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/* $OpenBSD: ohash_lookup_interval.c,v 1.1 2001/03/02 13:27:07 espie Exp $ */
/* ex:ts=8 sw=4:
*/
/*
* Copyright (c) 1999 Marc Espie.
*
* Code written for the OpenBSD project.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD
* PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "ohash_int.h"
unsigned int
ohash_lookup_interval(h, start, end, hv)
struct ohash *h;
const char *start;
const char *end;
u_int32_t hv;
{
unsigned int i, incr;
unsigned int empty;
#ifdef STATS_HASH
STAT_HASH_LOOKUP++;
#endif
empty = NONE;
i = hv % h->size;
incr = ((hv % (h->size-2)) & ~1) + 1;
while (h->t[i].p != NULL) {
#ifdef STATS_HASH
STAT_HASH_LENGTH++;
#endif
if (h->t[i].p == DELETED) {
if (empty == NONE)
empty = i;
} else if (h->t[i].hv == hv &&
strncmp(h->t[i].p+h->info.key_offset, start,
end - start) == 0 &&
(h->t[i].p+h->info.key_offset)[end-start] == '\0') {
if (empty != NONE) {
h->t[empty].hv = hv;
h->t[empty].p = h->t[i].p;
h->t[i].p = DELETED;
return empty;
} else {
#ifdef STATS_HASH
STAT_HASH_POSITIVE++;
#endif
return i;
}
}
i += incr;
if (i >= h->size)
i -= h->size;
}
/* Found an empty position. */
if (empty != NONE)
i = empty;
h->t[i].hv = hv;
return i;
}
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