src/zlib/zutil.c

   1 /* zutil.c -- target dependent utility functions for the compression library
   2  * Copyright (C) 1995-2005 Jean-loup Gailly.
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6
   7 #include "zutil.h"
   8
   9 #ifndef NO_DUMMY_DECL
  10 struct internal_state      {int dummy;}; /* for buggy compilers */
  11 #endif
  12
  13 const char * const z_errmsg[10] = {
  14 "need dictionary",     /* Z_NEED_DICT       2  */
  15 "stream end",          /* Z_STREAM_END      1  */
  16 "",                    /* Z_OK              0  */
  17 "file error",          /* Z_ERRNO         (-1) */
  18 "stream error",        /* Z_STREAM_ERROR  (-2) */
  19 "data error",          /* Z_DATA_ERROR    (-3) */
  20 "insufficient memory", /* Z_MEM_ERROR     (-4) */
  21 "buffer error",        /* Z_BUF_ERROR     (-5) */
  22 "incompatible version",/* Z_VERSION_ERROR (-6) */
  23 ""};
  24
  25
  26 const char * ZEXPORT zlibVersion()
  27 {
  28     return ZLIB_VERSION;
  29 }
  30
  31 uLong ZEXPORT zlibCompileFlags()
  32 {
  33     uLong flags;
  34
  35     flags = 0;
  36     switch (sizeof(uInt)) {
  37     case 2:     break;
  38     case 4:     flags += 1;     break;
  39     case 8:     flags += 2;     break;
  40     default:    flags += 3;
  41     }
  42     switch (sizeof(uLong)) {
  43     case 2:     break;
  44     case 4:     flags += 1 << 2;        break;
  45     case 8:     flags += 2 << 2;        break;
  46     default:    flags += 3 << 2;
  47     }
  48     switch (sizeof(voidpf)) {
  49     case 2:     break;
  50     case 4:     flags += 1 << 4;        break;
  51     case 8:     flags += 2 << 4;        break;
  52     default:    flags += 3 << 4;
  53     }
  54     switch (sizeof(z_off_t)) {
  55     case 2:     break;
  56     case 4:     flags += 1 << 6;        break;
  57     case 8:     flags += 2 << 6;        break;
  58     default:    flags += 3 << 6;
  59     }
  60 #ifdef DEBUG
  61     flags += 1 << 8;
  62 #endif
  63 #if defined(ASMV) || defined(ASMINF)
  64     flags += 1 << 9;
  65 #endif
  66 #ifdef ZLIB_WINAPI
  67     flags += 1 << 10;
  68 #endif
  69 #ifdef BUILDFIXED
  70     flags += 1 << 12;
  71 #endif
  72 #ifdef DYNAMIC_CRC_TABLE
  73     flags += 1 << 13;
  74 #endif
  75 #ifdef NO_GZCOMPRESS
  76     flags += 1L << 16;
  77 #endif
  78 #ifdef NO_GZIP
  79     flags += 1L << 17;
  80 #endif
  81 #ifdef PKZIP_BUG_WORKAROUND
  82     flags += 1L << 20;
  83 #endif
  84 #ifdef FASTEST
  85     flags += 1L << 21;
  86 #endif
  87 #ifdef STDC
  88 #  ifdef NO_vsnprintf
  89         flags += 1L << 25;
  90 #    ifdef HAS_vsprintf_void
  91         flags += 1L << 26;
  92 #    endif
  93 #  else
  94 #    ifdef HAS_vsnprintf_void
  95         flags += 1L << 26;
  96 #    endif
  97 #  endif
  98 #else
  99         flags += 1L << 24;
 100 #  ifdef NO_snprintf
 101         flags += 1L << 25;
 102 #    ifdef HAS_sprintf_void
 103         flags += 1L << 26;
 104 #    endif
 105 #  else
 106 #    ifdef HAS_snprintf_void
 107         flags += 1L << 26;
 108 #    endif
 109 #  endif
 110 #endif
 111     return flags;
 112 }
 113
 114 #ifdef DEBUG
 115
 116 #  ifndef verbose
 117 #    define verbose 0
 118 #  endif
 119 int z_verbose = verbose;
 120
 121 void z_error (m)
 122     char *m;
 123 {
 124     fprintf(stderr, "%s\n", m);
 125     exit(1);
 126 }
 127 #endif
 128
 129 /* exported to allow conversion of error code to string for compress() and
 130  * uncompress()
 131  */
 132 const char * ZEXPORT zError(err)
 133     int err;
 134 {
 135     return ERR_MSG(err);
 136 }
 137
 138 #if defined(_WIN32_WCE)
 139     /* The Microsoft C Run-Time Library for Windows CE doesn't have
 140      * errno.  We define it as a global variable to simplify porting.
 141      * Its value is always 0 and should not be used.
 142      */
 143     int errno = 0;
 144 #endif
 145
 146 #ifndef HAVE_MEMCPY
 147
 148 void zmemcpy(dest, source, len)
 149     Bytef* dest;
 150     const Bytef* source;
 151     uInt  len;
 152 {
 153     if (len == 0) return;
 154     do {
 155         *dest++ = *source++; /* ??? to be unrolled */
 156     } while (--len != 0);
 157 }
 158
 159 int zmemcmp(s1, s2, len)
 160     const Bytef* s1;
 161     const Bytef* s2;
 162     uInt  len;
 163 {
 164     uInt j;
 165
 166     for (j = 0; j < len; j++) {
 167         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
 168     }
 169     return 0;
 170 }
 171
 172 void zmemzero(dest, len)
 173     Bytef* dest;
 174     uInt  len;
 175 {
 176     if (len == 0) return;
 177     do {
 178         *dest++ = 0;  /* ??? to be unrolled */
 179     } while (--len != 0);
 180 }
 181 #endif
 182
 183
 184 #ifdef SYS16BIT
 185
 186 #ifdef __TURBOC__
 187 /* Turbo C in 16-bit mode */
 188
 189 #  define MY_ZCALLOC
 190
 191 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 192  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 193  * must fix the pointer. Warning: the pointer must be put back to its
 194  * original form in order to free it, use zcfree().
 195  */
 196
 197 #define MAX_PTR 10
 198 /* 10*64K = 640K */
 199
 200 local int next_ptr = 0;
 201
 202 typedef struct ptr_table_s {
 203     voidpf org_ptr;
 204     voidpf new_ptr;
 205 } ptr_table;
 206
 207 local ptr_table table[MAX_PTR];
 208 /* This table is used to remember the original form of pointers
 209  * to large buffers (64K). Such pointers are normalized with a zero offset.
 210  * Since MSDOS is not a preemptive multitasking OS, this table is not
 211  * protected from concurrent access. This hack doesn't work anyway on
 212  * a protected system like OS/2. Use Microsoft C instead.
 213  */
 214
 215 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 216 {
 217     voidpf buf = opaque; /* just to make some compilers happy */
 218     ulg bsize = (ulg)items*size;
 219
 220     /* If we allocate less than 65520 bytes, we assume that farmalloc
 221      * will return a usable pointer which doesn't have to be normalized.
 222      */
 223     if (bsize < 65520L) {
 224         buf = farmalloc(bsize);
 225         if (*(ush*)&buf != 0) return buf;
 226     } else {
 227         buf = farmalloc(bsize + 16L);
 228     }
 229     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
 230     table[next_ptr].org_ptr = buf;
 231
 232     /* Normalize the pointer to seg:0 */
 233     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
 234     *(ush*)&buf = 0;
 235     table[next_ptr++].new_ptr = buf;
 236     return buf;
 237 }
 238
 239 void  zcfree (voidpf opaque, voidpf ptr)
 240 {
 241     int n;
 242     if (*(ush*)&ptr != 0) { /* object < 64K */
 243         farfree(ptr);
 244         return;
 245     }
 246     /* Find the original pointer */
 247     for (n = 0; n < next_ptr; n++) {
 248         if (ptr != table[n].new_ptr) continue;
 249
 250         farfree(table[n].org_ptr);
 251         while (++n < next_ptr) {
 252             table[n-1] = table[n];
 253         }
 254         next_ptr--;
 255         return;
 256     }
 257     ptr = opaque; /* just to make some compilers happy */
 258     Assert(0, "zcfree: ptr not found");
 259 }
 260
 261 #endif /* __TURBOC__ */
 262
 263
 264 #ifdef M_I86
 265 /* Microsoft C in 16-bit mode */
 266
 267 #  define MY_ZCALLOC
 268
 269 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 270 #  define _halloc  halloc
 271 #  define _hfree   hfree
 272 #endif
 273
 274 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 275 {
 276     if (opaque) opaque = 0; /* to make compiler happy */
 277     return _halloc((long)items, size);
 278 }
 279
 280 void  zcfree (voidpf opaque, voidpf ptr)
 281 {
 282     if (opaque) opaque = 0; /* to make compiler happy */
 283     _hfree(ptr);
 284 }
 285
 286 #endif /* M_I86 */
 287
 288 #endif /* SYS16BIT */
 289
 290
 291 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 292
 293 #ifndef STDC
 294 extern voidp  malloc OF((uInt size));
 295 extern voidp  calloc OF((uInt items, uInt size));
 296 extern void   free   OF((voidpf ptr));
 297 #endif
 298
 299 voidpf zcalloc (opaque, items, size)
 300     voidpf opaque;
 301     unsigned items;
 302     unsigned size;
 303 {
 304     if (opaque) items += size - size; /* make compiler happy */
 305     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
 306                               (voidpf)calloc(items, size);
 307 }
 308
 309 void  zcfree (opaque, ptr)
 310     voidpf opaque;
 311     voidpf ptr;
 312 {
 313     free(ptr);
 314     if (opaque) return; /* make compiler happy */
 315 }
 316
 317 #endif /* MY_ZCALLOC */