/*
* 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.ignite.internal.client;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import org.apache.ignite.IgniteException;
import org.apache.ignite.compute.ComputeJob;
import org.apache.ignite.compute.ComputeJobAdapter;
import org.apache.ignite.compute.ComputeJobResult;
import org.apache.ignite.compute.ComputeTaskSplitAdapter;
/**
* Adapter for {@link org.apache.ignite.compute.ComputeTaskSplitAdapter}
* overriding {@code split(...)} method to return singleton with self instance.
* This adapter should be used for tasks that always splits to a single task.
* @param <T> Type of the task execution argument.
* @param <R> Type of the task result returning from {@link org.apache.ignite.compute.ComputeTask#reduce(List)} method.
*/
public abstract class TaskSingleJobSplitAdapter<T, R> extends ComputeTaskSplitAdapter<T, R> {
/** Empty constructor. */
protected TaskSingleJobSplitAdapter() {
// No-op.
}
/** {@inheritDoc} */
@Override protected Collection<? extends ComputeJob> split(final int gridSize, final T arg) {
return Collections.singleton(new ComputeJobAdapter() {
@Override public Object execute() {
return executeJob(gridSize, arg);
}
});
}
/** {@inheritDoc} */
@Override public R reduce(List<ComputeJobResult> results) {
assert results.size() == 1;
ComputeJobResult res = results.get(0);
if (res.isCancelled())
throw new IgniteException("Reduce receives failed job.");
return res.getData();
}
/**
* Executes this task's job.
*
* @param gridSize Number of available grid nodes. Note that returned number of
* jobs can be less, equal or greater than this grid size.
* @param arg Task execution argument. Can be {@code null}.
* @return Job execution result (possibly {@code null}). This result will be returned
* in {@link org.apache.ignite.compute.ComputeJobResult#getData()} method passed into
* {@link org.apache.ignite.compute.ComputeTask#result(org.apache.ignite.compute.ComputeJobResult, List)} method into task on caller node.
*/
protected abstract Object executeJob(int gridSize, T arg);
}