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