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gzguts.h revision 1.1.1.3
      1 /* gzguts.h -- zlib internal header definitions for gz* operations
      2  * Copyright (C) 2004-2024 Mark Adler
      3  * For conditions of distribution and use, see copyright notice in zlib.h
      4  */
      5 
      6 #ifdef _LARGEFILE64_SOURCE
      7 #  ifndef _LARGEFILE_SOURCE
      8 #    define _LARGEFILE_SOURCE 1
      9 #  endif
     10 #  undef _FILE_OFFSET_BITS
     11 #  undef _TIME_BITS
     12 #endif
     13 
     14 #ifdef HAVE_HIDDEN
     15 #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
     16 #else
     17 #  define ZLIB_INTERNAL
     18 #endif
     19 
     20 #include <stdio.h>
     21 #include "zlib.h"
     22 #ifdef STDC
     23 #  include <string.h>
     24 #  include <stdlib.h>
     25 #  include <limits.h>
     26 #endif
     27 
     28 #ifndef _POSIX_SOURCE
     29 #  define _POSIX_SOURCE
     30 #endif
     31 #include <fcntl.h>
     32 
     33 #ifdef _WIN32
     34 #  include <stddef.h>
     35 #endif
     36 
     37 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
     38 #  include <io.h>
     39 #endif
     40 
     41 #if defined(_WIN32)
     42 #  define WIDECHAR
     43 #endif
     44 
     45 #ifdef WINAPI_FAMILY
     46 #  define open _open
     47 #  define read _read
     48 #  define write _write
     49 #  define close _close
     50 #endif
     51 
     52 #ifdef NO_DEFLATE       /* for compatibility with old definition */
     53 #  define NO_GZCOMPRESS
     54 #endif
     55 
     56 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
     57 #  ifndef HAVE_VSNPRINTF
     58 #    define HAVE_VSNPRINTF
     59 #  endif
     60 #endif
     61 
     62 #if defined(__CYGWIN__)
     63 #  ifndef HAVE_VSNPRINTF
     64 #    define HAVE_VSNPRINTF
     65 #  endif
     66 #endif
     67 
     68 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
     69 #  ifndef HAVE_VSNPRINTF
     70 #    define HAVE_VSNPRINTF
     71 #  endif
     72 #endif
     73 
     74 #ifndef HAVE_VSNPRINTF
     75 #  ifdef MSDOS
     76 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
     77    but for now we just assume it doesn't. */
     78 #    define NO_vsnprintf
     79 #  endif
     80 #  ifdef __TURBOC__
     81 #    define NO_vsnprintf
     82 #  endif
     83 #  ifdef WIN32
     84 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
     85 #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
     86 #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
     87 #         define vsnprintf _vsnprintf
     88 #      endif
     89 #    endif
     90 #  endif
     91 #  ifdef __SASC
     92 #    define NO_vsnprintf
     93 #  endif
     94 #  ifdef VMS
     95 #    define NO_vsnprintf
     96 #  endif
     97 #  ifdef __OS400__
     98 #    define NO_vsnprintf
     99 #  endif
    100 #  ifdef __MVS__
    101 #    define NO_vsnprintf
    102 #  endif
    103 #endif
    104 
    105 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
    106    null termination of the result -- however this is only used in gzlib.c where
    107    the result is assured to fit in the space provided */
    108 #if defined(_MSC_VER) && _MSC_VER < 1900
    109 #  define snprintf _snprintf
    110 #endif
    111 
    112 #ifndef local
    113 #  define local static
    114 #endif
    115 /* since "static" is used to mean two completely different things in C, we
    116    define "local" for the non-static meaning of "static", for readability
    117    (compile with -Dlocal if your debugger can't find static symbols) */
    118 
    119 /* gz* functions always use library allocation functions */
    120 #ifndef STDC
    121   extern voidp  malloc(uInt size);
    122   extern void   free(voidpf ptr);
    123 #endif
    124 
    125 /* get errno and strerror definition */
    126 #if defined UNDER_CE
    127 #  include <windows.h>
    128 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
    129 #else
    130 #  ifndef NO_STRERROR
    131 #    include <errno.h>
    132 #    define zstrerror() strerror(errno)
    133 #  else
    134 #    define zstrerror() "stdio error (consult errno)"
    135 #  endif
    136 #endif
    137 
    138 /* provide prototypes for these when building zlib without LFS */
    139 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
    140     ZEXTERN gzFile ZEXPORT gzopen64(const char *, const char *);
    141     ZEXTERN z_off64_t ZEXPORT gzseek64(gzFile, z_off64_t, int);
    142     ZEXTERN z_off64_t ZEXPORT gztell64(gzFile);
    143     ZEXTERN z_off64_t ZEXPORT gzoffset64(gzFile);
    144 #endif
    145 
    146 /* default memLevel */
    147 #if MAX_MEM_LEVEL >= 8
    148 #  define DEF_MEM_LEVEL 8
    149 #else
    150 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
    151 #endif
    152 
    153 /* default i/o buffer size -- double this for output when reading (this and
    154    twice this must be able to fit in an unsigned type) */
    155 #define GZBUFSIZE 8192
    156 
    157 /* gzip modes, also provide a little integrity check on the passed structure */
    158 #define GZ_NONE 0
    159 #define GZ_READ 7247
    160 #define GZ_WRITE 31153
    161 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
    162 
    163 /* values for gz_state how */
    164 #define LOOK 0      /* look for a gzip header */
    165 #define COPY 1      /* copy input directly */
    166 #define GZIP 2      /* decompress a gzip stream */
    167 
    168 /* internal gzip file state data structure */
    169 typedef struct {
    170         /* exposed contents for gzgetc() macro */
    171     struct gzFile_s x;      /* "x" for exposed */
    172                             /* x.have: number of bytes available at x.next */
    173                             /* x.next: next output data to deliver or write */
    174                             /* x.pos: current position in uncompressed data */
    175         /* used for both reading and writing */
    176     int mode;               /* see gzip modes above */
    177     int fd;                 /* file descriptor */
    178     char *path;             /* path or fd for error messages */
    179     unsigned size;          /* buffer size, zero if not allocated yet */
    180     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
    181     unsigned char *in;      /* input buffer (double-sized when writing) */
    182     unsigned char *out;     /* output buffer (double-sized when reading) */
    183     int direct;             /* 0 if processing gzip, 1 if transparent */
    184         /* just for reading */
    185     int how;                /* 0: get header, 1: copy, 2: decompress */
    186     z_off64_t start;        /* where the gzip data started, for rewinding */
    187     int eof;                /* true if end of input file reached */
    188     int past;               /* true if read requested past end */
    189         /* just for writing */
    190     int level;              /* compression level */
    191     int strategy;           /* compression strategy */
    192     int reset;              /* true if a reset is pending after a Z_FINISH */
    193         /* seek request */
    194     z_off64_t skip;         /* amount to skip (already rewound if backwards) */
    195     int seek;               /* true if seek request pending */
    196         /* error information */
    197     int err;                /* error code */
    198     char *msg;              /* error message */
    199         /* zlib inflate or deflate stream */
    200     z_stream strm;          /* stream structure in-place (not a pointer) */
    201 } gz_state;
    202 typedef gz_state FAR *gz_statep;
    203 
    204 /* shared functions */
    205 void ZLIB_INTERNAL gz_error(gz_statep, int, const char *);
    206 #if defined UNDER_CE
    207 char ZLIB_INTERNAL *gz_strwinerror(DWORD error);
    208 #endif
    209 
    210 /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
    211    value -- needed when comparing unsigned to z_off64_t, which is signed
    212    (possible z_off64_t types off_t, off64_t, and long are all signed) */
    213 unsigned ZLIB_INTERNAL gz_intmax(void);
    214 #define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
    215