hunt.shiro.cache.AbstractCacheManager source code

1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements.  See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership.  The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License.  You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied.  See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  */
19 module hunt.shiro.cache.AbstractCacheManager;
20 
21 import hunt.shiro.cache.Cache;
22 import hunt.shiro.cache.CacheManager;
23 
24 import hunt.shiro.util.Common;
25 import hunt.shiro.util.LifecycleUtils;
26 // import hunt.shiro.util.StringUtils;
27 
28 import hunt.Exceptions;
29 import hunt.util.StringBuilder;
30 
31 import std.array;
32 
33 // import java.util.Collection;
34 // import java.util.concurrent.ConcurrentHashMap;
35 // import java.util.concurrent.ConcurrentMap;
36 
37 /**
38  * Very simple abstract {@code CacheManager} implementation that retains all created {@link Cache Cache} instances in
39  * an in-memory {@link ConcurrentMap ConcurrentMap}.  {@code Cache} instance creation is left to subclasses via
40  * the {@link #createCache createCache} method implementation.
41  *
42  * @since 1.0
43  */
44 abstract class AbstractCacheManager(K, V) : CacheManager, Destroyable {
45 
46     /**
47      * Retains all Cache objects maintained by this cache manager.
48      */
49     private Cache!(K, V)[string] caches;
50 
51     /**
52      * Default no-arg constructor that instantiates an internal name-to-cache {@code ConcurrentMap}.
53      */
54     this() {
55         // this.caches = new ConcurrentHashMap<string, Cache>();
56     }
57 
58     /**
59      * Returns the cache with the specified {@code name}.  If the cache instance does not yet exist, it will be lazily
60      * created, retained for further access, and then returned.
61      *
62      * @param name the name of the cache to acquire.
63      * @return the cache with the specified {@code name}.
64      * @throws IllegalArgumentException if the {@code name} argument is {@code null} or does not contain text.
65      * @throws CacheException           if there is a problem lazily creating a {@code Cache} instance.
66      */
67     Cache!(K, V) getCache(string name) {
68         if (name.empty()) {
69             throw new IllegalArgumentException("Cache name cannot be null or empty.");
70         }
71         Cache!(K, V) cache = caches.get(name, null);
72         if (cache is null) {
73             cache = createCache(name);
74             caches[name] = cache;
75         }
76 
77         //noinspection unchecked
78         return cache;
79     }
80 
81     /**
82      * Creates a new {@code Cache} instance associated with the specified {@code name}.
83      *
84      * @param name the name of the cache to create
85      * @return a new {@code Cache} instance associated with the specified {@code name}.
86      * @throws CacheException if the {@code Cache} instance cannot be created.
87      */
88     protected abstract Cache!(K, V) createCache(string name);
89 
90     /**
91      * Cleanup method that first {@link LifecycleUtils#destroy destroys} all of it's managed caches and then
92      * {@link java.util.Map#clear clears} out the internally referenced cache map.
93      *
94      * @throws Exception if any of the managed caches can't destroy properly.
95      */
96     void destroy() {
97         while (caches !is null) {
98             foreach (Cache!(K, V) cache; caches.byValue) {
99                 LifecycleUtils.destroy(cast(Object)cache);
100             }
101             caches.clear();
102         }
103     }
104 
105     override string toString() {
106         
107         StringBuilder sb = new StringBuilder(typeof(this).stringof)
108                 .append(" with ")
109                 .append(caches.length)
110                 .append(" cache(s)): [");
111         int i = 0;
112         foreach (Cache!(K, V) cache ; caches.byValue) {
113             if (i > 0) {
114                 sb.append(", ");
115             }
116             sb.append((cast(Object)cache).toString());
117             i++;
118         }
119         sb.append("]");
120         return sb.toString();
121     }
122 }