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
51extern "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 */
92void *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 */
101void *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 */
108void *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 */
122void *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 */
188void *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 */
198void *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 */
218void *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 */
227void 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 */
235void ralloc_steal(const void *new_ctx, void *ptr);
236
237/**
238 * Return the given pointer's ralloc context.
239 */
240void *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 */
249void *ralloc_autofree_context(void);
250
251/**
252 * Set a callback to occur just before an object is freed.
253 */
254void 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 */
260char *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 */
268char *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 */
281bool 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 */
295bool 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 */
305char *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 */
315char *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 */
337bool 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 */
362bool 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 */
381bool 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 */
400bool 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