contrib/bind9/lib/dns/rriterator.c

   1 /*
   2  * Copyright (C) 2009, 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
   9  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  10  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  11  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  12  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  13  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  14  * PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 /* $Id$ */
  18
  19 /*! \file */
  20
  21 /***
  22  *** Imports
  23  ***/
  24
  25 #include <config.h>
  26
  27 #include <isc/string.h>
  28 #include <isc/util.h>
  29
  30 #include <dns/db.h>
  31 #include <dns/dbiterator.h>
  32 #include <dns/rdata.h>
  33 #include <dns/rdataset.h>
  34 #include <dns/rdatasetiter.h>
  35 #include <dns/result.h>
  36 #include <dns/rriterator.h>
  37
  38 /***
  39  *** RRiterator methods
  40  ***/
  41
  42 isc_result_t
  43 dns_rriterator_init(dns_rriterator_t *it, dns_db_t *db, dns_dbversion_t *ver,
  44                     isc_stdtime_t now)
  45 {
  46         isc_result_t result;
  47         it->magic = RRITERATOR_MAGIC;
  48         it->db = db;
  49         it->dbit = NULL;
  50         it->ver = ver;
  51         it->now = now;
  52         it->node = NULL;
  53         result = dns_db_createiterator(it->db, 0, &it->dbit);
  54         if (result != ISC_R_SUCCESS)
  55                 return (result);
  56         it->rdatasetit = NULL;
  57         dns_rdata_init(&it->rdata);
  58         dns_rdataset_init(&it->rdataset);
  59         dns_fixedname_init(&it->fixedname);
  60         INSIST(! dns_rdataset_isassociated(&it->rdataset));
  61         it->result = ISC_R_SUCCESS;
  62         return (it->result);
  63 }
  64
  65 isc_result_t
  66 dns_rriterator_first(dns_rriterator_t *it) {
  67         REQUIRE(VALID_RRITERATOR(it));
  68         /* Reset state */
  69         if (dns_rdataset_isassociated(&it->rdataset))
  70                 dns_rdataset_disassociate(&it->rdataset);
  71         if (it->rdatasetit != NULL)
  72                 dns_rdatasetiter_destroy(&it->rdatasetit);
  73         if (it->node != NULL)
  74                 dns_db_detachnode(it->db, &it->node);
  75         it->result = dns_dbiterator_first(it->dbit);
  76
  77         /*
  78          * The top node may be empty when out of zone glue exists.
  79          * Walk the tree to find the first node with data.
  80          */
  81         while (it->result == ISC_R_SUCCESS) {
  82                 it->result = dns_dbiterator_current(it->dbit, &it->node,
  83                                            dns_fixedname_name(&it->fixedname));
  84                 if (it->result != ISC_R_SUCCESS)
  85                         return (it->result);
  86
  87                 it->result = dns_db_allrdatasets(it->db, it->node, it->ver,
  88                                                  it->now, &it->rdatasetit);
  89                 if (it->result != ISC_R_SUCCESS)
  90                         return (it->result);
  91
  92                 it->result = dns_rdatasetiter_first(it->rdatasetit);
  93                 if (it->result != ISC_R_SUCCESS) {
  94                         /*
  95                          * This node is empty. Try next node.
  96                          */
  97                         dns_rdatasetiter_destroy(&it->rdatasetit);
  98                         dns_db_detachnode(it->db, &it->node);
  99                         it->result = dns_dbiterator_next(it->dbit);
 100                         continue;
 101                 }
 102                 dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);
 103                 it->rdataset.attributes |= DNS_RDATASETATTR_LOADORDER;
 104                 it->result = dns_rdataset_first(&it->rdataset);
 105                 return (it->result);
 106         }
 107         return (it->result);
 108 }
 109
 110 isc_result_t
 111 dns_rriterator_nextrrset(dns_rriterator_t *it) {
 112         REQUIRE(VALID_RRITERATOR(it));
 113         if (dns_rdataset_isassociated(&it->rdataset))
 114                 dns_rdataset_disassociate(&it->rdataset);
 115         it->result = dns_rdatasetiter_next(it->rdatasetit);
 116         /*
 117          * The while loop body is executed more than once
 118          * only when an empty dbnode needs to be skipped.
 119          */
 120         while (it->result == ISC_R_NOMORE) {
 121                 dns_rdatasetiter_destroy(&it->rdatasetit);
 122                 dns_db_detachnode(it->db, &it->node);
 123                 it->result = dns_dbiterator_next(it->dbit);
 124                 if (it->result == ISC_R_NOMORE) {
 125                         /* We are at the end of the entire database. */
 126                         return (it->result);
 127                 }
 128                 if (it->result != ISC_R_SUCCESS)
 129                         return (it->result);
 130                 it->result = dns_dbiterator_current(it->dbit, &it->node,
 131                                            dns_fixedname_name(&it->fixedname));
 132                 if (it->result != ISC_R_SUCCESS)
 133                         return (it->result);
 134                 it->result = dns_db_allrdatasets(it->db, it->node, it->ver,
 135                                                  it->now, &it->rdatasetit);
 136                 if (it->result != ISC_R_SUCCESS)
 137                         return (it->result);
 138                 it->result = dns_rdatasetiter_first(it->rdatasetit);
 139         }
 140         if (it->result != ISC_R_SUCCESS)
 141                 return (it->result);
 142         dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);
 143         it->rdataset.attributes |= DNS_RDATASETATTR_LOADORDER;
 144         it->result = dns_rdataset_first(&it->rdataset);
 145         return (it->result);
 146 }
 147
 148 isc_result_t
 149 dns_rriterator_next(dns_rriterator_t *it) {
 150         REQUIRE(VALID_RRITERATOR(it));
 151         if (it->result != ISC_R_SUCCESS)
 152                 return (it->result);
 153
 154         INSIST(it->dbit != NULL);
 155         INSIST(it->node != NULL);
 156         INSIST(it->rdatasetit != NULL);
 157
 158         it->result = dns_rdataset_next(&it->rdataset);
 159         if (it->result == ISC_R_NOMORE)
 160                 return (dns_rriterator_nextrrset(it));
 161         return (it->result);
 162 }
 163
 164 void
 165 dns_rriterator_pause(dns_rriterator_t *it) {
 166         REQUIRE(VALID_RRITERATOR(it));
 167         RUNTIME_CHECK(dns_dbiterator_pause(it->dbit) == ISC_R_SUCCESS);
 168 }
 169
 170 void
 171 dns_rriterator_destroy(dns_rriterator_t *it) {
 172         REQUIRE(VALID_RRITERATOR(it));
 173         if (dns_rdataset_isassociated(&it->rdataset))
 174                 dns_rdataset_disassociate(&it->rdataset);
 175         if (it->rdatasetit != NULL)
 176                 dns_rdatasetiter_destroy(&it->rdatasetit);
 177         if (it->node != NULL)
 178                 dns_db_detachnode(it->db, &it->node);
 179         dns_dbiterator_destroy(&it->dbit);
 180 }
 181
 182 void
 183 dns_rriterator_current(dns_rriterator_t *it, dns_name_t **name,
 184                        isc_uint32_t *ttl, dns_rdataset_t **rdataset,
 185                        dns_rdata_t **rdata)
 186 {
 187         REQUIRE(name != NULL && *name == NULL);
 188         REQUIRE(VALID_RRITERATOR(it));
 189         REQUIRE(it->result == ISC_R_SUCCESS);
 190         REQUIRE(rdataset == NULL || *rdataset == NULL);
 191         REQUIRE(rdata == NULL || *rdata == NULL);
 192
 193         *name = dns_fixedname_name(&it->fixedname);
 194         *ttl = it->rdataset.ttl;
 195
 196         dns_rdata_reset(&it->rdata);
 197         dns_rdataset_current(&it->rdataset, &it->rdata);
 198
 199         if (rdataset != NULL)
 200                 *rdataset = &it->rdataset;
 201
 202         if (rdata != NULL)
 203                 *rdata = &it->rdata;
 204 }