/*
 * 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.spans;

import java.io.IOException;
import java.util.Objects;

import org.apache.lucene.index.PostingsEnum;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.LeafSimScorer;

Expert: Public for extension only. This does not work correctly for terms that indexed at position Integer.MAX_VALUE.
/** * Expert: * Public for extension only. * This does not work correctly for terms that indexed at position Integer.MAX_VALUE. */
public class TermSpans extends Spans { protected final PostingsEnum postings; protected final Term term; protected int doc; protected int freq; protected int count; protected int position; protected boolean readPayload; private final float positionsCost; public TermSpans(LeafSimScorer scorer, PostingsEnum postings, Term term, float positionsCost) { this.postings = Objects.requireNonNull(postings); this.term = Objects.requireNonNull(term); this.doc = -1; this.position = -1; assert positionsCost > 0; // otherwise the TermSpans should not be created. this.positionsCost = positionsCost; } @Override public int nextDoc() throws IOException { doc = postings.nextDoc(); if (doc != DocIdSetIterator.NO_MORE_DOCS) { freq = postings.freq(); assert freq >= 1; count = 0; } position = -1; return doc; } @Override public int advance(int target) throws IOException { assert target > doc; doc = postings.advance(target); if (doc != DocIdSetIterator.NO_MORE_DOCS) { freq = postings.freq(); assert freq >= 1; count = 0; } position = -1; return doc; } @Override public int docID() { return doc; } @Override public int nextStartPosition() throws IOException { if (count == freq) { assert position != NO_MORE_POSITIONS; return position = NO_MORE_POSITIONS; } int prevPosition = position; position = postings.nextPosition(); assert position >= prevPosition : "prevPosition="+prevPosition+" > position="+position; assert position != NO_MORE_POSITIONS; // int endPosition not possible count++; readPayload = false; return position; } @Override public int startPosition() { return position; } @Override public int endPosition() { return (position == -1) ? -1 : (position != NO_MORE_POSITIONS) ? position + 1 : NO_MORE_POSITIONS; } @Override public int width() { return 0; } @Override public long cost() { return postings.cost(); } @Override public void collect(SpanCollector collector) throws IOException { collector.collectLeaf(postings, position, term); } @Override public float positionsCost() { return positionsCost; } @Override public String toString() { return "spans(" + term.toString() + ")@" + (doc == -1 ? "START" : (doc == NO_MORE_DOCS) ? "ENDDOC" : doc + " - " + (position == NO_MORE_POSITIONS ? "ENDPOS" : position)); } public PostingsEnum getPostings() { return postings; } }