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15637ed4 RG |
1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Ed James. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
35 | */ | |
36 | ||
37 | /* | |
38 | * Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved. | |
39 | * | |
40 | * Copy permission is hereby granted provided that this notice is | |
41 | * retained on all partial or complete copies. | |
42 | * | |
43 | * For more info on this and all of my stuff, mail edjames@berkeley.edu. | |
44 | */ | |
45 | ||
46 | #ifndef lint | |
47 | static char sccsid[] = "@(#)list.c 5.2 (Berkeley) 4/30/90"; | |
48 | #endif /* not lint */ | |
49 | ||
50 | #include "include.h" | |
51 | ||
52 | PLANE * | |
53 | newplane() | |
54 | { | |
55 | return ((PLANE *) calloc(1, sizeof (PLANE))); | |
56 | } | |
57 | ||
58 | append(l, p) | |
59 | LIST *l; | |
60 | 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 | delete(l, p) | |
97 | LIST *l; | |
98 | PLANE *p; | |
99 | { | |
100 | if (l->head == NULL) | |
101 | loser(p, "deleted a non-existant plane! Get help!"); | |
102 | ||
103 | if (l->head == p && l->tail == p) | |
104 | l->head = l->tail = NULL; | |
105 | else if (l->head == p) { | |
106 | l->head = p->next; | |
107 | l->head->prev = NULL; | |
108 | } else if (l->tail == p) { | |
109 | l->tail = p->prev; | |
110 | l->tail->next = NULL; | |
111 | } else { | |
112 | p->prev->next = p->next; | |
113 | p->next->prev = p->prev; | |
114 | } | |
115 | } |