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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2001-2002 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include "gnu_msgfmt.h"
#include "gnu_prime.h"
/*
* hashpjw
*
* Calculates the hash value from the specified string.
* Actual hashid will be mod(hash value, PRIME_NUMBER).
*
* Ref: Compilers - Principles, Techniques, and Tools
* Aho, Sethi, and Ullman
*/
unsigned int
hashpjw(const char *str)
{
const char *p;
unsigned int h = 0, g;
for (p = str; *p; p++) {
h = (h << 4) + *p;
g = h & 0xf0000000;
if (g) {
h = h ^ (g >> 24);
h = h ^ g;
}
}
return (h);
}
static unsigned int
find_prime_big(unsigned int n)
{
int t;
unsigned int max_tbl_prime, prd;
max_tbl_prime = prime[MAX_PRIME_INDEX] + 2;
for (; ; ) {
for (t = 1; t <= MAX_PRIME_INDEX; t++) {
if (n % prime[t] == 0) {
/* n is not a prime number */
break;
}
}
if (t <= MAX_PRIME_INDEX) {
n += 2;
continue;
}
prd = max_tbl_prime;
while ((prd * prd < n) && (n % prd != 0)) {
prd += 2;
}
if (n % prd == 0) {
n += 2;
continue;
}
return (n);
}
/* NOTREACHED */
}
unsigned int
find_prime(unsigned int tbl_size)
{
int t, d;
unsigned int n, prd;
/* for compatibility with GNU msgfmt */
if (tbl_size == 1)
return (1);
else if (tbl_size == 2)
return (5);
n = 4 * tbl_size / 3;
/* make n an odd number */
n |= 1;
prd = n / 100;
if (prd <= MAX_INDEX_INDEX) {
/* first, search the table */
for (t = index[prd] + 1; t <= MAX_PRIME_INDEX; t++) {
if (prime[t] >= n)
return (prime[t]);
}
error(ERR_PRIME, n);
/* NOTREACHED */
}
t = START_SEARCH_INDEX;
for (; ; ) {
while (prime[t] * prime[t] < n) {
if (t == MAX_PRIME_INDEX) {
return (find_prime_big(n));
}
t++;
}
for (d = 1; d <= t; d++) {
if (n % prime[d] == 0) {
/* n is not a prime number */
break;
}
}
if (d > t) {
/* n is a prime number */
return (n);
}
n += 2;
}
/* NOTREACHED */
}
unsigned int
get_hash_index(unsigned int *hash_tbl, unsigned int hash_value,
unsigned int hash_size)
{
unsigned int idx, inc;
idx = hash_value % hash_size;
inc = 1 + (hash_value % (hash_size - 2));
for (; ; ) {
if (!hash_tbl[idx])
return (idx);
idx = (idx + inc) % hash_size;
}
/* NOTREACHED */
}
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