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