| /* |
| * 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.core.partition.impl.btree; |
| |
| |
| import java.util.NoSuchElementException; |
| import java.util.regex.Pattern; |
| |
| import javax.naming.NamingEnumeration; |
| import javax.naming.NamingException; |
| |
| |
| /** |
| * A NamingEnumeration over an Index which returns IndexRecords. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| * @version $Rev$ |
| */ |
| public class IndexEnumeration<T> implements NamingEnumeration<IndexRecord> |
| { |
| /** */ |
| private final Pattern re; |
| /** */ |
| private final IndexRecord tmp = new IndexRecord(); |
| /** */ |
| private final IndexRecord returned = new IndexRecord(); |
| /** */ |
| private final IndexRecord prefetched = new IndexRecord(); |
| /** */ |
| private final boolean swapKeyVal; |
| /** */ |
| private final NamingEnumeration<Tuple> underlying; |
| |
| /** */ |
| private boolean hasMore = true; |
| |
| |
| // ------------------------------------------------------------------------ |
| // C O N S T R U C T O R S |
| // ------------------------------------------------------------------------ |
| |
| |
| public IndexEnumeration( NamingEnumeration<Tuple> list ) throws NamingException |
| { |
| this( list, false, null ); |
| } |
| |
| |
| public IndexEnumeration( NamingEnumeration<Tuple> list, boolean swapKeyVal ) throws NamingException |
| { |
| this( list, swapKeyVal, null ); |
| } |
| |
| |
| public IndexEnumeration( NamingEnumeration<Tuple> list, boolean swapKeyVal, Pattern regex ) |
| throws NamingException |
| { |
| re = regex; |
| underlying = list; |
| this.swapKeyVal = swapKeyVal; |
| |
| if ( !underlying.hasMore() ) |
| { |
| hasMore = false; |
| return; |
| } |
| |
| prefetch(); |
| } |
| |
| |
| // ------------------------------------------------------------------------ |
| // NamingEnumeration Interface Methods |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * @see javax.naming.NamingEnumeration#next() |
| */ |
| public IndexRecord next() throws NamingException |
| { |
| returned.copy( prefetched ); |
| prefetch(); |
| return returned; |
| } |
| |
| |
| /** |
| * @see java.util.Enumeration#nextElement() |
| */ |
| public IndexRecord nextElement() |
| { |
| try |
| { |
| return next(); |
| } |
| catch ( NamingException ne ) |
| { |
| throw new NoSuchElementException(); |
| } |
| } |
| |
| |
| /** |
| * @see javax.naming.NamingEnumeration#hasMore() |
| */ |
| public boolean hasMore() |
| { |
| return hasMore; |
| } |
| |
| |
| /** |
| * @see javax.naming.NamingEnumeration#hasMoreElements() |
| */ |
| public boolean hasMoreElements() |
| { |
| return hasMore; |
| } |
| |
| |
| /** |
| * @see javax.naming.NamingEnumeration#close() |
| */ |
| public void close() throws NamingException |
| { |
| hasMore = false; |
| underlying.close(); |
| } |
| |
| |
| // ------------------------------------------------------------------------ |
| // Private Methods |
| // ------------------------------------------------------------------------ |
| |
| private void prefetch() throws NamingException |
| { |
| while ( underlying.hasMore() ) |
| { |
| Tuple tuple = underlying.next(); |
| |
| if ( swapKeyVal ) |
| { |
| tmp.setSwapped( tuple, null ); |
| } |
| else |
| { |
| tmp.setTuple( tuple, null ); |
| } |
| |
| // If regex is null just transfer into prefetched from tmp record |
| // but if it is not then use it to match. Successful match shorts |
| // while loop. |
| if ( null == re || re.matcher( ( String ) tmp.getIndexKey() ).matches() ) |
| { |
| prefetched.copy( tmp ); |
| return; |
| } |
| } |
| |
| // If we got down here then cursor has been consumed without a match! |
| hasMore = false; |
| } |
| } |