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Edit File: symtab.h
/* * Portions Copyright (C) Internet Systems Consortium, Inc. ("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. * * Portions 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. */ #ifndef ISCCC_SYMTAB_H #define ISCCC_SYMTAB_H 1 /***** ***** 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 #endif /* ISCCC_SYMTAB_H */