/* * 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.uhighlight; import java.util.ArrayList; import java.util.List; import java.util.function.Predicate; import java.util.function.Supplier; import org.apache.lucene.search.AutomatonQuery; import org.apache.lucene.search.BooleanClause; import org.apache.lucene.search.FuzzyQuery; import org.apache.lucene.search.Query; import org.apache.lucene.search.QueryVisitor; import org.apache.lucene.search.spans.SpanQuery; import org.apache.lucene.util.automaton.ByteRunAutomaton; /** * Support for highlighting multi-term queries. * * @lucene.internal */ final class MultiTermHighlighting { private MultiTermHighlighting() { } /** * Extracts MultiTermQueries that match the provided field predicate. * Returns equivalent automata that will match terms. */ static LabelledCharArrayMatcher[] extractAutomata(Query query, Predicate<String> fieldMatcher, boolean lookInSpan) { AutomataCollector collector = new AutomataCollector(lookInSpan, fieldMatcher); query.visit(collector); return collector.runAutomata.toArray(new LabelledCharArrayMatcher[0]); } /** * Indicates if the the leaf query (from {@link QueryVisitor#visitLeaf(Query)}) is a type of query that * we can extract automata from. */ public static boolean canExtractAutomataFromLeafQuery(Query query) { return query instanceof AutomatonQuery || query instanceof FuzzyQuery; } private static class AutomataCollector extends QueryVisitor { List<LabelledCharArrayMatcher> runAutomata = new ArrayList<>(); final boolean lookInSpan; final Predicate<String> fieldMatcher; private AutomataCollector(boolean lookInSpan, Predicate<String> fieldMatcher) { this.lookInSpan = lookInSpan; this.fieldMatcher = fieldMatcher; } @Override public boolean acceptField(String field) { return fieldMatcher.test(field); } @Override public QueryVisitor getSubVisitor(BooleanClause.Occur occur, Query parent) { if (lookInSpan == false && parent instanceof SpanQuery) { return QueryVisitor.EMPTY_VISITOR; } return super.getSubVisitor(occur, parent); } @Override public void consumeTermsMatching(Query query, String field, Supplier<ByteRunAutomaton> automaton) { runAutomata.add(LabelledCharArrayMatcher.wrap(query.toString(), automaton.get())); } } }