/*

 * $Id: arraylist.c,v 1.4 2006/01/26 02:16:28 mclark Exp $

 *

 * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.

 * Michael Clark <michael@metaparadigm.com>

 *

 * This library is free software; you can redistribute it and/or modify

 * it under the terms of the MIT license. See COPYING for details.

 *

 */

#include "config.h"

#include <limits.h>

#ifdef STDC_HEADERS

#include <stdlib.h>

#include <string.h>

#endif /* STDC_HEADERS */

#if defined(HAVE_STRINGS_H) && !defined(_STRING_H) && !defined(__USE_BSD)

#include <strings.h>

#endif /* HAVE_STRINGS_H */

#ifndef SIZE_T_MAX

#if SIZEOF_SIZE_T == SIZEOF_INT

#define SIZE_T_MAX UINT_MAX

#elif SIZEOF_SIZE_T == SIZEOF_LONG

#define SIZE_T_MAX ULONG_MAX

#elif SIZEOF_SIZE_T == SIZEOF_LONG_LONG

#define SIZE_T_MAX ULLONG_MAX

#else

#error Unable to determine size of size_t

#endif

#endif

#include "arraylist.h"

struct array_list *array_list_new(array_list_free_fn *free_fn)

{

  return array_list_new2(free_fn, ARRAY_LIST_DEFAULT_SIZE);

}

struct array_list *array_list_new2(array_list_free_fn *free_fn, int initial_size)

{

  struct array_list *arr;

  if (initial_size < 0 || (size_t)initial_size >= SIZE_T_MAX / sizeof(void *))

    return NULL;

  arr = (struct array_list *)malloc(sizeof(struct array_list));

  if (!arr)

    return NULL;

  arr->size = initial_size;

  arr->length = 0;

  arr->free_fn = free_fn;

  if (!(arr->array = (void **)malloc(arr->size * sizeof(void *))))

  {

    free(arr);

    return NULL;

  }

  return arr;

}

extern void array_list_free(struct array_list *arr)

{

  size_t i;

  for (i = 0; i < arr->length; i++)

    if (arr->array[i])

      arr->free_fn(arr->array[i]);

  free(arr->array);

  free(arr);

}

void *array_list_get_idx(struct array_list *arr, size_t i)

{

  if (i >= arr->length)

    return NULL;

  return arr->array[i];

}

static int array_list_expand_internal(struct array_list *arr, size_t max)

{

  void *t;

  size_t new_size;

  /* The array can already hold max entries when max == arr->size, since

   * the caller only ever indexes up to max - 1.

   */

  if (max <= arr->size)

    return 0;

  /* Avoid undefined behaviour on size_t overflow */

  if (arr->size >= SIZE_T_MAX / 2)

    new_size = max;

  else

  {

    new_size = arr->size << 1;

    if (new_size < max)

      new_size = max;

  }

  if (new_size > (~((size_t)0)) / sizeof(void *))

    return -1;

  if (!(t = realloc(arr->array, new_size * sizeof(void *))))

    return -1;

  arr->array = (void **)t;

  arr->size = new_size;

  return 0;

}

int array_list_shrink(struct array_list *arr, size_t empty_slots)

{

  void *t;

  size_t new_size;

  if (empty_slots >= SIZE_T_MAX / sizeof(void *) - arr->length)

    return -1;

  new_size = arr->length + empty_slots;

  if (new_size == arr->size)

    return 0;

  if (new_size > arr->size)

    return array_list_expand_internal(arr, new_size);

  if (new_size == 0)

    new_size = 1;

  if (!(t = realloc(arr->array, new_size * sizeof(void *))))

    return -1;

  arr->array = (void **)t;

  arr->size = new_size;

  return 0;

}

int array_list_insert_idx(struct array_list *arr, size_t idx, void *data)

{

  size_t move_amount;

  if (idx >= arr->length)

    return array_list_put_idx(arr, idx, data);

  /* we're at full size, what size_t can support */

  if (arr->length == SIZE_T_MAX)

    return -1;

  if (array_list_expand_internal(arr, arr->length + 1))

    return -1;

  move_amount = (arr->length - idx) * sizeof(void *);

  memmove(arr->array + idx + 1, arr->array + idx, move_amount);

  arr->array[idx] = data;

  arr->length++;

  return 0;

}

//static inline int _array_list_put_idx(struct array_list *arr, size_t idx, void *data)

int array_list_put_idx(struct array_list *arr, size_t idx, void *data)

{

  if (idx > SIZE_T_MAX - 1)

    return -1;

  if (array_list_expand_internal(arr, idx + 1))

    return -1;

  if (idx < arr->length && arr->array[idx])

    arr->free_fn(arr->array[idx]);

  arr->array[idx] = data;

  if (idx > arr->length)

  {

    /* Zero out the arraylist slots in between the old length

       and the newly added entry so we know those entries are

       empty.

       e.g. when setting array[7] in an array that used to be 

       only 5 elements longs, array[5] and array[6] need to be

       set to 0.

     */

    memset(arr->array + arr->length, 0, (idx - arr->length) * sizeof(void *));

  }

  if (arr->length <= idx)

    arr->length = idx + 1;

  return 0;

}

int array_list_set_idx(struct array_list *arr, size_t idx, void *data)

{

  if (idx >= arr->length)

    return -1;

  arr->array[idx] = data;

  return 0;

}

int array_list_add(struct array_list *arr, void *data)

{

  /* Repeat some of array_list_put_idx() so we can skip several

     checks that we know are unnecessary when appending at the end

   */

  size_t idx = arr->length;

  if (idx > SIZE_T_MAX - 1)

    return -1;

  if (array_list_expand_internal(arr, idx + 1))

    return -1;

  arr->array[idx] = data;

  arr->length++;

  return 0;

}

void array_list_sort(struct array_list *arr, int (*compar)(const void *, const void *))

{

  qsort(arr->array, arr->length, sizeof(arr->array[0]), compar);

}

void *array_list_bsearch(const void **key, struct array_list *arr,

                         int (*compar)(const void *, const void *))

{

  return bsearch(key, arr->array, arr->length, sizeof(arr->array[0]), compar);

}

size_t array_list_length(struct array_list *arr)

{

  return arr->length;

}

int array_list_del_idx(struct array_list *arr, size_t idx, size_t count)

{

  size_t i, stop;

  /* Avoid overflow in calculation with large indices. */

  if (idx > SIZE_T_MAX - count)

    return -1;

  stop = idx + count;

  if (idx >= arr->length || stop > arr->length)

    return -1;

  for (i = idx; i < stop; ++i)

  {

    // Because put_idx can skip entries, we need to check if

    // there's actually anything in each slot we're erasing.

    if (arr->array[i])

      arr->free_fn(arr->array[i]);

  }

  memmove(arr->array + idx, arr->array + stop, (arr->length - stop) * sizeof(void *));

  arr->length -= count;

  return 0;

}