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Posted 23 May 2000

Remote Control PCs

, 20 Sep 2013
Two projects that work together to remote control PCs across a LAN.
/* inflate.h -- internal inflate state definition
 * Copyright (C) 1995-2004 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

/* Possible inflate modes between inflate() calls */
typedef enum {
    HEAD,       /* i: waiting for magic header */
    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) */
    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 */
    LENGTH,     /* i: waiting for 32-bit length (gzip) */
    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 dmax;              /* zlib header max distance (INFLATE_STRICT) */
    unsigned long check;        /* protected copy of check value */
    unsigned long total;        /* protected copy of output count */
    gz_headerp head;            /* where to save gzip header information */
        /* 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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About the Author

Andy Bantly
United States United States
Working as a software developer since 1989. Started out with Basic, FORTRAN and JCL, moved into Visual Basic 1.0, C, then C++, and now I work mainly in C++ using MFC, Win32, and ATL/COM. I use Microsoft Products only because that is what gives me gainful employment. Through work, I have a lot of experience with HTML, JavaScript, XSL transformations, the XMLHTTP object, PHP 4.x, and simple COM object integrations.

I've worked for the University of Oklahoma in the school of meteorology (Go SOONERS!), consulting, and now as a Senior Software Engineer. These things keep my lights on and electricity going. My dream job is to own a bowling alley and rub elbows with pro-bowlers! I'm also an avid pedicab driver and have my own cab. I like the hustle of picking up people in downtown and biking them to their destination.

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