| /* |
| * 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.List; |
| |
| import org.apache.lucene.search.DocIdSetIterator; |
| import org.apache.lucene.search.ConjunctionDISI; |
| import org.apache.lucene.search.TwoPhaseIterator; |
| |
| /** |
| * Common super class for multiple sub spans required in a document. |
| */ |
| abstract class ConjunctionSpans extends Spans { |
| final Spans[] subSpans; // in query order |
| final DocIdSetIterator conjunction; // use to move to next doc with all clauses |
| boolean atFirstInCurrentDoc; // a first start position is available in current doc for nextStartPosition |
| boolean oneExhaustedInCurrentDoc; // one subspans exhausted in current doc |
| |
| ConjunctionSpans(List<Spans> subSpans) { |
| if (subSpans.size() < 2) { |
| throw new IllegalArgumentException("Less than 2 subSpans.size():" + subSpans.size()); |
| } |
| this.subSpans = subSpans.toArray(new Spans[subSpans.size()]); |
| this.conjunction = ConjunctionDISI.intersectSpans(subSpans); |
| this.atFirstInCurrentDoc = true; // ensure for doc -1 that start/end positions are -1 |
| } |
| |
| @Override |
| public int docID() { |
| return conjunction.docID(); |
| } |
| |
| @Override |
| public long cost() { |
| return conjunction.cost(); |
| } |
| |
| @Override |
| public int nextDoc() throws IOException { |
| return (conjunction.nextDoc() == NO_MORE_DOCS) |
| ? NO_MORE_DOCS |
| : toMatchDoc(); |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| return (conjunction.advance(target) == NO_MORE_DOCS) |
| ? NO_MORE_DOCS |
| : toMatchDoc(); |
| } |
| |
| int toMatchDoc() throws IOException { |
| oneExhaustedInCurrentDoc = false; |
| while (true) { |
| if (twoPhaseCurrentDocMatches()) { |
| return docID(); |
| } |
| if (conjunction.nextDoc() == NO_MORE_DOCS) { |
| return NO_MORE_DOCS; |
| } |
| } |
| } |
| |
| |
| abstract boolean twoPhaseCurrentDocMatches() throws IOException; |
| |
| /** |
| * Return a {@link TwoPhaseIterator} view of this ConjunctionSpans. |
| */ |
| @Override |
| public TwoPhaseIterator asTwoPhaseIterator() { |
| float totalMatchCost = 0; |
| // Compute the matchCost as the total matchCost/positionsCostant of the sub spans. |
| for (Spans spans : subSpans) { |
| TwoPhaseIterator tpi = spans.asTwoPhaseIterator(); |
| if (tpi != null) { |
| totalMatchCost += tpi.matchCost(); |
| } else { |
| totalMatchCost += spans.positionsCost(); |
| } |
| } |
| final float matchCost = totalMatchCost; |
| |
| return new TwoPhaseIterator(conjunction) { |
| @Override |
| public boolean matches() throws IOException { |
| return twoPhaseCurrentDocMatches(); |
| } |
| |
| @Override |
| public float matchCost() { |
| return matchCost; |
| } |
| }; |
| } |
| |
| @Override |
| public float positionsCost() { |
| throw new UnsupportedOperationException(); // asTwoPhaseIterator never returns null here. |
| } |
| |
| public Spans[] getSubSpans() { |
| return subSpans; |
| } |
| } |