/**
* 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.jena.atlas.lib.cache;
import java.util.concurrent.Callable ;
import org.apache.jena.atlas.AtlasException ;
import org.apache.jena.atlas.lib.Cache ;
/** Support operations for Cache functions */
class CacheOps {
/** Implementation of getOrFill based on Cache.get and Cache.put */
public static <K,V> V getOrFill(Cache<K,V> cache, K key, Callable<V> callable) {
V value = cache.getIfPresent(key) ;
if ( value == null ) {
try { value = callable.call() ; }
catch (Exception e) {
throw new AtlasException("Exception on cache fill", e) ;
}
if ( value != null )
cache.put(key, value) ;
}
return value ;
}
/** Thread safe implementation of getOrFill based on Cache.get and Cache.put */
public static <K,V> V getOrFillSync(Cache<K,V> cache, K key, Callable<V> callable) {
synchronized(cache) {
return getOrFill(cache, key, callable) ;
}
}
}