/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* JBoss, Home of Professional Open Source
* Copyright 2011 Red Hat Inc. and/or its affiliates and other contributors
* as indicated by the @authors tag. All rights reserved.
* See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License, v. 2.1.
* This program is distributed in the hope that it will be useful, but WITHOUT A
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public License,
* v.2.1 along with this distribution; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
package org.hibernate.search.indexes.serialization.impl;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.util.AttributeImpl;
import org.hibernate.search.indexes.serialization.spi.SerializableTokenStream;
import org.hibernate.search.util.logging.impl.Log;
import org.hibernate.search.util.logging.impl.LoggerFactory;
/**
* Copy all AttributeImpl for each incrementToken
*
* Inspired by org.apache.lucene.analysis.CachingTokenFilter
* Original file released under the ASL 2.0 license
* http://www.apache.org/licenses/LICENSE-2.0
*
* @author Emmanuel Bernard <emmanuel@hibernate.org>
*/
public class CopyTokenStream extends TokenStream implements Serializable {
private static final Log log = LoggerFactory.make();
private List<List<AttributeImpl>> cache;
private int index;
public static SerializableTokenStream buildSerializabletokenStream(TokenStream tokenStream) {
try {
List<List<AttributeImpl>> stream = fillCache( tokenStream );
return new SerializableTokenStream(stream);
}
catch ( IOException e ) {
throw log.unableToReadTokenStream();
}
}
public CopyTokenStream(List<List<AttributeImpl>> stream) {
this.index = 0;
this.cache = stream;
}
@Override
public final boolean incrementToken() throws IOException {
if ( index >= cache.size() ) {
// the cache is exhausted, return false
return false;
}
// Since the TokenFilter can be reset, the tokens need to be preserved as immutable.
setState(index);
index++;
return true;
}
private void setState(int localIndex) {
for ( AttributeImpl attr : cache.get(localIndex) ) {
addAttributeImpl( attr );
}
}
@Override
public final void end() throws IOException {
if (cache.size() > 0) {
setState(cache.size()-1);
}
}
@Override
public void reset() throws IOException {
index = 0;
}
private static List<List<AttributeImpl>> fillCache(TokenStream input) throws IOException {
List<List<AttributeImpl>> results = new ArrayList<List<AttributeImpl>>();
while ( input.incrementToken() ) {
List<AttributeImpl> attrs = new ArrayList<AttributeImpl>( );
results.add( attrs );
Iterator<AttributeImpl> iter = input.getAttributeImplsIterator();
while ( iter.hasNext() ) {
//we need to clone as AttributeImpl instances can be reused across incrementToken() calls
attrs.add( (AttributeImpl) iter.next().clone() );
}
}
input.end();
return results;
}
}