io.trino.cost.SimpleStatsRule 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.cost;
import io.trino.cost.ComposableStatsCalculator.Rule;
import io.trino.cost.StatsCalculator.Context;
import io.trino.sql.planner.plan.PlanNode;
import java.util.Optional;
import static java.util.Objects.requireNonNull;
public abstract class SimpleStatsRule
implements Rule
{
private final StatsNormalizer normalizer;
protected SimpleStatsRule(StatsNormalizer normalizer)
{
this.normalizer = requireNonNull(normalizer, "normalizer is null");
}
@Override
public final Optional calculate(T node, Context context)
{
return doCalculate(node, context)
.map(estimate -> normalizer.normalize(estimate, node.getOutputSymbols()));
}
protected abstract Optional doCalculate(T node, Context context);
}