| /* |
| * 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.impl; |
| |
| |
| import org.apache.directory.server.i18n.I18n; |
| import org.apache.directory.server.xdbm.AbstractIndexCursor; |
| import org.apache.directory.server.xdbm.IndexCursor; |
| import org.apache.directory.server.xdbm.IndexEntry; |
| import org.apache.directory.server.xdbm.Store; |
| import org.apache.directory.shared.ldap.model.cursor.InvalidCursorPositionException; |
| import org.apache.directory.shared.ldap.model.entry.Entry; |
| import org.apache.directory.shared.ldap.model.schema.MutableAttributeTypeImpl; |
| |
| |
| /** |
| * A returning candidates satisfying an attribute presence expression. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class PresenceCursor<ID extends Comparable<ID>> extends AbstractIndexCursor<String, Entry, ID> |
| { |
| private static final String UNSUPPORTED_MSG = I18n.err( I18n.ERR_724 ); |
| private final IndexCursor<String, Entry, ID> ndnCursor; |
| private final IndexCursor<String, Entry, ID> presenceCursor; |
| private final PresenceEvaluator<ID> presenceEvaluator; |
| private boolean available = false; |
| |
| |
| public PresenceCursor( Store<Entry, ID> db, PresenceEvaluator<ID> presenceEvaluator ) throws Exception |
| { |
| this.presenceEvaluator = presenceEvaluator; |
| MutableAttributeTypeImpl type = presenceEvaluator.getAttributeType(); |
| |
| // we don't maintain a presence index for objectClass, entryUUID, and entryCSN |
| // as it doesn't make sense because every entry has such an attribute |
| // instead for those attributes and all un-indexed attributes we use the ndn index |
| if ( db.hasUserIndexOn( type ) ) |
| { |
| presenceCursor = db.getPresenceIndex().forwardCursor( type.getOid() ); |
| ndnCursor = null; |
| } |
| else |
| { |
| presenceCursor = null; |
| ndnCursor = db.getNdnIndex().forwardCursor(); |
| } |
| } |
| |
| |
| public boolean available() |
| { |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.available(); |
| } |
| |
| return available; |
| } |
| |
| |
| public void beforeValue( ID id, String value ) throws Exception |
| { |
| checkNotClosed( "beforeValue()" ); |
| |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.beforeValue( id, value ); |
| return; |
| } |
| |
| throw new UnsupportedOperationException( UNSUPPORTED_MSG ); |
| } |
| |
| |
| public void before( IndexEntry<String, Entry, ID> element ) throws Exception |
| { |
| checkNotClosed( "before()" ); |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.before( element ); |
| return; |
| } |
| |
| throw new UnsupportedOperationException( UNSUPPORTED_MSG ); |
| } |
| |
| |
| public void afterValue( ID id, String value ) throws Exception |
| { |
| checkNotClosed( "afterValue()" ); |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.afterValue( id, value ); |
| return; |
| } |
| |
| throw new UnsupportedOperationException( UNSUPPORTED_MSG ); |
| } |
| |
| |
| public void after( IndexEntry<String, Entry, ID> element ) throws Exception |
| { |
| checkNotClosed( "after()" ); |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.after( element ); |
| return; |
| } |
| |
| throw new UnsupportedOperationException( UNSUPPORTED_MSG ); |
| } |
| |
| |
| public void beforeFirst() throws Exception |
| { |
| checkNotClosed( "beforeFirst()" ); |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.beforeFirst(); |
| return; |
| } |
| |
| ndnCursor.beforeFirst(); |
| available = false; |
| } |
| |
| |
| public void afterLast() throws Exception |
| { |
| checkNotClosed( "afterLast()" ); |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.afterLast(); |
| return; |
| } |
| |
| ndnCursor.afterLast(); |
| available = false; |
| } |
| |
| |
| public boolean first() throws Exception |
| { |
| checkNotClosed( "first()" ); |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.first(); |
| } |
| |
| beforeFirst(); |
| return next(); |
| } |
| |
| |
| public boolean last() throws Exception |
| { |
| checkNotClosed( "last()" ); |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.last(); |
| } |
| |
| afterLast(); |
| return previous(); |
| } |
| |
| |
| public boolean previous() throws Exception |
| { |
| checkNotClosed( "previous()" ); |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.previous(); |
| } |
| |
| while ( ndnCursor.previous() ) |
| { |
| checkNotClosed( "previous()" ); |
| IndexEntry<?, Entry, ID> candidate = ndnCursor.get(); |
| if ( presenceEvaluator.evaluate( candidate ) ) |
| { |
| return available = true; |
| } |
| } |
| |
| return available = false; |
| } |
| |
| |
| public boolean next() throws Exception |
| { |
| checkNotClosed( "next()" ); |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.next(); |
| } |
| |
| while ( ndnCursor.next() ) |
| { |
| checkNotClosed( "next()" ); |
| IndexEntry<?, Entry, ID> candidate = ndnCursor.get(); |
| if ( presenceEvaluator.evaluate( candidate ) ) |
| { |
| return available = true; |
| } |
| } |
| |
| return available = false; |
| } |
| |
| |
| public IndexEntry<String, Entry, ID> get() throws Exception |
| { |
| checkNotClosed( "get()" ); |
| if ( presenceCursor != null ) |
| { |
| if ( presenceCursor.available() ) |
| { |
| return presenceCursor.get(); |
| } |
| |
| throw new InvalidCursorPositionException( I18n.err( I18n.ERR_708 ) ); |
| } |
| |
| if ( available ) |
| { |
| /* |
| * The value of NDN indices is the normalized dn and we want the |
| * value to be the value of the attribute in question. So we will |
| * set that accordingly here. |
| */ |
| IndexEntry<String, Entry, ID> indexEntry = ndnCursor.get(); |
| indexEntry.setValue( presenceEvaluator.getAttributeType().getOid() ); |
| return indexEntry; |
| } |
| |
| throw new InvalidCursorPositionException( I18n.err( I18n.ERR_708 ) ); |
| } |
| |
| |
| public boolean isElementReused() |
| { |
| if ( presenceCursor != null ) |
| { |
| return presenceCursor.isElementReused(); |
| } |
| |
| return ndnCursor.isElementReused(); |
| } |
| |
| |
| public void close() throws Exception |
| { |
| super.close(); |
| |
| if ( presenceCursor != null ) |
| { |
| presenceCursor.close(); |
| } |
| else |
| { |
| ndnCursor.close(); |
| } |
| } |
| } |