org.opendaylight.infrautils.caches.CheckedCacheFunction Maven / Gradle / Ivy
/*
* Copyright (c) 2017 Red Hat, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.infrautils.caches;
import com.google.common.collect.ImmutableMap;
import java.util.function.Function;
/**
* {@link CheckedCache}'s Function, can throw checked Exception.
*
* See also {@link CacheFunction}.
*
* @author Michael Vorburger.ch
*/
@FunctionalInterface
public interface CheckedCacheFunction {
/**
* Calculate the value of the cache entry for the given key.
* @param key the key for which to "calculate" (lookup, remote call, ...) a value.
* @return value for the given key
* @throws E checked exception thrown if no value for the given key could be obtained
*/
V get(K key) throws E;
/**
* See {@link CacheFunction#get(Iterable)}.
*/
default ImmutableMap get(Iterable keys) throws E {
ImmutableMap.Builder mapBuilder = ImmutableMap.builder();
for (K key : keys) {
mapBuilder.put(key, get(key));
}
return mapBuilder.build();
}
/**
* See {@link CacheFunction#from(Function)}.
*/
default CacheFunction from(Function function) throws E {
return function::apply;
}
}