%line | %branch | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
org.apache.turbine.services.cache.RefreshableCachedObject |
|
|
1 | package org.apache.turbine.services.cache; |
|
2 | ||
3 | /* |
|
4 | * Copyright 2001-2004 The Apache Software Foundation. |
|
5 | * |
|
6 | * Licensed under the Apache License, Version 2.0 (the "License") |
|
7 | * you may not use this file except in compliance with the License. |
|
8 | * 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, software |
|
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
|
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
15 | * See the License for the specific language governing permissions and |
|
16 | * limitations under the License. |
|
17 | */ |
|
18 | ||
19 | /** |
|
20 | * The idea of the RefreshableCachedObject is that, rather than |
|
21 | * removing items from the cache when they become stale, we'll tell them to |
|
22 | * refresh themselves instead. That way they'll always be in the |
|
23 | * cache, and the code to refresh them will be run by the background |
|
24 | * thread rather than by a user request thread. You can also set a TTL (Time |
|
25 | * To Live) for the object. This way, if the object hasn't been touched |
|
26 | * for the TTL period, then it will be removed from the cache. |
|
27 | * |
|
28 | * This extends CachedObject and provides a method for refreshing the |
|
29 | * cached object, and resetting its expire time. |
|
30 | * |
|
31 | * @author <a href="mailto:nissim@nksystems.com">Nissim Karpenstein</a> |
|
32 | * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> |
|
33 | * @version $Id: RefreshableCachedObject.java,v 1.5.2.2 2004/05/20 03:05:19 seade Exp $ |
|
34 | */ |
|
35 | public class RefreshableCachedObject |
|
36 | extends CachedObject |
|
37 | { |
|
38 | ||
39 | /** |
|
40 | * How long to wait before removing an untouched object from the cache. |
|
41 | * Negative numbers mean never remove (the default). |
|
42 | */ |
|
43 | 0 | private long timeToLive = -1; |
44 | ||
45 | /** |
|
46 | * The last time the Object was accessed from the cache. |
|
47 | */ |
|
48 | private long lastAccess; |
|
49 | ||
50 | /** |
|
51 | * Constructor; sets the object to expire in the default time (30 |
|
52 | * minutes). |
|
53 | * |
|
54 | * @param o The object you want to cache. |
|
55 | */ |
|
56 | public RefreshableCachedObject(Refreshable o) |
|
57 | { |
|
58 | 0 | super(o); |
59 | 0 | lastAccess = System.currentTimeMillis(); |
60 | 0 | } |
61 | ||
62 | /** |
|
63 | * Constructor. |
|
64 | * |
|
65 | * @param o The object to cache. |
|
66 | * @param expires How long before the object expires, in ms, |
|
67 | * e.g. 1000 = 1 second. |
|
68 | */ |
|
69 | public RefreshableCachedObject(Refreshable o, |
|
70 | long expires) |
|
71 | { |
|
72 | 0 | super(o, expires); |
73 | 0 | lastAccess = System.currentTimeMillis(); |
74 | 0 | } |
75 | ||
76 | /** |
|
77 | * Sets the timeToLive value |
|
78 | * |
|
79 | * @param timeToLive the new Value in milliseconds |
|
80 | */ |
|
81 | public synchronized void setTTL(long timeToLive) |
|
82 | { |
|
83 | 0 | this.timeToLive = timeToLive; |
84 | 0 | } |
85 | ||
86 | /** |
|
87 | * Gets the timeToLive value. |
|
88 | * |
|
89 | * @return The current timeToLive value (in milliseconds) |
|
90 | */ |
|
91 | public synchronized long getTTL() |
|
92 | { |
|
93 | 0 | return timeToLive; |
94 | } |
|
95 | ||
96 | /** |
|
97 | * Sets the last acccess time to the current time. |
|
98 | */ |
|
99 | public synchronized void touch() |
|
100 | { |
|
101 | 0 | lastAccess = System.currentTimeMillis(); |
102 | 0 | } |
103 | ||
104 | /** |
|
105 | * Returns true if the object hasn't been touched |
|
106 | * in the previous TTL period. |
|
107 | */ |
|
108 | public synchronized boolean isUntouched() |
|
109 | { |
|
110 | 0 | if (timeToLive < 0) |
111 | 0 | return false; |
112 | ||
113 | 0 | if (lastAccess + timeToLive < System.currentTimeMillis()) |
114 | 0 | return true; |
115 | else |
|
116 | 0 | return false; |
117 | } |
|
118 | ||
119 | /** |
|
120 | * Refresh the object and the created time. |
|
121 | */ |
|
122 | public void refresh() |
|
123 | { |
|
124 | 0 | Refreshable r = (Refreshable) getContents(); |
125 | 0 | synchronized (this) |
126 | { |
|
127 | 0 | created = System.currentTimeMillis(); |
128 | 0 | r.refresh(); |
129 | 0 | } |
130 | 0 | } |
131 | } |
This report is generated by jcoverage, Maven and Maven JCoverage Plugin. |