package org.apache.lucene.search.grouping.function;
/*
* 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.
*/
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.FieldComparator;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.grouping.AbstractAllGroupHeadsCollector;
import org.apache.lucene.util.mutable.MutableValue;
import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* An implementation of {@link AbstractAllGroupHeadsCollector} for retrieving the most relevant groups when grouping
* by {@link ValueSource}.
*
* @lucene.experimental
*/
public class FunctionAllGroupHeadsCollector extends AbstractAllGroupHeadsCollector<FunctionAllGroupHeadsCollector.GroupHead> {
private final ValueSource groupBy;
private final Map<?, ?> vsContext;
private final Map<MutableValue, GroupHead> groups;
private final Sort sortWithinGroup;
private FunctionValues.ValueFiller filler;
private MutableValue mval;
private AtomicReaderContext readerContext;
private Scorer scorer;
/**
* Constructs a {@link FunctionAllGroupHeadsCollector} instance.
*
* @param groupBy The {@link ValueSource} to group by
* @param vsContext The ValueSource context
* @param sortWithinGroup The sort within a group
*/
public FunctionAllGroupHeadsCollector(ValueSource groupBy, Map<?, ?> vsContext, Sort sortWithinGroup) {
super(sortWithinGroup.getSort().length);
groups = new HashMap<MutableValue, GroupHead>();
this.sortWithinGroup = sortWithinGroup;
this.groupBy = groupBy;
this.vsContext = vsContext;
final SortField[] sortFields = sortWithinGroup.getSort();
for (int i = 0; i < sortFields.length; i++) {
reversed[i] = sortFields[i].getReverse() ? -1 : 1;
}
}
@Override
protected void retrieveGroupHeadAndAddIfNotExist(int doc) throws IOException {
filler.fillValue(doc);
GroupHead groupHead = groups.get(mval);
if (groupHead == null) {
MutableValue groupValue = mval.duplicate();
groupHead = new GroupHead(groupValue, sortWithinGroup, doc);
groups.put(groupValue, groupHead);
temporalResult.stop = true;
} else {
temporalResult.stop = false;
}
this.temporalResult.groupHead = groupHead;
}
@Override
protected Collection<GroupHead> getCollectedGroupHeads() {
return groups.values();
}
@Override
public void setScorer(Scorer scorer) throws IOException {
this.scorer = scorer;
for (GroupHead groupHead : groups.values()) {
for (FieldComparator<?> comparator : groupHead.comparators) {
comparator.setScorer(scorer);
}
}
}
@Override
public void setNextReader(AtomicReaderContext context) throws IOException {
this.readerContext = context;
FunctionValues values = groupBy.getValues(vsContext, context);
filler = values.getValueFiller();
mval = filler.getValue();
for (GroupHead groupHead : groups.values()) {
for (int i = 0; i < groupHead.comparators.length; i++) {
groupHead.comparators[i] = groupHead.comparators[i].setNextReader(context);
}
}
}
/** Holds current head document for a single group.
*
* @lucene.experimental */
public class GroupHead extends AbstractAllGroupHeadsCollector.GroupHead<MutableValue> {
final FieldComparator<?>[] comparators;
@SuppressWarnings({"unchecked","rawtypes"})
private GroupHead(MutableValue groupValue, Sort sort, int doc) throws IOException {
super(groupValue, doc + readerContext.docBase);
final SortField[] sortFields = sort.getSort();
comparators = new FieldComparator[sortFields.length];
for (int i = 0; i < sortFields.length; i++) {
comparators[i] = sortFields[i].getComparator(1, i).setNextReader(readerContext);
comparators[i].setScorer(scorer);
comparators[i].copy(0, doc);
comparators[i].setBottom(0);
}
}
@Override
public int compare(int compIDX, int doc) throws IOException {
return comparators[compIDX].compareBottom(doc);
}
@Override
public void updateDocHead(int doc) throws IOException {
for (FieldComparator<?> comparator : comparators) {
comparator.copy(0, doc);
comparator.setBottom(0);
}
this.doc = doc + readerContext.docBase;
}
}
}