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File: [cvs.NetBSD.org] / src / lib / libc / stdlib / tsearch.c (download)

Revision 1.4, Mon Sep 20 04:39:43 1999 UTC (20 years, 5 months ago) by lukem
Branch: MAIN
CVS Tags: wrstuden-devbsize-base, wrstuden-devbsize-19991221, wrstuden-devbsize, netbsd-3-base, netbsd-3-1-RELEASE, netbsd-3-1-RC4, netbsd-3-1-RC3, netbsd-3-1-RC2, netbsd-3-1-RC1, netbsd-3-1-1-RELEASE, netbsd-3-1, netbsd-3-0-RELEASE, netbsd-3-0-RC6, netbsd-3-0-RC5, netbsd-3-0-RC4, netbsd-3-0-RC3, netbsd-3-0-RC2, netbsd-3-0-RC1, netbsd-3-0-3-RELEASE, netbsd-3-0-2-RELEASE, netbsd-3-0-1-RELEASE, netbsd-3-0, netbsd-3, netbsd-2-base, netbsd-2-1-RELEASE, netbsd-2-1-RC6, netbsd-2-1-RC5, netbsd-2-1-RC4, netbsd-2-1-RC3, netbsd-2-1-RC2, netbsd-2-1-RC1, netbsd-2-1, netbsd-2-0-base, netbsd-2-0-RELEASE, netbsd-2-0-RC5, netbsd-2-0-RC4, netbsd-2-0-RC3, netbsd-2-0-RC2, netbsd-2-0-RC1, netbsd-2-0-3-RELEASE, netbsd-2-0-2-RELEASE, netbsd-2-0-1-RELEASE, netbsd-2-0, netbsd-2, netbsd-1-6-base, netbsd-1-6-RELEASE, netbsd-1-6-RC3, netbsd-1-6-RC2, netbsd-1-6-RC1, netbsd-1-6-PATCH002-RELEASE, netbsd-1-6-PATCH002-RC4, netbsd-1-6-PATCH002-RC3, netbsd-1-6-PATCH002-RC2, netbsd-1-6-PATCH002-RC1, netbsd-1-6-PATCH002, netbsd-1-6-PATCH001-RELEASE, netbsd-1-6-PATCH001-RC3, netbsd-1-6-PATCH001-RC2, netbsd-1-6-PATCH001-RC1, netbsd-1-6-PATCH001, netbsd-1-6, netbsd-1-5-base, netbsd-1-5-RELEASE, netbsd-1-5-PATCH003, netbsd-1-5-PATCH002, netbsd-1-5-PATCH001, netbsd-1-5-BETA2, netbsd-1-5-BETA, netbsd-1-5-ALPHA2, netbsd-1-5, nathanw_sa_end, nathanw_sa_before_merge, nathanw_sa_base, nathanw_sa, minoura-xpg4dl-base, minoura-xpg4dl, fvdl_fs64_base, comdex-fall-1999-base, comdex-fall-1999
Changes since 1.3: +2 -6 lines

back out the #ifdef _DIAGNOSTIC argument checks; too many people complained.
_DIAGASSERT() is still retained.

/*	$NetBSD: tsearch.c,v 1.4 1999/09/20 04:39:43 lukem Exp $	*/

/*
 * Tree search generalized from Knuth (6.2.2) Algorithm T just like
 * the AT&T man page says.
 *
 * The node_t structure is for internal use only, lint doesn't grok it.
 *
 * Written by reading the System V Interface Definition, not the code.
 *
 * Totally public domain.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: tsearch.c,v 1.4 1999/09/20 04:39:43 lukem Exp $");
#endif /* LIBC_SCCS and not lint */

#include <assert.h>
#define _SEARCH_PRIVATE
#include <search.h>
#include <stdlib.h>

/* find or insert datum into search tree */
void *
tsearch(vkey, vrootp, compar)
	const void *vkey;		/* key to be located */
	void **vrootp;			/* address of tree root */
	int (*compar) __P((const void *, const void *));
{
	node_t *q;
	node_t **rootp = (node_t **)vrootp;

	_DIAGASSERT(vkey != NULL);
	_DIAGASSERT(compar != NULL);

	if (rootp == NULL)
		return NULL;

	while (*rootp != NULL) {	/* Knuth's T1: */
		int r;

		if ((r = (*compar)(vkey, (*rootp)->key)) == 0)	/* T2: */
			return *rootp;		/* we found it! */

		rootp = (r < 0) ?
		    &(*rootp)->llink :		/* T3: follow left branch */
		    &(*rootp)->rlink;		/* T4: follow right branch */
	}

	q = malloc(sizeof(node_t));		/* T5: key not found */
	if (q != 0) {				/* make new node */
		*rootp = q;			/* link new node to old */
		/* LINTED const castaway ok */
		q->key = (void *)vkey;		/* initialize new node */
		q->llink = q->rlink = NULL;
	}
	return q;
}