/*
  * 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);

 
 /**

  * 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.
  * 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 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 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;
 
 /**

  * 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;
 
 /**

  * 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.

  * @note passing a pointer to a NULL pointer is safe and leads to no action.

  * @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_dynarray_add_nofree(), av_dynarray2_add()

  */
 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
 

 /**

  * Add an element to a dynamic array.
  *
  * Function has the same functionality as av_dynarray_add(),
  * but it doesn't free memory on fails. It returns error code
  * instead and leave current buffer untouched.
  *
  * @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
  * @return >=0 on success, negative otherwise.
  * @see av_dynarray_add(), av_dynarray2_add()
  */
 int av_dynarray_add_nofree(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(), av_dynarray_add_nofree()

  */
 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);
 
 /**

  * 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);
 
 /**

  * 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 */