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/*
* Copyright (C) 2013 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup core_util
* @{
* @file lifo.c
* @brief LIFO buffer implementation
*
* @author Heiko Will <hwill@inf.fu-berlin.de>
* @}
*/
#include "lifo.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
int lifo_empty(int *array)
{
return array[0] == -1;
}
void lifo_init(int *array, int n)
{
DEBUG("lifo_init(%i)\n", n);
for (int i = 0; i <= n; i++) {
array[i] = -1;
}
}
void lifo_insert(int *array, int i)
{
DEBUG("lifo_insert(%i)\n", i);
int index = i + 1;
#if DEVELHELP
if ((array[index] != -1) && (array[0] != -1)) {
printf("lifo_insert: overwriting array[%i] == %i with %i\n\n\n\t\tThe lifo is broken now.\n\n\n", index, array[index], array[0]);
}
#endif
array[index] = array[0];
array[0] = i;
}
int lifo_get(int *array)
{
DEBUG("lifo_get\n");
int head = array[0];
if (head != -1) {
array[0] = array[head + 1];
}
#if DEVELHELP
/* make sure a double insert does not result in an infinite
* resource of values */
array[head+1] = -1;
#endif
DEBUG("lifo_get: returning %i\n", head);
return head;
}
#ifdef WITH_MAIN
#include <stdio.h>
int main()
{
int array[5];
lifo_init(array, 4);
lifo_insert(array, 2);
lifo_insert(array, 1);
lifo_insert(array, 3);
lifo_insert(array, 0);
lifo_insert(array, 3);
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
printf("get: %i\n", lifo_get(array));
return 0;
}
#endif