1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * Tree search algorithm, generalized from Knuth (6.2.2) Algorithm T.
32 *
33 *
34 * The NODE * arguments are declared in the lint files as char *,
35 * because the definition of NODE isn't available to the user.
36 */
37
38 #pragma weak _tdelete = tdelete
39 #pragma weak _tsearch = tsearch
40 #pragma weak _twalk = twalk
41
42 #include "lint.h"
43 #include "mtlib.h"
44 #include "libc.h"
45 #include <sys/types.h>
46 #include <search.h>
47 #include <stdlib.h>
48 #include <thread.h>
49 #include <synch.h>
50
51
52
53 typedef struct node { char *key; struct node *llink, *rlink; } NODE;
54
55 static void __twalk(NODE *, void (*)(const void *, VISIT, int), int);
56
57
58 /* Find or insert key into search tree */
59 void *
tsearch(const void * ky,void ** rtp,int (* compar)())60 tsearch(const void *ky, void **rtp, int (*compar)())
61 {
62 char *key = (char *)ky;
63 NODE **rootp = (NODE **)rtp;
64 NODE *q; /* New node if key not found */
65
66 if (rootp == NULL)
67 return (NULL);
68 while (*rootp != NULL) { /* T1: */
69 int r = (*compar)(key, (*rootp)->key); /* T2: */
70 if (r == 0)
71 return ((void *)*rootp); /* Key found */
72 rootp = (r < 0) ?
73 &(*rootp)->llink : /* T3: Take left branch */
74 &(*rootp)->rlink; /* T4: Take right branch */
75 }
76 q = lmalloc(sizeof (NODE)); /* T5: Not found */
77 if (q != NULL) { /* Allocate new node */
78 *rootp = q; /* Link new node to old */
79 q->key = key; /* Initialize new node */
80 q->llink = q->rlink = NULL;
81 }
82 return ((void *)q);
83 }
84
85 /* Delete node with key key */
86 void *
tdelete(const void * ky,void ** rtp,int (* compar)())87 tdelete(const void *ky, void **rtp, int (*compar)())
88 {
89 char *key = (char *)ky;
90 NODE **rootp = (NODE **)rtp;
91 NODE *p; /* Parent of node to be deleted */
92 NODE *q; /* Successor node */
93 NODE *r; /* Right son node */
94 int ans; /* Result of comparison */
95
96 if (rootp == NULL || (p = *rootp) == NULL)
97 return (NULL);
98 while ((ans = (*compar)(key, (*rootp)->key)) != 0) {
99 p = *rootp;
100 rootp = (ans < 0) ?
101 &(*rootp)->llink : /* Take left branch */
102 &(*rootp)->rlink; /* Take right branch */
103 if (*rootp == NULL)
104 return (NULL); /* Key not found */
105 }
106 r = (*rootp)->rlink; /* D1: */
107 if ((q = (*rootp)->llink) == NULL) /* Llink NULL? */
108 q = r;
109 else if (r != NULL) { /* Rlink NULL? */
110 if (r->llink == NULL) { /* D2: Find successor */
111 r->llink = q;
112 q = r;
113 } else { /* D3: Find NULL link */
114 for (q = r->llink; q->llink != NULL; q = r->llink)
115 r = q;
116 r->llink = q->rlink;
117 q->llink = (*rootp)->llink;
118 q->rlink = (*rootp)->rlink;
119 }
120 }
121 lfree(*rootp, sizeof (NODE)); /* D4: Free node */
122 *rootp = q; /* Link parent to replacement */
123 return ((void *)p);
124 }
125
126
127 /* Walk the nodes of a tree */
128 void
twalk(const void * rt,void (* action)(const void *,VISIT,int))129 twalk(const void *rt, /* Root of the tree to be walked */
130 void (*action)(const void *, VISIT, int))
131 {
132 NODE *root = (NODE *)rt;
133
134 if (root != NULL && action != NULL)
135 __twalk(root, action, 0);
136 }
137
138
139 /* Walk the nodes of a tree */
140 static void
__twalk(NODE * root,void (* action)(const void *,VISIT,int),int level)141 __twalk(NODE *root, /* Root of the tree to be walked */
142 void (*action)(const void *, VISIT, int),
143 int level)
144 {
145 if (root->llink == NULL && root->rlink == NULL)
146 (*action)(root, leaf, level);
147 else {
148 (*action)(root, preorder, level);
149 if (root->llink != NULL)
150 __twalk(root->llink, action, level + 1);
151 (*action)(root, postorder, level);
152 if (root->rlink != NULL)
153 __twalk(root->rlink, action, level + 1);
154 (*action)(root, endorder, level);
155 }
156 }
157