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 * Linear search algorithm, generalized from Knuth (6.1) Algorithm Q. 32 * 33 * This version no longer has anything to do with Knuth's Algorithm Q, 34 * which first copies the new element into the table, then looks for it. 35 * The assumption there was that the cost of checking for the end of the 36 * table before each comparison outweighed the cost of the comparison, which 37 * isn't true when an arbitrary comparison function must be called and when the 38 * copy itself takes a significant number of cycles. 39 * Actually, it has now reverted to Algorithm S, which is "simpler." 40 */ 41 42 #pragma weak _lsearch = lsearch 43 44 #include "lint.h" 45 #include <mtlib.h> 46 #include <sys/types.h> 47 #include <stddef.h> 48 #include <string.h> 49 #include <thread.h> 50 #include <synch.h> 51 52 void * 53 lsearch(const void *ky, void *bs, size_t *nelp, size_t width, 54 int (*compar)(const void *, const void *)) 55 { 56 char *key = (char *)ky; 57 char *base = (char *)bs; 58 char *next = base + *nelp * width; /* End of table */ 59 void *res; 60 61 for (; base < next; base += width) 62 if ((*compar)(key, base) == 0) 63 return (base); /* Key found */ 64 ++*nelp; /* Not found, add to table */ 65 res = memcpy(base, key, width); /* base now == next */ 66 return (res); 67 } 68