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1 /* zutil.c -- target dependent utility functions for the compression library |
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2 * Copyright (C) 1995-2002 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 #ifndef STDC |
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11 extern void exit OF((int)); |
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12 #endif |
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13 |
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14 |
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15 #ifndef HAVE_MEMCPY |
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16 |
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17 void zmemcpy(dest, source, len) |
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18 Bytef* dest; |
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19 const Bytef* source; |
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20 uInt len; |
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21 { |
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22 if (len == 0) return; |
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23 do { |
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24 *dest++ = *source++; /* ??? to be unrolled */ |
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25 } while (--len != 0); |
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26 } |
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27 |
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28 int zmemcmp(s1, s2, len) |
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29 const Bytef* s1; |
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30 const Bytef* s2; |
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31 uInt len; |
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32 { |
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33 uInt j; |
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34 |
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35 for (j = 0; j < len; j++) { |
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36 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; |
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37 } |
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38 return 0; |
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39 } |
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40 |
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41 void zmemzero(dest, len) |
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42 Bytef* dest; |
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43 uInt len; |
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44 { |
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45 if (len == 0) return; |
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46 do { |
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47 *dest++ = 0; /* ??? to be unrolled */ |
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48 } while (--len != 0); |
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49 } |
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50 #endif |
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51 |
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52 #if defined( MSDOS ) && defined( __TURBOC__ ) && !defined( MY_ZCALLOC ) |
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53 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) |
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54 /* Small and medium model in Turbo C are for now limited to near allocation |
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55 * with reduced MAX_WBITS and MAX_MEM_LEVEL |
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56 */ |
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57 # define MY_ZCALLOC |
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58 |
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59 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes |
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60 * and farmalloc(64K) returns a pointer with an offset of 8, so we |
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61 * must fix the pointer. Warning: the pointer must be put back to its |
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62 * original form in order to free it, use zcfree(). |
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63 */ |
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64 |
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65 #define MAX_PTR 10 |
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66 /* 10*64K = 640K */ |
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67 |
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68 local int next_ptr = 0; |
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69 |
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70 typedef struct ptr_table_s { |
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71 voidpf org_ptr; |
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72 voidpf new_ptr; |
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73 } ptr_table; |
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74 |
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75 local ptr_table table[MAX_PTR]; |
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76 /* This table is used to remember the original form of pointers |
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77 * to large buffers (64K). Such pointers are normalized with a zero offset. |
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78 * Since MSDOS is not a preemptive multitasking OS, this table is not |
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79 * protected from concurrent access. This hack doesn't work anyway on |
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80 * a protected system like OS/2. Use Microsoft C instead. |
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81 */ |
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82 |
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83 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) |
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84 { |
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85 voidpf buf = opaque; /* just to make some compilers happy */ |
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86 ulg bsize = (ulg)items*size; |
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87 |
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88 /* If we allocate less than 65520 bytes, we assume that farmalloc |
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89 * will return a usable pointer which doesn't have to be normalized. |
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90 */ |
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91 if (bsize < 65520L) { |
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92 buf = farmalloc(bsize); |
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93 if (*(ush*)&buf != 0) return buf; |
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94 } else { |
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95 buf = farmalloc(bsize + 16L); |
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96 } |
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97 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; |
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98 table[next_ptr].org_ptr = buf; |
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99 |
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100 /* Normalize the pointer to seg:0 */ |
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101 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; |
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102 *(ush*)&buf = 0; |
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103 table[next_ptr++].new_ptr = buf; |
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104 return buf; |
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105 } |
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106 |
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107 void zcfree (voidpf opaque, voidpf ptr) |
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108 { |
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109 int n; |
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110 if (*(ush*)&ptr != 0) { /* object < 64K */ |
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111 farfree(ptr); |
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112 return; |
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113 } |
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114 /* Find the original pointer */ |
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115 for (n = 0; n < next_ptr; n++) { |
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116 if (ptr != table[n].new_ptr) continue; |
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117 |
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118 farfree(table[n].org_ptr); |
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119 while (++n < next_ptr) { |
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120 table[n-1] = table[n]; |
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121 } |
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122 next_ptr--; |
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123 return; |
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124 } |
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125 ptr = opaque; /* just to make some compilers happy */ |
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126 Assert(0, "zcfree: ptr not found"); |
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127 } |
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128 #endif |
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129 #endif /* MSDOS && __TURBOC__ */ |
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130 |
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131 |
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132 #if defined(M_I86) && !defined(__32BIT__) && !defined( MY_ZCALLOC ) |
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133 /* Microsoft C in 16-bit mode */ |
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134 |
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135 # define MY_ZCALLOC |
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136 |
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137 #if (!defined(_MSC_VER) || (_MSC_VER <= 600)) |
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138 # define _halloc halloc |
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139 # define _hfree hfree |
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140 #endif |
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141 |
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142 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) |
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143 { |
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144 if (opaque) opaque = 0; /* to make compiler happy */ |
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145 return _halloc((long)items, size); |
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146 } |
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147 |
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148 void zcfree (voidpf opaque, voidpf ptr) |
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149 { |
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150 if (opaque) opaque = 0; /* to make compiler happy */ |
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151 _hfree(ptr); |
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152 } |
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153 |
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154 #endif /* MSC */ |
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155 |
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156 |
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157 #ifndef MY_ZCALLOC /* Any system without a special alloc function */ |
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158 |
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159 #ifndef STDC |
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160 extern voidp ft_scalloc OF((uInt items, uInt size)); |
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161 extern void ft_sfree OF((voidpf ptr)); |
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162 #endif |
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163 |
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164 voidpf zcalloc (opaque, items, size) |
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165 voidpf opaque; |
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166 unsigned items; |
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167 unsigned size; |
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168 { |
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169 if (opaque) items += size - size; /* make compiler happy */ |
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170 return (voidpf)ft_scalloc(items, size); |
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171 } |
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172 |
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173 void zcfree (opaque, ptr) |
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174 voidpf opaque; |
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175 voidpf ptr; |
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176 { |
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177 ft_sfree(ptr); |
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178 if (opaque) return; /* make compiler happy */ |
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179 } |
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180 |
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181 #endif /* MY_ZCALLOC */ |