f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/* $NetBSD: tsearch.c,v 1.7 2012/06/25 22:32:45 abs Exp $ */
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/*
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* Tree search generalized from Knuth (6.2.2) Algorithm T just like
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* the AT&T man page says.
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*
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* The node_t structure is for internal use only, lint doesn't grok it.
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*
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* Written by reading the System V Interface Definition, not the code.
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*
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* Totally public domain.
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*/
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#include <sys/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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__RCSID("$NetBSD: tsearch.c,v 1.7 2012/06/25 22:32:45 abs Exp $");
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#endif /* LIBC_SCCS and not lint */
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#include <assert.h>
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#define _SEARCH_PRIVATE
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#include <search.h>
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#include <stdlib.h>
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/* find or insert datum into search tree */
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void *
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tsearch(const void *vkey, void **vrootp,
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int (*compar)(const void *, const void *))
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{
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node_t *q;
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node_t **rootp = (node_t **)vrootp;
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_DIAGASSERT(vkey != NULL);
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_DIAGASSERT(compar != NULL);
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if (rootp == NULL)
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return NULL;
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while (*rootp != NULL) { /* Knuth's T1: */
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int r;
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if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */
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return *rootp; /* we found it! */
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rootp = (r < 0) ?
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&(*rootp)->llink : /* T3: follow left branch */
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&(*rootp)->rlink; /* T4: follow right branch */
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}
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q = malloc(sizeof(node_t)); /* T5: key not found */
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if (q != 0) { /* make new node */
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*rootp = q; /* link new node to old */
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q->key = __UNCONST(vkey); /* initialize new node */
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q->llink = q->rlink = NULL;
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}
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return q;
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}
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