| /* |
| * 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.grouping; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.lucene.index.DocValues; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.SortedDocValues; |
| import org.apache.lucene.search.Scorable; |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.BytesRefHash; |
| |
| /** |
| * A GroupSelector implementation that groups via SortedDocValues |
| */ |
| public class TermGroupSelector extends GroupSelector<BytesRef> { |
| |
| private final String field; |
| private final BytesRefHash values = new BytesRefHash(); |
| private final Map<Integer, Integer> ordsToGroupIds = new HashMap<>(); |
| |
| private SortedDocValues docValues; |
| private int groupId; |
| |
| private boolean secondPass; |
| private boolean includeEmpty; |
| |
| /** |
| * Create a new TermGroupSelector |
| * @param field the SortedDocValues field to use for grouping |
| */ |
| public TermGroupSelector(String field) { |
| this.field = field; |
| } |
| |
| @Override |
| public void setNextReader(LeafReaderContext readerContext) throws IOException { |
| this.docValues = DocValues.getSorted(readerContext.reader(), field); |
| this.ordsToGroupIds.clear(); |
| BytesRef scratch = new BytesRef(); |
| for (int i = 0; i < values.size(); i++) { |
| values.get(i, scratch); |
| int ord = this.docValues.lookupTerm(scratch); |
| if (ord >= 0) |
| ordsToGroupIds.put(ord, i); |
| } |
| } |
| |
| @Override |
| public void setScorer(Scorable scorer) throws IOException { } |
| |
| @Override |
| public State advanceTo(int doc) throws IOException { |
| if (this.docValues.advanceExact(doc) == false) { |
| groupId = -1; |
| return includeEmpty ? State.ACCEPT : State.SKIP; |
| } |
| int ord = docValues.ordValue(); |
| if (ordsToGroupIds.containsKey(ord)) { |
| groupId = ordsToGroupIds.get(ord); |
| return State.ACCEPT; |
| } |
| if (secondPass) |
| return State.SKIP; |
| groupId = values.add(docValues.binaryValue()); |
| ordsToGroupIds.put(ord, groupId); |
| return State.ACCEPT; |
| } |
| |
| private BytesRef scratch = new BytesRef(); |
| |
| @Override |
| public BytesRef currentValue() { |
| if (groupId == -1) |
| return null; |
| values.get(groupId, scratch); |
| return scratch; |
| } |
| |
| @Override |
| public BytesRef copyValue() { |
| if (groupId == -1) |
| return null; |
| return BytesRef.deepCopyOf(currentValue()); |
| } |
| |
| @Override |
| public void setGroups(Collection<SearchGroup<BytesRef>> searchGroups) { |
| this.values.clear(); |
| this.values.reinit(); |
| for (SearchGroup<BytesRef> sg : searchGroups) { |
| if (sg.groupValue == null) |
| includeEmpty = true; |
| else |
| this.values.add(sg.groupValue); |
| } |
| this.secondPass = true; |
| } |
| } |