1 /* $NetBSD: list.c,v 1.8 2014/03/22 22:09:14 dholland 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved. 37 * 38 * Copy permission is hereby granted provided that this notice is 39 * retained on all partial or complete copies. 40 * 41 * For more info on this and all of my stuff, mail edjames@berkeley.edu. 42 */ 43 44 #include <sys/cdefs.h> 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)list.c 8.1 (Berkeley) 5/31/93"; 48 #else 49 __RCSID("$NetBSD: list.c,v 1.8 2014/03/22 22:09:14 dholland Exp $"); 50 #endif 51 #endif /* not lint */ 52 53 #include "include.h" 54 55 PLANE * 56 newplane(void) 57 { 58 return calloc(1, sizeof (PLANE)); 59 } 60 61 void 62 append(LIST *l, PLANE *p) 63 { 64 PLANE *q = NULL, *r = NULL; 65 66 if (l->head == NULL) { 67 p->next = p->prev = NULL; 68 l->head = l->tail = p; 69 } else { 70 q = l -> head; 71 72 while (q != NULL && q->plane_no < p->plane_no) { 73 r = q; 74 q = q -> next; 75 } 76 77 if (q) { 78 if (r) { 79 p->prev = r; 80 r->next = p; 81 p->next = q; 82 q->prev = p; 83 } else { 84 p->next = q; 85 p->prev = NULL; 86 q->prev = p; 87 l->head = p; 88 } 89 } else { 90 l->tail->next = p; 91 p->next = NULL; 92 p->prev = l->tail; 93 l->tail = p; 94 } 95 } 96 } 97 98 void 99 delete(LIST *l, PLANE *p) 100 { 101 if (l->head == NULL) 102 loser(p, "deleted a non-existent plane! Get help!"); 103 104 if (l->head == p && l->tail == p) 105 l->head = l->tail = NULL; 106 else if (l->head == p) { 107 l->head = p->next; 108 l->head->prev = NULL; 109 } else if (l->tail == p) { 110 l->tail = p->prev; 111 l->tail->next = NULL; 112 } else { 113 p->prev->next = p->next; 114 p->next->prev = p->prev; 115 } 116 } 117