"Fossies" - the Fresh Open Source Software Archive

Member "src/Common/zlib/inflate.h" (10 Oct 2018, 6618 Bytes) of package /windows/misc/VeraCrypt_1.23-Hotfix-2_Source.zip:


As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) C and C++ source code syntax highlighting (style: standard) with prefixed line numbers and code folding option. Alternatively you can here view or download the uninterpreted source code file. For more information about "inflate.h" see the Fossies "Dox" file reference documentation.

    1 /* inflate.h -- internal inflate state definition
    2  * Copyright (C) 1995-2016 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 = 16180,   /* 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 7K bytes, not
   81    including the allocated sliding window, which is up to 32K bytes. */
   82 struct inflate_state {
   83     z_streamp strm;             /* pointer back to this zlib stream */
   84     inflate_mode mode;          /* current inflate mode */
   85     int last;                   /* true if processing last block */
   86     int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip,
   87                                    bit 2 true to validate check value */
   88     int havedict;               /* true if dictionary provided */
   89     int flags;                  /* gzip header method and flags (0 if zlib) */
   90     unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
   91     unsigned long check;        /* protected copy of check value */
   92     unsigned long total;        /* protected copy of output count */
   93     gz_headerp head;            /* where to save gzip header information */
   94         /* sliding window */
   95     unsigned wbits;             /* log base 2 of requested window size */
   96     unsigned wsize;             /* window size or zero if not using window */
   97     unsigned whave;             /* valid bytes in the window */
   98     unsigned wnext;             /* window write index */
   99     unsigned char FAR *window;  /* allocated sliding window, if needed */
  100         /* bit accumulator */
  101     unsigned long hold;         /* input bit accumulator */
  102     unsigned bits;              /* number of bits in "in" */
  103         /* for string and stored block copying */
  104     unsigned length;            /* literal or length of data to copy */
  105     unsigned offset;            /* distance back to copy string from */
  106         /* for table and code decoding */
  107     unsigned extra;             /* extra bits needed */
  108         /* fixed and dynamic code tables */
  109     code const FAR *lencode;    /* starting table for length/literal codes */
  110     code const FAR *distcode;   /* starting table for distance codes */
  111     unsigned lenbits;           /* index bits for lencode */
  112     unsigned distbits;          /* index bits for distcode */
  113         /* dynamic table building */
  114     unsigned ncode;             /* number of code length code lengths */
  115     unsigned nlen;              /* number of length code lengths */
  116     unsigned ndist;             /* number of distance code lengths */
  117     unsigned have;              /* number of code lengths in lens[] */
  118     code FAR *next;             /* next available space in codes[] */
  119     unsigned short lens[320];   /* temporary storage for code lengths */
  120     unsigned short work[288];   /* work area for code table building */
  121     code codes[ENOUGH];         /* space for code tables */
  122     int sane;                   /* if false, allow invalid distance too far */
  123     int back;                   /* bits back of last unprocessed length/lit */
  124     unsigned was;               /* initial length of match */
  125 };