1 /* hash.h
2 
3    Definitions for hashing... */
4 
5 /*
6  * Copyright (c) 2004-2017 by Internet Systems Consortium, Inc. ("ISC")
7  * Copyright (c) 1995-2003 by Internet Software Consortium
8  *
9  * This Source Code Form is subject to the terms of the Mozilla Public
10  * License, v. 2.0. If a copy of the MPL was not distributed with this
11  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
19  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  *
21  *   Internet Systems Consortium, Inc.
22  *   950 Charter Street
23  *   Redwood City, CA 94063
24  *   <info@isc.org>
25  *   https://www.isc.org/
26  *
27  */
28 
29 #ifndef OMAPI_HASH_H
30 #define OMAPI_HASH_H
31 
32 #if !defined (DEFAULT_HASH_SIZE)
33 # define DEFAULT_HASH_SIZE	9973
34 #endif
35 
36 #if !defined (KEY_HASH_SIZE)
37 # define KEY_HASH_SIZE		1009
38 #endif
39 
40 /* The purpose of the hashed_object_t struct is to not match anything else. */
41 typedef struct {
42 	int foo;
43 } hashed_object_t;
44 
45 typedef isc_result_t (*hash_foreach_func)(const void *, unsigned, void *);
46 typedef int (*hash_reference) (hashed_object_t **, hashed_object_t *,
47 			       const char *, int);
48 typedef int (*hash_dereference) (hashed_object_t **, const char *, int);
49 
50 struct hash_bucket {
51 	struct hash_bucket *next;
52 	const unsigned char *name;
53 	unsigned len;
54 	hashed_object_t *value;
55 };
56 
57 typedef int (*hash_comparator_t)(const void *, const void *, size_t);
58 
59 struct hash_table {
60 	unsigned hash_count;
61 	hash_reference referencer;
62 	hash_dereference dereferencer;
63 	hash_comparator_t cmp;
64 	unsigned (*do_hash)(const void *, unsigned, unsigned);
65 
66 	/* This must remain the last entry in this table. */
67 	struct hash_bucket *buckets [1];
68 };
69 
70 struct named_hash {
71 	struct named_hash *next;
72 	const char *name;
73 	struct hash_table *hash;
74 };
75 
76 #define HASH_FUNCTIONS_DECL(name, bufarg, type, hashtype)		      \
77 void name##_hash_add (hashtype *, bufarg, unsigned, type *,		      \
78 		      const char *, int);				      \
79 void name##_hash_delete (hashtype *, bufarg, unsigned,			      \
80 			 const char *, int);				      \
81 int name##_hash_lookup (type **, hashtype *, bufarg, unsigned,		      \
82 			const char *, int);				      \
83 unsigned char * name##_hash_report(hashtype *);				      \
84 int name##_hash_foreach (hashtype *, hash_foreach_func);		      \
85 int name##_new_hash (hashtype **, unsigned, const char *, int);		      \
86 void name##_free_hash_table (hashtype **, const char *, int);
87 
88 
89 #define HASH_FUNCTIONS(name, bufarg, type, hashtype, ref, deref, hasher)      \
90 void name##_hash_add (hashtype *table,					      \
91 		      bufarg buf, unsigned len, type *ptr,		      \
92 		      const char *file, int line)			      \
93 {									      \
94 	add_hash ((struct hash_table *)table, buf,			      \
95 		  len, (hashed_object_t *)ptr, file, line);		      \
96 }									      \
97 									      \
98 void name##_hash_delete (hashtype *table, bufarg buf, unsigned len,	      \
99 			 const char *file, int line)			      \
100 {									      \
101 	delete_hash_entry ((struct hash_table *)table, buf, len,	      \
102 			   file, line);					      \
103 }									      \
104 									      \
105 int name##_hash_lookup (type **ptr, hashtype *table,			      \
106 			bufarg buf, unsigned len, const char *file, int line) \
107 {									      \
108 	return hash_lookup ((hashed_object_t **)ptr,			      \
109 			    (struct hash_table *)table,			      \
110 			    buf, len, file, line);			      \
111 }									      \
112 									      \
113 unsigned char * name##_hash_report(hashtype *table)			      \
114 {									      \
115 	return hash_report((struct hash_table *)table);			      \
116 }									      \
117 									      \
118 int name##_hash_foreach (hashtype *table, hash_foreach_func func)	      \
119 {									      \
120 	return hash_foreach ((struct hash_table *)table,		      \
121 			     func);					      \
122 }									      \
123 									      \
124 int name##_new_hash (hashtype **tp, unsigned c, const char *file, int line)   \
125 {									      \
126 	return new_hash ((struct hash_table **)tp,			      \
127 			 (hash_reference)ref, (hash_dereference)deref, c,     \
128 			 hasher, file, line);				      \
129 }									      \
130 									      \
131 void name##_free_hash_table (hashtype **table, const char *file, int line)    \
132 {									      \
133 	free_hash_table ((struct hash_table **)table, file, line);	      \
134 }
135 
136 void relinquish_hash_bucket_hunks (void);
137 int new_hash_table (struct hash_table **, unsigned, const char *, int);
138 void free_hash_table (struct hash_table **, const char *, int);
139 struct hash_bucket *new_hash_bucket (const char *, int);
140 void free_hash_bucket (struct hash_bucket *, const char *, int);
141 int new_hash(struct hash_table **,
142 	     hash_reference, hash_dereference, unsigned,
143 	     unsigned (*do_hash)(const void *, unsigned, unsigned),
144 	     const char *, int);
145 unsigned do_string_hash(const void *, unsigned, unsigned);
146 unsigned do_case_hash(const void *, unsigned, unsigned);
147 unsigned do_id_hash(const void *, unsigned, unsigned);
148 unsigned do_number_hash(const void *, unsigned, unsigned);
149 unsigned do_ip4_hash(const void *, unsigned, unsigned);
150 unsigned char *hash_report(struct hash_table *);
151 void add_hash (struct hash_table *,
152 		      const void *, unsigned, hashed_object_t *,
153 		      const char *, int);
154 void delete_hash_entry (struct hash_table *, const void *,
155 			       unsigned, const char *, int);
156 int hash_lookup (hashed_object_t **, struct hash_table *,
157 			const void *, unsigned, const char *, int);
158 int hash_foreach (struct hash_table *, hash_foreach_func);
159 int casecmp (const void *s, const void *t, size_t len);
160 
161 #endif /* OMAPI_HASH_H */
162