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Diffstat (limited to 'media/libav/libavutil/mem.h')
| -rw-r--r-- | media/libav/libavutil/mem.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/media/libav/libavutil/mem.h b/media/libav/libavutil/mem.h new file mode 100644 index 000000000..9f667c270 --- /dev/null +++ b/media/libav/libavutil/mem.h @@ -0,0 +1,275 @@ +/* + * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of Libav. + * + * Libav 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, + * 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 + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * memory handling functions + */ + +#ifndef AVUTIL_MEM_H +#define AVUTIL_MEM_H + +#include <limits.h> +#include <stdint.h> + +#include "attributes.h" +#include "avutil.h" + +/** + * @addtogroup lavu_mem + * @{ + */ + + +#if defined(__ICC) && __ICC < 1200 || 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__) + #define DECLARE_ALIGNED(n,t,v) \ + AV_PRAGMA(DATA_ALIGN(v,n)) \ + t __attribute__((aligned(n))) v + #define DECLARE_ASM_CONST(n,t,v) \ + AV_PRAGMA(DATA_ALIGN(v,n)) \ + static const t __attribute__((aligned(n))) v +#elif defined(__GNUC__) + #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v + #define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v +#elif defined(_MSC_VER) + #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v + #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v +#else + #define DECLARE_ALIGNED(n,t,v) t v + #define DECLARE_ASM_CONST(n,t,v) static const t v +#endif + +#if AV_GCC_VERSION_AT_LEAST(3,1) + #define av_malloc_attrib __attribute__((__malloc__)) +#else + #define av_malloc_attrib +#endif + +#if AV_GCC_VERSION_AT_LEAST(4,3) + #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) +#else + #define av_alloc_size(...) +#endif + +/** + * Allocate a block of size bytes with alignment suitable for all + * memory accesses (including vectors if available on the CPU). + * @param size Size in bytes for the memory block to be allocated. + * @return Pointer to the allocated block, NULL if the block cannot + * be allocated. + * @see av_mallocz() + */ +void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); + +/** + * 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 + * be allocated. + * @see av_malloc() + */ +av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size) +{ + if (!size || nmemb >= INT_MAX / size) + return NULL; + return av_malloc(nmemb * size); +} + +/** + * 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 memory block already allocated with + * 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 + * 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); + +/** + * 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(). + * @param ptr Pointer to the memory block which should be freed. + * @note ptr = NULL is explicitly allowed. + * @note It is recommended that you use av_freep() instead. + * @see av_freep() + */ +void av_free(void *ptr); + +/** + * Allocate a block of size bytes with alignment suitable for all + * memory accesses (including vectors if available on the CPU) and + * zero all the bytes of the block. + * @param size Size in bytes for the memory block to be allocated. + * @return Pointer to the allocated block, NULL if it cannot be allocated. + * @see av_malloc() + */ +void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); + +/** + * 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 + * be allocated. + * @see av_mallocz() + * @see av_malloc_array() + */ +av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size) +{ + if (!size || nmemb >= INT_MAX / size) + return NULL; + return av_mallocz(nmemb * size); +} + +/** + * Duplicate the string s. + * @param s string to be duplicated + * @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 a substring of the string s. + * @param s string to be duplicated + * @param len the maximum length of the resulting string (not counting the + * terminating byte). + * @return Pointer to a newly-allocated string containing a + * copy of s or NULL if the string cannot be allocated. + */ +char *av_strndup(const char *s, size_t len) av_malloc_attrib; + +/** + * 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 + * be freed. + * @see av_free() + */ +void av_freep(void *ptr); + +/** + * deliberately overlapping memcpy implementation + * @param dst destination buffer + * @param back how many bytes back we start (the initial size of the overlapping window) + * @param cnt number of bytes to copy, must be >= 0 + * + * cnt > back is valid, this will copy the bytes we just copied, + * thus creating a repeating pattern with a period length of back. + */ +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); + +/** + * @} + */ + +#endif /* AVUTIL_MEM_H */ |