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.grouping.AbstractAllGroupsCollector;
import org.apache.lucene.util.mutable.MutableValue;
import java.io.IOException;
import java.util.Collection;
import java.util.Map;
import java.util.SortedSet;
import java.util.TreeSet;
/**
* A collector that collects all groups that match the
* query. Only the group value is collected, and the order
* is undefined. This collector does not determine
* the most relevant document of a group.
*
* <p/>
* Implementation detail: Uses {@link ValueSource} and {@link FunctionValues} to retrieve the
* field values to group by.
*
* @lucene.experimental
*/
public class FunctionAllGroupsCollector extends AbstractAllGroupsCollector<MutableValue> {
private final Map<?, ?> vsContext;
private final ValueSource groupBy;
private final SortedSet<MutableValue> groups = new TreeSet<MutableValue>();
private FunctionValues.ValueFiller filler;
private MutableValue mval;
/**
* Constructs a {@link FunctionAllGroupsCollector} instance.
*
* @param groupBy The {@link ValueSource} to group by
* @param vsContext The ValueSource context
*/
public FunctionAllGroupsCollector(ValueSource groupBy, Map<?, ?> vsContext) {
this.vsContext = vsContext;
this.groupBy = groupBy;
}
@Override
public Collection<MutableValue> getGroups() {
return groups;
}
@Override
public void collect(int doc) throws IOException {
filler.fillValue(doc);
if (!groups.contains(mval)) {
groups.add(mval.duplicate());
}
}
@Override
public void setNextReader(AtomicReaderContext context) throws IOException {
FunctionValues values = groupBy.getValues(vsContext, context);
filler = values.getValueFiller();
mval = filler.getValue();
}
}