io.druid.query.aggregation.cardinality.CardinalityBufferAggregator Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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package io.druid.query.aggregation.cardinality;
import io.druid.hll.HyperLogLogCollector;
import io.druid.query.ColumnSelectorPlus;
import io.druid.query.aggregation.BufferAggregator;
import io.druid.query.aggregation.cardinality.types.CardinalityAggregatorColumnSelectorStrategy;
import io.druid.query.monomorphicprocessing.RuntimeShapeInspector;
import java.nio.ByteBuffer;
public class CardinalityBufferAggregator implements BufferAggregator
{
private final ColumnSelectorPlus[] selectorPluses;
private final boolean byRow;
private static final byte[] EMPTY_BYTES = HyperLogLogCollector.makeEmptyVersionedByteArray();
CardinalityBufferAggregator(
ColumnSelectorPlus[] selectorPluses,
boolean byRow
)
{
this.selectorPluses = selectorPluses;
this.byRow = byRow;
}
@Override
public void init(ByteBuffer buf, int position)
{
final ByteBuffer mutationBuffer = buf.duplicate();
mutationBuffer.position(position);
mutationBuffer.put(EMPTY_BYTES);
}
@Override
public void aggregate(ByteBuffer buf, int position)
{
// Save position, limit and restore later instead of allocating a new ByteBuffer object
final int oldPosition = buf.position();
final int oldLimit = buf.limit();
buf.limit(position + HyperLogLogCollector.getLatestNumBytesForDenseStorage());
buf.position(position);
try {
final HyperLogLogCollector collector = HyperLogLogCollector.makeCollector(buf);
if (byRow) {
CardinalityAggregator.hashRow(selectorPluses, collector);
} else {
CardinalityAggregator.hashValues(selectorPluses, collector);
}
}
finally {
buf.limit(oldLimit);
buf.position(oldPosition);
}
}
@Override
public Object get(ByteBuffer buf, int position)
{
ByteBuffer dataCopyBuffer = ByteBuffer.allocate(HyperLogLogCollector.getLatestNumBytesForDenseStorage());
ByteBuffer mutationBuffer = buf.duplicate();
mutationBuffer.position(position);
mutationBuffer.get(dataCopyBuffer.array());
return HyperLogLogCollector.makeCollector(dataCopyBuffer);
}
@Override
public float getFloat(ByteBuffer buf, int position)
{
throw new UnsupportedOperationException("CardinalityBufferAggregator does not support getFloat()");
}
@Override
public long getLong(ByteBuffer buf, int position)
{
throw new UnsupportedOperationException("CardinalityBufferAggregator does not support getLong()");
}
@Override
public double getDouble(ByteBuffer buf, int position)
{
throw new UnsupportedOperationException("CardinalityBufferAggregators does not support getDouble()");
}
@Override
public void close()
{
// no resources to cleanup
}
@Override
public void inspectRuntimeShape(RuntimeShapeInspector inspector)
{
inspector.visit("selectorPluses", selectorPluses);
}
}