/*
* 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.solr.analytics.statistics;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
/**
* <code>UniqueValueCounter</code> computes the number of unique values.
*/
public class UniqueStatsCollector extends AbstractDelegatingStatsCollector{
private final Set<Object> uniqueValues = new HashSet<>();
public UniqueStatsCollector(StatsCollector delegate) {
super(delegate);
}
@Override
public void collect(int doc) throws IOException {
super.collect(doc);
if (value.exists) {
uniqueValues.add(value.toObject());
}
}
@Override
public Comparable getStat(String stat) {
if (stat.equals("unique")) {
return new Long(uniqueValues.size());
}
return delegate.getStat(stat);
}
@Override
public void compute() {
delegate.compute();
}
}