src/main/java/org/apache/accumulo/testing/performance/util/TestExecutor.java

/*
 * 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.accumulo.testing.performance.util;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.stream.Stream;

public class TestExecutor<T> implements Iterable<T>, AutoCloseable {
  private ExecutorService es;
  private List<Future<T>> futures = new ArrayList<>();

  public TestExecutor(int numThreads) {
    es = Executors.newFixedThreadPool(numThreads);
  }

  public void submit(Callable<T> task) {
    futures.add(es.submit(task));
  }

  @Override
  public void close() {
    es.shutdownNow();
  }

  public Stream<T> stream() {
    return futures.stream().map(f -> {
      try {
        return f.get();
      } catch (InterruptedException | ExecutionException e) {
        throw new RuntimeException(e);
      }
    });
  }

  @Override
  public Iterator<T> iterator() {
    return stream().iterator();
  }
}