1 /* $OpenBSD: list.c,v 1.9 2015/12/31 16:50:29 mestre Exp $ */ 2 /* $NetBSD: list.c,v 1.3 1995/03/21 15:04:18 cgd Exp $ */ 3 4 /*- 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Ed James. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /* 37 * Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved. 38 * 39 * Copy permission is hereby granted provided that this notice is 40 * retained on all partial or complete copies. 41 * 42 * For more info on this and all of my stuff, mail edjames@berkeley.edu. 43 */ 44 45 #include <stdlib.h> 46 47 #include "extern.h" 48 49 PLANE * 50 newplane(void) 51 { 52 PLANE *p; 53 54 if ((p = calloc(1, sizeof (PLANE))) == NULL) 55 loser(NULL, "Out of memory"); 56 return (p); 57 } 58 59 void 60 append(LIST *l, PLANE *p) 61 { 62 PLANE *q = NULL, *r = NULL; 63 64 if (l->head == NULL) { 65 p->next = p->prev = NULL; 66 l->head = l->tail = p; 67 } else { 68 q = l -> head; 69 70 while (q != NULL && q->plane_no < p->plane_no) { 71 r = q; 72 q = q -> next; 73 } 74 75 if (q) { 76 if (r) { 77 p->prev = r; 78 r->next = p; 79 p->next = q; 80 q->prev = p; 81 } else { 82 p->next = q; 83 p->prev = NULL; 84 q->prev = p; 85 l->head = p; 86 } 87 } else { 88 l->tail->next = p; 89 p->next = NULL; 90 p->prev = l->tail; 91 l->tail = p; 92 } 93 } 94 } 95 96 void 97 delete(LIST *l, PLANE *p) 98 { 99 if (l->head == NULL) 100 loser(p, "deleted a non-existent plane! Get help!"); 101 102 if (l->head == p && l->tail == p) 103 l->head = l->tail = NULL; 104 else if (l->head == p) { 105 l->head = p->next; 106 l->head->prev = NULL; 107 } else if (l->tail == p) { 108 l->tail = p->prev; 109 l->tail->next = NULL; 110 } else { 111 p->prev->next = p->next; 112 p->next->prev = p->prev; 113 } 114 } 115