From f7813a5324be39d13ab536c245d15dfc602a7849 Mon Sep 17 00:00:00 2001 From: Tim Redfern Date: Sun, 29 Dec 2013 12:19:38 +0000 Subject: basic type mechanism working --- ffmpeg/libavutil/mem.h | 156 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 142 insertions(+), 14 deletions(-) (limited to 'ffmpeg/libavutil/mem.h') diff --git a/ffmpeg/libavutil/mem.h b/ffmpeg/libavutil/mem.h index ced9453..703ce81 100644 --- a/ffmpeg/libavutil/mem.h +++ b/ffmpeg/libavutil/mem.h @@ -83,8 +83,7 @@ void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); /** - * Helper function to allocate a block of size * nmemb bytes with - * using av_malloc() + * Allocate a block of size * nmemb bytes with av_malloc(). * @param nmemb Number of elements * @param size Size of the single element * @return Pointer to the allocated block, NULL if the block cannot @@ -93,7 +92,7 @@ void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); */ av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size) { - if (size <= 0 || nmemb >= INT_MAX / size) + if (!size || nmemb >= INT_MAX / size) return NULL; return av_malloc(nmemb * size); } @@ -103,11 +102,17 @@ av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t siz * 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 memory block already allocated with - * av_malloc(z)() or av_realloc() or NULL. - * @param size Size in bytes for the memory block to be allocated or + * av_realloc() or NULL. + * @param size Size in bytes of the memory block to be allocated or * reallocated. - * @return Pointer to a newly reallocated block or NULL if the block + * @return Pointer to a newly-reallocated block or NULL if the block * cannot be reallocated or the function is used to free the memory block. + * @warning Pointers originating from the av_malloc() family of functions must + * not be passed to av_realloc(). The former can be implemented using + * memalign() (or other functions), and there is no guarantee that + * pointers from such functions can be passed to realloc() at all. + * The situation is undefined according to POSIX and may crash with + * some libc implementations. * @see av_fast_realloc() */ void *av_realloc(void *ptr, size_t size) av_alloc_size(2); @@ -122,6 +127,63 @@ void *av_realloc(void *ptr, size_t size) av_alloc_size(2); */ 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 + * with av_realloc(), or pointer to a pointer to NULL. + * The pointer is updated on success, or freed on failure. + * @param size Size in bytes for the memory block to be allocated or + * reallocated + * @return Zero on success, an AVERROR error code on failure. + * @warning Pointers originating from the av_malloc() family of functions must + * not be passed to av_reallocp(). The former can be implemented using + * memalign() (or other functions), and there is no guarantee that + * pointers from such functions can be passed to realloc() at all. + * The situation is undefined according to POSIX and may crash with + * some libc implementations. + */ +int av_reallocp(void *ptr, size_t size); + +/** + * Allocate or reallocate an array. + * If ptr is NULL and nmemb > 0, allocate a new block. If + * nmemb is zero, free the memory block pointed to by ptr. + * @param ptr Pointer to a memory block already allocated with + * av_realloc() or NULL. + * @param nmemb Number of elements + * @param size Size of the single element + * @return Pointer to a newly-reallocated block or NULL if the block + * cannot be reallocated or the function is used to free the memory block. + * @warning Pointers originating from the av_malloc() family of functions must + * not be passed to av_realloc(). The former can be implemented using + * memalign() (or other functions), and there is no guarantee that + * pointers from such functions can be passed to realloc() at all. + * The situation is undefined according to POSIX and may crash with + * some libc implementations. + */ +av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size); + +/** + * Allocate or reallocate an array through a pointer to a pointer. + * If *ptr is NULL and nmemb > 0, allocate a new block. If + * nmemb is zero, free the memory block pointed to by ptr. + * @param ptr Pointer to a pointer to a memory block already allocated + * with av_realloc(), or pointer to a pointer to NULL. + * The pointer is updated on success, or freed on failure. + * @param nmemb Number of elements + * @param size Size of the single element + * @return Zero on success, an AVERROR error code on failure. + * @warning Pointers originating from the av_malloc() family of functions must + * not be passed to av_realloc(). The former can be implemented using + * memalign() (or other functions), and there is no guarantee that + * pointers from such functions can be passed to realloc() at all. + * The situation is undefined according to POSIX and may crash with + * some libc implementations. + */ +av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size); + /** * Free a memory block which has been allocated with av_malloc(z)() or * av_realloc(). @@ -155,8 +217,7 @@ void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib; /** - * Helper function to allocate a block of size * nmemb bytes with - * using av_mallocz() + * Allocate a block of size * nmemb bytes with av_mallocz(). * @param nmemb Number of elements * @param size Size of the single element * @return Pointer to the allocated block, NULL if the block cannot @@ -166,7 +227,7 @@ void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib; */ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size) { - if (size <= 0 || nmemb >= INT_MAX / size) + if (!size || nmemb >= INT_MAX / size) return NULL; return av_mallocz(nmemb * size); } @@ -174,11 +235,19 @@ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t si /** * Duplicate the string s. * @param s string to be duplicated - * @return Pointer to a newly allocated string containing a + * @return Pointer to a newly-allocated string containing a * copy of s or NULL if the string cannot be allocated. */ 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. @@ -191,12 +260,50 @@ void av_freep(void *ptr); /** * Add an element to a dynamic array. * - * @param tab_ptr Pointer to the array. - * @param nb_ptr Pointer to the number of elements in the array. - * @param elem Element to be added. + * 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. @@ -218,7 +325,7 @@ static inline int av_size_mult(size_t a, size_t b, size_t *r) void av_max_alloc(size_t max); /** - * @brief deliberately overlapping memcpy implementation + * deliberately overlapping memcpy implementation * @param dst destination buffer * @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 @@ -228,6 +335,27 @@ void av_max_alloc(size_t max); */ void av_memcpy_backptr(uint8_t *dst, int back, int cnt); +/** + * Reallocate the given block if it is not large enough, otherwise do nothing. + * + * @see av_realloc + */ +void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size); + +/** + * Allocate a buffer, reusing the given one if large enough. + * + * Contrary to av_fast_realloc the current buffer contents might not be + * preserved and on error the old buffer is freed, thus no special + * handling to avoid memleaks is necessary. + * + * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer + * @param size size of the buffer *ptr points to + * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and + * *size 0 if an error occurred. + */ +void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size); + /** * @} */ -- cgit v1.2.3