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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Tree search algorithm, generalized from Knuth (6.2.2) Algorithm T.
*
*
* The NODE * arguments are declared in the lint files as char *,
* because the definition of NODE isn't available to the user.
*/
#pragma weak _tdelete = tdelete
#pragma weak _tsearch = tsearch
#pragma weak _twalk = twalk
#include "lint.h"
#include "mtlib.h"
#include "libc.h"
#include <sys/types.h>
#include <search.h>
#include <stdlib.h>
#include <thread.h>
#include <synch.h>
typedef struct node { char *key; struct node *llink, *rlink; } NODE;
static void __twalk(NODE *, void (*)(const void *, VISIT, int), int);
/* Find or insert key into search tree */
void *
tsearch(const void *ky, void **rtp, int (*compar)())
{
char *key = (char *)ky;
NODE **rootp = (NODE **)rtp;
NODE *q; /* New node if key not found */
if (rootp == NULL)
return (NULL);
while (*rootp != NULL) { /* T1: */
int r = (*compar)(key, (*rootp)->key); /* T2: */
if (r == 0)
return ((void *)*rootp); /* Key found */
rootp = (r < 0) ?
&(*rootp)->llink : /* T3: Take left branch */
&(*rootp)->rlink; /* T4: Take right branch */
}
q = lmalloc(sizeof (NODE)); /* T5: Not found */
if (q != NULL) { /* Allocate new node */
*rootp = q; /* Link new node to old */
q->key = key; /* Initialize new node */
q->llink = q->rlink = NULL;
}
return ((void *)q);
}
/* Delete node with key key */
void *
tdelete(const void *ky, void **rtp, int (*compar)())
{
char *key = (char *)ky;
NODE **rootp = (NODE **)rtp;
NODE *p; /* Parent of node to be deleted */
NODE *q; /* Successor node */
NODE *r; /* Right son node */
int ans; /* Result of comparison */
if (rootp == NULL || (p = *rootp) == NULL)
return (NULL);
while ((ans = (*compar)(key, (*rootp)->key)) != 0) {
p = *rootp;
rootp = (ans < 0) ?
&(*rootp)->llink : /* Take left branch */
&(*rootp)->rlink; /* Take right branch */
if (*rootp == NULL)
return (NULL); /* Key not found */
}
r = (*rootp)->rlink; /* D1: */
if ((q = (*rootp)->llink) == NULL) /* Llink NULL? */
q = r;
else if (r != NULL) { /* Rlink NULL? */
if (r->llink == NULL) { /* D2: Find successor */
r->llink = q;
q = r;
} else { /* D3: Find NULL link */
for (q = r->llink; q->llink != NULL; q = r->llink)
r = q;
r->llink = q->rlink;
q->llink = (*rootp)->llink;
q->rlink = (*rootp)->rlink;
}
}
lfree(*rootp, sizeof (NODE)); /* D4: Free node */
*rootp = q; /* Link parent to replacement */
return ((void *)p);
}
/* Walk the nodes of a tree */
void
twalk(const void *rt, /* Root of the tree to be walked */
void (*action)(const void *, VISIT, int))
{
NODE *root = (NODE *)rt;
if (root != NULL && action != NULL)
__twalk(root, action, 0);
}
/* Walk the nodes of a tree */
static void
__twalk(NODE *root, /* Root of the tree to be walked */
void (*action)(const void *, VISIT, int),
int level)
{
if (root->llink == NULL && root->rlink == NULL)
(*action)(root, leaf, level);
else {
(*action)(root, preorder, level);
if (root->llink != NULL)
__twalk(root->llink, action, level + 1);
(*action)(root, postorder, level);
if (root->rlink != NULL)
__twalk(root->rlink, action, level + 1);
(*action)(root, endorder, level);
}
}
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