org.apache.druid.sql.calcite.planner.PlannerResult Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.druid.sql.calcite.planner;
import com.google.common.base.Supplier;
import com.google.common.collect.ImmutableSet;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.druid.java.util.common.guava.Sequence;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
public class PlannerResult
{
private final Supplier> resultsSupplier;
private final RelDataType rowType;
private final Set datasourceNames;
private final AtomicBoolean didRun = new AtomicBoolean();
public PlannerResult(
final Supplier> resultsSupplier,
final RelDataType rowType,
final Set datasourceNames
)
{
this.resultsSupplier = resultsSupplier;
this.rowType = rowType;
this.datasourceNames = ImmutableSet.copyOf(datasourceNames);
}
public Sequence run()
{
if (!didRun.compareAndSet(false, true)) {
// Safety check.
throw new IllegalStateException("Cannot run more than once");
}
return resultsSupplier.get();
}
public RelDataType rowType()
{
return rowType;
}
public Set datasourceNames()
{
return datasourceNames;
}
}