/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* 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.
*
* 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 FFmpeg; 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 "error.h"
#include "avutil.h"
/**
* @addtogroup lavu_mem
* @{
*/
#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__)
#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);
/**
* Helper function to allocate a block of size * nmemb bytes with
* using 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 <= 0 || 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_malloc(z)() or av_realloc() or NULL.
* @param size Size in bytes for 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.
* @see av_fast_realloc()
*/
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 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_malloc(z)() or 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.
*/
av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, 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 pointer to a memory block already allocated
* with av_malloc(z)() or 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.
*/
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 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;
/**
* Helper function to allocate a block of size * nmemb bytes with
* using 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 <= 0 || 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 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
* be freed.
* @see av_free()
*/
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);
/**
* @brief 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
*
* 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);
/**
* @}
*/
#endif /* AVUTIL_MEM_H */