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''.
45 static char copyright
[] =
46 "$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";
51 static __inline
int do_hash
PROTO ((unsigned char *, int, int));
53 struct hash_table
*new_hash ()
55 struct hash_table
*rv
= new_hash_table (DEFAULT_HASH_SIZE
);
58 memset (&rv
-> buckets
[0], 0,
59 DEFAULT_HASH_SIZE
* sizeof (struct hash_bucket
*));
63 static __inline
int do_hash (name
, len
, size
)
68 register int accum
= 0;
69 register unsigned char *s
= name
;
72 /* Add the character in... */
74 /* Add carry back in... */
76 accum
= (accum
& 255) + (accum
>> 8);
82 void add_hash (table
, name
, len
, pointer
)
83 struct hash_table
*table
;
86 unsigned char *pointer
;
89 struct hash_bucket
*bp
;
94 len
= strlen ((char *)name
);
96 hashno
= do_hash (name
, len
, table
-> hash_count
);
97 bp
= new_hash_bucket ();
100 warn ("Can't add %s to hash table.", name
);
104 bp
-> value
= pointer
;
105 bp
-> next
= table
-> buckets
[hashno
];
107 table
-> buckets
[hashno
] = bp
;
110 void delete_hash_entry (table
, name
, len
)
111 struct hash_table
*table
;
116 struct hash_bucket
*bp
, *pbp
= (struct hash_bucket
*)0;
121 len
= strlen ((char *)name
);
123 hashno
= do_hash (name
, len
, table
-> hash_count
);
125 /* Go through the list looking for an entry that matches;
126 if we find it, delete it. */
127 for (bp
= table
-> buckets
[hashno
]; bp
; bp
= bp
-> next
) {
129 !strcmp ((char *)bp
-> name
, (char *)name
)) ||
131 !memcmp (bp
-> name
, name
, len
))) {
133 pbp
-> next
= bp
-> next
;
135 table
-> buckets
[hashno
] = bp
-> next
;
137 free_hash_bucket (bp
, "delete_hash_entry");
140 pbp
= bp
; /* jwg, 9/6/96 - nice catch! */
144 unsigned char *hash_lookup (table
, name
, len
)
145 struct hash_table
*table
;
150 struct hash_bucket
*bp
;
153 return (unsigned char *)0;
156 len
= strlen ((char *)name
);
158 hashno
= do_hash (name
, len
, table
-> hash_count
);
160 for (bp
= table
-> buckets
[hashno
]; bp
; bp
= bp
-> next
) {
161 if (len
== bp
-> len
&& !memcmp (bp
-> name
, name
, len
))
164 return (unsigned char *)0;