/* ms.c - resizable multiset implementation */
/* Copyright (C) 2008 Keith Rarick and Philotic Inc.
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* This program 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 General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <stdlib.h>
#include "ms.h"
#include "util.h"
void
ms_init(ms a, ms_event_fn oninsert, ms_event_fn onremove)
{
a->used = a->cap = a->last = 0;
a->items = NULL;
a->oninsert = oninsert;
a->onremove = onremove;
}
static void
grow(ms a)
{
void **nitems;
size_t ncap = (a->cap << 1) ? : 1;
nitems = malloc(ncap * sizeof(void *));
if (!nitems) return;
memcpy(nitems, a->items, a->used * sizeof(void *));
free(a->items);
a->items = nitems;
a->cap = ncap;
}
int
ms_append(ms a, void *item)
{
if (a->used >= a->cap) grow(a);
if (a->used >= a->cap) return 0;
a->items[a->used++] = item;
if (a->oninsert) a->oninsert(a, item, a->used - 1);
return 1;
}
static int
ms_delete(ms a, size_t i)
{
void *item;
if (i >= a->used) return 0;
item = a->items[i];
a->items[i] = a->items[--a->used];
/* it has already been removed now */
if (a->onremove) a->onremove(a, item, i);
return 1;
}
void
ms_clear(ms a)
{
while (ms_delete(a, 0));
free(a->items);
ms_init(a, a->oninsert, a->onremove);
}
int
ms_remove(ms a, void *item)
{
size_t i;
for (i = 0; i < a->used; i++) {
if (a->items[i] == item) return ms_delete(a, i);
}
return 0;
}
int
ms_contains(ms a, void *item)
{
size_t i;
for (i = 0; i < a->used; i++) {
if (a->items[i] == item) return 1;
}
return 0;
}
void *
ms_take(ms a)
{
void *item;
if (!a->used) return NULL;
a->last = a->last % a->used;
item = a->items[a->last];
ms_delete(a, a->last);
++a->last;
return item;
}
