/*
* 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 org.apache.directory.shared.ldap.NotImplementedException;
import org.apache.directory.server.xdbm.ForwardIndexEntry;
import org.apache.directory.server.xdbm.IndexEntry;
import org.apache.directory.server.xdbm.Tuple;
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: 917231 $
*/
public class IndexEnumeration<T> implements NamingEnumeration<IndexEntry>
{
/** */
private final Pattern re;
/** */
private final ForwardIndexEntry tmp = new ForwardIndexEntry();
/** */
private final ForwardIndexEntry returned = new ForwardIndexEntry();
/** */
private final ForwardIndexEntry prefetched = new ForwardIndexEntry();
/** */
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 IndexEntry next() throws NamingException
{
returned.copy( prefetched );
prefetch();
return returned;
}
/**
* @see java.util.Enumeration#nextElement()
*/
public IndexEntry 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 )
{
throw new NotImplementedException();
// 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.getValue() ).matches() )
{
prefetched.copy( tmp );
return;
}
}
// If we got down here then cursor has been consumed without a match!
hasMore = false;
}
}