001 /*
002 * Copyright (C) 2011 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package com.google.common.cache;
018
019 import com.google.common.annotations.Beta;
020
021 /**
022 * Calculates the weights of cache entries.
023 *
024 * @author fry@google.com (Charles Fry)
025 * @since 11.0
026 */
027 @Beta
028 public interface Weigher<K, V> {
029
030 /**
031 * Returns the weight of a cache entry. There is no unit for entry weights; rather they are simply
032 * relative to each other.
033 *
034 * @return the weight of the entry; must be non-negative
035 */
036 int weigh(K key, V value);
037
038 }