|
1
32
33 package com.imagero.uio.buffer.fm;
34
35 import com.imagero.uio.RandomAccess;
36 import com.imagero.uio.RandomAccessFactory;
37 import com.imagero.uio.RandomAccessRO;
38 import com.imagero.uio.buffer.BufferManager;
39 import com.imagero.uio.buffer.MutableBufferManager;
40 import com.imagero.uio.io.IOutils;
41
42 import java.awt.event.ActionEvent  ;
43 import java.awt.event.ActionListener ;
44 import java.io.File ;
45 import java.io.IOException ;
46 import java.util.Hashtable ;
47 import java.util.Vector ;
48
49
54 public class OpenFileManager {
55
56 static final String GET = "get";
57 static final String OPEN = "open";
58 static final String CLOSE = "close";
59
60 static boolean debug;
61
62 public static boolean isDebug() {
63 return debug;
64 }
65
66 public static void setDebug(boolean debug) {
67 OpenFileManager.debug = debug;
68 }
69
70 Vector v = new Vector ();
71 Hashtable ros = new Hashtable ();
72
73 int maxOpenCount = 100;
74
75 ActionListener handler = new ActionListener () {
76 public void actionPerformed(ActionEvent e) {
77 String actionCommand = e.getActionCommand();
78 Object manager = e.getSource();
79 if (actionCommand == GET || actionCommand == OPEN) {
80 v.removeElement(manager);
81 v.addElement(manager);
82 }
83 else if(actionCommand == CLOSE) {
84 v.removeElement(manager);
85 }
86 }
87 };
88
89
95 public RandomAccessRO createRO(File f) throws IOException {
96 RandomAccessRO ro = openFileRO(f);
97 return ro;
98 }
99
100
106 public RandomAccess create(File f) throws IOException {
107 RandomAccess ra = openFile(f);
108 return ra;
109 }
110
111 private RandomAccessRO openFileRO(File f) throws IOException {
112 BufferManager manager = createBufferManager(f, false);
113 RandomAccessRO ro = RandomAccessFactory.createBufferedRO(manager);
114 ros.put(ro, manager);
115 v.addElement(manager);
116 checkSize();
117
118 return ro;
119 }
120
121 private RandomAccess openFile(File f) throws IOException {
122 BufferManager manager = createBufferManager(f, true);
123 RandomAccess ra = RandomAccessFactory.createBuffered((MutableBufferManager) manager);
124 ros.put(ra, manager);
125 v.addElement(manager);
126 checkSize();
127
128 return ra;
129 }
130
131 private void checkSize() {
132 if (v.size() > maxOpenCount) {
133 int closeCount = v.size() - maxOpenCount;
134 for (int i = 0; i < v.size(); i++) {
135 BufferManager manager = (BufferManager) v.elementAt(i);
136 if (manager instanceof FMBufferManager) {
137 if (((FMBufferManager) manager).canClose()) {
138 manager.close();
139 v.removeElementAt(0);
140 if (--closeCount == 0) {
141 break;
142 }
143 }
144 }
145 }
146 }
147 }
148
149
152 public void close(RandomAccessRO ro) {
153 Object mgr = ros.remove(ro);
154 if (mgr == null) {
155 throw new NullPointerException ();
156 }
157 IOutils.closeStream(ro);
158 v.removeElement(mgr);
159 if (mgr instanceof FMBufferManagerRO) {
160 ((FMBufferManagerRO) mgr)._close();
161 }
162 else if (mgr instanceof FMBufferManager) {
163 ((FMBufferManager) mgr)._close();
164 }
165 }
166
167
170 public int getMaxOpenCount() {
171 return maxOpenCount;
172 }
173
174
177 public void setMaxOpenCount(int maxOpenCount) {
178 this.maxOpenCount = maxOpenCount;
179 }
180
181 private BufferManager createBufferManager(File f, boolean writeable) throws IOException {
182 if (writeable) {
183 return new FMBufferManager(f, handler);
184 }
185 else {
186 return new FMBufferManagerRO(f, handler);
187 }
188 }
189 }
190 |
Popular Tags |
Java API By Example, From Geeks To Geeks.