zlib/zutil.c

   1 /* zutil.c -- target dependent utility functions for the compression library
   2  * Copyright (C) 1995-2003 Jean-loup Gailly.
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* @(#) $Id: zutil.c,v 1.1.1.2 2002/03/11 21:53:27 tromey Exp $ */
   7
   8 #include "zutil.h"
   9
  10 #ifndef NO_DUMMY_DECL
  11 struct internal_state      {int dummy;}; /* for buggy compilers */
  12 #endif
  13
  14 #ifndef STDC
  15 extern void exit OF((int));
  16 #endif
  17
  18 const char * const z_errmsg[10] = {
  19 "need dictionary",     /* Z_NEED_DICT       2  */
  20 "stream end",          /* Z_STREAM_END      1  */
  21 "",                    /* Z_OK              0  */
  22 "file error",          /* Z_ERRNO         (-1) */
  23 "stream error",        /* Z_STREAM_ERROR  (-2) */
  24 "data error",          /* Z_DATA_ERROR    (-3) */
  25 "insufficient memory", /* Z_MEM_ERROR     (-4) */
  26 "buffer error",        /* Z_BUF_ERROR     (-5) */
  27 "incompatible version",/* Z_VERSION_ERROR (-6) */
  28 ""};
  29
  30
  31 const char * ZEXPORT zlibVersion()
  32 {
  33     return ZLIB_VERSION;
  34 }
  35
  36 uLong ZEXPORT zlibCompileFlags()
  37 {
  38     uLong flags;
  39
  40     flags = 0;
  41     switch (sizeof(uInt)) {
  42     case 2:     break;
  43     case 4:     flags += 1;     break;
  44     case 8:     flags += 2;     break;
  45     default:    flags += 3;
  46     }
  47     switch (sizeof(uLong)) {
  48     case 2:     break;
  49     case 4:     flags += 1 << 2;        break;
  50     case 8:     flags += 2 << 2;        break;
  51     default:    flags += 3 << 2;
  52     }
  53     switch (sizeof(voidpf)) {
  54     case 2:     break;
  55     case 4:     flags += 1 << 4;        break;
  56     case 8:     flags += 2 << 4;        break;
  57     default:    flags += 3 << 4;
  58     }
  59     switch (sizeof(z_off_t)) {
  60     case 2:     break;
  61     case 4:     flags += 1 << 6;        break;
  62     case 8:     flags += 2 << 6;        break;
  63     default:    flags += 3 << 6;
  64     }
  65 #ifdef DEBUG
  66     flags += 1 << 8;
  67 #endif
  68 #if defined(ASMV) || defined(ASMINF)
  69     flags += 1 << 9;
  70 #endif
  71 #ifdef ZLIB_WINAPI
  72     flags += 1 << 10;
  73 #endif
  74 #ifdef BUILDFIXED
  75     flags += 1 << 12;
  76 #endif
  77 #ifdef DYNAMIC_CRC_TABLE
  78     flags += 1 << 13;
  79 #endif
  80 #ifdef NO_GZCOMPRESS
  81     flags += 1 << 16;
  82 #endif
  83 #ifdef NO_GZIP
  84     flags += 1 << 17;
  85 #endif
  86 #ifdef PKZIP_BUG_WORKAROUND
  87     flags += 1 << 20;
  88 #endif
  89 #ifdef FASTEST
  90     flags += 1 << 21;
  91 #endif
  92 #ifdef STDC
  93 #  ifdef NO_vsnprintf
  94         flags += 1 << 25;
  95 #    ifdef HAS_vsprintf_void
  96         flags += 1 << 26;
  97 #    endif
  98 #  else
  99 #    ifdef HAS_vsnprintf_void
 100         flags += 1 << 26;
 101 #    endif
 102 #  endif
 103 #else
 104         flags += 1 << 24;
 105 #  ifdef NO_snprintf
 106         flags += 1 << 25;
 107 #    ifdef HAS_sprintf_void
 108         flags += 1 << 26;
 109 #    endif
 110 #  else
 111 #    ifdef HAS_snprintf_void
 112         flags += 1 << 26;
 113 #    endif
 114 #  endif
 115 #endif
 116     return flags;
 117 }
 118
 119 #ifdef DEBUG
 120
 121 #  ifndef verbose
 122 #    define verbose 0
 123 #  endif
 124 int z_verbose = verbose;
 125
 126 void z_error (m)
 127     char *m;
 128 {
 129     fprintf(stderr, "%s\n", m);
 130     exit(1);
 131 }
 132 #endif
 133
 134 /* exported to allow conversion of error code to string for compress() and
 135  * uncompress()
 136  */
 137 const char * ZEXPORT zError(err)
 138     int err;
 139 {
 140     return ERR_MSG(err);
 141 }
 142
 143 #if defined(_WIN32_WCE)
 144     /* does not exist on WCE */
 145     int errno = 0;
 146 #endif
 147
 148 #ifndef HAVE_MEMCPY
 149
 150 void zmemcpy(dest, source, len)
 151     Bytef* dest;
 152     const Bytef* source;
 153     uInt  len;
 154 {
 155     if (len == 0) return;
 156     do {
 157         *dest++ = *source++; /* ??? to be unrolled */
 158     } while (--len != 0);
 159 }
 160
 161 int zmemcmp(s1, s2, len)
 162     const Bytef* s1;
 163     const Bytef* s2;
 164     uInt  len;
 165 {
 166     uInt j;
 167
 168     for (j = 0; j < len; j++) {
 169         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
 170     }
 171     return 0;
 172 }
 173
 174 void zmemzero(dest, len)
 175     Bytef* dest;
 176     uInt  len;
 177 {
 178     if (len == 0) return;
 179     do {
 180         *dest++ = 0;  /* ??? to be unrolled */
 181     } while (--len != 0);
 182 }
 183 #endif
 184
 185
 186 #ifdef SYS16BIT
 187
 188 #ifdef __TURBOC__
 189 /* Turbo C in 16-bit mode */
 190
 191 #  define MY_ZCALLOC
 192
 193 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 194  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 195  * must fix the pointer. Warning: the pointer must be put back to its
 196  * original form in order to free it, use zcfree().
 197  */
 198
 199 #define MAX_PTR 10
 200 /* 10*64K = 640K */
 201
 202 local int next_ptr = 0;
 203
 204 typedef struct ptr_table_s {
 205     voidpf org_ptr;
 206     voidpf new_ptr;
 207 } ptr_table;
 208
 209 local ptr_table table[MAX_PTR];
 210 /* This table is used to remember the original form of pointers
 211  * to large buffers (64K). Such pointers are normalized with a zero offset.
 212  * Since MSDOS is not a preemptive multitasking OS, this table is not
 213  * protected from concurrent access. This hack doesn't work anyway on
 214  * a protected system like OS/2. Use Microsoft C instead.
 215  */
 216
 217 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 218 {
 219     voidpf buf = opaque; /* just to make some compilers happy */
 220     ulg bsize = (ulg)items*size;
 221
 222     /* If we allocate less than 65520 bytes, we assume that farmalloc
 223      * will return a usable pointer which doesn't have to be normalized.
 224      */
 225     if (bsize < 65520L) {
 226         buf = farmalloc(bsize);
 227         if (*(ush*)&buf != 0) return buf;
 228     } else {
 229         buf = farmalloc(bsize + 16L);
 230     }
 231     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
 232     table[next_ptr].org_ptr = buf;
 233
 234     /* Normalize the pointer to seg:0 */
 235     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
 236     *(ush*)&buf = 0;
 237     table[next_ptr++].new_ptr = buf;
 238     return buf;
 239 }
 240
 241 void  zcfree (voidpf opaque, voidpf ptr)
 242 {
 243     int n;
 244     if (*(ush*)&ptr != 0) { /* object < 64K */
 245         farfree(ptr);
 246         return;
 247     }
 248     /* Find the original pointer */
 249     for (n = 0; n < next_ptr; n++) {
 250         if (ptr != table[n].new_ptr) continue;
 251
 252         farfree(table[n].org_ptr);
 253         while (++n < next_ptr) {
 254             table[n-1] = table[n];
 255         }
 256         next_ptr--;
 257         return;
 258     }
 259     ptr = opaque; /* just to make some compilers happy */
 260     Assert(0, "zcfree: ptr not found");
 261 }
 262
 263 #endif /* __TURBOC__ */
 264
 265
 266 #ifdef M_I86
 267 /* Microsoft C in 16-bit mode */
 268
 269 #  define MY_ZCALLOC
 270
 271 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 272 #  define _halloc  halloc
 273 #  define _hfree   hfree
 274 #endif
 275
 276 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
 277 {
 278     if (opaque) opaque = 0; /* to make compiler happy */
 279     return _halloc((long)items, size);
 280 }
 281
 282 void  zcfree (voidpf opaque, voidpf ptr)
 283 {
 284     if (opaque) opaque = 0; /* to make compiler happy */
 285     _hfree(ptr);
 286 }
 287
 288 #endif /* M_I86 */
 289
 290 #endif /* SYS16BIT */
 291
 292
 293 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 294
 295 #ifndef STDC
 296 extern voidp  malloc OF((uInt size));
 297 extern voidp  calloc OF((uInt items, uInt size));
 298 extern void   free   OF((voidpf ptr));
 299 #endif
 300
 301 voidpf zcalloc (opaque, items, size)
 302     voidpf opaque;
 303     unsigned items;
 304     unsigned size;
 305 {
 306     if (opaque) items += size - size; /* make compiler happy */
 307     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
 308                               (voidpf)calloc(items, size);
 309 }
 310
 311 void  zcfree (opaque, ptr)
 312     voidpf opaque;
 313     voidpf ptr;
 314 {
 315     free(ptr);
 316     if (opaque) return; /* make compiler happy */
 317 }
 318
 319 #endif /* MY_ZCALLOC */