summaryrefslogtreecommitdiffstats
path: root/lib/isccc/include/isccc/symtab.h
blob: a156c061b7e4aaf0ae3eea2fc5054ba02e0f5ef0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0 AND ISC
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*
 * Copyright (C) 2001 Nominum, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#pragma once

/*****
***** Module Info
*****/

/*! \file isccc/symtab.h
 * \brief
 * Provides a simple memory-based symbol table.
 *
 * Keys are C strings.  A type may be specified when looking up,
 * defining, or undefining.  A type value of 0 means "match any type";
 * any other value will only match the given type.
 *
 * It's possible that a client will attempt to define a <key, type,
 * value> tuple when a tuple with the given key and type already
 * exists in the table.  What to do in this case is specified by the
 * client.  Possible policies are:
 *
 *\li	isccc_symexists_reject	Disallow the define, returning #ISC_R_EXISTS
 *\li	isccc_symexists_replace	Replace the old value with the new.  The
 *				undefine action (if provided) will be called
 *				with the old <key, type, value> tuple.
 *\li	isccc_symexists_add	Add the new tuple, leaving the old tuple in
 *				the table.  Subsequent lookups will retrieve
 *				the most-recently-defined tuple.
 *
 * A lookup of a key using type 0 will return the most-recently
 * defined symbol with that key.  An undefine of a key using type 0
 * will undefine the most-recently defined symbol with that key.
 * Trying to define a key with type 0 is illegal.
 *
 * The symbol table library does not make a copy the key field, so the
 * caller must ensure that any key it passes to isccc_symtab_define()
 * will not change until it calls isccc_symtab_undefine() or
 * isccc_symtab_destroy().
 *
 * A user-specified action will be called (if provided) when a symbol
 * is undefined.  It can be used to free memory associated with keys
 * and/or values.
 */

/***
 *** Imports.
 ***/

#include <stdbool.h>

#include <isc/lang.h>

#include <isccc/types.h>

/***
 *** Symbol Tables.
 ***/

typedef union isccc_symvalue {
	void	    *as_pointer;
	int	     as_integer;
	unsigned int as_uinteger;
} isccc_symvalue_t;

typedef void (*isccc_symtabundefaction_t)(char *key, unsigned int type,
					  isccc_symvalue_t value,
					  void		  *userarg);

typedef bool (*isccc_symtabforeachaction_t)(char *key, unsigned int type,
					    isccc_symvalue_t value,
					    void	    *userarg);

typedef enum {
	isccc_symexists_reject = 0,
	isccc_symexists_replace = 1,
	isccc_symexists_add = 2
} isccc_symexists_t;

ISC_LANG_BEGINDECLS

isc_result_t
isccc_symtab_create(unsigned int	      size,
		    isccc_symtabundefaction_t undefine_action,
		    void *undefine_arg, bool case_sensitive,
		    isccc_symtab_t **symtabp);

void
isccc_symtab_destroy(isccc_symtab_t **symtabp);

isc_result_t
isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
		    isccc_symvalue_t *value);

isc_result_t
isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
		    isccc_symvalue_t value, isccc_symexists_t exists_policy);

isc_result_t
isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key,
		      unsigned int type);

void
isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
		     void *arg);

ISC_LANG_ENDDECLS