/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.search.lookup;
import org.apache.lucene.index.PostingsEnum;
import org.elasticsearch.ElasticsearchException;
import java.io.IOException;
import java.util.Iterator;
public class PositionIterator implements Iterator<TermPosition> {
private boolean resetted = false;
protected IndexFieldTerm indexFieldTerm;
protected int freq = -1;
// current position of iterator
private int currentPos;
protected final TermPosition termPosition = new TermPosition();
private PostingsEnum postings;
public PositionIterator(IndexFieldTerm indexFieldTerm) {
this.indexFieldTerm = indexFieldTerm;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Cannot remove anything from TermPosition iterator.");
}
@Override
public boolean hasNext() {
return currentPos < freq;
}
@Override
public TermPosition next() {
try {
termPosition.position = postings.nextPosition();
termPosition.startOffset = postings.startOffset();
termPosition.endOffset = postings.endOffset();
termPosition.payload = postings.getPayload();
} catch (IOException ex) {
throw new ElasticsearchException("can not advance iterator", ex);
}
currentPos++;
return termPosition;
}
public void nextDoc() throws IOException {
resetted = false;
currentPos = 0;
freq = indexFieldTerm.tf();
postings = indexFieldTerm.postings;
}
public Iterator<TermPosition> reset() {
if (resetted) {
throw new ElasticsearchException(
"Cannot iterate twice! If you want to iterate more that once, add _CACHE explicitly.");
}
resetted = true;
return this;
}
}