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20 package org.eclipse.jetty.util;
21
22 import java.io.File;
23 import java.io.FilenameFilter;
24 import java.io.IOException;
25 import java.util.ArrayList;
26 import java.util.Collections;
27 import java.util.HashMap;
28 import java.util.HashSet;
29 import java.util.Iterator;
30 import java.util.List;
31 import java.util.Map;
32 import java.util.Map.Entry;
33 import java.util.Set;
34 import java.util.Timer;
35 import java.util.TimerTask;
36
37 import org.eclipse.jetty.util.component.AbstractLifeCycle;
38 import org.eclipse.jetty.util.log.Log;
39 import org.eclipse.jetty.util.log.Logger;
40
41
42
43
44
45
46
47
48
49 public class Scanner extends AbstractLifeCycle
50 {
51 private static final Logger LOG = Log.getLogger(Scanner.class);
52 private static int __scannerId=0;
53 private int _scanInterval;
54 private int _scanCount = 0;
55 private final List<Listener> _listeners = new ArrayList<Listener>();
56 private final Map<String,TimeNSize> _prevScan = new HashMap<String,TimeNSize> ();
57 private final Map<String,TimeNSize> _currentScan = new HashMap<String,TimeNSize> ();
58 private FilenameFilter _filter;
59 private final List<File> _scanDirs = new ArrayList<File>();
60 private volatile boolean _running = false;
61 private boolean _reportExisting = true;
62 private boolean _reportDirs = true;
63 private Timer _timer;
64 private TimerTask _task;
65 private int _scanDepth=0;
66
67 public enum Notification { ADDED, CHANGED, REMOVED };
68 private final Map<String,Notification> _notifications = new HashMap<String,Notification>();
69
70 static class TimeNSize
71 {
72 final long _lastModified;
73 final long _size;
74
75 public TimeNSize(long lastModified, long size)
76 {
77 _lastModified = lastModified;
78 _size = size;
79 }
80
81 @Override
82 public int hashCode()
83 {
84 return (int)_lastModified^(int)_size;
85 }
86
87 @Override
88 public boolean equals(Object o)
89 {
90 if (o instanceof TimeNSize)
91 {
92 TimeNSize tns = (TimeNSize)o;
93 return tns._lastModified==_lastModified && tns._size==_size;
94 }
95 return false;
96 }
97
98 @Override
99 public String toString()
100 {
101 return "[lm="+_lastModified+",s="+_size+"]";
102 }
103 }
104
105
106
107
108
109
110 public interface Listener
111 {
112 }
113
114 public interface ScanListener extends Listener
115 {
116 public void scan();
117 }
118
119 public interface DiscreteListener extends Listener
120 {
121 public void fileChanged (String filename) throws Exception;
122 public void fileAdded (String filename) throws Exception;
123 public void fileRemoved (String filename) throws Exception;
124 }
125
126
127 public interface BulkListener extends Listener
128 {
129 public void filesChanged (List<String> filenames) throws Exception;
130 }
131
132
133
134
135 public interface ScanCycleListener extends Listener
136 {
137 public void scanStarted(int cycle) throws Exception;
138 public void scanEnded(int cycle) throws Exception;
139 }
140
141
142
143
144 public Scanner ()
145 {
146 }
147
148
149
150
151
152 public synchronized int getScanInterval()
153 {
154 return _scanInterval;
155 }
156
157
158
159
160
161 public synchronized void setScanInterval(int scanInterval)
162 {
163 _scanInterval = scanInterval;
164 schedule();
165 }
166
167 public void setScanDirs (List<File> dirs)
168 {
169 _scanDirs.clear();
170 _scanDirs.addAll(dirs);
171 }
172
173 public synchronized void addScanDir( File dir )
174 {
175 _scanDirs.add( dir );
176 }
177
178 public List<File> getScanDirs ()
179 {
180 return Collections.unmodifiableList(_scanDirs);
181 }
182
183
184
185
186
187
188 public void setRecursive (boolean recursive)
189 {
190 _scanDepth=recursive?-1:0;
191 }
192
193
194
195
196
197
198 public boolean getRecursive ()
199 {
200 return _scanDepth==-1;
201 }
202
203
204
205
206
207 public int getScanDepth()
208 {
209 return _scanDepth;
210 }
211
212
213
214
215
216 public void setScanDepth(int scanDepth)
217 {
218 _scanDepth = scanDepth;
219 }
220
221
222
223
224
225
226 public void setFilenameFilter (FilenameFilter filter)
227 {
228 _filter = filter;
229 }
230
231
232
233
234
235 public FilenameFilter getFilenameFilter ()
236 {
237 return _filter;
238 }
239
240
241
242
243
244
245
246
247 public void setReportExistingFilesOnStartup (boolean reportExisting)
248 {
249 _reportExisting = reportExisting;
250 }
251
252
253 public boolean getReportExistingFilesOnStartup()
254 {
255 return _reportExisting;
256 }
257
258
259
260
261
262 public void setReportDirs(boolean dirs)
263 {
264 _reportDirs=dirs;
265 }
266
267
268 public boolean getReportDirs()
269 {
270 return _reportDirs;
271 }
272
273
274
275
276
277
278 public synchronized void addListener (Listener listener)
279 {
280 if (listener == null)
281 return;
282 _listeners.add(listener);
283 }
284
285
286
287
288
289
290 public synchronized void removeListener (Listener listener)
291 {
292 if (listener == null)
293 return;
294 _listeners.remove(listener);
295 }
296
297
298
299
300
301 @Override
302 public synchronized void doStart()
303 {
304 if (_running)
305 return;
306
307 _running = true;
308
309 if (_reportExisting)
310 {
311
312 scan();
313 scan();
314 }
315 else
316 {
317
318 scanFiles();
319 _prevScan.putAll(_currentScan);
320 }
321 schedule();
322 }
323
324 public TimerTask newTimerTask ()
325 {
326 return new TimerTask()
327 {
328 @Override
329 public void run() { scan(); }
330 };
331 }
332
333 public Timer newTimer ()
334 {
335 return new Timer("Scanner-"+__scannerId++, true);
336 }
337
338 public void schedule ()
339 {
340 if (_running)
341 {
342 if (_timer!=null)
343 _timer.cancel();
344 if (_task!=null)
345 _task.cancel();
346 if (getScanInterval() > 0)
347 {
348 _timer = newTimer();
349 _task = newTimerTask();
350 _timer.schedule(_task, 1010L*getScanInterval(),1010L*getScanInterval());
351 }
352 }
353 }
354
355
356
357 @Override
358 public synchronized void doStop()
359 {
360 if (_running)
361 {
362 _running = false;
363 if (_timer!=null)
364 _timer.cancel();
365 if (_task!=null)
366 _task.cancel();
367 _task=null;
368 _timer=null;
369 }
370 }
371
372
373
374
375 public boolean exists(String path)
376 {
377 for (File dir : _scanDirs)
378 if (new File(dir,path).exists())
379 return true;
380 return false;
381 }
382
383
384
385
386
387 public synchronized void scan ()
388 {
389 reportScanStart(++_scanCount);
390 scanFiles();
391 reportDifferences(_currentScan, _prevScan);
392 _prevScan.clear();
393 _prevScan.putAll(_currentScan);
394 reportScanEnd(_scanCount);
395
396 for (Listener l : _listeners)
397 {
398 try
399 {
400 if (l instanceof ScanListener)
401 ((ScanListener)l).scan();
402 }
403 catch (Exception e)
404 {
405 LOG.warn(e);
406 }
407 catch (Error e)
408 {
409 LOG.warn(e);
410 }
411 }
412 }
413
414
415
416
417 public synchronized void scanFiles ()
418 {
419 if (_scanDirs==null)
420 return;
421
422 _currentScan.clear();
423 Iterator<File> itor = _scanDirs.iterator();
424 while (itor.hasNext())
425 {
426 File dir = itor.next();
427
428 if ((dir != null) && (dir.exists()))
429 try
430 {
431 scanFile(dir.getCanonicalFile(), _currentScan,0);
432 }
433 catch (IOException e)
434 {
435 LOG.warn("Error scanning files.", e);
436 }
437 }
438 }
439
440
441
442
443
444
445
446
447 public synchronized void reportDifferences (Map<String,TimeNSize> currentScan, Map<String,TimeNSize> oldScan)
448 {
449
450
451 Set<String> oldScanKeys = new HashSet<String>(oldScan.keySet());
452
453
454 for (Map.Entry<String, TimeNSize> entry: currentScan.entrySet())
455 {
456 String file = entry.getKey();
457 if (!oldScanKeys.contains(file))
458 {
459 Notification old=_notifications.put(file,Notification.ADDED);
460 if (old!=null)
461 {
462 switch(old)
463 {
464 case REMOVED:
465 case CHANGED:
466 _notifications.put(file,Notification.CHANGED);
467 }
468 }
469 }
470 else if (!oldScan.get(file).equals(currentScan.get(file)))
471 {
472 Notification old=_notifications.put(file,Notification.CHANGED);
473 if (old!=null)
474 {
475 switch(old)
476 {
477 case ADDED:
478 _notifications.put(file,Notification.ADDED);
479 }
480 }
481 }
482 }
483
484
485 for (String file : oldScan.keySet())
486 {
487 if (!currentScan.containsKey(file))
488 {
489 Notification old=_notifications.put(file,Notification.REMOVED);
490 if (old!=null)
491 {
492 switch(old)
493 {
494 case ADDED:
495 _notifications.remove(file);
496 }
497 }
498 }
499 }
500
501 if (LOG.isDebugEnabled())
502 LOG.debug("scanned "+_scanDirs+": "+_notifications);
503
504
505
506 List<String> bulkChanges = new ArrayList<String>();
507 for (Iterator<Entry<String,Notification>> iter = _notifications.entrySet().iterator();iter.hasNext();)
508 {
509 Entry<String,Notification> entry=iter.next();
510 String file=entry.getKey();
511
512
513 if (oldScan.containsKey(file))
514 {
515 if (!oldScan.get(file).equals(currentScan.get(file)))
516 continue;
517 }
518 else if (currentScan.containsKey(file))
519 continue;
520
521
522 Notification notification=entry.getValue();
523 iter.remove();
524 bulkChanges.add(file);
525 switch(notification)
526 {
527 case ADDED:
528 reportAddition(file);
529 break;
530 case CHANGED:
531 reportChange(file);
532 break;
533 case REMOVED:
534 reportRemoval(file);
535 break;
536 }
537 }
538 if (!bulkChanges.isEmpty())
539 reportBulkChanges(bulkChanges);
540 }
541
542
543
544
545
546
547
548
549 private void scanFile (File f, Map<String,TimeNSize> scanInfoMap, int depth)
550 {
551 try
552 {
553 if (!f.exists())
554 return;
555
556 if (f.isFile() || depth>0&& _reportDirs && f.isDirectory())
557 {
558 if ((_filter == null) || ((_filter != null) && _filter.accept(f.getParentFile(), f.getName())))
559 {
560 if (LOG.isDebugEnabled())
561 LOG.debug("scan accepted {}",f);
562 String name = f.getCanonicalPath();
563 scanInfoMap.put(name, new TimeNSize(f.lastModified(),f.length()));
564 }
565 else
566 {
567 if (LOG.isDebugEnabled())
568 LOG.debug("scan rejected {}",f);
569 }
570 }
571
572
573 if (f.isDirectory() && (depth<_scanDepth || _scanDepth==-1 || _scanDirs.contains(f)))
574 {
575 File[] files = f.listFiles();
576 if (files != null)
577 {
578 for (int i=0;i<files.length;i++)
579 scanFile(files[i], scanInfoMap,depth+1);
580 }
581 else
582 LOG.warn("Error listing files in directory {}", f);
583 }
584 }
585 catch (IOException e)
586 {
587 LOG.warn("Error scanning watched files", e);
588 }
589 }
590
591 private void warn(Object listener,String filename,Throwable th)
592 {
593 LOG.warn(listener+" failed on '"+filename, th);
594 }
595
596
597
598
599
600 private void reportAddition (String filename)
601 {
602 Iterator<Listener> itor = _listeners.iterator();
603 while (itor.hasNext())
604 {
605 Listener l = itor.next();
606 try
607 {
608 if (l instanceof DiscreteListener)
609 ((DiscreteListener)l).fileAdded(filename);
610 }
611 catch (Exception e)
612 {
613 warn(l,filename,e);
614 }
615 catch (Error e)
616 {
617 warn(l,filename,e);
618 }
619 }
620 }
621
622
623
624
625
626
627 private void reportRemoval (String filename)
628 {
629 Iterator<Listener> itor = _listeners.iterator();
630 while (itor.hasNext())
631 {
632 Object l = itor.next();
633 try
634 {
635 if (l instanceof DiscreteListener)
636 ((DiscreteListener)l).fileRemoved(filename);
637 }
638 catch (Exception e)
639 {
640 warn(l,filename,e);
641 }
642 catch (Error e)
643 {
644 warn(l,filename,e);
645 }
646 }
647 }
648
649
650
651
652
653
654 private void reportChange (String filename)
655 {
656 Iterator<Listener> itor = _listeners.iterator();
657 while (itor.hasNext())
658 {
659 Listener l = itor.next();
660 try
661 {
662 if (l instanceof DiscreteListener)
663 ((DiscreteListener)l).fileChanged(filename);
664 }
665 catch (Exception e)
666 {
667 warn(l,filename,e);
668 }
669 catch (Error e)
670 {
671 warn(l,filename,e);
672 }
673 }
674 }
675
676 private void reportBulkChanges (List<String> filenames)
677 {
678 Iterator<Listener> itor = _listeners.iterator();
679 while (itor.hasNext())
680 {
681 Listener l = itor.next();
682 try
683 {
684 if (l instanceof BulkListener)
685 ((BulkListener)l).filesChanged(filenames);
686 }
687 catch (Exception e)
688 {
689 warn(l,filenames.toString(),e);
690 }
691 catch (Error e)
692 {
693 warn(l,filenames.toString(),e);
694 }
695 }
696 }
697
698
699
700
701 private void reportScanStart(int cycle)
702 {
703 for (Listener listener : _listeners)
704 {
705 try
706 {
707 if (listener instanceof ScanCycleListener)
708 {
709 ((ScanCycleListener)listener).scanStarted(cycle);
710 }
711 }
712 catch (Exception e)
713 {
714 LOG.warn(listener + " failed on scan start for cycle " + cycle, e);
715 }
716 }
717 }
718
719
720
721
722 private void reportScanEnd(int cycle)
723 {
724 for (Listener listener : _listeners)
725 {
726 try
727 {
728 if (listener instanceof ScanCycleListener)
729 {
730 ((ScanCycleListener)listener).scanEnded(cycle);
731 }
732 }
733 catch (Exception e)
734 {
735 LOG.warn(listener + " failed on scan end for cycle " + cycle, e);
736 }
737 }
738 }
739
740 }