1 /* 2 * Copyright 2010 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 21 * DEALINGS IN THE SOFTWARE. 22 */ 23 24 /** 25 * \file ralloc.h 26 * 27 * ralloc: a recursive memory allocator 28 * 29 * The ralloc memory allocator creates a hierarchy of allocated 30 * objects. Every allocation is in reference to some parent, and 31 * every allocated object can in turn be used as the parent of a 32 * subsequent allocation. This allows for extremely convenient 33 * discarding of an entire tree/sub-tree of allocations by calling 34 * ralloc_free on any particular object to free it and all of its 35 * children. 36 * 37 * The conceptual working of ralloc was directly inspired by Andrew 38 * Tridgell's talloc, but ralloc is an independent implementation 39 * released under the MIT license and tuned for Mesa. 40 * 41 * The talloc implementation is available under the GNU Lesser 42 * General Public License (GNU LGPL), version 3 or later. It is 43 * more sophisticated than ralloc in that it includes reference 44 * counting and debugging features. See: http://talloc.samba.org/ 45 */ 46 47 #ifndef RALLOC_H 48 #define RALLOC_H 49 50 #ifdef __cplusplus 51 extern "C" { 52 #endif 53 54 #include <stddef.h> 55 #include <stdarg.h> 56 #include <stdbool.h> 57 #include "main/compiler.h" 58 59 /** 60 * \def ralloc(ctx, type) 61 * Allocate a new object chained off of the given context. 62 * 63 * This is equivalent to: 64 * \code 65 * ((type *) ralloc_size(ctx, sizeof(type)) 66 * \endcode 67 */ 68 #define ralloc(ctx, type) ((type *) ralloc_size(ctx, sizeof(type))) 69 70 /** 71 * \def rzalloc(ctx, type) 72 * Allocate a new object out of the given context and initialize it to zero. 73 * 74 * This is equivalent to: 75 * \code 76 * ((type *) rzalloc_size(ctx, sizeof(type)) 77 * \endcode 78 */ 79 #define rzalloc(ctx, type) ((type *) rzalloc_size(ctx, sizeof(type))) 80 81 /** 82 * Allocate a new ralloc context. 83 * 84 * While any ralloc'd pointer can be used as a context, sometimes it is useful 85 * to simply allocate a context with no associated memory. 86 * 87 * It is equivalent to: 88 * \code 89 * ((type *) ralloc_size(ctx, 0) 90 * \endcode 91 */ 92 void *ralloc_context(const void *ctx); 93 94 /** 95 * Allocate memory chained off of the given context. 96 * 97 * This is the core allocation routine which is used by all others. It 98 * simply allocates storage for \p size bytes and returns the pointer, 99 * similar to \c malloc. 100 */ 101 void *ralloc_size(const void *ctx, size_t size); 102 103 /** 104 * Allocate zero-initialized memory chained off of the given context. 105 * 106 * This is similar to \c calloc with a size of 1. 107 */ 108 void *rzalloc_size(const void *ctx, size_t size); 109 110 /** 111 * Resize a piece of ralloc-managed memory, preserving data. 112 * 113 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 114 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 115 * calling ralloc_size(ctx, 0). This is different from talloc. 116 * 117 * \param ctx The context to use for new allocation. If \p ptr != NULL, 118 * it must be the same as ralloc_parent(\p ptr). 119 * \param ptr Pointer to the memory to be resized. May be NULL. 120 * \param size The amount of memory to allocate, in bytes. 121 */ 122 void *reralloc_size(const void *ctx, void *ptr, size_t size); 123 124 /// \defgroup array Array Allocators @{ 125 126 /** 127 * \def ralloc_array(ctx, type, count) 128 * Allocate an array of objects chained off the given context. 129 * 130 * Similar to \c calloc, but does not initialize the memory to zero. 131 * 132 * More than a convenience function, this also checks for integer overflow when 133 * multiplying \c sizeof(type) and \p count. This is necessary for security. 134 * 135 * This is equivalent to: 136 * \code 137 * ((type *) ralloc_array_size(ctx, sizeof(type), count) 138 * \endcode 139 */ 140 #define ralloc_array(ctx, type, count) \ 141 ((type *) ralloc_array_size(ctx, sizeof(type), count)) 142 143 /** 144 * \def rzalloc_array(ctx, type, count) 145 * Allocate a zero-initialized array chained off the given context. 146 * 147 * Similar to \c calloc. 148 * 149 * More than a convenience function, this also checks for integer overflow when 150 * multiplying \c sizeof(type) and \p count. This is necessary for security. 151 * 152 * This is equivalent to: 153 * \code 154 * ((type *) rzalloc_array_size(ctx, sizeof(type), count) 155 * \endcode 156 */ 157 #define rzalloc_array(ctx, type, count) \ 158 ((type *) rzalloc_array_size(ctx, sizeof(type), count)) 159 160 /** 161 * \def reralloc(ctx, ptr, type, count) 162 * Resize a ralloc-managed array, preserving data. 163 * 164 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 165 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 166 * calling ralloc_size(ctx, 0). This is different from talloc. 167 * 168 * More than a convenience function, this also checks for integer overflow when 169 * multiplying \c sizeof(type) and \p count. This is necessary for security. 170 * 171 * \param ctx The context to use for new allocation. If \p ptr != NULL, 172 * it must be the same as ralloc_parent(\p ptr). 173 * \param ptr Pointer to the array to be resized. May be NULL. 174 * \param type The element type. 175 * \param count The number of elements to allocate. 176 */ 177 #define reralloc(ctx, ptr, type, count) \ 178 ((type *) reralloc_array_size(ctx, ptr, sizeof(type), count)) 179 180 /** 181 * Allocate memory for an array chained off the given context. 182 * 183 * Similar to \c calloc, but does not initialize the memory to zero. 184 * 185 * More than a convenience function, this also checks for integer overflow when 186 * multiplying \p size and \p count. This is necessary for security. 187 */ 188 void *ralloc_array_size(const void *ctx, size_t size, unsigned count); 189 190 /** 191 * Allocate a zero-initialized array chained off the given context. 192 * 193 * Similar to \c calloc. 194 * 195 * More than a convenience function, this also checks for integer overflow when 196 * multiplying \p size and \p count. This is necessary for security. 197 */ 198 void *rzalloc_array_size(const void *ctx, size_t size, unsigned count); 199 200 /** 201 * Resize a ralloc-managed array, preserving data. 202 * 203 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 204 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 205 * calling ralloc_size(ctx, 0). This is different from talloc. 206 * 207 * More than a convenience function, this also checks for integer overflow when 208 * multiplying \c sizeof(type) and \p count. This is necessary for security. 209 * 210 * \param ctx The context to use for new allocation. If \p ptr != NULL, 211 * it must be the same as ralloc_parent(\p ptr). 212 * \param ptr Pointer to the array to be resized. May be NULL. 213 * \param size The size of an individual element. 214 * \param count The number of elements to allocate. 215 * 216 * \return True unless allocation failed. 217 */ 218 void *reralloc_array_size(const void *ctx, void *ptr, size_t size, 219 unsigned count); 220 /// @} 221 222 /** 223 * Free a piece of ralloc-managed memory. 224 * 225 * This will also free the memory of any children allocated this context. 226 */ 227 void ralloc_free(void *ptr); 228 229 /** 230 * "Steal" memory from one context, changing it to another. 231 * 232 * This changes \p ptr's context to \p new_ctx. This is quite useful if 233 * memory is allocated out of a temporary context. 234 */ 235 void ralloc_steal(const void *new_ctx, void *ptr); 236 237 /** 238 * Return the given pointer's ralloc context. 239 */ 240 void *ralloc_parent(const void *ptr); 241 242 /** 243 * Return a context whose memory will be automatically freed at program exit. 244 * 245 * The first call to this function creates a context and registers a handler 246 * to free it using \c atexit. This may cause trouble if used in a library 247 * loaded with \c dlopen. 248 */ 249 void *ralloc_autofree_context(void); 250 251 /** 252 * Set a callback to occur just before an object is freed. 253 */ 254 void ralloc_set_destructor(const void *ptr, void(*destructor)(void *)); 255 256 /// \defgroup array String Functions @{ 257 /** 258 * Duplicate a string, allocating the memory from the given context. 259 */ 260 char *ralloc_strdup(const void *ctx, const char *str); 261 262 /** 263 * Duplicate a string, allocating the memory from the given context. 264 * 265 * Like \c strndup, at most \p n characters are copied. If \p str is longer 266 * than \p n characters, \p n are copied, and a termining \c '\0' byte is added. 267 */ 268 char *ralloc_strndup(const void *ctx, const char *str, size_t n); 269 270 /** 271 * Concatenate two strings, allocating the necessary space. 272 * 273 * This appends \p str to \p *dest, similar to \c strcat, using ralloc_resize 274 * to expand \p *dest to the appropriate size. \p dest will be updated to the 275 * new pointer unless allocation fails. 276 * 277 * The result will always be null-terminated. 278 * 279 * \return True unless allocation failed. 280 */ 281 bool ralloc_strcat(char **dest, const char *str); 282 283 /** 284 * Concatenate two strings, allocating the necessary space. 285 * 286 * This appends at most \p n bytes of \p str to \p *dest, using ralloc_resize 287 * to expand \p *dest to the appropriate size. \p dest will be updated to the 288 * new pointer unless allocation fails. 289 * 290 * The result will always be null-terminated; \p str does not need to be null 291 * terminated if it is longer than \p n. 292 * 293 * \return True unless allocation failed. 294 */ 295 bool ralloc_strncat(char **dest, const char *str, size_t n); 296 297 /** 298 * Print to a string. 299 * 300 * This is analogous to \c sprintf, but allocates enough space (using \p ctx 301 * as the context) for the resulting string. 302 * 303 * \return The newly allocated string. 304 */ 305 char *ralloc_asprintf (const void *ctx, const char *fmt, ...) PRINTFLIKE(2, 3); 306 307 /** 308 * Print to a string, given a va_list. 309 * 310 * This is analogous to \c vsprintf, but allocates enough space (using \p ctx 311 * as the context) for the resulting string. 312 * 313 * \return The newly allocated string. 314 */ 315 char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args); 316 317 /** 318 * Rewrite the tail of an existing string, starting at a given index. 319 * 320 * Overwrites the contents of *str starting at \p start with newly formatted 321 * text, including a new null-terminator. Allocates more memory as necessary. 322 * 323 * This can be used to append formatted text when the length of the existing 324 * string is already known, saving a strlen() call. 325 * 326 * \sa ralloc_asprintf_append 327 * 328 * \param str The string to be updated. 329 * \param start The index to start appending new data at. 330 * \param fmt A printf-style formatting string 331 * 332 * \p str will be updated to the new pointer unless allocation fails. 333 * \p start will be increased by the length of the newly formatted text. 334 * 335 * \return True unless allocation failed. 336 */ 337 bool ralloc_asprintf_rewrite_tail(char **str, size_t *start, 338 const char *fmt, ...) 339 PRINTFLIKE(3, 4); 340 341 /** 342 * Rewrite the tail of an existing string, starting at a given index. 343 * 344 * Overwrites the contents of *str starting at \p start with newly formatted 345 * text, including a new null-terminator. Allocates more memory as necessary. 346 * 347 * This can be used to append formatted text when the length of the existing 348 * string is already known, saving a strlen() call. 349 * 350 * \sa ralloc_vasprintf_append 351 * 352 * \param str The string to be updated. 353 * \param start The index to start appending new data at. 354 * \param fmt A printf-style formatting string 355 * \param args A va_list containing the data to be formatted 356 * 357 * \p str will be updated to the new pointer unless allocation fails. 358 * \p start will be increased by the length of the newly formatted text. 359 * 360 * \return True unless allocation failed. 361 */ 362 bool ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt, 363 va_list args); 364 365 /** 366 * Append formatted text to the supplied string. 367 * 368 * This is equivalent to 369 * \code 370 * ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...) 371 * \endcode 372 * 373 * \sa ralloc_asprintf 374 * \sa ralloc_asprintf_rewrite_tail 375 * \sa ralloc_strcat 376 * 377 * \p str will be updated to the new pointer unless allocation fails. 378 * 379 * \return True unless allocation failed. 380 */ 381 bool ralloc_asprintf_append (char **str, const char *fmt, ...) 382 PRINTFLIKE(2, 3); 383 384 /** 385 * Append formatted text to the supplied string, given a va_list. 386 * 387 * This is equivalent to 388 * \code 389 * ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args) 390 * \endcode 391 * 392 * \sa ralloc_vasprintf 393 * \sa ralloc_vasprintf_rewrite_tail 394 * \sa ralloc_strcat 395 * 396 * \p str will be updated to the new pointer unless allocation fails. 397 * 398 * \return True unless allocation failed. 399 */ 400 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args); 401 /// @} 402 403 #ifdef __cplusplus 404 } /* end of extern "C" */ 405 #endif 406 407 #endif 408
