/*
 * The copyright in this software is being made available under the 2-clauses 
 * BSD License, included below. This software may be subject to other third 
 * party and contributor rights, including patent rights, and no such rights
 * are granted under this license.
 *
 * Copyright (c) 2015, Mathieu Malaterre <mathieu.malaterre@gmail.com>
 * Copyright (c) 2015, Matthieu Darbois
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#define OPJ_SKIP_POISON
#include "opj_includes.h"

#ifndef SIZE_MAX
# define SIZE_MAX ((size_t) -1)
#endif

static INLINE void *opj_aligned_alloc_n(size_t alignment, size_t size)
{
  void* ptr;

  /* alignment shall be power of 2 */
  assert( (alignment != 0U) && ((alignment & (alignment - 1U)) == 0U));
  /* alignment shall be at least sizeof(void*) */
  assert( alignment >= sizeof(void*));

  if (size == 0U) { /* prevent implementation defined behavior of realloc */
    return NULL;
  }

#if defined(OPJ_HAVE_POSIX_MEMALIGN)
  /* aligned_alloc requires c11, restrict to posix_memalign for now. Quote:
   * This function was introduced in POSIX 1003.1d. Although this function is
   * superseded by aligned_alloc, it is more portable to older POSIX systems
   * that do not support ISO C11.  */
  if (posix_memalign (&ptr, alignment, size))
  {
    ptr = NULL;
  }
  /* older linux */
#elif defined(OPJ_HAVE_MEMALIGN)
  ptr = memalign( alignment, size );
/* _MSC_VER */
#elif defined(OPJ_HAVE__ALIGNED_MALLOC)
  ptr = _aligned_malloc(size, alignment);
#else
  /*
   * Generic aligned malloc implementation.
   * Uses size_t offset for the integer manipulation of the pointer,
   * as uintptr_t is not available in C89 to do 
   * bitwise operations on the pointer itself.
   */
  alignment--;
  {
    size_t offset;
    OPJ_UINT8 *mem;

    /* Room for padding and extra pointer stored in front of allocated area */
    size_t overhead = alignment + sizeof(void *);
		
    /* let's be extra careful */
    assert(alignment <= (SIZE_MAX - sizeof(void *)));

    /* Avoid integer overflow */
    if (size > (SIZE_MAX - overhead)) {
      return NULL;
    }

    mem = (OPJ_UINT8*)malloc(size + overhead);
    if (mem == NULL) {
      return mem;
    }
    /* offset = ((alignment + 1U) - ((size_t)(mem + sizeof(void*)) & alignment)) & alignment; */
    /* Use the fact that alignment + 1U is a power of 2 */
    offset = ((alignment ^ ((size_t)(mem + sizeof(void*)) & alignment)) + 1U) & alignment;
    ptr = (void *)(mem + sizeof(void*) + offset);
    ((void**) ptr)[-1] = mem;
  }
#endif
  return ptr;
}
static INLINE void *opj_aligned_realloc_n(void *ptr, size_t alignment, size_t new_size)
{
  void *r_ptr;

  /* alignment shall be power of 2 */
  assert( (alignment != 0U) && ((alignment & (alignment - 1U)) == 0U));
  /* alignment shall be at least sizeof(void*) */
  assert( alignment >= sizeof(void*));

  if (new_size == 0U) { /* prevent implementation defined behavior of realloc */
    return NULL;
  }

/* no portable aligned realloc */
#if defined(OPJ_HAVE_POSIX_MEMALIGN) || defined(OPJ_HAVE_MEMALIGN)
  /* glibc doc states one can mix aligned malloc with realloc */
  r_ptr = realloc( ptr, new_size ); /* fast path */
  /* we simply use `size_t` to cast, since we are only interest in binary AND
   * operator */
  if( ((size_t)r_ptr & (alignment - 1U)) != 0U ) {
    /* this is non-trivial to implement a portable aligned realloc, so use a
     * simple approach where we do not need a function that return the size of an
     * allocated array (eg. _msize on Windows, malloc_size on MacOS,
     * malloc_usable_size on systems with glibc) */
    void *a_ptr = opj_aligned_alloc_n(alignment, new_size);
    if (a_ptr != NULL) {
      memcpy(a_ptr, r_ptr, new_size);
    }
    free( r_ptr );
    r_ptr = a_ptr;
  }
/* _MSC_VER */
#elif defined(OPJ_HAVE__ALIGNED_MALLOC)
  r_ptr = _aligned_realloc( ptr, new_size, alignment );
#else
  if (ptr == NULL) {
    return opj_aligned_alloc_n(alignment, new_size);
  }
  alignment--;
  {
    void *oldmem;
    OPJ_UINT8 *newmem;
    size_t overhead = alignment + sizeof(void *);

    /* let's be extra careful */
    assert(alignment <= (SIZE_MAX - sizeof(void *)));

    /* Avoid integer overflow */
    if (new_size > SIZE_MAX - overhead) {
      return NULL;
    }
		
    oldmem = ((void**) ptr)[-1];
    newmem = (OPJ_UINT8*)realloc(oldmem, new_size + overhead);
    if (newmem == NULL) {
      return newmem;
    }

    if (newmem == oldmem) {
      r_ptr = ptr;
    }
    else {
      size_t old_offset;
      size_t new_offset;

      /* realloc created a new copy, realign the copied memory block */
      old_offset = (size_t)((OPJ_UINT8*)ptr - (OPJ_UINT8*)oldmem);

      /* offset = ((alignment + 1U) - ((size_t)(mem + sizeof(void*)) & alignment)) & alignment; */
      /* Use the fact that alignment + 1U is a power of 2 */
      new_offset  = ((alignment ^ ((size_t)(newmem + sizeof(void*)) & alignment)) + 1U) & alignment;
			new_offset += sizeof(void*);
      r_ptr = (void *)(newmem + new_offset);

      if (new_offset != old_offset) {
        memmove(newmem + new_offset, newmem + old_offset, new_size);
      }
      ((void**) r_ptr)[-1] = newmem;
    }
  }
#endif
	return r_ptr;
}
void * opj_malloc(size_t size)
{
  if (size == 0U) { /* prevent implementation defined behavior of realloc */
    return NULL;
  }
  return malloc(size);
}
void * opj_calloc(size_t num, size_t size)
{
  if (size == 0U) { /* prevent implementation defined behavior of realloc */
    return NULL;
  }
  /* according to C89 standard, num == 0 shall return a valid pointer */
  return calloc(num, size);
}

void *opj_aligned_malloc(size_t size)
{
  return opj_aligned_alloc_n(16U, size);
}
void * opj_aligned_realloc(void *ptr, size_t size)
{
  return opj_aligned_realloc_n(ptr, 16U, size);
}

void opj_aligned_free(void* ptr)
{
#if defined(OPJ_HAVE_POSIX_MEMALIGN) || defined(OPJ_HAVE_MEMALIGN)
  free( ptr );
#elif defined(OPJ_HAVE__ALIGNED_MALLOC)
  _aligned_free( ptr );
#else
  /* Generic implementation has malloced pointer stored in front of used area */
  if (ptr != NULL) {
    free(((void**) ptr)[-1]);
  }
#endif
}

void * opj_realloc(void *ptr, size_t new_size)
{
  if (new_size == 0U) { /* prevent implementation defined behavior of realloc */
    return NULL;
  }
  return realloc(ptr, new_size);
}
void opj_free(void *ptr)
{
  free(ptr);
}