1 /* $OpenBSD: ohash_lookup_memory.c,v 1.3 2006/01/16 15:52:25 espie Exp $ */ 2 /* ex:ts=8 sw=4: 3 */ 4 5 /* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 * 19 * $FreeBSD: src/usr.bin/m4/lib/ohash_lookup_memory.c,v 1.2 2012/11/17 01:54:24 svnexp Exp $ 20 */ 21 22 #include "ohash_int.h" 23 24 unsigned int 25 ohash_lookup_memory(struct ohash *h, const char *k, size_t size, uint32_t hv) 26 { 27 unsigned int i, incr; 28 unsigned int empty; 29 30 #ifdef STATS_HASH 31 STAT_HASH_LOOKUP++; 32 #endif 33 empty = NONE; 34 i = hv % h->size; 35 incr = ((hv % (h->size-2)) & ~1) + 1; 36 while (h->t[i].p != NULL) { 37 #ifdef STATS_HASH 38 STAT_HASH_LENGTH++; 39 #endif 40 if (h->t[i].p == DELETED) { 41 if (empty == NONE) 42 empty = i; 43 } else if (h->t[i].hv == hv && 44 memcmp(h->t[i].p+h->info.key_offset, k, size) == 0) { 45 if (empty != NONE) { 46 h->t[empty].hv = hv; 47 h->t[empty].p = h->t[i].p; 48 h->t[i].p = DELETED; 49 return empty; 50 } else { 51 #ifdef STATS_HASH 52 STAT_HASH_POSITIVE++; 53 #endif 54 } 55 return i; 56 } 57 i += incr; 58 if (i >= h->size) 59 i -= h->size; 60 } 61 62 /* Found an empty position. */ 63 if (empty != NONE) 64 i = empty; 65 h->t[i].hv = hv; 66 return i; 67 } 68