Current File : //usr/include/bind9/dns/rdatasetiter.h
/*
* 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 http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#ifndef DNS_RDATASETITER_H
#define DNS_RDATASETITER_H 1
/*****
***** Module Info
*****/
/*! \file dns/rdatasetiter.h
* \brief
* The DNS Rdataset Iterator interface allows iteration of all of the
* rdatasets at a node.
*
* The dns_rdatasetiter_t type is like a "virtual class". To actually use
* it, an implementation of the class is required. This implementation is
* supplied by the database.
*
* It is the client's responsibility to call dns_rdataset_disassociate()
* on all rdatasets returned.
*
* XXX more XXX
*
* MP:
*\li The iterator itself is not locked. The caller must ensure
* synchronization.
*
*\li The iterator methods ensure appropriate database locking.
*
* Reliability:
*\li No anticipated impact.
*
* Resources:
*\li TBS
*
* Security:
*\li No anticipated impact.
*
* Standards:
*\li None.
*/
/*****
***** Imports
*****/
#include <isc/lang.h>
#include <isc/magic.h>
#include <isc/stdtime.h>
#include <dns/types.h>
ISC_LANG_BEGINDECLS
/*****
***** Types
*****/
typedef struct dns_rdatasetitermethods {
void (*destroy)(dns_rdatasetiter_t **iteratorp);
isc_result_t (*first)(dns_rdatasetiter_t *iterator);
isc_result_t (*next)(dns_rdatasetiter_t *iterator);
void (*current)(dns_rdatasetiter_t *iterator,
dns_rdataset_t *rdataset);
} dns_rdatasetitermethods_t;
#define DNS_RDATASETITER_MAGIC ISC_MAGIC('D','N','S','i')
#define DNS_RDATASETITER_VALID(i) ISC_MAGIC_VALID(i, DNS_RDATASETITER_MAGIC)
/*%
* This structure is actually just the common prefix of a DNS db
* implementation's version of a dns_rdatasetiter_t.
* \brief
* Direct use of this structure by clients is forbidden. DB implementations
* may change the structure. 'magic' must be #DNS_RDATASETITER_MAGIC for
* any of the dns_rdatasetiter routines to work. DB implementations must
* maintain all DB rdataset iterator invariants.
*/
struct dns_rdatasetiter {
/* Unlocked. */
unsigned int magic;
dns_rdatasetitermethods_t * methods;
dns_db_t * db;
dns_dbnode_t * node;
dns_dbversion_t * version;
isc_stdtime_t now;
};
void
dns_rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
/*%<
* Destroy '*iteratorp'.
*
* Requires:
*
*\li '*iteratorp' is a valid iterator.
*
* Ensures:
*
*\li All resources used by the iterator are freed.
*
*\li *iteratorp == NULL.
*/
isc_result_t
dns_rdatasetiter_first(dns_rdatasetiter_t *iterator);
/*%<
* Move the rdataset cursor to the first rdataset at the node (if any).
*
* Requires:
*\li 'iterator' is a valid iterator.
*
* Returns:
*\li ISC_R_SUCCESS
*\li ISC_R_NOMORE There are no rdatasets at the node.
*
*\li Other results are possible, depending on the DB implementation.
*/
isc_result_t
dns_rdatasetiter_next(dns_rdatasetiter_t *iterator);
/*%<
* Move the rdataset cursor to the next rdataset at the node (if any).
*
* Requires:
*\li 'iterator' is a valid iterator.
*
* Returns:
*\li ISC_R_SUCCESS
*\li ISC_R_NOMORE There are no more rdatasets at the
* node.
*
*\li Other results are possible, depending on the DB implementation.
*/
void
dns_rdatasetiter_current(dns_rdatasetiter_t *iterator,
dns_rdataset_t *rdataset);
/*%<
* Return the current rdataset.
*
* Requires:
*\li 'iterator' is a valid iterator.
*
*\li 'rdataset' is a valid, disassociated rdataset.
*
*\li The rdataset cursor of 'iterator' is at a valid location (i.e. the
* result of last call to a cursor movement command was #ISC_R_SUCCESS).
*/
ISC_LANG_ENDDECLS
#endif /* DNS_RDATASETITER_H */
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