io.trino.operator.output.SkewedPartitionFunction Maven / Gradle / Ivy
/*
* 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 io.trino.operator.output;
import io.trino.operator.PartitionFunction;
import io.trino.spi.Page;
import static java.util.Objects.requireNonNull;
public class SkewedPartitionFunction
implements PartitionFunction
{
private final PartitionFunction partitionFunction;
private final SkewedPartitionRebalancer skewedPartitionRebalancer;
private final long[] partitionRowCount;
public SkewedPartitionFunction(PartitionFunction partitionFunction, SkewedPartitionRebalancer skewedPartitionRebalancer)
{
this.partitionFunction = requireNonNull(partitionFunction, "partitionFunction is null");
this.skewedPartitionRebalancer = requireNonNull(skewedPartitionRebalancer, "skewedPartitionRebalancer is null");
this.partitionRowCount = new long[partitionFunction.partitionCount()];
}
@Override
public int partitionCount()
{
return skewedPartitionRebalancer.getTaskCount();
}
@Override
public int getPartition(Page page, int position)
{
int partition = partitionFunction.getPartition(page, position);
return skewedPartitionRebalancer.getTaskId(partition, partitionRowCount[partition]++);
}
public void flushPartitionRowCountToRebalancer()
{
for (int partition = 0; partition < partitionFunction.partitionCount(); partition++) {
skewedPartitionRebalancer.addPartitionRowCount(partition, partitionRowCount[partition]);
partitionRowCount[partition] = 0;
}
}
}