comparison src/org/eclipse/jetty/util/Scanner.java @ 802:3428c60d7cfc

replace jetty jars with source
author Franklin Schmidt <fschmidt@gmail.com>
date Wed, 07 Sep 2016 21:15:48 -0600
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children 8e9db0bbf4f9
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801:6a21393191c1 802:3428c60d7cfc
1 //
2 // ========================================================================
3 // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19
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 * Scanner
44 *
45 * Utility for scanning a directory for added, removed and changed
46 * files and reporting these events via registered Listeners.
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 * Listener
107 *
108 * Marker for notifications re file changes.
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 * Listener that notifies when a scan has started and when it has ended.
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 * Get the scan interval
150 * @return interval between scans in seconds
151 */
152 public int getScanInterval()
153 {
154 return _scanInterval;
155 }
156
157 /**
158 * Set the scan interval
159 * @param scanInterval pause between scans in seconds, or 0 for no scan after the initial scan.
160 */
161 public synchronized void setScanInterval(int scanInterval)
162 {
163 _scanInterval = scanInterval;
164 schedule();
165 }
166
167 /**
168 * Set the location of the directory to scan.
169 * @param dir
170 * @deprecated use setScanDirs(List dirs) instead
171 */
172 @Deprecated
173 public void setScanDir (File dir)
174 {
175 _scanDirs.clear();
176 _scanDirs.add(dir);
177 }
178
179 /**
180 * Get the location of the directory to scan
181 * @return the first directory (of {@link #getScanDirs()} being scanned)
182 * @deprecated use getScanDirs() instead
183 */
184 @Deprecated
185 public File getScanDir ()
186 {
187 return (_scanDirs==null?null:(File)_scanDirs.get(0));
188 }
189
190 public void setScanDirs (List<File> dirs)
191 {
192 _scanDirs.clear();
193 _scanDirs.addAll(dirs);
194 }
195
196 public synchronized void addScanDir( File dir )
197 {
198 _scanDirs.add( dir );
199 }
200
201 public List<File> getScanDirs ()
202 {
203 return Collections.unmodifiableList(_scanDirs);
204 }
205
206 /* ------------------------------------------------------------ */
207 /**
208 * @param recursive True if scanning is recursive
209 * @see #setScanDepth(int)
210 */
211 public void setRecursive (boolean recursive)
212 {
213 _scanDepth=recursive?-1:0;
214 }
215
216 /* ------------------------------------------------------------ */
217 /**
218 * @return True if scanning is fully recursive (scandepth==-1)
219 * @see #getScanDepth()
220 */
221 public boolean getRecursive ()
222 {
223 return _scanDepth==-1;
224 }
225
226 /* ------------------------------------------------------------ */
227 /** Get the scanDepth.
228 * @return the scanDepth
229 */
230 public int getScanDepth()
231 {
232 return _scanDepth;
233 }
234
235 /* ------------------------------------------------------------ */
236 /** Set the scanDepth.
237 * @param scanDepth the scanDepth to set
238 */
239 public void setScanDepth(int scanDepth)
240 {
241 _scanDepth = scanDepth;
242 }
243
244 /**
245 * Apply a filter to files found in the scan directory.
246 * Only files matching the filter will be reported as added/changed/removed.
247 * @param filter
248 */
249 public void setFilenameFilter (FilenameFilter filter)
250 {
251 _filter = filter;
252 }
253
254 /**
255 * Get any filter applied to files in the scan dir.
256 * @return the filename filter
257 */
258 public FilenameFilter getFilenameFilter ()
259 {
260 return _filter;
261 }
262
263 /* ------------------------------------------------------------ */
264 /**
265 * Whether or not an initial scan will report all files as being
266 * added.
267 * @param reportExisting if true, all files found on initial scan will be
268 * reported as being added, otherwise not
269 */
270 public void setReportExistingFilesOnStartup (boolean reportExisting)
271 {
272 _reportExisting = reportExisting;
273 }
274
275 /* ------------------------------------------------------------ */
276 public boolean getReportExistingFilesOnStartup()
277 {
278 return _reportExisting;
279 }
280
281 /* ------------------------------------------------------------ */
282 /** Set if found directories should be reported.
283 * @param dirs
284 */
285 public void setReportDirs(boolean dirs)
286 {
287 _reportDirs=dirs;
288 }
289
290 /* ------------------------------------------------------------ */
291 public boolean getReportDirs()
292 {
293 return _reportDirs;
294 }
295
296 /* ------------------------------------------------------------ */
297 /**
298 * Add an added/removed/changed listener
299 * @param listener
300 */
301 public synchronized void addListener (Listener listener)
302 {
303 if (listener == null)
304 return;
305 _listeners.add(listener);
306 }
307
308
309
310 /**
311 * Remove a registered listener
312 * @param listener the Listener to be removed
313 */
314 public synchronized void removeListener (Listener listener)
315 {
316 if (listener == null)
317 return;
318 _listeners.remove(listener);
319 }
320
321
322 /**
323 * Start the scanning action.
324 */
325 @Override
326 public synchronized void doStart()
327 {
328 if (_running)
329 return;
330
331 _running = true;
332
333 if (_reportExisting)
334 {
335 // if files exist at startup, report them
336 scan();
337 scan(); // scan twice so files reported as stable
338 }
339 else
340 {
341 //just register the list of existing files and only report changes
342 scanFiles();
343 _prevScan.putAll(_currentScan);
344 }
345 schedule();
346 }
347
348 public TimerTask newTimerTask ()
349 {
350 return new TimerTask()
351 {
352 @Override
353 public void run() { scan(); }
354 };
355 }
356
357 public Timer newTimer ()
358 {
359 return new Timer("Scanner-"+__scannerId++, true);
360 }
361
362 public void schedule ()
363 {
364 if (_running)
365 {
366 if (_timer!=null)
367 _timer.cancel();
368 if (_task!=null)
369 _task.cancel();
370 if (getScanInterval() > 0)
371 {
372 _timer = newTimer();
373 _task = newTimerTask();
374 _timer.schedule(_task, 1010L*getScanInterval(),1010L*getScanInterval());
375 }
376 }
377 }
378 /**
379 * Stop the scanning.
380 */
381 @Override
382 public synchronized void doStop()
383 {
384 if (_running)
385 {
386 _running = false;
387 if (_timer!=null)
388 _timer.cancel();
389 if (_task!=null)
390 _task.cancel();
391 _task=null;
392 _timer=null;
393 }
394 }
395
396 /**
397 * Perform a pass of the scanner and report changes
398 */
399 public synchronized void scan ()
400 {
401 reportScanStart(++_scanCount);
402 scanFiles();
403 reportDifferences(_currentScan, _prevScan);
404 _prevScan.clear();
405 _prevScan.putAll(_currentScan);
406 reportScanEnd(_scanCount);
407
408 for (Listener l : _listeners)
409 {
410 try
411 {
412 if (l instanceof ScanListener)
413 ((ScanListener)l).scan();
414 }
415 catch (Exception e)
416 {
417 LOG.warn(e);
418 }
419 catch (Error e)
420 {
421 LOG.warn(e);
422 }
423 }
424 }
425
426 /**
427 * Recursively scan all files in the designated directories.
428 */
429 public synchronized void scanFiles ()
430 {
431 if (_scanDirs==null)
432 return;
433
434 _currentScan.clear();
435 Iterator<File> itor = _scanDirs.iterator();
436 while (itor.hasNext())
437 {
438 File dir = itor.next();
439
440 if ((dir != null) && (dir.exists()))
441 try
442 {
443 scanFile(dir.getCanonicalFile(), _currentScan,0);
444 }
445 catch (IOException e)
446 {
447 LOG.warn("Error scanning files.", e);
448 }
449 }
450 }
451
452
453 /**
454 * Report the adds/changes/removes to the registered listeners
455 *
456 * @param currentScan the info from the most recent pass
457 * @param oldScan info from the previous pass
458 */
459 public synchronized void reportDifferences (Map<String,TimeNSize> currentScan, Map<String,TimeNSize> oldScan)
460 {
461 // scan the differences and add what was found to the map of notifications:
462
463 Set<String> oldScanKeys = new HashSet<String>(oldScan.keySet());
464
465 // Look for new and changed files
466 for (Map.Entry<String, TimeNSize> entry: currentScan.entrySet())
467 {
468 String file = entry.getKey();
469 if (!oldScanKeys.contains(file))
470 {
471 Notification old=_notifications.put(file,Notification.ADDED);
472 if (old!=null)
473 {
474 switch(old)
475 {
476 case REMOVED:
477 case CHANGED:
478 _notifications.put(file,Notification.CHANGED);
479 }
480 }
481 }
482 else if (!oldScan.get(file).equals(currentScan.get(file)))
483 {
484 Notification old=_notifications.put(file,Notification.CHANGED);
485 if (old!=null)
486 {
487 switch(old)
488 {
489 case ADDED:
490 _notifications.put(file,Notification.ADDED);
491 }
492 }
493 }
494 }
495
496 // Look for deleted files
497 for (String file : oldScan.keySet())
498 {
499 if (!currentScan.containsKey(file))
500 {
501 Notification old=_notifications.put(file,Notification.REMOVED);
502 if (old!=null)
503 {
504 switch(old)
505 {
506 case ADDED:
507 _notifications.remove(file);
508 }
509 }
510 }
511 }
512
513 if (LOG.isDebugEnabled())
514 LOG.debug("scanned "+_scanDirs+": "+_notifications);
515
516 // Process notifications
517 // Only process notifications that are for stable files (ie same in old and current scan).
518 List<String> bulkChanges = new ArrayList<String>();
519 for (Iterator<Entry<String,Notification>> iter = _notifications.entrySet().iterator();iter.hasNext();)
520 {
521 Entry<String,Notification> entry=iter.next();
522 String file=entry.getKey();
523
524 // Is the file stable?
525 if (oldScan.containsKey(file))
526 {
527 if (!oldScan.get(file).equals(currentScan.get(file)))
528 continue;
529 }
530 else if (currentScan.containsKey(file))
531 continue;
532
533 // File is stable so notify
534 Notification notification=entry.getValue();
535 iter.remove();
536 bulkChanges.add(file);
537 switch(notification)
538 {
539 case ADDED:
540 reportAddition(file);
541 break;
542 case CHANGED:
543 reportChange(file);
544 break;
545 case REMOVED:
546 reportRemoval(file);
547 break;
548 }
549 }
550 if (!bulkChanges.isEmpty())
551 reportBulkChanges(bulkChanges);
552 }
553
554
555 /**
556 * Get last modified time on a single file or recurse if
557 * the file is a directory.
558 * @param f file or directory
559 * @param scanInfoMap map of filenames to last modified times
560 */
561 private void scanFile (File f, Map<String,TimeNSize> scanInfoMap, int depth)
562 {
563 try
564 {
565 if (!f.exists())
566 return;
567
568 if (f.isFile() || depth>0&& _reportDirs && f.isDirectory())
569 {
570 if ((_filter == null) || ((_filter != null) && _filter.accept(f.getParentFile(), f.getName())))
571 {
572 String name = f.getCanonicalPath();
573 scanInfoMap.put(name, new TimeNSize(f.lastModified(),f.length()));
574 }
575 }
576
577 // If it is a directory, scan if it is a known directory or the depth is OK.
578 if (f.isDirectory() && (depth<_scanDepth || _scanDepth==-1 || _scanDirs.contains(f)))
579 {
580 File[] files = f.listFiles();
581 if (files != null)
582 {
583 for (int i=0;i<files.length;i++)
584 scanFile(files[i], scanInfoMap,depth+1);
585 }
586 else
587 LOG.warn("Error listing files in directory {}", f);
588
589 }
590 }
591 catch (IOException e)
592 {
593 LOG.warn("Error scanning watched files", e);
594 }
595 }
596
597 private void warn(Object listener,String filename,Throwable th)
598 {
599 LOG.warn(listener+" failed on '"+filename, th);
600 }
601
602 /**
603 * Report a file addition to the registered FileAddedListeners
604 * @param filename
605 */
606 private void reportAddition (String filename)
607 {
608 Iterator<Listener> itor = _listeners.iterator();
609 while (itor.hasNext())
610 {
611 Listener l = itor.next();
612 try
613 {
614 if (l instanceof DiscreteListener)
615 ((DiscreteListener)l).fileAdded(filename);
616 }
617 catch (Exception e)
618 {
619 warn(l,filename,e);
620 }
621 catch (Error e)
622 {
623 warn(l,filename,e);
624 }
625 }
626 }
627
628
629 /**
630 * Report a file removal to the FileRemovedListeners
631 * @param filename
632 */
633 private void reportRemoval (String filename)
634 {
635 Iterator<Listener> itor = _listeners.iterator();
636 while (itor.hasNext())
637 {
638 Object l = itor.next();
639 try
640 {
641 if (l instanceof DiscreteListener)
642 ((DiscreteListener)l).fileRemoved(filename);
643 }
644 catch (Exception e)
645 {
646 warn(l,filename,e);
647 }
648 catch (Error e)
649 {
650 warn(l,filename,e);
651 }
652 }
653 }
654
655
656 /**
657 * Report a file change to the FileChangedListeners
658 * @param filename
659 */
660 private void reportChange (String filename)
661 {
662 Iterator<Listener> itor = _listeners.iterator();
663 while (itor.hasNext())
664 {
665 Listener l = itor.next();
666 try
667 {
668 if (l instanceof DiscreteListener)
669 ((DiscreteListener)l).fileChanged(filename);
670 }
671 catch (Exception e)
672 {
673 warn(l,filename,e);
674 }
675 catch (Error e)
676 {
677 warn(l,filename,e);
678 }
679 }
680 }
681
682 private void reportBulkChanges (List<String> filenames)
683 {
684 Iterator<Listener> itor = _listeners.iterator();
685 while (itor.hasNext())
686 {
687 Listener l = itor.next();
688 try
689 {
690 if (l instanceof BulkListener)
691 ((BulkListener)l).filesChanged(filenames);
692 }
693 catch (Exception e)
694 {
695 warn(l,filenames.toString(),e);
696 }
697 catch (Error e)
698 {
699 warn(l,filenames.toString(),e);
700 }
701 }
702 }
703
704 /**
705 * signal any scan cycle listeners that a scan has started
706 */
707 private void reportScanStart(int cycle)
708 {
709 for (Listener listener : _listeners)
710 {
711 try
712 {
713 if (listener instanceof ScanCycleListener)
714 {
715 ((ScanCycleListener)listener).scanStarted(cycle);
716 }
717 }
718 catch (Exception e)
719 {
720 LOG.warn(listener + " failed on scan start for cycle " + cycle, e);
721 }
722 }
723 }
724
725 /**
726 * sign
727 */
728 private void reportScanEnd(int cycle)
729 {
730 for (Listener listener : _listeners)
731 {
732 try
733 {
734 if (listener instanceof ScanCycleListener)
735 {
736 ((ScanCycleListener)listener).scanEnded(cycle);
737 }
738 }
739 catch (Exception e)
740 {
741 LOG.warn(listener + " failed on scan end for cycle " + cycle, e);
742 }
743 }
744 }
745
746 }