rdataset iterator support

lib/dns/Makefile.in

@@ -31,8 +31,9 @@ CDEFINES =
 CWARNINGS =
 
 OBJS =		name.o db.o dbiterator.o rbt.o rbtdb.o rbtdb64.o \
-		rdata.o rdatalist.o rdataset.o result.o version.o \
-		rdataslab.o master.o callbacks.o compress.o
+		rdata.o rdatalist.o rdataset.o rdatasetiter.c \
+		rdataslab.o master.o callbacks.o compress.o \
+		result.o version.o
 
 SUBDIRS =	include
 TARGETS =	include/dns/enumtype.h include/dns/enumclass.h timestamp

lib/dns/include/dns/Makefile.in

@@ -21,8 +21,8 @@ top_srcdir =	@top_srcdir@
 
 HEADERS =	callbacks.h cert.h compress.h db.h dbiterator.h fixedname.h \
 		master.h name.h rbt.h rcode.h rdata.h rdataclass.h \
-		rdatalist.h rdataset.h rdataslab.h rdatatype.h result.h \
-		secalg.h types.h
+		rdatalist.h rdataset.h rdatasetiter.h rdataslab.h \
+		rdatatype.h result.h secalg.h types.h
 GENHEADERS =	enumclass.h enumtype.h
 
 SUBDIRS =

lib/dns/include/dns/rdatasetiter.h

@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) 1999  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM 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 DNS_RDATASETITER_H
+#define DNS_RDATASETITER_H 1
+
+/*****
+ ***** Module Info
+ *****/
+
+/*
+ * DNS Rdataset Iterator
+ *
+ * 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_db_detachnode() on all
+ * nodes returned.
+ *
+ * XXX <more> XXX
+ *
+ * MP:
+ *	The iterator itself is not locked.  The caller must ensure
+ *	synchronization.
+ *	
+ *	The iterator methods ensure appropriate database locking.
+ *
+ * Reliability:
+ *	No anticipated impact.
+ *
+ * Resources:
+ *	<TBS>
+ *
+ * Security:
+ *	No anticipated impact.
+ *
+ * Standards:
+ *	None.
+ */
+
+/*****
+ ***** Imports
+ *****/
+
+#include <isc/boolean.h>
+#include <isc/buffer.h>
+#include <isc/lang.h>
+
+#include <dns/types.h>
+#include <dns/result.h>
+
+ISC_LANG_BEGINDECLS
+
+/*****
+ ***** Types
+ *****/
+
+typedef struct dns_rdatasetitermethods {
+	void		(*destroy)(dns_rdatasetiter_t **iteratorp);
+	dns_result_t	(*first)(dns_rdatasetiter_t *iterator);
+	dns_result_t	(*next)(dns_rdatasetiter_t *iterator);
+	dns_result_t	(*current)(dns_rdatasetiter_t *iterator,
+				   dns_rdataset_t *rdataset);
+} dns_rdatasetitermethods_t;
+
+#define DNS_RDATASETITER_MAGIC		0x444E5369U		/* DNSi. */
+#define DNS_RDATASETITER_VALID(dbi)	((dbi) != NULL && \
+					 (dbi)->magic == \
+					 DNS_RDATASETITER_MAGIC)
+
+/*
+ * This structure is actually just the common prefix of a DNS db
+ * implementation's version of a dns_rdatasetiter_t.
+ *
+ * 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;
+};
+
+void
+dns_rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
+/*
+ * Destroy '*iteratorp'.
+ *
+ * Requires:
+ *
+ *	'*iteratorp' is a valid iterator.
+ *
+ * Ensures:
+ *
+ *	All resources used by the iterator are freed.
+ *
+ *	*iteratorp == NULL.
+ */
+
+dns_result_t
+dns_rdatasetiter_first(dns_rdatasetiter_t *iterator);
+/*
+ * Move the rdataset cursor to the first rdataset at the node (if any).
+ *
+ * Requires:
+ *	'iterator' is a valid iterator.
+ *
+ * Returns:
+ *	DNS_R_SUCCESS
+ *	DNS_R_NOMORE			There are no rdatasets at the node.
+ *
+ *	Other results are possible, depending on the DB implementation.
+ */
+
+dns_result_t
+dns_rdatasetiter_next(dns_rdatasetiter_t *iterator);
+/*
+ * Move the rdataset cursor to the next rdataset at the node (if any).
+ *
+ * Requires:
+ *	'iterator' is a valid iterator.
+ *
+ * Returns:
+ *	DNS_R_SUCCESS
+ *	DNS_R_NOMORE			There are no more rdatasets at the
+ *					node.
+ *
+ *	Other results are possible, depending on the DB implementation.
+ */
+
+dns_result_t
+dns_rdatasetiter_current(dns_rdatasetiter_t *iterator,
+			 dns_rdataset_t *rdataset);
+/*
+ * Return the current rdataset.
+ *
+ * Requires:
+ *	'iterator' is a valid iterator.
+ *
+ *	'rdataset' is a valid, disassociated rdataset.
+ *
+ *	The rdataset cursor of 'iterator' is at a valid location (i.e. the
+ *	result of last call to a cursor movement command was DNS_R_SUCCESS).
+ *
+ * Returns:
+ *
+ *	DNS_R_SUCCESS
+ *
+ *	Other results are possible, depending on the DB implementation.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* DNS_RDATASETITER_H */

lib/dns/rdatasetiter.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 1999  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM 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.
+ */
+
+#include <config.h>
+
+#include <stddef.h>
+
+#include <isc/assertions.h>
+
+#include <dns/rdatasetiter.h>
+
+void
+dns_rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) {
+	/*
+	 * Destroy '*iteratorp'.
+	 */
+
+	REQUIRE(iteratorp != NULL);
+	REQUIRE(DNS_RDATASETITER_VALID(*iteratorp));
+
+	(*iteratorp)->methods->destroy(iteratorp);
+
+	ENSURE(*iteratorp == NULL);
+}
+
+dns_result_t
+dns_rdatasetiter_first(dns_rdatasetiter_t *iterator) {
+	/*
+	 * Move the rdataset cursor to the first rdataset at the node (if any).
+	 */
+
+	REQUIRE(DNS_RDATASETITER_VALID(iterator));
+
+	return (iterator->methods->first(iterator));
+}
+
+dns_result_t
+dns_rdatasetiter_next(dns_rdatasetiter_t *iterator) {
+	/*
+	 * Move the rdataset cursor to the next rdataset at the node (if any).
+	 */
+
+	REQUIRE(DNS_RDATASETITER_VALID(iterator));
+
+	return (iterator->methods->next(iterator));
+}
+
+dns_result_t
+dns_rdatasetiter_current(dns_rdatasetiter_t *iterator, 
+			 dns_rdataset_t *rdataset)
+{
+	/*
+	 * Return the current rdataset.
+	 */
+
+	REQUIRE(DNS_RDATASETITER_VALID(iterator));
+	REQUIRE(DNS_RDATASET_VALID(rdataset));
+	REQUIRE(rdataset->methods == NULL);
+
+	return (iterator->methods->current(iterator, rdataset));
+}