moving out OptionalCacheLoader
Change-Id: If929ed119df1a0282e311188a00776e971f78991
diff --git a/core/store/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java b/core/store/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java
index 1834a50..df4e70a 100644
--- a/core/store/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java
+++ b/core/store/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java
@@ -7,9 +7,24 @@
import com.google.common.cache.ForwardingLoadingCache.SimpleForwardingLoadingCache;
import com.google.common.cache.LoadingCache;
+/**
+ * Wrapper around LoadingCache to handle negative hit scenario.
+ * <p>
+ * When the LoadingCache returned Absent,
+ * this implementation will invalidate the entry immediately to avoid
+ * caching negative hits.
+ *
+ * @param <K> Cache key type
+ * @param <V> Cache value type. (Optional{@literal <V>})
+ */
public class AbsentInvalidatingLoadingCache<K, V> extends
SimpleForwardingLoadingCache<K, Optional<V>> {
+ /**
+ * Constructor.
+ *
+ * @param delegate actual {@link LoadingCache} to delegate loading.
+ */
public AbsentInvalidatingLoadingCache(LoadingCache<K, Optional<V>> delegate) {
super(delegate);
}