/*
* Licensed 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 com.facebook.presto.operator.aggregation;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.block.BlockBuilderStatus;
import com.facebook.presto.spi.type.SqlVarbinary;
import com.facebook.presto.spi.type.StandardTypes;
import com.google.common.collect.ImmutableList;
import io.airlift.stats.cardinality.HyperLogLog;
import java.util.List;
import static com.facebook.presto.spi.type.HyperLogLogType.HYPER_LOG_LOG;
public class TestMergeHyperLogLogAggregation
extends AbstractTestAggregationFunction
{
private static final int NUMBER_OF_BUCKETS = 16;
@Override
public Block[] getSequenceBlocks(int start, int length)
{
BlockBuilder blockBuilder = HYPER_LOG_LOG.createBlockBuilder(new BlockBuilderStatus(), length);
for (int i = start; i < start + length; i++) {
HyperLogLog hll = HyperLogLog.newInstance(NUMBER_OF_BUCKETS);
hll.add(i);
HYPER_LOG_LOG.writeSlice(blockBuilder, hll.serialize());
}
return new Block[] {blockBuilder.build()};
}
@Override
protected String getFunctionName()
{
return "merge";
}
@Override
protected List<String> getFunctionParameterTypes()
{
return ImmutableList.of(StandardTypes.HYPER_LOG_LOG);
}
@Override
public Object getExpectedValue(int start, int length)
{
if (length == 0) {
return null;
}
HyperLogLog hll = HyperLogLog.newInstance(NUMBER_OF_BUCKETS);
for (int i = start; i < start + length; i++) {
hll.add(i);
}
return new SqlVarbinary(hll.serialize().getBytes());
}
}