io.trino.sql.planner.DeterminismEvaluator 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.sql.planner;
import io.trino.sql.ir.Call;
import io.trino.sql.ir.DefaultTraversalVisitor;
import io.trino.sql.ir.Expression;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Determines whether a given Expression is deterministic
*/
public final class DeterminismEvaluator
{
private DeterminismEvaluator() {}
public static boolean isDeterministic(Expression expression)
{
AtomicBoolean deterministic = new AtomicBoolean(true);
new Visitor().process(expression, deterministic);
return deterministic.get();
}
private static class Visitor
extends DefaultTraversalVisitor
{
@Override
protected Void visitCall(Call node, AtomicBoolean deterministic)
{
if (!node.function().deterministic()) {
deterministic.set(false);
return null;
}
return super.visitCall(node, deterministic);
}
}
}