip */
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    int havedict;               /* true if dictionary provided */
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    int flags;                  /* gzip header method and flags (0 if zlib) */
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    unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
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    unsigned long check;        /* protected copy of check value */
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    unsigned long total;        /* protected copy of output count */
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    gz_headerp head;            /* where to save gzip header information */
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        /* sliding window */
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    unsigned wbits;             /* log base 2 of requested window size */
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    unsigned wsize;             /* window size or zero if not using window */
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    unsigned whave;             /* valid bytes in the window */
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    unsigned write;             /* window write index */
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    unsigned char FAR *window;  /* allocated sliding window, if needed */
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        /* bit accumulator */
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    unsigned long hold;         /* input bit accumulator */
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    unsigned bits;              /* number of bits in "in" */
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        /* for string and stored block copying */
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    unsigned length;            /* literal or length of data to copy */
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    unsigned offset;            /* distance back to copy string from */
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        /* for table and code decoding */
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    unsigned extra;             /* extra bits needed */
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        /* fixed and dynamic code tables */
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    code const FAR *lencode;    /* starting table for length/literal codes */
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    code const FAR *distcode;   /* starting table for distance codes */
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    unsigned lenbits;           /* index bits for lencode */
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    unsigned distbits;          /* index bits for distcode */
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        /* dynamic table building */
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    unsigned ncode;             /* number of code length code lengths */
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    unsigned nlen;              /* number of length code lengths */
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    unsigned ndist;             /* number of distance code lengths */
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    unsigned have;              /* number of code lengths in lens[] */
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    code FAR *next;             /* next available space in codes[] */
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    unsigned short lens[320];   /* temporary storage for code lengths */
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    unsigned short work[288];   /* work area for code table building */
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    code codes[ENOUGH];         /* space for code tables */
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};