    /* gzguts.h -- zlib internal header definitions for gz* operations
     * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
     * For conditions of distribution and use, see copyright notice in zlib.h
     */

    #ifdef _MSC_VER
    // Disable the following warnings for Visual Studio
    // This is a warning you get from visual studio 2005 about things in the standard C++
    // library being "deprecated."  I checked the C++ standard and it doesn't say jack
    // about any of them (I checked the searchable PDF).   So this warning is total Bunk.
    #pragma warning(disable : 4996)
    #endif

    #ifdef _LARGEFILE64_SOURCE
    #  ifndef _LARGEFILE_SOURCE
    #    define _LARGEFILE_SOURCE 1
    #  endif
    #  ifdef _FILE_OFFSET_BITS
    #    undef _FILE_OFFSET_BITS
    #  endif
    #endif

    #ifdef HAVE_HIDDEN
    #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
    #else
    #  define ZLIB_INTERNAL
    #endif

    #include <stdio.h>
    #include "zlib.h"
    #ifdef STDC
    #  include <string.h>
    #  include <stdlib.h>
    #  include <limits.h>
    #endif

    #ifndef _POSIX_SOURCE
    #  define _POSIX_SOURCE
    #endif
    #include <fcntl.h>

    #ifdef _WIN32
    #  include <stddef.h>
    #endif

    #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
    #  include <io.h>
    #else
    #  include <unistd.h>
    #endif

    #if defined(_WIN32) || defined(__CYGWIN__)
    #  define WIDECHAR
    #endif

    #ifdef WINAPI_FAMILY
    #  define open _open
    #  define read _read
    #  define write _write
    #  define close _close
    #endif

    #ifdef NO_DEFLATE       /* for compatibility with old definition */
    #  define NO_GZCOMPRESS
    #endif

    #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
    #  ifndef HAVE_VSNPRINTF
    #    define HAVE_VSNPRINTF
    #  endif
    #endif

    #if defined(__CYGWIN__)
    #  ifndef HAVE_VSNPRINTF
    #    define HAVE_VSNPRINTF
    #  endif
    #endif

    #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
    #  ifndef HAVE_VSNPRINTF
    #    define HAVE_VSNPRINTF
    #  endif
    #endif

    #ifndef HAVE_VSNPRINTF
    #  ifdef MSDOS
    /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
       but for now we just assume it doesn't. */
    #    define NO_vsnprintf
    #  endif
    #  ifdef __TURBOC__
    #    define NO_vsnprintf
    #  endif
    #  ifdef WIN32
    /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
    #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
    #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
    #         define vsnprintf _vsnprintf
    #      endif
    #    endif
    #  endif
    #  ifdef __SASC
    #    define NO_vsnprintf
    #  endif
    #  ifdef VMS
    #    define NO_vsnprintf
    #  endif
    #  ifdef __OS400__
    #    define NO_vsnprintf
    #  endif
    #  ifdef __MVS__
    #    define NO_vsnprintf
    #  endif
    #endif

    /* unlike snprintf (which is required in C99), _snprintf does not guarantee
       null termination of the result -- however this is only used in gzlib.c where
       the result is assured to fit in the space provided */
    #if defined(_MSC_VER) && _MSC_VER < 1900
    #  define snprintf _snprintf
    #endif

    #ifndef local
    #  define local static
    #endif
    /* since "static" is used to mean two completely different things in C, we
       define "local" for the non-static meaning of "static", for readability
       (compile with -Dlocal if your debugger can't find static symbols) */

    /* gz* functions always use library allocation functions */
    #ifndef STDC
      extern voidp  malloc OF((uInt size));
      extern void   free   OF((voidpf ptr));
    #endif

    /* get errno and strerror definition */
    #if defined UNDER_CE
    #  include <windows.h>
    #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
    #else
    #  ifndef NO_STRERROR
    #    include <errno.h>
    #    define zstrerror() strerror(errno)
    #  else
    #    define zstrerror() "stdio error (consult errno)"
    #  endif
    #endif

    /* provide prototypes for these when building zlib without LFS */
    #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
        ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
        ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
        ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
        ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
    #endif

    /* default memLevel */
    #if MAX_MEM_LEVEL >= 8
    #  define DEF_MEM_LEVEL 8
    #else
    #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
    #endif

    /* default i/o buffer size -- double this for output when reading (this and
       twice this must be able to fit in an unsigned type) */
    #define GZBUFSIZE 8192

    /* gzip modes, also provide a little integrity check on the passed structure */
    #define GZ_NONE 0
    #define GZ_READ 7247
    #define GZ_WRITE 31153
    #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */

    /* values for gz_state how */
    #define LOOK 0      /* look for a gzip header */
    #define COPY 1      /* copy input directly */
    #define GZIP 2      /* decompress a gzip stream */

    /* internal gzip file state data structure */
    typedef struct {
            /* exposed contents for gzgetc() macro */
        struct gzFile_s x;      /* "x" for exposed */
                                /* x.have: number of bytes available at x.next */
                                /* x.next: next output data to deliver or write */
                                /* x.pos: current position in uncompressed data */
            /* used for both reading and writing */
        int mode;               /* see gzip modes above */
        int fd;                 /* file descriptor */
        char *path;             /* path or fd for error messages */
        unsigned size;          /* buffer size, zero if not allocated yet */
        unsigned want;          /* requested buffer size, default is GZBUFSIZE */
        unsigned char *in;      /* input buffer (double-sized when writing) */
        unsigned char *out;     /* output buffer (double-sized when reading) */
        int direct;             /* 0 if processing gzip, 1 if transparent */
            /* just for reading */
        int how;                /* 0: get header, 1: copy, 2: decompress */
        z_off64_t start;        /* where the gzip data started, for rewinding */
        int eof;                /* true if end of input file reached */
        int past;               /* true if read requested past end */
            /* just for writing */
        int level;              /* compression level */
        int strategy;           /* compression strategy */
            /* seek request */
        z_off64_t skip;         /* amount to skip (already rewound if backwards) */
        int seek;               /* true if seek request pending */
            /* error information */
        int err;                /* error code */
        char *msg;              /* error message */
            /* zlib inflate or deflate stream */
        z_stream strm;          /* stream structure in-place (not a pointer) */
    } gz_state;
    typedef gz_state FAR *gz_statep;

    /* shared functions */
    void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
    #if defined UNDER_CE
    char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
    #endif

    /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
       value -- needed when comparing unsigned to z_off64_t, which is signed
       (possible z_off64_t types off_t, off64_t, and long are all signed) */
    #ifdef INT_MAX
    #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
    #else
    unsigned ZLIB_INTERNAL gz_intmax OF((void));
    #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
    #endif