src/zlib/zutil.c

   1 /* zutil.c -- target dependent utility functions for the compression library
   2  * Copyright (C) 1995-1998 Jean-loup Gailly.
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* @(#) $Id$ */
   7
   8 #include "zutil.h"
   9
  10 struct internal_state      {int dummy;}; /* for buggy compilers */
  11
  12 #ifndef STDC
  13 extern void exit OF((int));
  14 #endif
  15
  16 const char *z_errmsg[10] = {
  17 "need dictionary",     /* Z_NEED_DICT       2  */
  18 "stream end",          /* Z_STREAM_END      1  */
  19 "",                    /* Z_OK              0  */
  20 "file error",          /* Z_ERRNO         (-1) */
  21 "stream error",        /* Z_STREAM_ERROR  (-2) */
  22 "data error",          /* Z_DATA_ERROR    (-3) */
  23 "insufficient memory", /* Z_MEM_ERROR     (-4) */
  24 "buffer error",        /* Z_BUF_ERROR     (-5) */
  25 "incompatible version",/* Z_VERSION_ERROR (-6) */
  26 ""};
  27
  28
  29 const char * ZEXPORT zlibVersion()
  30 {
  31     return ZLIB_VERSION;
  32 }
  33
  34 #ifdef __WXDEBUG__
  35
  36 #  ifndef verbose
  37 #    define verbose 0
  38 #  endif
  39 int z_verbose = verbose;
  40
  41 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
  42 void z_error (char* m)
  43 #else
  44 void z_error (m)
  45     char *m;
  46 #endif
  47 {
  48     fprintf(stderr, "%s\n", m);
  49     exit(1);
  50 }
  51 #endif
  52
  53 /* exported to allow conversion of error code to string for compress() and
  54  * uncompress()
  55  */
  56 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
  57 const char* ZEXPORT zError(int err)
  58 #else
  59 const char * ZEXPORT zError(err)
  60     int err;
  61 #endif
  62 {
  63     return ERR_MSG(err);
  64 }
  65
  66
  67 #ifndef HAVE_MEMCPY
  68
  69 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
  70 void zmemcpy(Bytef* dest, Bytef* source, Uint len)
  71 #else
  72 void zmemcpy(dest, source, len)
  73     Bytef* dest;
  74     Bytef* source;
  75     uInt  len;
  76 #endif
  77 {
  78     if (len == 0) return;
  79     do {
  80         *dest++ = *source++; /* ??? to be unrolled */
  81     } while (--len != 0);
  82 }
  83
  84 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
  85 int zmemcmp(Bytef* s1, Bytef* s2, int len)
  86 #else
  87 int zmemcmp(s1, s2, len)
  88     Bytef* s1;
  89     Bytef* s2;
  90     uInt  len;
  91 #endif
  92 {
  93     uInt j;
  94
  95     for (j = 0; j < len; j++) {
  96         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
  97     }
  98     return 0;
  99 }
 100
 101 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
 102 void zmemzero(Bytef* dest, uInt len)
 103 #else
 104 void zmemzero(dest, len)
 105     Bytef* dest;
 106     uInt  len;
 107 #endif
 108 {
 109     if (len == 0) return;
 110     do {
 111         *dest++ = 0;  /* ??? to be unrolled */
 112     } while (--len != 0);
 113 }
 114 #endif
 115
 116 #ifdef __TURBOC__
 117 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
 118 /* Small and medium model in Turbo C are for now limited to near allocation
 119  * with reduced MAX_WBITS and MAX_MEM_LEVEL
 120  */
 121 #  define MY_ZCALLOC
 122
 123 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 124  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 125  * must fix the pointer. Warning: the pointer must be put back to its
 126  * original form in order to free it, use zcfree().
 127  */
 128
 129 #define MAX_PTR 10
 130 /* 10*64K = 640K */
 131
 132 local int next_ptr = 0;
 133
 134 typedef struct ptr_table_s {
 135     voidpf org_ptr;
 136     voidpf new_ptr;
 137 } ptr_table;
 138
 139 local ptr_table table[MAX_PTR];
 140 /* This table is used to remember the original form of pointers
 141  * to large buffers (64K). Such pointers are normalized with a zero offset.
 142  * Since MSDOS is not a preemptive multitasking OS, this table is not
 143  * protected from concurrent access. This hack doesn't work anyway on
 144  * a protected system like OS/2. Use Microsoft C instead.
 145  */
 146
 147 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 148 {
 149     voidpf buf = opaque; /* just to make some compilers happy */
 150     ulg bsize = (ulg)items*size;
 151
 152     /* If we allocate less than 65520 bytes, we assume that farmalloc
 153      * will return a usable pointer which doesn't have to be normalized.
 154      */
 155     if (bsize < 65520L) {
 156         buf = farmalloc(bsize);
 157         if (*(ush*)&buf != 0) return buf;
 158     } else {
 159         buf = farmalloc(bsize + 16L);
 160     }
 161     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
 162     table[next_ptr].org_ptr = buf;
 163
 164     /* Normalize the pointer to seg:0 */
 165     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
 166     *(ush*)&buf = 0;
 167     table[next_ptr++].new_ptr = buf;
 168     return buf;
 169 }
 170
 171 void  zcfree (voidpf opaque, voidpf ptr)
 172 {
 173     int n;
 174     if (*(ush*)&ptr != 0) { /* object < 64K */
 175         farfree(ptr);
 176         return;
 177     }
 178     /* Find the original pointer */
 179     for (n = 0; n < next_ptr; n++) {
 180         if (ptr != table[n].new_ptr) continue;
 181
 182         farfree(table[n].org_ptr);
 183         while (++n < next_ptr) {
 184             table[n-1] = table[n];
 185         }
 186         next_ptr--;
 187         return;
 188     }
 189     ptr = opaque; /* just to make some compilers happy */
 190     Assert(0, "zcfree: ptr not found");
 191 }
 192 #endif
 193 #endif /* __TURBOC__ */
 194
 195
 196 #if defined(M_I86) && !defined(__32BIT__)
 197 /* Microsoft C in 16-bit mode */
 198
 199 #  define MY_ZCALLOC
 200
 201 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
 202 #  define _halloc  halloc
 203 #  define _hfree   hfree
 204 #endif
 205
 206 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 207 {
 208     if (opaque) opaque = 0; /* to make compiler happy */
 209     return _halloc((long)items, size);
 210 }
 211
 212 void  zcfree (voidpf opaque, voidpf ptr)
 213 {
 214     if (opaque) opaque = 0; /* to make compiler happy */
 215     _hfree(ptr);
 216 }
 217
 218 #endif /* MSC */
 219
 220
 221 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 222
 223 #ifndef STDC
 224 extern voidp  calloc OF((uInt items, uInt size));
 225 extern void   free   OF((voidpf ptr));
 226 #endif
 227
 228 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
 229 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 230 #else
 231 voidpf zcalloc (opaque, items, size)
 232     voidpf opaque;
 233     unsigned items;
 234     unsigned size;
 235 #endif
 236 {
 237     if (opaque) items += size - size; /* make compiler happy */
 238     return (voidpf)calloc(items, size);
 239 }
 240
 241 #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
 242 void zcfree(voidpf opaque, voidpf ptr)
 243 #else
 244 void  zcfree (opaque, ptr)
 245     voidpf opaque;
 246     voidpf ptr;
 247 #endif
 248 {
 249     free(ptr);
 250     if (opaque) return; /* make compiler happy */
 251 }
 252
 253 #endif /* MY_ZCALLOC */