core/src/list.c

   1 /*
   2  * list.c -- list utility functions
   3  *
   4  * Copyright (C) 2005, 2007 Michal Januszewski <spock@gentoo.org>
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License v2.  See the file COPYING in the main directory of this archive for
   8  * more details.
   9  *
  10  */
  11 #include <stdlib.h>
  12 #include "common.h"
  13 #include "render.h"
  14
  15 void list_add(list *l, void *obj)
  16 {
  17         if (l->tail != NULL) {
  18                 l->tail->next = malloc(sizeof(item));
  19                 l->tail->next->p = obj;
  20                 l->tail->next->next = NULL;
  21                 l->tail = l->tail->next;
  22         } else {
  23                 l->head = l->tail = malloc(sizeof(item));
  24                 l->tail->next = NULL;
  25                 l->tail->p = obj;
  26         }
  27 }
  28
  29 /**
  30  * Append an element to the end of the list while simultaneously discarding
  31  * the list head.
  32  */
  33 void list_ringadd(list *l, void *obj)
  34 {
  35         item *i = l->head;
  36
  37         l->head = i->next;
  38         free(i->p);
  39         free(i);
  40         list_add(l, obj);
  41 }
  42
  43 void list_free(list l, bool free_item)
  44 {
  45         item *i, *j;
  46
  47         for (i = l.head; i != NULL; ) {
  48                 j = i->next;
  49                 if (free_item)
  50                         free(i->p);
  51                 free(i);
  52                 i = j;
  53         }
  54
  55         list_init(l);
  56 }
  57
  58 void list_del(list *l, item *prev, item *curr)
  59 {
  60         if (prev)
  61                 prev->next = curr->next;
  62
  63         if (l->tail == curr)
  64                 l->tail = prev;
  65
  66         if (l->head == curr)
  67                 l->head = curr->next;
  68
  69         free(curr);
  70 }