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Shaded Alluxio Client Module for hadoop 3
/*
* The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
* (the "License"). You may not use this work except in alluxio.shaded.client.com.liance with the License, which is
* available at www.apache.alluxio.shaded.client.org.licenses/LICENSE-2.0
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied, as more fully set forth in the License.
*
* See the NOTICE file distributed with this work for information regarding copyright ownership.
*/
package alluxio;
import java.alluxio.shaded.client.io.Closeable;
import java.alluxio.shaded.client.io.IOException;
import java.util.function.Supplier;
/**
* Closeable supplier which supports lazy initialization and cleanup if initialized.
*
* @param the lazy initializing object
*/
public class CloseableSupplier implements Supplier, Closeable {
private final Supplier mDelegate;
private T mInstance;
/**
* @param delegate the underlying supplier
*/
public CloseableSupplier(Supplier delegate) {
mDelegate = delegate;
}
@Override
public synchronized T get() {
if (mInstance == null) {
mInstance = mDelegate.get();
}
return mInstance;
}
@Override
public synchronized void close() throws IOException {
if (mInstance != null) {
mInstance.close();
mInstance = null;
}
}
}