rriterator.c

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/*
 * Copyright (C) 2009, 2011, 2012, 2015  Internet Systems Consortium, Inc. ("ISC")
 *
 * 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 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.
 */

/* $Id$ */

/*! \file */

/***
 *** Imports
 ***/

#include <config.h>

#include <isc/string.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/result.h>
#include <dns/rriterator.h>

/***
 *** RRiterator methods
 ***/

isc_result_t
dns_rriterator_init(dns_rriterator_t *it, dns_db_t *db, dns_dbversion_t *ver,
                    isc_stdtime_t now)
{
        isc_result_t result;
        it->magic = RRITERATOR_MAGIC;
        it->db = db;
        it->dbit = NULL;
        it->ver = ver;
        it->now = now;
        it->node = NULL;
        result = dns_db_createiterator(it->db, 0, &it->dbit);
        if (result != ISC_R_SUCCESS)
                return (result);
        it->rdatasetit = NULL;
        dns_rdata_init(&it->rdata);
        dns_rdataset_init(&it->rdataset);
        dns_fixedname_init(&it->fixedname);
        INSIST(! dns_rdataset_isassociated(&it->rdataset));
        it->result = ISC_R_SUCCESS;
        return (it->result);
}

isc_result_t
dns_rriterator_first(dns_rriterator_t *it) {
        REQUIRE(VALID_RRITERATOR(it));
        /* Reset state */
        if (dns_rdataset_isassociated(&it->rdataset))
                dns_rdataset_disassociate(&it->rdataset);
        if (it->rdatasetit != NULL)
                dns_rdatasetiter_destroy(&it->rdatasetit);
        if (it->node != NULL)
                dns_db_detachnode(it->db, &it->node);
        it->result = dns_dbiterator_first(it->dbit);

        /*
         * The top node may be empty when out of zone glue exists.
         * Walk the tree to find the first node with data.
         */
        while (it->result == ISC_R_SUCCESS) {
                it->result = dns_dbiterator_current(it->dbit, &it->node,
                                           dns_fixedname_name(&it->fixedname));
                if (it->result != ISC_R_SUCCESS)
                        return (it->result);

                it->result = dns_db_allrdatasets(it->db, it->node, it->ver,
                                                 it->now, &it->rdatasetit);
                if (it->result != ISC_R_SUCCESS)
                        return (it->result);

                it->result = dns_rdatasetiter_first(it->rdatasetit);
                if (it->result != ISC_R_SUCCESS) {
                        /*
                         * This node is empty. Try next node.
                         */
                        dns_rdatasetiter_destroy(&it->rdatasetit);
                        dns_db_detachnode(it->db, &it->node);
                        it->result = dns_dbiterator_next(it->dbit);
                        continue;
                }
                dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);
                dns_rdataset_getownercase(&it->rdataset,
                                          dns_fixedname_name(&it->fixedname));
                it->rdataset.attributes |= DNS_RDATASETATTR_LOADORDER;
                it->result = dns_rdataset_first(&it->rdataset);
                return (it->result);
        }
        return (it->result);
}

isc_result_t
dns_rriterator_nextrrset(dns_rriterator_t *it) {
        REQUIRE(VALID_RRITERATOR(it));
        if (dns_rdataset_isassociated(&it->rdataset))
                dns_rdataset_disassociate(&it->rdataset);
        it->result = dns_rdatasetiter_next(it->rdatasetit);
        /*
         * The while loop body is executed more than once
         * only when an empty dbnode needs to be skipped.
         */
        while (it->result == ISC_R_NOMORE) {
                dns_rdatasetiter_destroy(&it->rdatasetit);
                dns_db_detachnode(it->db, &it->node);
                it->result = dns_dbiterator_next(it->dbit);
                if (it->result == ISC_R_NOMORE) {
                        /* We are at the end of the entire database. */
                        return (it->result);
                }
                if (it->result != ISC_R_SUCCESS)
                        return (it->result);
                it->result = dns_dbiterator_current(it->dbit, &it->node,
                                           dns_fixedname_name(&it->fixedname));
                if (it->result != ISC_R_SUCCESS)
                        return (it->result);
                it->result = dns_db_allrdatasets(it->db, it->node, it->ver,
                                                 it->now, &it->rdatasetit);
                if (it->result != ISC_R_SUCCESS)
                        return (it->result);
                it->result = dns_rdatasetiter_first(it->rdatasetit);
        }
        if (it->result != ISC_R_SUCCESS)
                return (it->result);
        dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);
        dns_rdataset_getownercase(&it->rdataset,
                                  dns_fixedname_name(&it->fixedname));
        it->rdataset.attributes |= DNS_RDATASETATTR_LOADORDER;
        it->result = dns_rdataset_first(&it->rdataset);
        return (it->result);
}

isc_result_t
dns_rriterator_next(dns_rriterator_t *it) {
        REQUIRE(VALID_RRITERATOR(it));
        if (it->result != ISC_R_SUCCESS)
                return (it->result);

        INSIST(it->dbit != NULL);
        INSIST(it->node != NULL);
        INSIST(it->rdatasetit != NULL);

        it->result = dns_rdataset_next(&it->rdataset);
        if (it->result == ISC_R_NOMORE)
                return (dns_rriterator_nextrrset(it));
        return (it->result);
}

void
dns_rriterator_pause(dns_rriterator_t *it) {
        REQUIRE(VALID_RRITERATOR(it));
        RUNTIME_CHECK(dns_dbiterator_pause(it->dbit) == ISC_R_SUCCESS);
}

void
dns_rriterator_destroy(dns_rriterator_t *it) {
        REQUIRE(VALID_RRITERATOR(it));
        if (dns_rdataset_isassociated(&it->rdataset))
                dns_rdataset_disassociate(&it->rdataset);
        if (it->rdatasetit != NULL)
                dns_rdatasetiter_destroy(&it->rdatasetit);
        if (it->node != NULL)
                dns_db_detachnode(it->db, &it->node);
        dns_dbiterator_destroy(&it->dbit);
}

void
dns_rriterator_current(dns_rriterator_t *it, dns_name_t **name,
                       isc_uint32_t *ttl, dns_rdataset_t **rdataset,
                       dns_rdata_t **rdata)
{
        REQUIRE(name != NULL && *name == NULL);
        REQUIRE(VALID_RRITERATOR(it));
        REQUIRE(it->result == ISC_R_SUCCESS);
        REQUIRE(rdataset == NULL || *rdataset == NULL);
        REQUIRE(rdata == NULL || *rdata == NULL);

        *name = dns_fixedname_name(&it->fixedname);
        *ttl = it->rdataset.ttl;

        dns_rdata_reset(&it->rdata);
        dns_rdataset_current(&it->rdataset, &it->rdata);

        if (rdataset != NULL)
                *rdataset = &it->rdataset;

        if (rdata != NULL)
                *rdata = &it->rdata;
}

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