io.trino.operator.TransformWork 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;
import java.util.function.Function;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;
public final class TransformWork
implements Work
{
private final Work work;
private final Function transformation;
private boolean finished;
private O result;
public TransformWork(Work work, Function transformation)
{
this.work = requireNonNull(work, "work is null");
this.transformation = requireNonNull(transformation, "transformation is null");
}
@Override
public boolean process()
{
checkState(!finished);
finished = work.process();
if (!finished) {
return false;
}
result = transformation.apply(work.getResult());
return true;
}
@Override
public O getResult()
{
checkState(finished, "process has not finished");
return result;
}
}