atc/list.c

   1 /*      $NetBSD: list.c,v 1.4 1997/10/10 02:07:23 lukem Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Ed James.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 /*
  40  * Copyright (c) 1987 by Ed James, UC Berkeley.  All rights reserved.
  41  *
  42  * Copy permission is hereby granted provided that this notice is
  43  * retained on all partial or complete copies.
  44  *
  45  * For more info on this and all of my stuff, mail edjames@berkeley.edu.
  46  */
  47
  48 #include <sys/cdefs.h>
  49 #ifndef lint
  50 #if 0
  51 static char sccsid[] = "@(#)list.c      8.1 (Berkeley) 5/31/93";
  52 #else
  53 __RCSID("$NetBSD: list.c,v 1.4 1997/10/10 02:07:23 lukem Exp $");
  54 #endif
  55 #endif /* not lint */
  56
  57 #include "include.h"
  58
  59 PLANE   *
  60 newplane()
  61 {
  62         return ((PLANE *) calloc(1, sizeof (PLANE)));
  63 }
  64
  65 void
  66 append(l, p)
  67         LIST    *l;
  68         PLANE   *p;
  69 {
  70         PLANE   *q = NULL, *r = NULL;
  71
  72         if (l->head == NULL) {
  73                 p->next = p->prev = NULL;
  74                 l->head = l->tail = p;
  75         } else {
  76                 q = l -> head;
  77
  78                 while (q != NULL && q->plane_no < p->plane_no) {
  79                         r = q;
  80                         q = q -> next;
  81                 }
  82
  83                 if (q) {
  84                         if (r) {
  85                                 p->prev = r;
  86                                 r->next = p;
  87                                 p->next = q;
  88                                 q->prev = p;
  89                         } else {
  90                                 p->next = q;
  91                                 p->prev = NULL;
  92                                 q->prev = p;
  93                                 l->head = p;
  94                         }
  95                 } else {
  96                         l->tail->next = p;
  97                         p->next = NULL;
  98                         p->prev = l->tail;
  99                         l->tail = p;
 100                 }
 101         }
 102 }
 103
 104 void
 105 delete(l, p)
 106         LIST    *l;
 107         PLANE   *p;
 108 {
 109         if (l->head == NULL)
 110                 loser(p, "deleted a non-existant plane! Get help!");
 111
 112         if (l->head == p && l->tail == p)
 113                 l->head = l->tail = NULL;
 114         else if (l->head == p) {
 115                 l->head = p->next;
 116                 l->head->prev = NULL;
 117         } else if (l->tail == p) {
 118                 l->tail = p->prev;
 119                 l->tail->next = NULL;
 120         } else {
 121                 p->prev->next = p->next;
 122                 p->next->prev = p->prev;
 123         }
 124 }