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/*
* 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;
/**
* 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 */