1/*	$NetBSD: list.c,v 1.10 2021/05/02 12:50:43 rillig 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
47static char sccsid[] = "@(#)list.c	8.1 (Berkeley) 5/31/93";
48#else
49__RCSID("$NetBSD: list.c,v 1.10 2021/05/02 12:50:43 rillig Exp $");
50#endif
51#endif /* not lint */
52
53#include <stdlib.h>
54
55#include "def.h"
56#include "struct.h"
57#include "extern.h"
58#include "tunable.h"
59
60PLANE *
61newplane(void)
62{
63	return calloc(1, sizeof (PLANE));
64}
65
66void
67append(LIST *l, PLANE *p)
68{
69	PLANE 	*q = NULL, *r = NULL;
70
71	if (l->head == NULL) {
72		p->next = p->prev = NULL;
73		l->head = l->tail = p;
74	} else {
75		q = l -> head;
76
77		while (q != NULL && q->plane_no < p->plane_no) {
78			r = q;
79			q = q -> next;
80		}
81
82		if (q) {
83			if (r) {
84				p->prev = r;
85				r->next = p;
86				p->next = q;
87				q->prev = p;
88			} else {
89				p->next = q;
90				p->prev = NULL;
91				q->prev = p;
92				l->head = p;
93			}
94		} else {
95			l->tail->next = p;
96			p->next = NULL;
97			p->prev = l->tail;
98			l->tail = p;
99		}
100	}
101}
102
103void
104delete(LIST *l, PLANE *p)
105{
106	if (l->head == NULL)
107		loser(p, "deleted a non-existent plane! Get help!");
108
109	if (l->head == p && l->tail == p)
110		l->head = l->tail = NULL;
111	else if (l->head == p) {
112		l->head = p->next;
113		l->head->prev = NULL;
114	} else if (l->tail == p) {
115		l->tail = p->prev;
116		l->tail->next = NULL;
117	} else {
118		p->prev->next = p->next;
119		p->next->prev = p->prev;
120	}
121}
122