| /* |
| * 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 java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Objects; |
| |
| import org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| |
| /** |
| * Utility class to help extract the set of sub queries that have matched from |
| * a larger query. |
| * |
| * Individual subqueries may be wrapped using {@link #wrapQuery(String, Query)}, and |
| * the matching queries for a particular document can then be pulled from the parent |
| * Query's {@link Matches} object by calling {@link #findNamedMatches(Matches)} |
| */ |
| public class NamedMatches implements Matches { |
| |
| private final Matches in; |
| private final String name; |
| |
| /** |
| * Wraps a {@link Matches} object and associates a name with it |
| */ |
| public NamedMatches(String name, Matches in) { |
| this.in = Objects.requireNonNull(in); |
| this.name = name; |
| } |
| |
| /** |
| * Returns the name of this {@link Matches} |
| */ |
| public String getName() { |
| return name; |
| } |
| |
| @Override |
| public MatchesIterator getMatches(String field) throws IOException { |
| return in.getMatches(field); |
| } |
| |
| @Override |
| public Collection<Matches> getSubMatches() { |
| return Collections.singleton(in); |
| } |
| |
| @Override |
| public Iterator<String> iterator() { |
| return in.iterator(); |
| } |
| |
| /** |
| * Wrap a Query so that it associates a name with its {@link Matches} |
| */ |
| public static Query wrapQuery(String name, Query in) { |
| return new NamedQuery(name, in); |
| } |
| |
| /** |
| * Finds all {@link NamedMatches} in a {@link Matches} tree |
| */ |
| public static List<NamedMatches> findNamedMatches(Matches matches) { |
| List<NamedMatches> nm = new ArrayList<>(); |
| List<Matches> toProcess = new LinkedList<>(); |
| toProcess.add(matches); |
| while (toProcess.size() > 0) { |
| matches = toProcess.remove(0); |
| if (matches instanceof NamedMatches) { |
| nm.add((NamedMatches) matches); |
| } |
| toProcess.addAll(matches.getSubMatches()); |
| } |
| return nm; |
| } |
| |
| private static class NamedQuery extends Query { |
| |
| private final String name; |
| private final Query in; |
| |
| private NamedQuery(String name, Query in) { |
| this.name = name; |
| this.in = in; |
| } |
| |
| @Override |
| public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException { |
| Weight w = in.createWeight(searcher, scoreMode, boost); |
| return new FilterWeight(w) { |
| @Override |
| public Matches matches(LeafReaderContext context, int doc) throws IOException { |
| Matches m = in.matches(context, doc); |
| if (m == null) { |
| return null; |
| } |
| return new NamedMatches(name, m); |
| } |
| }; |
| } |
| |
| @Override |
| public Query rewrite(IndexReader reader) throws IOException { |
| Query rewritten = in.rewrite(reader); |
| if (rewritten != in) { |
| return new NamedQuery(name, rewritten); |
| } |
| return this; |
| } |
| |
| @Override |
| public String toString(String field) { |
| return "NamedQuery(" + name + "," + in.toString(field) + ")"; |
| } |
| |
| @Override |
| public void visit(QueryVisitor visitor) { |
| QueryVisitor sub = visitor.getSubVisitor(BooleanClause.Occur.MUST, this); |
| in.visit(sub); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) return false; |
| NamedQuery that = (NamedQuery) o; |
| return Objects.equals(name, that.name) && |
| Objects.equals(in, that.in); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(name, in); |
| } |
| } |
| } |