package org.exoplatform.commons.cache.future;
import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
/** @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> */
class Retrieval<K, V, C> implements Callable<V> {
/** . */
private final C context;
/** . */
private final K key;
/** . */
private final FutureCache<K, V, C> cache;
/** . */
final FutureTask<V> future;
/** Avoid reentrancy. */
transient Thread current;
public Retrieval(C context, K key, FutureCache<K, V, C> cache) {
this.key = key;
this.context = context;
this.future = new FutureTask<V>(this);
this.cache = cache;
this.current = null;
}
public V call() throws Exception {
// Retrieve the value from the loader
V value = cache.loader.retrieve(context, key);
//
if (value != null) {
// Cache it, it is made available to other threads (unless someone removes it)
cache.put(key, value);
// Return value
return value;
} else {
return null;
}
}
}