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1
25
26 package org.snipsnap.cache;
27
28 import org.snipsnap.snip.storage.Storage;
29 import org.snipsnap.snip.storage.query.Query;
30
31 import java.util.*;
32
33
39 public class Cache {
40 private Map caches;
41 private Map loaders;
42
43 public static Cache instance;
44 private static Object  monitor = new Object ();
45
46 public static Cache getInstance() {
47 synchronized (monitor) {
48 if (null == instance) {
49 instance = new Cache();
50 }
51 }
52 return instance;
53 }
54
55 public static void removeInstance() {
56 synchronized (monitor) {
57 if (null != instance) {
58 instance = null;
59 }
60 }
61 }
62
63 private Cache() {
64 caches = new HashMap();
65 loaders = new HashMap();
66 }
67
68 public void setLoader(Class type, Storage loader) {
69 loaders.put(type, loader);
70 if (!caches.containsKey(type)) {
71 caches.put(type, new HashMap());
72 }
73 }
74
75 public void put(Class type, String name, Object snip) {
76 Map cache = (Map) caches.get(type);
77 if (null != cache) {
78 cache.put(name.toUpperCase(), snip);
79 }
80 return;
81 }
82
83 public boolean contains(Class type, String name) {
84 Map cache = (Map) caches.get(type);
85 if (null != cache) {
86 return cache.containsKey(name.toUpperCase());
87 } else {
88 return false;
89 }
90 }
91
92 public List getCache(Class type) {
93
102 return new ArrayList(((Map) caches.get(type)).values());
103 }
104
105
106 public List querySorted(Comparator c, int size, Class type) {
107 ArrayList result = new ArrayList(getCache(type));
108 Collections.sort(result, c);
109 return result.subList(0, Math.min(size, result.size()));
110 }
111
112 public List querySorted(Query query, Comparator c, Class type) {
113 List result = query(query, type);
114 Collections.sort(result, c);
115 return result;
116 }
117
118 public List querySorted(Query query, Comparator c, int size, Class type) {
119 List result = query(query, type);
120 Collections.sort(result, c);
121 return result.subList(0, Math.min(size, result.size()));
122 }
123
124 public List query(Query query, Class type) {
125 Iterator iterator = getCache(type).iterator();
126 List result = new ArrayList();
127 while (iterator.hasNext()) {
128 Object object = iterator.next();
129 if (query.fit(object)) {
130 result.add(object);
131 }
132 }
133 return result;
134 }
135
136 public Object get(Class type, String name) {
137 Map cache = (Map) caches.get(type);
138 if (null != cache) {
139 return cache.get(name.toUpperCase());
140 } else {
141 return null;
142 }
143 }
144
145 public void remove(Class type, String name) {
146 Map cache = (Map) caches.get(type);
147 if (null != cache) {
148 cache.remove(name.toUpperCase());
149 }
150 return;
151 }
152
153 public Object load(Class type, String name) {
154 Map cache = (Map) caches.get(type);
155 Object object = null;
156 if (contains(type, name)) {
157 object = get(type, name);
158 } else {
159 Storage loader = (Storage) loaders.get(type);
160 object = loader.loadObject(name);
161 if (null != object) {
162 put(type, name, object);
163 }
164 }
165 return object;
166 }
167 }
168 |
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