org.opendaylight.infrautils.caches.CacheStats 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;
/**
* Statistics about a Cache.
*
* The data returned by this interface may not be 100% accurate, due to concurrency optimizations in implementations.
*
* @author Michael Vorburger.ch
*/
public interface CacheStats {
// Following are strongly typed getter for stats which all cache implementations will be able to provide
/**
* Number of key/value pair entries currently in the cache.
*/
long estimatedCurrentEntries();
/**
* Number of "misses" in the cache.
* A "miss" causes the {@link CacheFunction} to have to be invoked on a {@link Cache#get(Object)}.
*/
long missCount();
/**
* Number of "hits" in the cache. A "hit" is when a Cache can return from a
* {@link Cache#get(Object)} without having to use its {@link CacheFunction}.
*/
long hitCount();
/**
* Extensions provide implementation specific cache stats.
* This is good enough for e.g. a CLI to dump and display to end-users.
*/
ImmutableMap extensions();
}