/*
* Druid - a distributed column store.
* Copyright (C) 2012, 2013 Metamarkets Group Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package io.druid.query.aggregation.hyperloglog;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Charsets;
import com.metamx.common.IAE;
import io.druid.query.aggregation.Aggregator;
import io.druid.query.aggregation.AggregatorFactory;
import io.druid.query.aggregation.Aggregators;
import io.druid.query.aggregation.BufferAggregator;
import io.druid.segment.ColumnSelectorFactory;
import io.druid.segment.ObjectColumnSelector;
import org.apache.commons.codec.binary.Base64;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
/**
*/
public class HyperUniquesAggregatorFactory implements AggregatorFactory
{
public static Object estimateCardinality(Object object)
{
if (object == null) {
return 0;
}
return ((HyperLogLogCollector) object).estimateCardinality();
}
private static final byte CACHE_TYPE_ID = 0x5;
private final String name;
private final String fieldName;
@JsonCreator
public HyperUniquesAggregatorFactory(
@JsonProperty("name") String name,
@JsonProperty("fieldName") String fieldName
)
{
this.name = name;
this.fieldName = fieldName.toLowerCase();
}
@Override
public Aggregator factorize(ColumnSelectorFactory metricFactory)
{
ObjectColumnSelector selector = metricFactory.makeObjectColumnSelector(fieldName);
if (selector == null) {
return Aggregators.noopAggregator();
}
final Class classOfObject = selector.classOfObject();
if (classOfObject.equals(Object.class) || HyperLogLogCollector.class.isAssignableFrom(classOfObject)) {
return new HyperUniquesAggregator(name, selector);
}
throw new IAE(
"Incompatible type for metric[%s], expected a HyperUnique, got a %s", fieldName, classOfObject
);
}
@Override
public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory)
{
ObjectColumnSelector selector = metricFactory.makeObjectColumnSelector(fieldName);
if (selector == null) {
return Aggregators.noopBufferAggregator();
}
final Class classOfObject = selector.classOfObject();
if (classOfObject.equals(Object.class) || HyperLogLogCollector.class.isAssignableFrom(classOfObject)) {
return new HyperUniquesBufferAggregator(selector);
}
throw new IAE(
"Incompatible type for metric[%s], expected a HyperUnique, got a %s", fieldName, classOfObject
);
}
@Override
public Comparator getComparator()
{
return new Comparator<HyperLogLogCollector>()
{
@Override
public int compare(HyperLogLogCollector lhs, HyperLogLogCollector rhs)
{
return lhs.compareTo(rhs);
}
};
}
@Override
public Object combine(Object lhs, Object rhs)
{
if (rhs == null) {
return lhs;
}
if (lhs == null) {
return rhs;
}
return ((HyperLogLogCollector) lhs).fold((HyperLogLogCollector) rhs);
}
@Override
public AggregatorFactory getCombiningFactory()
{
return new HyperUniquesAggregatorFactory(name, name);
}
@Override
public List<AggregatorFactory> getRequiredColumns()
{
return Arrays.<AggregatorFactory>asList(new HyperUniquesAggregatorFactory(fieldName, fieldName));
}
@Override
public Object deserialize(Object object)
{
if (object instanceof byte[]) {
return HyperLogLogCollector.makeCollector(ByteBuffer.wrap((byte[]) object));
} else if (object instanceof ByteBuffer) {
return HyperLogLogCollector.makeCollector((ByteBuffer) object);
} else if (object instanceof String) {
return HyperLogLogCollector.makeCollector(
ByteBuffer.wrap(Base64.decodeBase64(((String) object).getBytes(Charsets.UTF_8)))
);
}
return object;
}
@Override
public Object finalizeComputation(Object object)
{
return estimateCardinality(object);
}
@Override
@JsonProperty
public String getName()
{
return name;
}
@Override
public List<String> requiredFields()
{
return Arrays.asList(fieldName);
}
@JsonProperty
public String getFieldName()
{
return fieldName;
}
@Override
public byte[] getCacheKey()
{
byte[] fieldNameBytes = fieldName.getBytes(Charsets.UTF_8);
return ByteBuffer.allocate(1 + fieldNameBytes.length).put(CACHE_TYPE_ID).put(fieldNameBytes).array();
}
@Override
public String getTypeName()
{
return "hyperUnique";
}
@Override
public int getMaxIntermediateSize()
{
return HyperLogLogCollector.getLatestNumBytesForDenseStorage();
}
@Override
public Object getAggregatorStartValue()
{
return HyperLogLogCollector.makeLatestCollector();
}
@Override
public String toString()
{
return "HyperUniquesAggregatorFactory{" +
"name='" + name + '\'' +
", fieldName='" + fieldName + '\'' +
'}';
}
@Override
public boolean equals(Object o)
{
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
HyperUniquesAggregatorFactory that = (HyperUniquesAggregatorFactory) o;
if (!fieldName.equals(that.fieldName)) return false;
if (!name.equals(that.name)) return false;
return true;
}
@Override
public int hashCode()
{
int result = name.hashCode();
result = 31 * result + fieldName.hashCode();
return result;
}
}