1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License.  You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied.  See the License for the specific language governing permissions and limitations
12 * under the License.
13 */
14
15package com.google.common.cache;
16
17import com.google.common.annotations.Beta;
18import com.google.common.annotations.GwtCompatible;
19
20/**
21 * Calculates the weights of cache entries.
22 *
23 * @author Charles Fry
24 * @since 11.0
25 */
26@Beta
27@GwtCompatible
28public interface Weigher<K, V> {
29
30  /**
31   * Returns the weight of a cache entry. There is no unit for entry weights; rather they are simply
32   * relative to each other.
33   *
34   * @return the weight of the entry; must be non-negative
35   */
36  int weigh(K key, V value);
37}
38