1 | |
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2 | /* pngmem.c - stub functions for memory allocation |
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3 | * |
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4 | * libpng 1.2.1 - December 12, 2001 |
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5 | * For conditions of distribution and use, see copyright notice in png.h |
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6 | * Copyright (c) 1998-2001 Glenn Randers-Pehrson |
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7 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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8 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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9 | * |
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10 | * This file provides a location for all memory allocation. Users who |
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11 | * need special memory handling are expected to supply replacement |
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12 | * functions for png_malloc() and png_free(), and to use |
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13 | * png_create_read_struct_2() and png_create_write_struct_2() to |
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14 | * identify the replacement functions. |
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15 | */ |
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16 | |
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17 | #define PNG_INTERNAL |
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18 | #include "png.h" |
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19 | |
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20 | /* Borland DOS special memory handler */ |
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21 | #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) |
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22 | /* if you change this, be sure to change the one in png.h also */ |
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23 | |
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24 | /* Allocate memory for a png_struct. The malloc and memset can be replaced |
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25 | by a single call to calloc() if this is thought to improve performance. */ |
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26 | png_voidp /* PRIVATE */ |
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27 | png_create_struct(int type) |
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28 | { |
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29 | #ifdef PNG_USER_MEM_SUPPORTED |
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30 | return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL)); |
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31 | } |
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32 | |
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33 | /* Alternate version of png_create_struct, for use with user-defined malloc. */ |
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34 | png_voidp /* PRIVATE */ |
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35 | png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr) |
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36 | { |
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37 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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38 | png_size_t size; |
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39 | png_voidp struct_ptr; |
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40 | |
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41 | if (type == PNG_STRUCT_INFO) |
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42 | size = sizeof(png_info); |
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43 | else if (type == PNG_STRUCT_PNG) |
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44 | size = sizeof(png_struct); |
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45 | else |
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46 | return (NULL); |
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47 | |
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48 | #ifdef PNG_USER_MEM_SUPPORTED |
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49 | if(malloc_fn != NULL) |
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50 | { |
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51 | png_struct dummy_struct; |
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52 | png_structp png_ptr = &dummy_struct; |
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53 | png_ptr->mem_ptr=mem_ptr; |
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54 | struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size); |
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55 | } |
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56 | else |
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57 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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58 | struct_ptr = (png_voidp)farmalloc(size)); |
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59 | if (struct_ptr != NULL) |
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60 | png_memset(struct_ptr, 0, size); |
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61 | return (struct_ptr); |
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62 | } |
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63 | |
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64 | /* Free memory allocated by a png_create_struct() call */ |
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65 | void /* PRIVATE */ |
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66 | png_destroy_struct(png_voidp struct_ptr) |
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67 | { |
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68 | #ifdef PNG_USER_MEM_SUPPORTED |
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69 | png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL); |
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70 | } |
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71 | |
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72 | /* Free memory allocated by a png_create_struct() call */ |
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73 | void /* PRIVATE */ |
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74 | png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, |
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75 | png_voidp mem_ptr) |
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76 | { |
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77 | #endif |
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78 | if (struct_ptr != NULL) |
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79 | { |
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80 | #ifdef PNG_USER_MEM_SUPPORTED |
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81 | if(free_fn != NULL) |
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82 | { |
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83 | png_struct dummy_struct; |
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84 | png_structp png_ptr = &dummy_struct; |
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85 | png_ptr->mem_ptr=mem_ptr; |
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86 | (*(free_fn))(png_ptr, struct_ptr); |
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87 | return; |
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88 | } |
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89 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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90 | farfree (struct_ptr); |
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91 | } |
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92 | } |
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93 | |
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94 | /* Allocate memory. For reasonable files, size should never exceed |
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95 | * 64K. However, zlib may allocate more then 64K if you don't tell |
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96 | * it not to. See zconf.h and png.h for more information. zlib does |
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97 | * need to allocate exactly 64K, so whatever you call here must |
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98 | * have the ability to do that. |
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99 | * |
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100 | * Borland seems to have a problem in DOS mode for exactly 64K. |
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101 | * It gives you a segment with an offset of 8 (perhaps to store its |
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102 | * memory stuff). zlib doesn't like this at all, so we have to |
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103 | * detect and deal with it. This code should not be needed in |
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104 | * Windows or OS/2 modes, and only in 16 bit mode. This code has |
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105 | * been updated by Alexander Lehmann for version 0.89 to waste less |
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106 | * memory. |
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107 | * |
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108 | * Note that we can't use png_size_t for the "size" declaration, |
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109 | * since on some systems a png_size_t is a 16-bit quantity, and as a |
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110 | * result, we would be truncating potentially larger memory requests |
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111 | * (which should cause a fatal error) and introducing major problems. |
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112 | */ |
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113 | png_voidp PNGAPI |
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114 | png_malloc(png_structp png_ptr, png_uint_32 size) |
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115 | { |
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116 | #ifndef PNG_USER_MEM_SUPPORTED |
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117 | png_voidp ret; |
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118 | #endif |
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119 | if (png_ptr == NULL || size == 0) |
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120 | return (NULL); |
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121 | |
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122 | #ifdef PNG_USER_MEM_SUPPORTED |
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123 | if(png_ptr->malloc_fn != NULL) |
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124 | { |
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125 | ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); |
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126 | if (ret == NULL) |
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127 | png_error(png_ptr, "Out of memory!"); |
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128 | return (ret); |
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129 | } |
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130 | else |
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131 | return png_malloc_default(png_ptr, size); |
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132 | } |
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133 | |
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134 | png_voidp PNGAPI |
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135 | png_malloc_default(png_structp png_ptr, png_uint_32 size) |
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136 | { |
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137 | png_voidp ret; |
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138 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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139 | |
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140 | #ifdef PNG_MAX_MALLOC_64K |
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141 | if (size > (png_uint_32)65536L) |
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142 | png_error(png_ptr, "Cannot Allocate > 64K"); |
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143 | #endif |
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144 | |
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145 | if (size == (png_uint_32)65536L) |
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146 | { |
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147 | if (png_ptr->offset_table == NULL) |
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148 | { |
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149 | /* try to see if we need to do any of this fancy stuff */ |
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150 | ret = farmalloc(size); |
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151 | if (ret == NULL || ((png_size_t)ret & 0xffff)) |
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152 | { |
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153 | int num_blocks; |
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154 | png_uint_32 total_size; |
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155 | png_bytep table; |
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156 | int i; |
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157 | png_byte huge * hptr; |
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158 | |
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159 | if (ret != NULL) |
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160 | { |
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161 | farfree(ret); |
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162 | ret = NULL; |
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163 | } |
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164 | |
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165 | if(png_ptr->zlib_window_bits > 14) |
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166 | num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); |
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167 | else |
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168 | num_blocks = 1; |
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169 | if (png_ptr->zlib_mem_level >= 7) |
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170 | num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); |
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171 | else |
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172 | num_blocks++; |
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173 | |
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174 | total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16; |
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175 | |
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176 | table = farmalloc(total_size); |
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177 | |
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178 | if (table == NULL) |
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179 | { |
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180 | png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */ |
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181 | } |
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182 | |
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183 | if ((png_size_t)table & 0xfff0) |
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184 | { |
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185 | png_error(png_ptr, "Farmalloc didn't return normalized pointer"); |
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186 | } |
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187 | |
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188 | png_ptr->offset_table = table; |
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189 | png_ptr->offset_table_ptr = farmalloc(num_blocks * |
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190 | sizeof (png_bytep)); |
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191 | |
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192 | if (png_ptr->offset_table_ptr == NULL) |
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193 | { |
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194 | png_error(png_ptr, "Out Of memory."); |
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195 | } |
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196 | |
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197 | hptr = (png_byte huge *)table; |
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198 | if ((png_size_t)hptr & 0xf) |
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199 | { |
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200 | hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L); |
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201 | hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */ |
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202 | } |
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203 | for (i = 0; i < num_blocks; i++) |
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204 | { |
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205 | png_ptr->offset_table_ptr[i] = (png_bytep)hptr; |
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206 | hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */ |
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207 | } |
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208 | |
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209 | png_ptr->offset_table_number = num_blocks; |
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210 | png_ptr->offset_table_count = 0; |
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211 | png_ptr->offset_table_count_free = 0; |
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212 | } |
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213 | } |
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214 | |
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215 | if (png_ptr->offset_table_count >= png_ptr->offset_table_number) |
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216 | png_error(png_ptr, "Out of Memory."); |
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217 | |
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218 | ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; |
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219 | } |
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220 | else |
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221 | ret = farmalloc(size); |
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222 | |
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223 | if (ret == NULL) |
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224 | { |
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225 | png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */ |
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226 | } |
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227 | |
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228 | return (ret); |
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229 | } |
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230 | |
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231 | /* free a pointer allocated by png_malloc(). In the default |
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232 | configuration, png_ptr is not used, but is passed in case it |
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233 | is needed. If ptr is NULL, return without taking any action. */ |
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234 | void PNGAPI |
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235 | png_free(png_structp png_ptr, png_voidp ptr) |
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236 | { |
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237 | if (png_ptr == NULL || ptr == NULL) |
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238 | return; |
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239 | |
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240 | #ifdef PNG_USER_MEM_SUPPORTED |
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241 | if (png_ptr->free_fn != NULL) |
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242 | { |
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243 | (*(png_ptr->free_fn))(png_ptr, ptr); |
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244 | return; |
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245 | } |
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246 | else png_free_default(png_ptr, ptr); |
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247 | } |
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248 | |
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249 | void PNGAPI |
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250 | png_free_default(png_structp png_ptr, png_voidp ptr) |
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251 | { |
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252 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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253 | |
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254 | if (png_ptr->offset_table != NULL) |
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255 | { |
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256 | int i; |
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257 | |
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258 | for (i = 0; i < png_ptr->offset_table_count; i++) |
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259 | { |
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260 | if (ptr == png_ptr->offset_table_ptr[i]) |
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261 | { |
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262 | ptr = NULL; |
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263 | png_ptr->offset_table_count_free++; |
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264 | break; |
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265 | } |
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266 | } |
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267 | if (png_ptr->offset_table_count_free == png_ptr->offset_table_count) |
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268 | { |
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269 | farfree(png_ptr->offset_table); |
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270 | farfree(png_ptr->offset_table_ptr); |
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271 | png_ptr->offset_table = NULL; |
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272 | png_ptr->offset_table_ptr = NULL; |
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273 | } |
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274 | } |
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275 | |
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276 | if (ptr != NULL) |
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277 | { |
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278 | farfree(ptr); |
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279 | } |
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280 | } |
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281 | |
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282 | #else /* Not the Borland DOS special memory handler */ |
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283 | |
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284 | /* Allocate memory for a png_struct or a png_info. The malloc and |
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285 | memset can be replaced by a single call to calloc() if this is thought |
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286 | to improve performance noticably.*/ |
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287 | png_voidp /* PRIVATE */ |
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288 | png_create_struct(int type) |
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289 | { |
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290 | #ifdef PNG_USER_MEM_SUPPORTED |
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291 | return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL)); |
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292 | } |
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293 | |
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294 | /* Allocate memory for a png_struct or a png_info. The malloc and |
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295 | memset can be replaced by a single call to calloc() if this is thought |
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296 | to improve performance noticably.*/ |
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297 | png_voidp /* PRIVATE */ |
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298 | png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr) |
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299 | { |
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300 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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301 | png_size_t size; |
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302 | png_voidp struct_ptr; |
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303 | |
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304 | if (type == PNG_STRUCT_INFO) |
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305 | size = sizeof(png_info); |
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306 | else if (type == PNG_STRUCT_PNG) |
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307 | size = sizeof(png_struct); |
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308 | else |
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309 | return (NULL); |
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310 | |
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311 | #ifdef PNG_USER_MEM_SUPPORTED |
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312 | if(malloc_fn != NULL) |
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313 | { |
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314 | png_struct dummy_struct; |
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315 | png_structp png_ptr = &dummy_struct; |
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316 | png_ptr->mem_ptr=mem_ptr; |
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317 | struct_ptr = (*(malloc_fn))(png_ptr, size); |
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318 | if (struct_ptr != NULL) |
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319 | png_memset(struct_ptr, 0, size); |
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320 | return (struct_ptr); |
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321 | } |
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322 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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323 | |
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324 | #if defined(__TURBOC__) && !defined(__FLAT__) |
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325 | if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) |
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326 | #else |
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327 | # if defined(_MSC_VER) && defined(MAXSEG_64K) |
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328 | if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL) |
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329 | # else |
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330 | if ((struct_ptr = (png_voidp)malloc(size)) != NULL) |
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331 | # endif |
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332 | #endif |
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333 | { |
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334 | png_memset(struct_ptr, 0, size); |
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335 | } |
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336 | |
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337 | return (struct_ptr); |
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338 | } |
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339 | |
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340 | |
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341 | /* Free memory allocated by a png_create_struct() call */ |
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342 | void /* PRIVATE */ |
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343 | png_destroy_struct(png_voidp struct_ptr) |
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344 | { |
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345 | #ifdef PNG_USER_MEM_SUPPORTED |
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346 | png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL); |
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347 | } |
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348 | |
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349 | /* Free memory allocated by a png_create_struct() call */ |
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350 | void /* PRIVATE */ |
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351 | png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, |
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352 | png_voidp mem_ptr) |
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353 | { |
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354 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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355 | if (struct_ptr != NULL) |
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356 | { |
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357 | #ifdef PNG_USER_MEM_SUPPORTED |
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358 | if(free_fn != NULL) |
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359 | { |
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360 | png_struct dummy_struct; |
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361 | png_structp png_ptr = &dummy_struct; |
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362 | png_ptr->mem_ptr=mem_ptr; |
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363 | (*(free_fn))(png_ptr, struct_ptr); |
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364 | return; |
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365 | } |
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366 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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367 | #if defined(__TURBOC__) && !defined(__FLAT__) |
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368 | farfree(struct_ptr); |
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369 | #else |
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370 | # if defined(_MSC_VER) && defined(MAXSEG_64K) |
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371 | hfree(struct_ptr); |
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372 | # else |
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373 | free(struct_ptr); |
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374 | # endif |
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375 | #endif |
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376 | } |
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377 | } |
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378 | |
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379 | |
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380 | /* Allocate memory. For reasonable files, size should never exceed |
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381 | 64K. However, zlib may allocate more then 64K if you don't tell |
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382 | it not to. See zconf.h and png.h for more information. zlib does |
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383 | need to allocate exactly 64K, so whatever you call here must |
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384 | have the ability to do that. */ |
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385 | |
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386 | png_voidp PNGAPI |
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387 | png_malloc(png_structp png_ptr, png_uint_32 size) |
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388 | { |
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389 | png_voidp ret; |
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390 | if (png_ptr == NULL || size == 0) |
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391 | return (NULL); |
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392 | |
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393 | #ifdef PNG_USER_MEM_SUPPORTED |
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394 | if(png_ptr->malloc_fn != NULL) |
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395 | { |
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396 | ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); |
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397 | if (ret == NULL) |
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398 | png_error(png_ptr, "Out of Memory!"); |
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399 | return (ret); |
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400 | } |
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401 | else |
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402 | return (png_malloc_default(png_ptr, size)); |
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403 | } |
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404 | png_voidp /* PRIVATE */ |
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405 | png_malloc_default(png_structp png_ptr, png_uint_32 size) |
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406 | { |
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407 | png_voidp ret; |
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408 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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409 | |
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410 | #ifdef PNG_MAX_MALLOC_64K |
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411 | if (size > (png_uint_32)65536L) |
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412 | png_error(png_ptr, "Cannot Allocate > 64K"); |
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413 | #endif |
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414 | |
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415 | #if defined(__TURBOC__) && !defined(__FLAT__) |
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416 | ret = farmalloc(size); |
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417 | #else |
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418 | # if defined(_MSC_VER) && defined(MAXSEG_64K) |
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419 | ret = halloc(size, 1); |
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420 | # else |
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421 | ret = malloc((size_t)size); |
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422 | # endif |
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423 | #endif |
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424 | |
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425 | if (ret == NULL) |
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426 | png_error(png_ptr, "Out of Memory"); |
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427 | |
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428 | return (ret); |
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429 | } |
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430 | |
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431 | /* Free a pointer allocated by png_malloc(). If ptr is NULL, return |
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432 | without taking any action. */ |
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433 | void PNGAPI |
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434 | png_free(png_structp png_ptr, png_voidp ptr) |
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435 | { |
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436 | if (png_ptr == NULL || ptr == NULL) |
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437 | return; |
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438 | |
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439 | #ifdef PNG_USER_MEM_SUPPORTED |
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440 | if (png_ptr->free_fn != NULL) |
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441 | { |
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442 | (*(png_ptr->free_fn))(png_ptr, ptr); |
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443 | return; |
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444 | } |
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445 | else png_free_default(png_ptr, ptr); |
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446 | } |
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447 | void /* PRIVATE */ |
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448 | png_free_default(png_structp png_ptr, png_voidp ptr) |
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449 | { |
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450 | if (png_ptr == NULL || ptr == NULL) |
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451 | return; |
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452 | |
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453 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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454 | |
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455 | #if defined(__TURBOC__) && !defined(__FLAT__) |
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456 | farfree(ptr); |
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457 | #else |
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458 | # if defined(_MSC_VER) && defined(MAXSEG_64K) |
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459 | hfree(ptr); |
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460 | # else |
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461 | free(ptr); |
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462 | # endif |
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463 | #endif |
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464 | } |
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465 | |
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466 | #endif /* Not Borland DOS special memory handler */ |
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467 | |
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468 | png_voidp /* PRIVATE */ |
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469 | png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2, |
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470 | png_uint_32 length) |
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471 | { |
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472 | png_size_t size; |
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473 | |
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474 | size = (png_size_t)length; |
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475 | if ((png_uint_32)size != length) |
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476 | png_error(png_ptr,"Overflow in png_memcpy_check."); |
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477 | |
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478 | return(png_memcpy (s1, s2, size)); |
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479 | } |
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480 | |
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481 | png_voidp /* PRIVATE */ |
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482 | png_memset_check (png_structp png_ptr, png_voidp s1, int value, |
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483 | png_uint_32 length) |
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484 | { |
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485 | png_size_t size; |
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486 | |
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487 | size = (png_size_t)length; |
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488 | if ((png_uint_32)size != length) |
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489 | png_error(png_ptr,"Overflow in png_memset_check."); |
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490 | |
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491 | return (png_memset (s1, value, size)); |
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492 | |
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493 | } |
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494 | |
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495 | #ifdef PNG_USER_MEM_SUPPORTED |
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496 | /* This function is called when the application wants to use another method |
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497 | * of allocating and freeing memory. |
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498 | */ |
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499 | void PNGAPI |
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500 | png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr |
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501 | malloc_fn, png_free_ptr free_fn) |
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502 | { |
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503 | png_ptr->mem_ptr = mem_ptr; |
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504 | png_ptr->malloc_fn = malloc_fn; |
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505 | png_ptr->free_fn = free_fn; |
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506 | } |
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507 | |
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508 | /* This function returns a pointer to the mem_ptr associated with the user |
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509 | * functions. The application should free any memory associated with this |
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510 | * pointer before png_write_destroy and png_read_destroy are called. |
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511 | */ |
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512 | png_voidp PNGAPI |
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513 | png_get_mem_ptr(png_structp png_ptr) |
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514 | { |
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515 | return ((png_voidp)png_ptr->mem_ptr); |
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516 | } |
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517 | #endif /* PNG_USER_MEM_SUPPORTED */ |
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