| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| package org.apache.directory.server.xdbm.search.evaluator; |
| |
| |
| import org.apache.directory.api.ldap.model.entry.Entry; |
| import org.apache.directory.api.ldap.model.exception.LdapException; |
| import org.apache.directory.api.ldap.model.filter.ScopeNode; |
| import org.apache.directory.api.ldap.model.message.SearchScope; |
| import org.apache.directory.api.ldap.model.name.Dn; |
| import org.apache.directory.server.core.api.partition.Partition; |
| import org.apache.directory.server.core.api.partition.PartitionTxn; |
| import org.apache.directory.server.i18n.I18n; |
| import org.apache.directory.server.xdbm.IndexEntry; |
| import org.apache.directory.server.xdbm.ParentIdAndRdn; |
| import org.apache.directory.server.xdbm.Store; |
| import org.apache.directory.server.xdbm.search.Evaluator; |
| |
| |
| /** |
| * Evaluates ScopeNode assertions with subtree scope on candidates using an |
| * entry database. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class SubtreeScopeEvaluator implements Evaluator<ScopeNode> |
| { |
| /** The ScopeNode containing initial search scope constraints */ |
| private final ScopeNode node; |
| |
| /** The entry identifier of the scope base */ |
| private final String baseId; |
| |
| /** |
| * Whether or not to accept all candidates. If this evaluator's baseId is |
| * set to the context entry's id, then obviously all candidates will be |
| * subordinate to this root ancestor or in subtree scope. This check is |
| * done on initialization and used there after. One reason we need do |
| * this is because the subtree scope index (sub level index) does not map |
| * the values for the context entry id to it's subordinates since it would |
| * have to include all entries. This is a waste of space and lookup time |
| * since we know all entries will be subordinates in this case. |
| */ |
| private final boolean baseIsContextEntry; |
| |
| /** True if the scope requires alias dereferencing while searching */ |
| private final boolean dereferencing; |
| |
| /** The entry database/store */ |
| private final Store db; |
| |
| |
| /** |
| * Creates a subtree scope node evaluator for search expressions. |
| * |
| * @param partitionTxn The transaction to use |
| * @param db the database used to evaluate scope node |
| * @param node the scope node |
| * @throws LdapException on db access failure |
| */ |
| public SubtreeScopeEvaluator( PartitionTxn partitionTxn, Store db, ScopeNode node ) throws LdapException |
| { |
| this.db = db; |
| this.node = node; |
| |
| if ( node.getScope() != SearchScope.SUBTREE ) |
| { |
| throw new IllegalStateException( I18n.err( I18n.ERR_727 ) ); |
| } |
| |
| baseId = node.getBaseId(); |
| |
| baseIsContextEntry = db.getSuffixId( partitionTxn ) == baseId; |
| |
| dereferencing = node.getDerefAliases().isDerefInSearching() || node.getDerefAliases().isDerefAlways(); |
| } |
| |
| |
| /** |
| * Tells if a candidate is a descendant of the base ID. We have to fetch all |
| * the parentIdAndRdn up to the baseId. If we terminate on the context entry without |
| * having found the baseId, then the candidate is not a descendant. |
| */ |
| private boolean isDescendant( PartitionTxn partitionTxn, String candidateId ) throws LdapException |
| { |
| String tmp = candidateId; |
| |
| while ( true ) |
| { |
| ParentIdAndRdn parentIdAndRdn = db.getRdnIndex().reverseLookup( partitionTxn, tmp ); |
| |
| if ( parentIdAndRdn == null ) |
| { |
| return false; |
| } |
| |
| tmp = parentIdAndRdn.getParentId(); |
| |
| if ( tmp.equals( Partition.ROOT_ID ) ) |
| { |
| return false; |
| } |
| |
| if ( tmp.equals( baseId ) ) |
| { |
| return true; |
| } |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean evaluate( PartitionTxn partitionTxn, IndexEntry<?, String> indexEntry ) throws LdapException |
| { |
| String id = indexEntry.getId(); |
| Entry entry = indexEntry.getEntry(); |
| |
| // Fetch the entry |
| if ( null == entry ) |
| { |
| entry = db.fetch( partitionTxn, indexEntry.getId() ); |
| |
| if ( null == entry ) |
| { |
| // The entry is not anymore present : get out |
| return false; |
| } |
| |
| indexEntry.setEntry( entry ); |
| } |
| |
| /* |
| * This condition catches situations where the candidate is equal to |
| * the base entry and when the base entry is the context entry. Note |
| * we do not store a mapping in the subtree index of the context entry |
| * to all it's subordinates since that would be the entire set of |
| * entries in the db. |
| */ |
| boolean isDescendant = baseIsContextEntry || baseId.equals( id ) || entry.getDn().isDescendantOf( node.getBaseDn() ); |
| |
| /* |
| * The candidate id could be any entry in the db. If search |
| * dereferencing is not enabled then we return the results of the |
| * descendant test. |
| */ |
| if ( !isDereferencing() ) |
| { |
| return isDescendant; |
| } |
| |
| /* |
| * From here down alias dereferencing is enabled. We determine if the |
| * candidate id is an alias, if so we reject it since aliases should |
| * not be returned. |
| */ |
| if ( db.getAliasCache() != null ) |
| { |
| Dn dn = db.getAliasCache().getIfPresent( id ); |
| |
| if ( dn != null ) |
| { |
| return false; |
| } |
| } |
| else if ( null != db.getAliasIndex().reverseLookup( partitionTxn, id ) ) |
| { |
| return false; |
| } |
| |
| /* |
| * The candidate is NOT an alias at this point. So if it is a |
| * descendant we just return true since it is in normal subtree scope. |
| */ |
| if ( isDescendant ) |
| { |
| return true; |
| } |
| |
| /* |
| * At this point the candidate is not a descendant and it is not an |
| * alias. We need to check if the candidate is in extended subtree |
| * scope by performing a lookup on the subtree alias index. This index |
| * stores a tuple mapping the baseId to the ids of objects brought |
| * into subtree scope of the base by an alias: |
| * |
| * ( baseId, aliasedObjId ) |
| * |
| * If the candidate id is an object brought into subtree scope then |
| * the lookup returns true accepting the candidate. Otherwise the |
| * candidate is rejected with a false return because it is not in scope. |
| */ |
| return db.getSubAliasIndex().forward( partitionTxn, baseId, id ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean evaluate( Entry candidate ) throws LdapException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_721 ) ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public ScopeNode getExpression() |
| { |
| return node; |
| } |
| |
| |
| /** |
| * @return The base ID |
| */ |
| public String getBaseId() |
| { |
| return baseId; |
| } |
| |
| |
| /** |
| * @return <tt>true</tt> if dereferencing |
| */ |
| public boolean isDereferencing() |
| { |
| return dereferencing; |
| } |
| |
| |
| /** |
| * @see Object#toString() |
| */ |
| public String toString( String tabs ) |
| { |
| StringBuilder sb = new StringBuilder(); |
| |
| sb.append( tabs ).append( "SubstreeScopeEvaluator : " ).append( node ).append( '\n' ); |
| |
| return sb.toString(); |
| } |
| |
| |
| /** |
| * @see Object#toString() |
| */ |
| public String toString() |
| { |
| return toString( "" ); |
| } |
| } |