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 /*
23 * Copyright 2001-2002 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include "gnu_msgfmt.h"
30 #include "gnu_prime.h"
31
32
33 /*
34 * hashpjw
35 *
36 * Calculates the hash value from the specified string.
37 * Actual hashid will be mod(hash value, PRIME_NUMBER).
38 *
39 * Ref: Compilers - Principles, Techniques, and Tools
40 * Aho, Sethi, and Ullman
41 */
42 unsigned int
hashpjw(const char * str)43 hashpjw(const char *str)
44 {
45 const char *p;
46 unsigned int h = 0, g;
47
48 for (p = str; *p; p++) {
49 h = (h << 4) + *p;
50 g = h & 0xf0000000;
51 if (g) {
52 h = h ^ (g >> 24);
53 h = h ^ g;
54 }
55 }
56
57 return (h);
58 }
59
60 static unsigned int
find_prime_big(unsigned int n)61 find_prime_big(unsigned int n)
62 {
63 int t;
64 unsigned int max_tbl_prime, prd;
65 max_tbl_prime = prime[MAX_PRIME_INDEX] + 2;
66
67 for (; ; ) {
68 for (t = 1; t <= MAX_PRIME_INDEX; t++) {
69 if (n % prime[t] == 0) {
70 /* n is not a prime number */
71 break;
72 }
73 }
74 if (t <= MAX_PRIME_INDEX) {
75 n += 2;
76 continue;
77 }
78
79 prd = max_tbl_prime;
80 while ((prd * prd < n) && (n % prd != 0)) {
81 prd += 2;
82 }
83 if (n % prd == 0) {
84 n += 2;
85 continue;
86 }
87 return (n);
88 }
89 /* NOTREACHED */
90 }
91
92 unsigned int
find_prime(unsigned int tbl_size)93 find_prime(unsigned int tbl_size)
94 {
95 int t, d;
96 unsigned int n, prd;
97
98 /* for compatibility with GNU msgfmt */
99 if (tbl_size == 1)
100 return (1);
101 else if (tbl_size == 2)
102 return (5);
103
104 n = 4 * tbl_size / 3;
105
106 /* make n an odd number */
107 n |= 1;
108
109 prd = n / 100;
110 if (prd <= MAX_INDEX_INDEX) {
111 /* first, search the table */
112 for (t = index[prd] + 1; t <= MAX_PRIME_INDEX; t++) {
113 if (prime[t] >= n)
114 return (prime[t]);
115 }
116 error(ERR_PRIME, n);
117 /* NOTREACHED */
118 }
119 t = START_SEARCH_INDEX;
120 for (; ; ) {
121 while (prime[t] * prime[t] < n) {
122 if (t == MAX_PRIME_INDEX) {
123 return (find_prime_big(n));
124 }
125 t++;
126 }
127 for (d = 1; d <= t; d++) {
128 if (n % prime[d] == 0) {
129 /* n is not a prime number */
130 break;
131 }
132 }
133 if (d > t) {
134 /* n is a prime number */
135 return (n);
136 }
137 n += 2;
138 }
139 /* NOTREACHED */
140 }
141
142 unsigned int
get_hash_index(unsigned int * hash_tbl,unsigned int hash_value,unsigned int hash_size)143 get_hash_index(unsigned int *hash_tbl, unsigned int hash_value,
144 unsigned int hash_size)
145 {
146 unsigned int idx, inc;
147
148 idx = hash_value % hash_size;
149 inc = 1 + (hash_value % (hash_size - 2));
150
151 for (; ; ) {
152 if (!hash_tbl[idx])
153 return (idx);
154 idx = (idx + inc) % hash_size;
155 }
156 /* NOTREACHED */
157 }
158