org.elasticsearch.common.util.CachedSupplier Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.common.util;
import java.util.function.Supplier;
/**
* A {@link Supplier} that caches its return value. This may be useful to make
* a {@link Supplier} idempotent or for performance reasons if always returning
* the same instance is acceptable.
*/
public final class CachedSupplier implements Supplier {
private Supplier supplier;
private T result;
private boolean resultSet;
public CachedSupplier(Supplier supplier) {
this.supplier = supplier;
}
@Override
public synchronized T get() {
if (resultSet == false) {
result = supplier.get();
resultSet = true;
}
return result;
}
}