/* * 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. */ #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 */