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19
20 package org.netbeans.modules.masterfs.filebasedfs.fileobjects;
21
22 import java.io.FileNotFoundException  ;
23 import java.lang.ref.WeakReference ;
24 import java.util.Collections ;
25 import java.util.Iterator ;
26 import org.netbeans.modules.masterfs.filebasedfs.utils.FSException;
27 import org.openide.filesystems.FileLock;
28
29 import java.io.File ;
30 import java.io.IOException ;
31 import java.io.RandomAccessFile ;
32 import java.lang.ref.Reference ;
33 import java.nio.channels.FileChannel ;
34 import java.util.ArrayList ;
35 import java.util.List ;
36 import java.util.Map ;
37 import java.util.Set ;
38 import java.util.Stack ;
39 import java.util.WeakHashMap ;
40 import org.openide.filesystems.FileAlreadyLockedException;
41 import org.openide.util.Exceptions;
42 import org.openide.util.NbBundle;
43
44
45
66
67
68 public class WriteLock extends FileLock {
69 static final Map allLocks = Collections.synchronizedMap(new WeakHashMap ());
70 private File lockFile;
71
72 static {
73 Runtime.getRuntime().addShutdownHook(new Thread () {
74 public void run() {
75 Set s = allLocks.keySet();
76 synchronized(allLocks) {
77 for (Iterator it = s.iterator(); it.hasNext();) {
78 File f = (File ) it.next();
79 if (f.exists() && WriteLockUtils.hasActiveLockFileSigns(f.getAbsolutePath())) {
80 f.delete();
81 }
82 }
83 }
84 }
85 });
86 }
87
88 static WriteLock tryLock(final File file) throws IOException {
89 return WriteLock.getInstance(file, false);
90 }
91
92 static WriteLock tryNioLock(final File file) throws IOException {
93 return WriteLock.getInstance(file, true);
94 }
95
96 static WriteLock tryLightWeightLock(final File file) throws IOException {
97 return WriteLock.getLightWeightInstance(file);
98 }
99
100 public static void relock(final File theOld, File theNew) {
101 List l = new ArrayList ();
102 Set s = allLocks.keySet();
103 synchronized(allLocks) {
104 for (Iterator it = s.iterator(); it.hasNext();) {
105 File f = (File ) it.next();
106 File nLockFile = null;
107 String relPath = getRelativePath(theOld, f);
108 if (relPath != null) {
109 nLockFile = new File (theNew, relPath);
110 } else if (f.equals(WriteLockUtils.getAssociatedLockFile(theOld))) {
111 nLockFile = WriteLockUtils.getAssociatedLockFile(theNew);
112 }
113
114 if (nLockFile != null) {
115 Reference r = (Reference )allLocks.get(f);
116 WriteLock wl = (WriteLock)r.get();
117 if (wl != null) {
118 it.remove();
119 wl.lockFile = nLockFile;
120 l.add(wl);
121 }
122
123 }
124 }
125 }
126 for (Iterator it2 = l.iterator(); it2.hasNext();) {
127 WriteLock wl = (WriteLock) it2.next();
128 allLocks.put(wl.lockFile, new WeakReference (wl));
129 }
130 }
131
132 private static String getRelativePath(final File dir, final File file) {
133 Stack stack = new Stack ();
134 File tempFile = file;
135 while(tempFile != null && !tempFile.equals(dir)) {
136 stack.push (tempFile.getName());
137 tempFile = tempFile.getParentFile();
138 }
139 if (tempFile == null) return null;
140 StringBuilder retval = new StringBuilder ();
141 while (!stack.isEmpty()) {
142 retval.append((String )stack.pop());
143 if (!stack.isEmpty()) {
144 retval.append("/"); }
146 }
147 return retval.toString();
148 }
149
150
151 private static WriteLock getLightWeightInstance(final File file) throws IOException {
152 File lckFile = WriteLockUtils.getAssociatedLockFile(file);
153 boolean isAlreadyLocked = WriteLock.allLocks.keySet().contains(lckFile);
154 if (isAlreadyLocked) {
155 throw new FileAlreadyLockedException(NbBundle.getMessage(
156 WriteLock.class, "EXC_FileAlreadyLocked", file.getAbsolutePath()));
157 }
158
159 return new WriteLock(lckFile);
160 }
161
162 private static WriteLock getInstance(final File file, boolean nioLock) throws IOException {
163 boolean isCreated = false;
164 IOException toFire = null;
165
166 File lckFile = WriteLockUtils.getAssociatedLockFile(file);
167 if (!lckFile.exists()) {
168 isCreated = true;
169 }
170 RandomAccessFile raf = getAccessToFile(lckFile); assert lckFile.exists();
172
173 FileChannel channel = raf.getChannel();
174
175
176 if (channel != null && channel.isOpen()) {
177 try {
178 String content = WriteLockUtils.getContentOfLckFile(lckFile, channel);
179 if (content == null && (isCreated || lckFile.length() == 0)) {
180 assert lckFile.length() == 0;
181 content = WriteLockUtils.writeContentOfLckFile(lckFile, channel);
182 }
183
184 if (content != null && !WriteLock.allLocks.keySet().contains(new File (content))) {
185 if (channel != null && channel.isOpen() && !nioLock) {
186 channel.close();
187 }
188 return (nioLock) ? new NioLock(lckFile, channel, channel.tryLock()) : new WriteLock(lckFile);
189 }
190 } catch (IOException iex) {
191 toFire = iex;
192 }
193 }
194
195 if (channel != null && channel.isOpen()) {
196 channel.close();
197 }
198
199 if (isCreated && lckFile.exists()) {
200 lckFile.delete();
201 }
202
203 if (toFire == null) {
204 if (lckFile.exists()) {
205 toFire = new FileAlreadyLockedException(NbBundle.getMessage(
206 WriteLock.class, "EXC_FileLockAlreadyExists", file.getAbsolutePath(), lckFile.getAbsolutePath()));
207 } else {
208 toFire = new FileAlreadyLockedException(NbBundle.getMessage(
209 WriteLock.class, "EXC_FileAlreadyLocked", file.getAbsolutePath()));
210 }
211 }
212
213 FSException.annotateException(toFire);
214 throw toFire;
215 }
216
217 private static RandomAccessFile getAccessToFile(final File f) throws FileNotFoundException {
218 RandomAccessFile raf = null;
219 try {
220 raf = new RandomAccessFile (f, "rwd"); } catch (FileNotFoundException e) {
222 FileNotFoundException fex = e;
223 if (!f.exists()) {
224 fex = (FileNotFoundException )new FileNotFoundException (e.getLocalizedMessage()).initCause(e);
225 } else if (!f.canRead()) {
226 fex = (FileNotFoundException )new FileNotFoundException (e.getLocalizedMessage()).initCause(e);
227 } else if (!f.canWrite()) {
228 fex = (FileNotFoundException )new FileNotFoundException (e.getLocalizedMessage()).initCause(e);
229 } else if (f.getParentFile() == null) {
230 fex = (FileNotFoundException )new FileNotFoundException (e.getLocalizedMessage()).initCause(e);
231 } else if (!f.getParentFile().exists()) {
232 fex = (FileNotFoundException )new FileNotFoundException (e.getLocalizedMessage()).initCause(e);
233 }
234 throw fex;
235 }
236 return raf;
237 }
238
239
240 private WriteLock(File lockFile) {
241 this.lockFile = lockFile;
242 register();
243 }
244
245 public boolean isValid(final File f) {
246 boolean retVal = isValid();
247
248 if (retVal) {
249 final File associatedLockFile = WriteLockUtils.getAssociatedLockFile(f);
250 retVal = lockFile.equals(associatedLockFile);
251 } else {
252 }
253 return retVal;
254 }
255
256 public void releaseLock() {
257 synchronized (WriteLockFactory.class) {
258 if (isValid()) {
259 deregister();
260 super.releaseLock();
261 if (getLockFile().exists()) {
262 final boolean isDeleted = getLockFile().delete();
263 }
265 }
266 }
267 }
268
269 private final void deregister() {
270 allLocks.remove(getLockFile());
271 }
272
273 private final void register() {
274 allLocks.put(this.getLockFile(), new WeakReference (this));
275 }
276
277 final File getLockFile() {
278 return lockFile;
279 }
280
281 public final String toString() {
282 final String name = getLockFile().getName();
283 final String newName = name.substring(WriteLockUtils.PREFIX.length(), (name.length() - WriteLockUtils.SUFFIX.length()));
284 return new File (getLockFile().getParentFile(), newName).getAbsolutePath();
285 }
286
287 private static class NioLock extends WriteLock {
288 private FileChannel channel;
289 private java.nio.channels.FileLock nioLock;
290
291 NioLock(File lockFile, FileChannel channel, java.nio.channels.FileLock nioLock) {
292 super(lockFile);
293
294 assert nioLock != null;
295 assert nioLock.isValid();
296 assert channel != null;
297
298 this.channel = channel;
299 this.nioLock = nioLock;
300 }
301
302 public void releaseLock() {
303 synchronized (WriteLockFactory.class) {
304 try {
305 if (nioLock.isValid()) {
306 nioLock.release();
307 }
308
309 if (channel.isOpen()) {
310 channel.close();
311 }
312 } catch (java.io.IOException e) {
313 Exceptions.printStackTrace(e);
314 }
315
316 super.releaseLock();
317 }
318 }
319 }
320 }
321 |
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