diff options
Diffstat (limited to 'libavutil/mem.h')
| -rw-r--r-- | libavutil/mem.h | 110 |
1 files changed, 104 insertions, 6 deletions
diff --git a/libavutil/mem.h b/libavutil/mem.h index 99dc4cc156..77b7adc373 100644 --- a/libavutil/mem.h +++ b/libavutil/mem.h @@ -1,20 +1,20 @@ /* * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -30,6 +30,7 @@ #include <stdint.h> #include "attributes.h" +#include "error.h" #include "avutil.h" /** @@ -38,7 +39,7 @@ */ -#if defined(__ICC) && __ICC < 1200 || defined(__SUNPRO_C) +#if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || defined(__SUNPRO_C) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v #elif defined(__TI_COMPILER_VERSION__) @@ -118,6 +119,16 @@ void *av_realloc(void *ptr, size_t size) av_alloc_size(2); /** * Allocate or reallocate a block of memory. + * This function does the same thing as av_realloc, except: + * - It takes two arguments and checks the result of the multiplication for + * integer overflow. + * - It frees the input block in case of failure, thus avoiding the memory + * leak with the classic "buf = realloc(buf); if (!buf) return -1;". + */ +void *av_realloc_f(void *ptr, size_t nelem, size_t elsize); + +/** + * Allocate or reallocate a block of memory. * If *ptr is NULL and size > 0, allocate a new block. If * size is zero, free the memory block pointed to by ptr. * @param ptr Pointer to a pointer to a memory block already allocated @@ -194,6 +205,18 @@ void av_free(void *ptr); void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); /** + * Allocate a block of nmemb * size bytes with alignment suitable for all + * memory accesses (including vectors if available on the CPU) and + * zero all the bytes of the block. + * The allocation will fail if nmemb * size is greater than or equal + * to INT_MAX. + * @param nmemb + * @param size + * @return Pointer to the allocated block, NULL if it cannot be allocated. + */ +void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib; + +/** * Allocate a block of size * nmemb bytes with av_mallocz(). * @param nmemb Number of elements * @param size Size of the single element @@ -218,6 +241,14 @@ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t si char *av_strdup(const char *s) av_malloc_attrib; /** + * Duplicate the buffer p. + * @param p buffer to be duplicated + * @return Pointer to a newly allocated buffer containing a + * copy of p or NULL if the buffer cannot be allocated. + */ +void *av_memdup(const void *p, size_t size); + +/** * Free a memory block which has been allocated with av_malloc(z)() or * av_realloc() and set the pointer pointing to it to NULL. * @param ptr Pointer to the pointer to the memory block which should @@ -227,9 +258,76 @@ char *av_strdup(const char *s) av_malloc_attrib; void av_freep(void *ptr); /** + * Add an element to a dynamic array. + * + * The array to grow is supposed to be an array of pointers to + * structures, and the element to add must be a pointer to an already + * allocated structure. + * + * The array is reallocated when its size reaches powers of 2. + * Therefore, the amortized cost of adding an element is constant. + * + * In case of success, the pointer to the array is updated in order to + * point to the new grown array, and the number pointed to by nb_ptr + * is incremented. + * In case of failure, the array is freed, *tab_ptr is set to NULL and + * *nb_ptr is set to 0. + * + * @param tab_ptr pointer to the array to grow + * @param nb_ptr pointer to the number of elements in the array + * @param elem element to add + * @see av_dynarray2_add() + */ +void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem); + +/** + * Add an element of size elem_size to a dynamic array. + * + * The array is reallocated when its number of elements reaches powers of 2. + * Therefore, the amortized cost of adding an element is constant. + * + * In case of success, the pointer to the array is updated in order to + * point to the new grown array, and the number pointed to by nb_ptr + * is incremented. + * In case of failure, the array is freed, *tab_ptr is set to NULL and + * *nb_ptr is set to 0. + * + * @param tab_ptr pointer to the array to grow + * @param nb_ptr pointer to the number of elements in the array + * @param elem_size size in bytes of the elements in the array + * @param elem_data pointer to the data of the element to add. If NULL, the space of + * the new added element is not filled. + * @return pointer to the data of the element to copy in the new allocated space. + * If NULL, the new allocated space is left uninitialized." + * @see av_dynarray_add() + */ +void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size, + const uint8_t *elem_data); + +/** + * Multiply two size_t values checking for overflow. + * @return 0 if success, AVERROR(EINVAL) if overflow. + */ +static inline int av_size_mult(size_t a, size_t b, size_t *r) +{ + size_t t = a * b; + /* Hack inspired from glibc: only try the division if nelem and elsize + * are both greater than sqrt(SIZE_MAX). */ + if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b) + return AVERROR(EINVAL); + *r = t; + return 0; +} + +/** + * Set the maximum size that may me allocated in one block. + */ +void av_max_alloc(size_t max); + +/** * deliberately overlapping memcpy implementation * @param dst destination buffer - * @param back how many bytes back we start (the initial size of the overlapping window) + * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0 * @param cnt number of bytes to copy, must be >= 0 * * cnt > back is valid, this will copy the bytes we just copied, |