/*
* 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.lucene.search;
import java.io.IOException;
import org.apache.lucene.index.*;
/**
* Position of a term in a document that takes into account the term offset within the phrase.
*/
final class PhrasePositions {
int position; // position in doc
int count; // remaining pos in this doc
int offset; // position in phrase
final int ord; // unique across all PhrasePositions instances
final PostingsEnum postings; // stream of docs & positions
PhrasePositions next; // used to make lists
int rptGroup = -1; // >=0 indicates that this is a repeating PP
int rptInd; // index in the rptGroup
final Term[] terms; // for repetitions initialization
PhrasePositions(PostingsEnum postings, int o, int ord, Term[] terms) {
this.postings = postings;
offset = o;
this.ord = ord;
this.terms = terms;
}
final void firstPosition() throws IOException {
count = postings.freq(); // read first pos
nextPosition();
}
/**
* Go to next location of this term current document, and set
* <code>position</code> as <code>location - offset</code>, so that a
* matching exact phrase is easily identified when all PhrasePositions
* have exactly the same <code>position</code>.
*/
final boolean nextPosition() throws IOException {
if (count-- > 0) { // read subsequent pos's
position = postings.nextPosition() - offset;
return true;
} else
return false;
}
/** for debug purposes */
@Override
public String toString() {
String s = "o:"+offset+" p:"+position+" c:"+count;
if (rptGroup >=0 ) {
s += " rpt:"+rptGroup+",i"+rptInd;
}
return s;
}
}