xref: /minix3/external/bsd/bind/dist/lib/isccc/include/isccc/symtab.h (revision 00b67f09dd46474d133c95011a48590a8e8f94c7)
1 /*	$NetBSD: symtab.h,v 1.4 2014/12/10 04:38:01 christos Exp $	*/
2 
3 /*
4  * Portions Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
5  * Portions Copyright (C) 2001  Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and/or distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
12  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
13  * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
14  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  *
19  * Portions Copyright (C) 2001  Nominum, Inc.
20  *
21  * Permission to use, copy, modify, and/or distribute this software for any
22  * purpose with or without fee is hereby granted, provided that the above
23  * copyright notice and this permission notice appear in all copies.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
26  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
28  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
29  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
30  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
31  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
32  */
33 
34 /* Id: symtab.h,v 1.10 2007/08/28 07:20:43 tbox Exp  */
35 
36 #ifndef ISCCC_SYMTAB_H
37 #define ISCCC_SYMTAB_H 1
38 
39 /*****
40  ***** Module Info
41  *****/
42 
43 /*! \file isccc/symtab.h
44  * \brief
45  * Provides a simple memory-based symbol table.
46  *
47  * Keys are C strings.  A type may be specified when looking up,
48  * defining, or undefining.  A type value of 0 means "match any type";
49  * any other value will only match the given type.
50  *
51  * It's possible that a client will attempt to define a <key, type,
52  * value> tuple when a tuple with the given key and type already
53  * exists in the table.  What to do in this case is specified by the
54  * client.  Possible policies are:
55  *
56  *\li	isccc_symexists_reject	Disallow the define, returning #ISC_R_EXISTS
57  *\li	isccc_symexists_replace	Replace the old value with the new.  The
58  *				undefine action (if provided) will be called
59  *				with the old <key, type, value> tuple.
60  *\li	isccc_symexists_add	Add the new tuple, leaving the old tuple in
61  *				the table.  Subsequent lookups will retrieve
62  *				the most-recently-defined tuple.
63  *
64  * A lookup of a key using type 0 will return the most-recently
65  * defined symbol with that key.  An undefine of a key using type 0
66  * will undefine the most-recently defined symbol with that key.
67  * Trying to define a key with type 0 is illegal.
68  *
69  * The symbol table library does not make a copy the key field, so the
70  * caller must ensure that any key it passes to isccc_symtab_define()
71  * will not change until it calls isccc_symtab_undefine() or
72  * isccc_symtab_destroy().
73  *
74  * A user-specified action will be called (if provided) when a symbol
75  * is undefined.  It can be used to free memory associated with keys
76  * and/or values.
77  */
78 
79 /***
80  *** Imports.
81  ***/
82 
83 #include <isc/lang.h>
84 #include <isccc/types.h>
85 
86 /***
87  *** Symbol Tables.
88  ***/
89 
90 typedef union isccc_symvalue {
91 	void *				as_pointer;
92 	int				as_integer;
93 	unsigned int			as_uinteger;
94 } isccc_symvalue_t;
95 
96 typedef void (*isccc_symtabundefaction_t)(char *key, unsigned int type,
97 					isccc_symvalue_t value, void *userarg);
98 
99 typedef isc_boolean_t (*isccc_symtabforeachaction_t)(char *key,
100 						   unsigned int type,
101 						   isccc_symvalue_t value,
102 						   void *userarg);
103 
104 typedef enum {
105 	isccc_symexists_reject = 0,
106 	isccc_symexists_replace = 1,
107 	isccc_symexists_add = 2
108 } isccc_symexists_t;
109 
110 ISC_LANG_BEGINDECLS
111 
112 isc_result_t
113 isccc_symtab_create(unsigned int size,
114 		  isccc_symtabundefaction_t undefine_action, void *undefine_arg,
115 		  isc_boolean_t case_sensitive, isccc_symtab_t **symtabp);
116 
117 void
118 isccc_symtab_destroy(isccc_symtab_t **symtabp);
119 
120 isc_result_t
121 isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
122 		  isccc_symvalue_t *value);
123 
124 isc_result_t
125 isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
126 		  isccc_symvalue_t value, isccc_symexists_t exists_policy);
127 
128 isc_result_t
129 isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key, unsigned int type);
130 
131 void
132 isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
133 		   void *arg);
134 
135 ISC_LANG_ENDDECLS
136 
137 #endif /* ISCCC_SYMTAB_H */
138