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243 lines
7.8 KiB
243 lines
7.8 KiB
/* |
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* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* memory handling functions |
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*/ |
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#ifndef AVUTIL_MEM_H |
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#define AVUTIL_MEM_H |
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#include <limits.h> |
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#include <stdint.h> |
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#include "attributes.h" |
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#include "error.h" |
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#include "avutil.h" |
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/** |
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* @addtogroup lavu_mem |
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* @{ |
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*/ |
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#if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || defined(__SUNPRO_C) |
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#define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v |
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#define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v |
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#elif defined(__TI_COMPILER_VERSION__) |
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#define DECLARE_ALIGNED(n,t,v) \ |
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AV_PRAGMA(DATA_ALIGN(v,n)) \ |
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t __attribute__((aligned(n))) v |
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#define DECLARE_ASM_CONST(n,t,v) \ |
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AV_PRAGMA(DATA_ALIGN(v,n)) \ |
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static const t __attribute__((aligned(n))) v |
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#elif defined(__GNUC__) |
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#define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v |
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#define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v |
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#elif defined(_MSC_VER) |
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#define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v |
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#define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v |
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#else |
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#define DECLARE_ALIGNED(n,t,v) t v |
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#define DECLARE_ASM_CONST(n,t,v) static const t v |
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#endif |
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#if AV_GCC_VERSION_AT_LEAST(3,1) |
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#define av_malloc_attrib __attribute__((__malloc__)) |
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#else |
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#define av_malloc_attrib |
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#endif |
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#if AV_GCC_VERSION_AT_LEAST(4,3) |
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#define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) |
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#else |
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#define av_alloc_size(...) |
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#endif |
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/** |
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* Allocate a block of size bytes with alignment suitable for all |
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* memory accesses (including vectors if available on the CPU). |
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* @param size Size in bytes for the memory block to be allocated. |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_mallocz() |
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*/ |
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void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); |
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/** |
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* Helper function to allocate a block of size * nmemb bytes with |
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* using av_malloc() |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_malloc() |
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*/ |
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av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size) |
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{ |
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if (size <= 0 || nmemb >= INT_MAX / size) |
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return NULL; |
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return av_malloc(nmemb * size); |
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} |
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/** |
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* Allocate or reallocate a block of memory. |
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* If ptr is NULL and size > 0, allocate a new block. If |
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* size is zero, free the memory block pointed to by ptr. |
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* @param ptr Pointer to a memory block already allocated with |
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* av_malloc(z)() or av_realloc() or NULL. |
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* @param size Size in bytes for the memory block to be allocated or |
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* reallocated. |
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* @return Pointer to a newly reallocated block or NULL if the block |
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* cannot be reallocated or the function is used to free the memory block. |
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* @see av_fast_realloc() |
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*/ |
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void *av_realloc(void *ptr, size_t size) av_alloc_size(2); |
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/** |
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* Allocate or reallocate a block of memory. |
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* This function does the same thing as av_realloc, except: |
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* - It takes two arguments and checks the result of the multiplication for |
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* integer overflow. |
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* - It frees the input block in case of failure, thus avoiding the memory |
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* leak with the classic "buf = realloc(buf); if (!buf) return -1;". |
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*/ |
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void *av_realloc_f(void *ptr, size_t nelem, size_t elsize); |
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/** |
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* Free a memory block which has been allocated with av_malloc(z)() or |
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* av_realloc(). |
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* @param ptr Pointer to the memory block which should be freed. |
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* @note ptr = NULL is explicitly allowed. |
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* @note It is recommended that you use av_freep() instead. |
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* @see av_freep() |
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*/ |
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void av_free(void *ptr); |
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/** |
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* Allocate a block of size bytes with alignment suitable for all |
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* memory accesses (including vectors if available on the CPU) and |
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* zero all the bytes of the block. |
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* @param size Size in bytes for the memory block to be allocated. |
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* @return Pointer to the allocated block, NULL if it cannot be allocated. |
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* @see av_malloc() |
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*/ |
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void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); |
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/** |
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* Allocate a block of nmemb * size bytes with alignment suitable for all |
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* memory accesses (including vectors if available on the CPU) and |
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* zero all the bytes of the block. |
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* The allocation will fail if nmemb * size is greater than or equal |
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* to INT_MAX. |
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* @param nmemb |
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* @param size |
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* @return Pointer to the allocated block, NULL if it cannot be allocated. |
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*/ |
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void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib; |
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/** |
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* Helper function to allocate a block of size * nmemb bytes with |
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* using av_mallocz() |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_mallocz() |
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* @see av_malloc_array() |
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*/ |
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av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size) |
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{ |
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if (size <= 0 || nmemb >= INT_MAX / size) |
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return NULL; |
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return av_mallocz(nmemb * size); |
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} |
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/** |
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* Duplicate the string s. |
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* @param s string to be duplicated |
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* @return Pointer to a newly allocated string containing a |
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* copy of s or NULL if the string cannot be allocated. |
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*/ |
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char *av_strdup(const char *s) av_malloc_attrib; |
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/** |
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* Duplicate the buffer p. |
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* @param p buffer to be duplicated |
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* @return Pointer to a newly allocated buffer containing a |
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* copy of p or NULL if the buffer cannot be allocated. |
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*/ |
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void *av_memdup(const void *p, size_t size); |
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/** |
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* Free a memory block which has been allocated with av_malloc(z)() or |
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* av_realloc() and set the pointer pointing to it to NULL. |
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* @param ptr Pointer to the pointer to the memory block which should |
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* be freed. |
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* @see av_free() |
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*/ |
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void av_freep(void *ptr); |
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/** |
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* Add an element to a dynamic array. |
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* |
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* @param tab_ptr Pointer to the array. |
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* @param nb_ptr Pointer to the number of elements in the array. |
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* @param elem Element to be added. |
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*/ |
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void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem); |
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/** |
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* Multiply two size_t values checking for overflow. |
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* @return 0 if success, AVERROR(EINVAL) if overflow. |
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*/ |
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static inline int av_size_mult(size_t a, size_t b, size_t *r) |
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{ |
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size_t t = a * b; |
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/* Hack inspired from glibc: only try the division if nelem and elsize |
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* are both greater than sqrt(SIZE_MAX). */ |
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if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b) |
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return AVERROR(EINVAL); |
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*r = t; |
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return 0; |
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} |
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/** |
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* Set the maximum size that may me allocated in one block. |
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*/ |
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void av_max_alloc(size_t max); |
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/** |
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* @brief deliberately overlapping memcpy implementation |
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* @param dst destination buffer |
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* @param back how many bytes back we start (the initial size of the overlapping window), must be > 0 |
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* @param cnt number of bytes to copy, must be >= 0 |
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* |
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* cnt > back is valid, this will copy the bytes we just copied, |
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* thus creating a repeating pattern with a period length of back. |
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*/ |
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void av_memcpy_backptr(uint8_t *dst, int back, int cnt); |
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/** |
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* @} |
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*/ |
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#endif /* AVUTIL_MEM_H */
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