/*
* 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 com.facebook.presto.execution.scheduler;
import com.facebook.presto.execution.RemoteTask;
import com.facebook.presto.execution.SqlStageExecution;
import com.facebook.presto.spi.Node;
import com.google.common.annotations.VisibleForTesting;
import java.util.List;
import java.util.Map;
import java.util.function.BiFunction;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static java.util.Objects.requireNonNull;
public class FixedCountScheduler
implements StageScheduler
{
private final BiFunction<Node, Integer, RemoteTask> taskScheduler;
private final Map<Integer, Node> partitionToNode;
public FixedCountScheduler(SqlStageExecution stage, Map<Integer, Node> partitionToNode)
{
requireNonNull(stage, "stage is null");
this.taskScheduler = stage::scheduleTask;
this.partitionToNode = requireNonNull(partitionToNode, "partitionToNode is null");
}
@VisibleForTesting
public FixedCountScheduler(BiFunction<Node, Integer, RemoteTask> taskScheduler, Map<Integer, Node> partitionToNode)
{
this.taskScheduler = requireNonNull(taskScheduler, "taskScheduler is null");
this.partitionToNode = requireNonNull(partitionToNode, "partitionToNode is null");
}
@Override
public ScheduleResult schedule()
{
List<RemoteTask> newTasks = partitionToNode.entrySet().stream()
.map(entry -> taskScheduler.apply(entry.getValue(), entry.getKey()))
.collect(toImmutableList());
return new ScheduleResult(true, newTasks, 0);
}
}