2 * Copyright (C) 2001, 2002 The Mir-coders group
4 * This file is part of Mir.
6 * Mir is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * Mir is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with Mir; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * In addition, as a special exception, The Mir-coders gives permission to link
21 * the code of this program with any library licensed under the Apache Software License,
22 * The Sun (tm) Java Advanced Imaging library (JAI), The Sun JIMI library
23 * (or with modified versions of the above that use the same license as the above),
24 * and distribute linked combinations including the two. You must obey the
25 * GNU General Public License in all respects for all of the code used other than
26 * the above mentioned libraries. If you modify this file, you may extend this
27 * exception to your version of the file, but you are not obligated to do so.
28 * If you do not wish to do so, delete this exception statement from your version.
31 package mir.generator.tal;
33 import java.io.BufferedInputStream;
35 import java.io.FileInputStream;
36 import java.io.FileNotFoundException;
37 import java.io.InputStream;
38 import java.util.ArrayList;
39 import java.util.HashMap;
40 import java.util.List;
43 public class CachingFileLoader {
44 private Map cachedObjects;
47 private CachedFileObjectFactory factory;
49 public CachingFileLoader(int aCapacity, CachedFileObjectFactory aFactory) {
51 cachedObjects = new HashMap();
52 history = new ArrayList();
56 private void cacheObject(String aFilename, long aLastModified, Object anObject) {
58 history.remove(aFilename);
59 history.add(aFilename);
60 while (history.size()>capacity && history.size()>0) {
63 cachedObjects.put(aFilename, new CachedObject(aFilename, aLastModified, anObject));
67 private Object constructObject(String aFilename) throws FileNotFoundException {
68 File file = new File(aFilename);
69 BufferedInputStream inputStream = new BufferedInputStream(
70 new FileInputStream(file), 8192);
72 Object result = factory.constructObject(inputStream);
73 cacheObject(aFilename, file.lastModified(), result);
86 private void revatilize(String aFilename) {
88 history.remove(aFilename);
89 history.add(aFilename);
93 private class CachedObject {
94 private String filename;
95 private long lastModified;
96 private Object object;
98 public CachedObject(String aFilename, long aLastModified, Object anObject) {
100 lastModified = aLastModified;
104 public Object getObject() {
108 public String getFilename() {
112 public long getLastModified() {
117 public Object retrieveFile(String aFilename) throws FileNotFoundException {
118 synchronized (this) {
119 if (!cachedObjects.containsKey(aFilename)) {
120 return constructObject(aFilename);
123 CachedObject cachedObject = (CachedObject) cachedObjects.get(aFilename);
124 File file = new File(aFilename);
125 if (file.lastModified() != cachedObject.getLastModified()) {
126 return constructObject(aFilename);
129 revatilize(aFilename);
131 return cachedObject.getObject();
135 public interface CachedFileObjectFactory {
136 Object constructObject(InputStream aStream);