/*
 * This file was stolen from ffmpeg and modified for usability here.
 *  The original is
 * 
 * Copyright (c) 2002 Fabrice Bellard
 *
 * This version is a derivative work of that version.  It is not free
 *  software; it is licensed under the GNU Lesser General Public
 *  License version 2.1, which places nontrivial restrictions on what
 *  may be done with it.  (I'm not terribly happy about that, but for
 *  my purposes accepting LGPL-infected code is a lower price than
 *  reimplementing it all myself.)
 *
 * The LGPL v2.1 as distributed with ffmpeg is in the accompanying file
 *  `LGPL-v2.1'.
 */

#define _XOPEN_SOURCE 600

#include <limits.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <strings.h>

#include "config.h"

#include "avutil-mem.h"

/* here we can use OS-dependent allocation functions */
#undef free
#undef malloc
#undef realloc

#ifdef MALLOC_PREFIX

#define malloc         AV_JOIN(MALLOC_PREFIX, malloc)
#define memalign       AV_JOIN(MALLOC_PREFIX, memalign)
#define posix_memalign AV_JOIN(MALLOC_PREFIX, posix_memalign)
#define realloc        AV_JOIN(MALLOC_PREFIX, realloc)
#define free           AV_JOIN(MALLOC_PREFIX, free)

void *malloc(size_t size);
void *memalign(size_t align, size_t size);
int   posix_memalign(void **ptr, size_t align, size_t size);
void *realloc(void *ptr, size_t size);
void  free(void *ptr);

#endif /* MALLOC_PREFIX */

#define ALIGN (HAVE_AVX ? 32 : 16)

/* You can redefine av_malloc and av_free in your project to use your
   memory allocator. You do not need to suppress this file because the
   linker will do it automatically. */

static size_t max_alloc_size= INT_MAX;

void av_max_alloc(size_t max){
    max_alloc_size = max;
}

void *av_malloc(size_t size)
{
    void *ptr = 0;

    /* let's disallow possible ambiguous cases */
    if (size > (max_alloc_size-32))
        return 0;

    ptr = malloc(size);
    if(!ptr && !size)
        ptr= av_malloc(1);
    return ptr;
}

void *av_realloc(void *ptr, size_t size)
{
    /* let's disallow possible ambiguous cases */
    if (size > (max_alloc_size-32))
        return 0;

    return realloc(ptr, size + !size);
}

void *av_realloc_f(void *ptr, size_t nelem, size_t elsize)
{
    size_t size;
    void *r;

    if (av_size_mult(elsize, nelem, &size)) {
        av_free(ptr);
        return NULL;
    }
    r = av_realloc(ptr, size);
    if (!r && size)
        av_free(ptr);
    return r;
}

void av_free(void *ptr)
{
    free(ptr);
}

void av_freep(void *arg)
{
    void **ptr= (void**)arg;
    av_free(*ptr);
    *ptr = NULL;
}

void *av_mallocz(size_t size)
{
    void *ptr = av_malloc(size);
    if (ptr)
        memset(ptr, 0, size);
    return ptr;
}

void *av_calloc(size_t nmemb, size_t size)
{
    if (size <= 0 || nmemb >= INT_MAX / size)
        return NULL;
    return av_mallocz(nmemb * size);
}

char *av_strdup(const char *s)
{
    char *ptr= NULL;
    if(s){
        int len = strlen(s) + 1;
        ptr = av_malloc(len);
        if (ptr)
            memcpy(ptr, s, len);
    }
    return ptr;
}

/* add one element to a dynamic array */
void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
{
    /* see similar ffmpeg.c:grow_array() */
    int nb, nb_alloc;
    intptr_t *tab;

    nb = *nb_ptr;
    tab = *(intptr_t**)tab_ptr;
    if ((nb & (nb - 1)) == 0) {
        if (nb == 0)
            nb_alloc = 1;
        else
            nb_alloc = nb * 2;
        tab = av_realloc(tab, nb_alloc * sizeof(intptr_t));
        *(intptr_t**)tab_ptr = tab;
    }
    tab[nb++] = (intptr_t)elem;
    *nb_ptr = nb;
}