1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.jexl3;
18
19 import java.util.Collection;
20 import java.util.Collections;
21 import java.util.Map;
22
23 /**
24 * Caching scripts or templates interface.
25 *
26 * @param <K> source
27 * @param <V> script or template
28 */
29 public interface JexlCache<K, V> {
30
31 /**
32 * Returns the cache capacity, the maximum number of elements it can contain.
33 *
34 * @return the cache capacity
35 */
36 int capacity();
37
38 /**
39 * Clears the cache.
40 */
41 void clear();
42
43 /**
44 * Produces the cache entry set.
45 *
46 * <p>
47 * For implementations testing only
48 * </p>
49 *
50 * @return the cache entry list
51 */
52 default Collection<Map.Entry<K, V>> entries() {
53 return Collections.emptyList();
54 }
55
56 /**
57 * Gets a value from cache.
58 *
59 * @param key the cache entry key
60 * @return the cache entry value
61 */
62 V get(K key);
63
64 /**
65 * Puts a value in cache.
66 *
67 * @param key the cache entry key
68 * @param script the cache entry value
69 * @return the previously associated value if any
70 */
71 V put(K key, V script);
72
73 /**
74 * Returns the cache size, the actual number of elements it contains.
75 *
76 * @return the cache size
77 */
78 int size();
79
80 /**
81 * A cached reference.
82 */
83 interface Reference {
84 /**
85 * Gets the referenced object.
86 * @return the referenced object
87 */
88 Object getCache();
89
90 /**
91 * Sets the referenced object.
92 * @param cache the referenced object
93 */
94 void setCache(Object cache);
95 }
96 }