3 Routines for manipulating hash tables... */
6 * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of The Internet Software Consortium nor the names
19 * of its contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
23 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
24 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
27 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
29 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
30 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * This software has been written for the Internet Software Consortium
37 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
38 * Enterprises. To learn more about the Internet Software Consortium,
39 * see ``http://www.vix.com/isc''. To learn more about Vixie
40 * Enterprises, see ``http://www.vix.com''.
44 static char copyright[] =
45 "$Id: hash.c,v 1.9.2.3 1999/04/09 17:39:41 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium. All rights reserved.\n";
50 static INLINE int do_hash PROTO ((unsigned char *, int, int));
52 struct hash_table *new_hash ()
54 struct hash_table *rv = new_hash_table (DEFAULT_HASH_SIZE, "new_hash");
57 memset (&rv -> buckets [0], 0,
58 DEFAULT_HASH_SIZE * sizeof (struct hash_bucket *));
62 static INLINE int do_hash (name, len, size)
67 register int accum = 0;
68 register unsigned char *s = name;
71 /* Add the character in... */
73 /* Add carry back in... */
75 accum = (accum & 255) + (accum >> 8);
81 void add_hash (table, name, len, pointer)
82 struct hash_table *table;
85 unsigned char *pointer;
88 struct hash_bucket *bp;
93 len = strlen ((char *)name);
95 hashno = do_hash (name, len, table -> hash_count);
96 bp = new_hash_bucket ("add_hash");
99 warn ("Can't add %s to hash table.", name);
103 bp -> value = pointer;
104 bp -> next = table -> buckets [hashno];
106 table -> buckets [hashno] = bp;
109 void delete_hash_entry (table, name, len)
110 struct hash_table *table;
115 struct hash_bucket *bp, *pbp = (struct hash_bucket *)0;
120 len = strlen ((char *)name);
122 hashno = do_hash (name, len, table -> hash_count);
124 /* Go through the list looking for an entry that matches;
125 if we find it, delete it. */
126 for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
128 !strcmp ((char *)bp -> name, (char *)name)) ||
130 !memcmp (bp -> name, name, len))) {
132 pbp -> next = bp -> next;
134 table -> buckets [hashno] = bp -> next;
136 free_hash_bucket (bp, "delete_hash_entry");
139 pbp = bp; /* jwg, 9/6/96 - nice catch! */
143 unsigned char *hash_lookup (table, name, len)
144 struct hash_table *table;
149 struct hash_bucket *bp;
152 return (unsigned char *)0;
155 len = strlen ((char *)name);
157 hashno = do_hash (name, len, table -> hash_count);
159 for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
160 if (len == bp -> len && !memcmp (bp -> name, name, len))
163 return (unsigned char *)0;