| /* |
| * 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.suggest.document; |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.Term; |
| import org.apache.lucene.search.IndexSearcher; |
| import org.apache.lucene.search.QueryVisitor; |
| import org.apache.lucene.search.ScoreMode; |
| import org.apache.lucene.search.Weight; |
| import org.apache.lucene.search.suggest.BitsProducer; |
| import org.apache.lucene.util.automaton.Automata; |
| import org.apache.lucene.util.automaton.Automaton; |
| import org.apache.lucene.util.automaton.Operations; |
| import org.apache.lucene.util.automaton.RegExp; |
| |
| /** |
| * A {@link CompletionQuery} which takes a regular expression |
| * as the prefix of the query term. |
| * |
| * <p> |
| * Example usage of querying a prefix of 'sug' and 'sub' |
| * as a regular expression against a suggest field 'suggest_field': |
| * |
| * <pre class="prettyprint"> |
| * CompletionQuery query = new RegexCompletionQuery(new Term("suggest_field", "su[g|b]")); |
| * </pre> |
| * |
| * <p> |
| * See {@link RegExp} for the supported regular expression |
| * syntax |
| * |
| * @lucene.experimental |
| */ |
| public class RegexCompletionQuery extends CompletionQuery { |
| |
| private final int flags; |
| private final int determinizeWorkLimit; |
| |
| /** |
| * Calls {@link RegexCompletionQuery#RegexCompletionQuery(Term, BitsProducer)} |
| * with no filter |
| */ |
| public RegexCompletionQuery(Term term) { |
| this(term, null); |
| } |
| |
| /** |
| * Calls {@link RegexCompletionQuery#RegexCompletionQuery(Term, int, int, BitsProducer)} |
| * enabling all optional regex syntax and <code>maxDeterminizedStates</code> of |
| * {@value Operations#DEFAULT_DETERMINIZE_WORK_LIMIT} |
| */ |
| public RegexCompletionQuery(Term term, BitsProducer filter) { |
| this(term, RegExp.ALL, Operations.DEFAULT_DETERMINIZE_WORK_LIMIT, filter); |
| } |
| /** |
| * Calls {@link RegexCompletionQuery#RegexCompletionQuery(Term, int, int, BitsProducer)} enabling |
| * all optional regex syntax and <code>determinizeWorkLimit</code> of {@value |
| * Operations#DEFAULT_DETERMINIZE_WORK_LIMIT} |
| */ |
| public RegexCompletionQuery(Term term, int flags, int determinizeWorkLimit) { |
| this(term, flags, determinizeWorkLimit, null); |
| } |
| |
| /** |
| * Constructs a regular expression completion query |
| * |
| * @param term query is run against {@link Term#field()} and {@link Term#text()} |
| * is interpreted as a regular expression |
| * @param flags used as syntax_flag in {@link RegExp#RegExp(String, int)} |
| * @param determinizeWorkLimit used in {@link RegExp#toAutomaton(int)} |
| * @param filter used to query on a sub set of documents |
| */ |
| public RegexCompletionQuery(Term term, int flags, int determinizeWorkLimit, BitsProducer filter) { |
| super(term, filter); |
| this.flags = flags; |
| this.determinizeWorkLimit = determinizeWorkLimit; |
| } |
| |
| @Override |
| public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException { |
| // If an empty regex is provided, we return an automaton that matches nothing. This ensures |
| // consistency with PrefixCompletionQuery, which returns no results for an empty term. |
| Automaton automaton = getTerm().text().isEmpty() |
| ? Automata.makeEmpty() |
| : new RegExp(getTerm().text(), flags).toAutomaton(determinizeWorkLimit); |
| return new CompletionWeight(this, automaton); |
| } |
| |
| /** |
| * Get the regex flags |
| */ |
| public int getFlags() { |
| return flags; |
| } |
| |
| /** Get the maximum effort permitted to determinize the automaton */ |
| public int getDeterminizeWorkLimit() { |
| return determinizeWorkLimit; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public int hashCode() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public void visit(QueryVisitor visitor) { |
| visitor.visitLeaf(this); |
| } |
| } |