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