1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/* $OpenBSD: lstConcat.c,v 1.2 1996/06/26 05:36:44 deraadt Exp $ */
/* $NetBSD: lstConcat.c,v 1.5 1995/06/14 15:20:53 christos Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)lstConcat.c 5.3 (Berkeley) 6/1/90";
#else
static char rcsid[] = "$OpenBSD: lstConcat.c,v 1.2 1996/06/26 05:36:44 deraadt Exp $";
#endif
#endif /* not lint */
/*-
* listConcat.c --
* Function to concatentate two lists.
*/
#include "lstInt.h"
/*-
*-----------------------------------------------------------------------
* Lst_Concat --
* Concatenate two lists. New elements are created to hold the data
* elements, if specified, but the elements themselves are not copied.
* If the elements should be duplicated to avoid confusion with another
* list, the Lst_Duplicate function should be called first.
* If LST_CONCLINK is specified, the second list is destroyed since
* its pointers have been corrupted and the list is no longer useable.
*
* Results:
* SUCCESS if all went well. FAILURE otherwise.
*
* Side Effects:
* New elements are created and appended the the first list.
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_Concat (l1, l2, flags)
Lst l1; /* The list to which l2 is to be appended */
Lst l2; /* The list to append to l1 */
int flags; /* LST_CONCNEW if LstNode's should be duplicated
* LST_CONCLINK if should just be relinked */
{
register ListNode ln; /* original LstNode */
register ListNode nln; /* new LstNode */
register ListNode last; /* the last element in the list. Keeps
* bookkeeping until the end */
register List list1 = (List)l1;
register List list2 = (List)l2;
if (!LstValid (l1) || !LstValid (l2)) {
return (FAILURE);
}
if (flags == LST_CONCLINK) {
if (list2->firstPtr != NilListNode) {
/*
* We set the nextPtr of the
* last element of list two to be NIL to make the loop easier and
* so we don't need an extra case should the first list turn
* out to be non-circular -- the final element will already point
* to NIL space and the first element will be untouched if it
* existed before and will also point to NIL space if it didn't.
*/
list2->lastPtr->nextPtr = NilListNode;
/*
* So long as the second list isn't empty, we just link the
* first element of the second list to the last element of the
* first list. If the first list isn't empty, we then link the
* last element of the list to the first element of the second list
* The last element of the second list, if it exists, then becomes
* the last element of the first list.
*/
list2->firstPtr->prevPtr = list1->lastPtr;
if (list1->lastPtr != NilListNode) {
list1->lastPtr->nextPtr = list2->firstPtr;
} else {
list1->firstPtr = list2->firstPtr;
}
list1->lastPtr = list2->lastPtr;
}
if (list1->isCirc && list1->firstPtr != NilListNode) {
/*
* If the first list is supposed to be circular and it is (now)
* non-empty, we must make sure it's circular by linking the
* first element to the last and vice versa
*/
list1->firstPtr->prevPtr = list1->lastPtr;
list1->lastPtr->nextPtr = list1->firstPtr;
}
free ((Address)l2);
} else if (list2->firstPtr != NilListNode) {
/*
* We set the nextPtr of the last element of list 2 to be nil to make
* the loop less difficult. The loop simply goes through the entire
* second list creating new LstNodes and filling in the nextPtr, and
* prevPtr to fit into l1 and its datum field from the
* datum field of the corresponding element in l2. The 'last' node
* follows the last of the new nodes along until the entire l2 has
* been appended. Only then does the bookkeeping catch up with the
* changes. During the first iteration of the loop, if 'last' is nil,
* the first list must have been empty so the newly-created node is
* made the first node of the list.
*/
list2->lastPtr->nextPtr = NilListNode;
for (last = list1->lastPtr, ln = list2->firstPtr;
ln != NilListNode;
ln = ln->nextPtr)
{
PAlloc (nln, ListNode);
nln->datum = ln->datum;
if (last != NilListNode) {
last->nextPtr = nln;
} else {
list1->firstPtr = nln;
}
nln->prevPtr = last;
nln->flags = nln->useCount = 0;
last = nln;
}
/*
* Finish bookkeeping. The last new element becomes the last element
* of list one.
*/
list1->lastPtr = last;
/*
* The circularity of both list one and list two must be corrected
* for -- list one because of the new nodes added to it; list two
* because of the alteration of list2->lastPtr's nextPtr to ease the
* above for loop.
*/
if (list1->isCirc) {
list1->lastPtr->nextPtr = list1->firstPtr;
list1->firstPtr->prevPtr = list1->lastPtr;
} else {
last->nextPtr = NilListNode;
}
if (list2->isCirc) {
list2->lastPtr->nextPtr = list2->firstPtr;
}
}
return (SUCCESS);
}
|
