Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
4349 | Serge | 1 | |
2 | * |
||
3 | * Last changed in libpng 1.6.0 [February 14, 2013] |
||
4 | * Copyright (c) 1998-2013 Glenn Randers-Pehrson |
||
5 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
||
6 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
||
7 | * |
||
8 | * This code is released under the libpng license. |
||
9 | * For conditions of distribution and use, see the disclaimer |
||
10 | * and license in png.h |
||
11 | * |
||
12 | * This file provides a location for all memory allocation. Users who |
||
13 | * need special memory handling are expected to supply replacement |
||
14 | * functions for png_malloc() and png_free(), and to use |
||
15 | * png_create_read_struct_2() and png_create_write_struct_2() to |
||
16 | * identify the replacement functions. |
||
17 | */ |
||
18 | |||
19 | |||
20 | |||
21 | |||
22 | /* Free a png_struct */ |
||
23 | void /* PRIVATE */ |
||
24 | png_destroy_png_struct(png_structrp png_ptr) |
||
25 | { |
||
26 | if (png_ptr != NULL) |
||
27 | { |
||
28 | /* png_free might call png_error and may certainly call |
||
29 | * png_get_mem_ptr, so fake a temporary png_struct to support this. |
||
30 | */ |
||
31 | png_struct dummy_struct = *png_ptr; |
||
32 | memset(png_ptr, 0, (sizeof *png_ptr)); |
||
33 | png_free(&dummy_struct, png_ptr); |
||
34 | |||
35 | |||
36 | /* We may have a jmp_buf left to deallocate. */ |
||
37 | png_free_jmpbuf(&dummy_struct); |
||
38 | # endif |
||
39 | } |
||
40 | } |
||
41 | |||
42 | |||
43 | * 64K. However, zlib may allocate more then 64K if you don't tell |
||
44 | * it not to. See zconf.h and png.h for more information. zlib does |
||
45 | * need to allocate exactly 64K, so whatever you call here must |
||
46 | * have the ability to do that. |
||
47 | */ |
||
48 | PNG_FUNCTION(png_voidp,PNGAPI |
||
49 | png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) |
||
50 | { |
||
51 | png_voidp ret; |
||
52 | |||
53 | |||
54 | |||
55 | |||
56 | memset(ret, 0, size); |
||
57 | |||
58 | |||
59 | } |
||
60 | |||
61 | |||
62 | * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED. |
||
63 | * Checking and error handling must happen outside this routine; it returns NULL |
||
64 | * if the allocation cannot be done (for any reason.) |
||
65 | */ |
||
66 | PNG_FUNCTION(png_voidp /* PRIVATE */, |
||
67 | png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size), |
||
68 | PNG_ALLOCATED) |
||
69 | { |
||
70 | /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS |
||
71 | * allocators have also been removed in 1.6.0, so any 16-bit system now has |
||
72 | * to implement a user memory handler. This checks to be sure it isn't |
||
73 | * called with big numbers. |
||
74 | */ |
||
75 | #ifdef PNG_USER_MEM_SUPPORTED |
||
76 | PNG_UNUSED(png_ptr) |
||
77 | #endif |
||
78 | if (size > 0 && size <= PNG_SIZE_MAX |
||
79 | # ifdef PNG_MAX_MALLOC_64K |
||
80 | && size <= 65536U |
||
81 | # endif |
||
82 | ) |
||
83 | { |
||
84 | #ifdef PNG_USER_MEM_SUPPORTED |
||
85 | if (png_ptr != NULL && png_ptr->malloc_fn != NULL) |
||
86 | return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size); |
||
87 | |||
88 | |||
89 | #endif |
||
90 | return malloc((size_t)size); /* checked for truncation above */ |
||
91 | } |
||
92 | |||
93 | |||
94 | return NULL; |
||
95 | } |
||
96 | |||
97 | |||
98 | * that arises because of the checks in png_realloc_array that are repeated in |
||
99 | * png_malloc_array. |
||
100 | */ |
||
101 | static png_voidp |
||
102 | png_malloc_array_checked(png_const_structrp png_ptr, int nelements, |
||
103 | size_t element_size) |
||
104 | { |
||
105 | png_alloc_size_t req = nelements; /* known to be > 0 */ |
||
106 | |||
107 | |||
108 | return png_malloc_base(png_ptr, req * element_size); |
||
109 | |||
110 | |||
111 | return NULL; |
||
112 | } |
||
113 | |||
114 | |||
115 | png_malloc_array,(png_const_structrp png_ptr, int nelements, |
||
116 | size_t element_size),PNG_ALLOCATED) |
||
117 | { |
||
118 | if (nelements <= 0 || element_size == 0) |
||
119 | png_error(png_ptr, "internal error: array alloc"); |
||
120 | |||
121 | |||
122 | } |
||
123 | |||
124 | |||
125 | png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array, |
||
126 | int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED) |
||
127 | { |
||
128 | /* These are internal errors: */ |
||
129 | if (add_elements <= 0 || element_size == 0 || old_elements < 0 || |
||
130 | (old_array == NULL && old_elements > 0)) |
||
131 | png_error(png_ptr, "internal error: array realloc"); |
||
132 | |||
133 | |||
134 | * check.) |
||
135 | */ |
||
136 | if (add_elements <= INT_MAX - old_elements) |
||
137 | { |
||
138 | png_voidp new_array = png_malloc_array_checked(png_ptr, |
||
139 | old_elements+add_elements, element_size); |
||
140 | |||
141 | |||
142 | { |
||
143 | /* Because png_malloc_array worked the size calculations below cannot |
||
144 | * overflow. |
||
145 | */ |
||
146 | if (old_elements > 0) |
||
147 | memcpy(new_array, old_array, element_size*(unsigned)old_elements); |
||
148 | |||
149 | |||
150 | element_size*(unsigned)add_elements); |
||
151 | |||
152 | |||
153 | } |
||
154 | } |
||
155 | |||
156 | |||
157 | } |
||
158 | |||
159 | |||
160 | * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate |
||
161 | * function png_malloc_default is also provided. |
||
162 | */ |
||
163 | PNG_FUNCTION(png_voidp,PNGAPI |
||
164 | png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) |
||
165 | { |
||
166 | png_voidp ret; |
||
167 | |||
168 | |||
169 | return NULL; |
||
170 | |||
171 | |||
172 | |||
173 | |||
174 | png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ |
||
175 | |||
176 | |||
177 | } |
||
178 | |||
179 | |||
180 | PNG_FUNCTION(png_voidp,PNGAPI |
||
181 | png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), |
||
182 | PNG_ALLOCATED PNG_DEPRECATED) |
||
183 | { |
||
184 | png_voidp ret; |
||
185 | |||
186 | |||
187 | return NULL; |
||
188 | |||
189 | |||
190 | ret = png_malloc_base(NULL/*use malloc*/, size); |
||
191 | |||
192 | |||
193 | png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ |
||
194 | |||
195 | |||
196 | } |
||
197 | #endif /* PNG_USER_MEM_SUPPORTED */ |
||
198 | |||
199 | |||
200 | * function will issue a png_warning and return NULL instead of issuing a |
||
201 | * png_error, if it fails to allocate the requested memory. |
||
202 | */ |
||
203 | PNG_FUNCTION(png_voidp,PNGAPI |
||
204 | png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size), |
||
205 | PNG_ALLOCATED) |
||
206 | { |
||
207 | if (png_ptr != NULL) |
||
208 | { |
||
209 | png_voidp ret = png_malloc_base(png_ptr, size); |
||
210 | |||
211 | |||
212 | return ret; |
||
213 | |||
214 | |||
215 | } |
||
216 | |||
217 | |||
218 | } |
||
219 | |||
220 | |||
221 | * without taking any action. |
||
222 | */ |
||
223 | void PNGAPI |
||
224 | png_free(png_const_structrp png_ptr, png_voidp ptr) |
||
225 | { |
||
226 | if (png_ptr == NULL || ptr == NULL) |
||
227 | return; |
||
228 | |||
229 | |||
230 | if (png_ptr->free_fn != NULL) |
||
231 | png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); |
||
232 | |||
233 | |||
234 | png_free_default(png_ptr, ptr); |
||
235 | } |
||
236 | |||
237 | |||
238 | png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) |
||
239 | { |
||
240 | if (png_ptr == NULL || ptr == NULL) |
||
241 | return; |
||
242 | #endif /* PNG_USER_MEM_SUPPORTED */ |
||
243 | |||
244 | |||
245 | } |
||
246 | |||
247 | |||
248 | /* This function is called when the application wants to use another method |
||
249 | * of allocating and freeing memory. |
||
250 | */ |
||
251 | void PNGAPI |
||
252 | png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr |
||
253 | malloc_fn, png_free_ptr free_fn) |
||
254 | { |
||
255 | if (png_ptr != NULL) |
||
256 | { |
||
257 | png_ptr->mem_ptr = mem_ptr; |
||
258 | png_ptr->malloc_fn = malloc_fn; |
||
259 | png_ptr->free_fn = free_fn; |
||
260 | } |
||
261 | } |
||
262 | |||
263 | |||
264 | * functions. The application should free any memory associated with this |
||
265 | * pointer before png_write_destroy and png_read_destroy are called. |
||
266 | */ |
||
267 | png_voidp PNGAPI |
||
268 | png_get_mem_ptr(png_const_structrp png_ptr) |
||
269 | { |
||
270 | if (png_ptr == NULL) |
||
271 | return NULL; |
||
272 | |||
273 | |||
274 | } |
||
275 | #endif /* PNG_USER_MEM_SUPPORTED */ |
||
276 | #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */=>>=>=>=>=>=> |
||
277 |