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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* Copyright (c) 1984 AT&T */ 23 /* All Rights Reserved */ 24 25 #pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 1.8 */ 26 27 /*LINTLIBRARY*/ 28 /* 29 * Linear search algorithm, generalized from Knuth (6.1) Algorithm Q. 30 * 31 * This version no longer has anything to do with Knuth's Algorithm Q, 32 * which first copies the new element into the table, then looks for it. 33 * The assumption there was that the cost of checking for the end of the 34 * table before each comparison outweighed the cost of the comparison, which 35 * isn't true when an arbitrary comparison function must be called and when the 36 * copy itself takes a significant number of cycles. 37 * Actually, it has now reverted to Algorithm S, which is "simpler." 38 */ 39 40 typedef char *POINTER; 41 extern POINTER memcpy(); 42 43 POINTER 44 lsearch(key, base, nelp, width, compar) 45 register POINTER key; /* Key to be located */ 46 register POINTER base; /* Beginning of table */ 47 unsigned *nelp; /* Pointer to current table size */ 48 register unsigned width; /* Width of an element (bytes) */ 49 int (*compar)(); /* Comparison function */ 50 { 51 register POINTER next = base + *nelp * width; /* End of table */ 52 53 for ( ; base < next; base += width) 54 if ((*compar)(key, base) == 0) 55 return (base); /* Key found */ 56 ++*nelp; /* Not found, add to table */ 57 return (memcpy(base, key, (int)width)); /* base now == next */ 58 } 59