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Java > Open Source Codes > org > openlaszlo > iv > flash > cache > MediaCache


1 /*
2  * $Id: MediaCache.java,v 1.3 2002/03/22 04:55:07 skavish Exp $
3  *
4  * ==========================================================================
5  *
6  * The JGenerator Software License, Version 1.0
7  *
8  * Copyright (c) 2000 Dmitry Skavish (skavish@usa.net). All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  * notice, this list of conditions and the following disclaimer in
18  * the documentation and/or other materials provided with the
19  * distribution.
20  *
21  * 3. The end-user documentation included with the redistribution, if
22  * any, must include the following acknowlegement:
23  * "This product includes software developed by Dmitry Skavish
24  * (skavish@usa.net, http://www.flashgap.com/)."
25  * Alternately, this acknowlegement may appear in the software itself,
26  * if and wherever such third-party acknowlegements normally appear.
27  *
28  * 4. The name "The JGenerator" must not be used to endorse or promote
29  * products derived from this software without prior written permission.
30  * For written permission, please contact skavish@usa.net.
31  *
32  * 5. Products derived from this software may not be called "The JGenerator"
33  * nor may "The JGenerator" appear in their names without prior written
34  * permission of Dmitry Skavish.
35  *
36  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39  * DISCLAIMED. IN NO EVENT SHALL DMITRY SKAVISH OR THE OTHER
40  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
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49  */
50
51 package org.openlaszlo.iv.flash.cache;
52
53 import org.openlaszlo.iv.flash.api.*;
54 import org.openlaszlo.iv.flash.util.*;
55 import org.openlaszlo.iv.flash.url.*;
56 import java.util.*;
57 import java.io.*;
58
59 public class MediaCache extends GenericCache {
60
61     private static MediaCache instance = new MediaCache();
62
63     private MediaCache() {
64     }
65
66     public static MediaCache getInstance() {
67         return instance;
68     }
69
70     public static CacheSettings getSettings() {
71         return instance.getMySettings();
72     }
73
74     /**
75      * Get cached media
76      *
77      * @param key cache key
78      */
79      public static Object JavaDoc getMedia( IVUrl url ) {
80         return getMedia( url.getName() );
81      }
82
83     /**
84      * Get cached media
85      *
86      * @param key cache key
87      */
88      public static Object JavaDoc getMedia( String JavaDoc key ) {
89         CacheItem item = instance.getItem( key );
90         if( item == null ) return null;
91         return item.getObject();
92      }
93
94     /**
95      * Add media to cache
96      *
97      * @param url url of media to cache
98      * @param media media object
99      * @param size size of the media
100      * @param templCache template parameter cache
101      */
102     public static void addMedia( IVUrl url, Object JavaDoc media, int size, boolean templCache ) {
103         // check whether we need to cache or not
104 long lifespan = getSettings().getDefaultExpire();
105         if( !getSettings().isForce() ) {
106             String JavaDoc gmcStr = url.getParameter( "gmc" );
107             if( gmcStr != null ) {
108                 if( !Util.toBool(gmcStr, false) ) return;
109                 String JavaDoc v = url.getParameter( "gme" );
110                 if( v != null ) {
111                     lifespan = Util.toLong( v, -1L )*1000L;
112                 }
113             } else {
114                 if( !templCache ) return;
115             }
116         }
117         // yes, let's cache the media
118 long now = System.currentTimeMillis();
119         if( lifespan <= 0 ) {
120             lifespan = Long.MAX_VALUE-now;
121         }
122         long expire = now + lifespan;
123         CacheItem item = new MediaCacheItem( url, media, size, now, expire, getSettings().isCheckModifiedSince() );
124         instance.addItem( item );
125     }
126
127     protected boolean isModified( CacheItem item ) {
128         if( !getSettings().isCheckModifiedSince() ) return super.isModified( item );
129         MediaCacheItem it = (MediaCacheItem) item;
130         it.getUrl().refresh();
131         return it.lastModified() != it.getUrl().lastModified();
132     }
133
134     public static class MediaCacheItem extends CacheItem {
135         private long lastModified = 0;
136         private IVUrl url;
137
138         public MediaCacheItem( IVUrl url, Object JavaDoc object, int size, long cacheTime, long expireAfter, boolean isCheckModifiedSince ) {
139             super( url.getName(), object, size, cacheTime, expireAfter );
140             this.url = url;
141             if( isCheckModifiedSince ) {
142                 this.lastModified = url.lastModified();
143             }
144         }
145
146         public IVUrl getUrl() { return url; }
147         public long lastModified() { return lastModified; }
148     }
149
150 }
151
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