| // |
| // ======================================================================== |
| // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // All rights reserved. This program and the accompanying materials |
| // are made available under the terms of the Eclipse Public License v1.0 |
| // and Apache License v2.0 which accompanies this distribution. |
| // |
| // The Eclipse Public License is available at |
| // http://www.eclipse.org/legal/epl-v10.html |
| // |
| // The Apache License v2.0 is available at |
| // http://www.opensource.org/licenses/apache2.0.php |
| // |
| // You may elect to redistribute this code under either of these licenses. |
| // ======================================================================== |
| // |
| |
| |
| package org.eclipse.jetty.util; |
| |
| import java.io.File; |
| import java.io.FilenameFilter; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import java.util.Set; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| |
| import org.eclipse.jetty.util.component.AbstractLifeCycle; |
| import org.eclipse.jetty.util.log.Log; |
| import org.eclipse.jetty.util.log.Logger; |
| |
| |
| /** |
| * Scanner |
| * |
| * Utility for scanning a directory for added, removed and changed |
| * files and reporting these events via registered Listeners. |
| * |
| */ |
| public class Scanner extends AbstractLifeCycle |
| { |
| private static final Logger LOG = Log.getLogger(Scanner.class); |
| private static int __scannerId=0; |
| private int _scanInterval; |
| private int _scanCount = 0; |
| private final List<Listener> _listeners = new ArrayList<Listener>(); |
| private final Map<String,TimeNSize> _prevScan = new HashMap<String,TimeNSize> (); |
| private final Map<String,TimeNSize> _currentScan = new HashMap<String,TimeNSize> (); |
| private FilenameFilter _filter; |
| private final List<File> _scanDirs = new ArrayList<File>(); |
| private volatile boolean _running = false; |
| private boolean _reportExisting = true; |
| private boolean _reportDirs = true; |
| private Timer _timer; |
| private TimerTask _task; |
| private int _scanDepth=0; |
| |
| public enum Notification { ADDED, CHANGED, REMOVED }; |
| private final Map<String,Notification> _notifications = new HashMap<String,Notification>(); |
| |
| static class TimeNSize |
| { |
| final long _lastModified; |
| final long _size; |
| |
| public TimeNSize(long lastModified, long size) |
| { |
| _lastModified = lastModified; |
| _size = size; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return (int)_lastModified^(int)_size; |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (o instanceof TimeNSize) |
| { |
| TimeNSize tns = (TimeNSize)o; |
| return tns._lastModified==_lastModified && tns._size==_size; |
| } |
| return false; |
| } |
| |
| @Override |
| public String toString() |
| { |
| return "[lm="+_lastModified+",s="+_size+"]"; |
| } |
| } |
| |
| /** |
| * Listener |
| * |
| * Marker for notifications re file changes. |
| */ |
| public interface Listener |
| { |
| } |
| |
| public interface ScanListener extends Listener |
| { |
| public void scan(); |
| } |
| |
| public interface DiscreteListener extends Listener |
| { |
| public void fileChanged (String filename) throws Exception; |
| public void fileAdded (String filename) throws Exception; |
| public void fileRemoved (String filename) throws Exception; |
| } |
| |
| |
| public interface BulkListener extends Listener |
| { |
| public void filesChanged (List<String> filenames) throws Exception; |
| } |
| |
| /** |
| * Listener that notifies when a scan has started and when it has ended. |
| */ |
| public interface ScanCycleListener extends Listener |
| { |
| public void scanStarted(int cycle) throws Exception; |
| public void scanEnded(int cycle) throws Exception; |
| } |
| |
| /** |
| * |
| */ |
| public Scanner () |
| { |
| } |
| |
| /** |
| * Get the scan interval |
| * @return interval between scans in seconds |
| */ |
| public int getScanInterval() |
| { |
| return _scanInterval; |
| } |
| |
| /** |
| * Set the scan interval |
| * @param scanInterval pause between scans in seconds, or 0 for no scan after the initial scan. |
| */ |
| public synchronized void setScanInterval(int scanInterval) |
| { |
| _scanInterval = scanInterval; |
| schedule(); |
| } |
| |
| /** |
| * Set the location of the directory to scan. |
| * @param dir |
| * @deprecated use setScanDirs(List dirs) instead |
| */ |
| @Deprecated |
| public void setScanDir (File dir) |
| { |
| _scanDirs.clear(); |
| _scanDirs.add(dir); |
| } |
| |
| /** |
| * Get the location of the directory to scan |
| * @return the first directory (of {@link #getScanDirs()} being scanned) |
| * @deprecated use getScanDirs() instead |
| */ |
| @Deprecated |
| public File getScanDir () |
| { |
| return (_scanDirs==null?null:(File)_scanDirs.get(0)); |
| } |
| |
| public void setScanDirs (List<File> dirs) |
| { |
| _scanDirs.clear(); |
| _scanDirs.addAll(dirs); |
| } |
| |
| public synchronized void addScanDir( File dir ) |
| { |
| _scanDirs.add( dir ); |
| } |
| |
| public List<File> getScanDirs () |
| { |
| return Collections.unmodifiableList(_scanDirs); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @param recursive True if scanning is recursive |
| * @see #setScanDepth(int) |
| */ |
| public void setRecursive (boolean recursive) |
| { |
| _scanDepth=recursive?-1:0; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @return True if scanning is fully recursive (scandepth==-1) |
| * @see #getScanDepth() |
| */ |
| public boolean getRecursive () |
| { |
| return _scanDepth==-1; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** Get the scanDepth. |
| * @return the scanDepth |
| */ |
| public int getScanDepth() |
| { |
| return _scanDepth; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** Set the scanDepth. |
| * @param scanDepth the scanDepth to set |
| */ |
| public void setScanDepth(int scanDepth) |
| { |
| _scanDepth = scanDepth; |
| } |
| |
| /** |
| * Apply a filter to files found in the scan directory. |
| * Only files matching the filter will be reported as added/changed/removed. |
| * @param filter |
| */ |
| public void setFilenameFilter (FilenameFilter filter) |
| { |
| _filter = filter; |
| } |
| |
| /** |
| * Get any filter applied to files in the scan dir. |
| * @return the filename filter |
| */ |
| public FilenameFilter getFilenameFilter () |
| { |
| return _filter; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * Whether or not an initial scan will report all files as being |
| * added. |
| * @param reportExisting if true, all files found on initial scan will be |
| * reported as being added, otherwise not |
| */ |
| public void setReportExistingFilesOnStartup (boolean reportExisting) |
| { |
| _reportExisting = reportExisting; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public boolean getReportExistingFilesOnStartup() |
| { |
| return _reportExisting; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** Set if found directories should be reported. |
| * @param dirs |
| */ |
| public void setReportDirs(boolean dirs) |
| { |
| _reportDirs=dirs; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public boolean getReportDirs() |
| { |
| return _reportDirs; |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * Add an added/removed/changed listener |
| * @param listener |
| */ |
| public synchronized void addListener (Listener listener) |
| { |
| if (listener == null) |
| return; |
| _listeners.add(listener); |
| } |
| |
| |
| |
| /** |
| * Remove a registered listener |
| * @param listener the Listener to be removed |
| */ |
| public synchronized void removeListener (Listener listener) |
| { |
| if (listener == null) |
| return; |
| _listeners.remove(listener); |
| } |
| |
| |
| /** |
| * Start the scanning action. |
| */ |
| @Override |
| public synchronized void doStart() |
| { |
| if (_running) |
| return; |
| |
| _running = true; |
| |
| if (_reportExisting) |
| { |
| // if files exist at startup, report them |
| scan(); |
| scan(); // scan twice so files reported as stable |
| } |
| else |
| { |
| //just register the list of existing files and only report changes |
| scanFiles(); |
| _prevScan.putAll(_currentScan); |
| } |
| schedule(); |
| } |
| |
| public TimerTask newTimerTask () |
| { |
| return new TimerTask() |
| { |
| @Override |
| public void run() { scan(); } |
| }; |
| } |
| |
| public Timer newTimer () |
| { |
| return new Timer("Scanner-"+__scannerId++, true); |
| } |
| |
| public void schedule () |
| { |
| if (_running) |
| { |
| if (_timer!=null) |
| _timer.cancel(); |
| if (_task!=null) |
| _task.cancel(); |
| if (getScanInterval() > 0) |
| { |
| _timer = newTimer(); |
| _task = newTimerTask(); |
| _timer.schedule(_task, 1010L*getScanInterval(),1010L*getScanInterval()); |
| } |
| } |
| } |
| /** |
| * Stop the scanning. |
| */ |
| @Override |
| public synchronized void doStop() |
| { |
| if (_running) |
| { |
| _running = false; |
| if (_timer!=null) |
| _timer.cancel(); |
| if (_task!=null) |
| _task.cancel(); |
| _task=null; |
| _timer=null; |
| } |
| } |
| |
| /** |
| * Perform a pass of the scanner and report changes |
| */ |
| public synchronized void scan () |
| { |
| reportScanStart(++_scanCount); |
| scanFiles(); |
| reportDifferences(_currentScan, _prevScan); |
| _prevScan.clear(); |
| _prevScan.putAll(_currentScan); |
| reportScanEnd(_scanCount); |
| |
| for (Listener l : _listeners) |
| { |
| try |
| { |
| if (l instanceof ScanListener) |
| ((ScanListener)l).scan(); |
| } |
| catch (Exception e) |
| { |
| LOG.warn(e); |
| } |
| catch (Error e) |
| { |
| LOG.warn(e); |
| } |
| } |
| } |
| |
| /** |
| * Recursively scan all files in the designated directories. |
| */ |
| public synchronized void scanFiles () |
| { |
| if (_scanDirs==null) |
| return; |
| |
| _currentScan.clear(); |
| Iterator<File> itor = _scanDirs.iterator(); |
| while (itor.hasNext()) |
| { |
| File dir = itor.next(); |
| |
| if ((dir != null) && (dir.exists())) |
| try |
| { |
| scanFile(dir.getCanonicalFile(), _currentScan,0); |
| } |
| catch (IOException e) |
| { |
| LOG.warn("Error scanning files.", e); |
| } |
| } |
| } |
| |
| |
| /** |
| * Report the adds/changes/removes to the registered listeners |
| * |
| * @param currentScan the info from the most recent pass |
| * @param oldScan info from the previous pass |
| */ |
| public synchronized void reportDifferences (Map<String,TimeNSize> currentScan, Map<String,TimeNSize> oldScan) |
| { |
| // scan the differences and add what was found to the map of notifications: |
| |
| Set<String> oldScanKeys = new HashSet<String>(oldScan.keySet()); |
| |
| // Look for new and changed files |
| for (Map.Entry<String, TimeNSize> entry: currentScan.entrySet()) |
| { |
| String file = entry.getKey(); |
| if (!oldScanKeys.contains(file)) |
| { |
| Notification old=_notifications.put(file,Notification.ADDED); |
| if (old!=null) |
| { |
| switch(old) |
| { |
| case REMOVED: |
| case CHANGED: |
| _notifications.put(file,Notification.CHANGED); |
| } |
| } |
| } |
| else if (!oldScan.get(file).equals(currentScan.get(file))) |
| { |
| Notification old=_notifications.put(file,Notification.CHANGED); |
| if (old!=null) |
| { |
| switch(old) |
| { |
| case ADDED: |
| _notifications.put(file,Notification.ADDED); |
| } |
| } |
| } |
| } |
| |
| // Look for deleted files |
| for (String file : oldScan.keySet()) |
| { |
| if (!currentScan.containsKey(file)) |
| { |
| Notification old=_notifications.put(file,Notification.REMOVED); |
| if (old!=null) |
| { |
| switch(old) |
| { |
| case ADDED: |
| _notifications.remove(file); |
| } |
| } |
| } |
| } |
| |
| if (LOG.isDebugEnabled()) |
| LOG.debug("scanned "+_scanDirs+": "+_notifications); |
| |
| // Process notifications |
| // Only process notifications that are for stable files (ie same in old and current scan). |
| List<String> bulkChanges = new ArrayList<String>(); |
| for (Iterator<Entry<String,Notification>> iter = _notifications.entrySet().iterator();iter.hasNext();) |
| { |
| Entry<String,Notification> entry=iter.next(); |
| String file=entry.getKey(); |
| |
| // Is the file stable? |
| if (oldScan.containsKey(file)) |
| { |
| if (!oldScan.get(file).equals(currentScan.get(file))) |
| continue; |
| } |
| else if (currentScan.containsKey(file)) |
| continue; |
| |
| // File is stable so notify |
| Notification notification=entry.getValue(); |
| iter.remove(); |
| bulkChanges.add(file); |
| switch(notification) |
| { |
| case ADDED: |
| reportAddition(file); |
| break; |
| case CHANGED: |
| reportChange(file); |
| break; |
| case REMOVED: |
| reportRemoval(file); |
| break; |
| } |
| } |
| if (!bulkChanges.isEmpty()) |
| reportBulkChanges(bulkChanges); |
| } |
| |
| |
| /** |
| * Get last modified time on a single file or recurse if |
| * the file is a directory. |
| * @param f file or directory |
| * @param scanInfoMap map of filenames to last modified times |
| */ |
| private void scanFile (File f, Map<String,TimeNSize> scanInfoMap, int depth) |
| { |
| try |
| { |
| if (!f.exists()) |
| return; |
| |
| if (f.isFile() || depth>0&& _reportDirs && f.isDirectory()) |
| { |
| if ((_filter == null) || ((_filter != null) && _filter.accept(f.getParentFile(), f.getName()))) |
| { |
| String name = f.getCanonicalPath(); |
| scanInfoMap.put(name, new TimeNSize(f.lastModified(),f.length())); |
| } |
| } |
| |
| // If it is a directory, scan if it is a known directory or the depth is OK. |
| if (f.isDirectory() && (depth<_scanDepth || _scanDepth==-1 || _scanDirs.contains(f))) |
| { |
| File[] files = f.listFiles(); |
| if (files != null) |
| { |
| for (int i=0;i<files.length;i++) |
| scanFile(files[i], scanInfoMap,depth+1); |
| } |
| else |
| LOG.warn("Error listing files in directory {}", f); |
| |
| } |
| } |
| catch (IOException e) |
| { |
| LOG.warn("Error scanning watched files", e); |
| } |
| } |
| |
| private void warn(Object listener,String filename,Throwable th) |
| { |
| LOG.warn(listener+" failed on '"+filename, th); |
| } |
| |
| /** |
| * Report a file addition to the registered FileAddedListeners |
| * @param filename |
| */ |
| private void reportAddition (String filename) |
| { |
| Iterator<Listener> itor = _listeners.iterator(); |
| while (itor.hasNext()) |
| { |
| Listener l = itor.next(); |
| try |
| { |
| if (l instanceof DiscreteListener) |
| ((DiscreteListener)l).fileAdded(filename); |
| } |
| catch (Exception e) |
| { |
| warn(l,filename,e); |
| } |
| catch (Error e) |
| { |
| warn(l,filename,e); |
| } |
| } |
| } |
| |
| |
| /** |
| * Report a file removal to the FileRemovedListeners |
| * @param filename |
| */ |
| private void reportRemoval (String filename) |
| { |
| Iterator<Listener> itor = _listeners.iterator(); |
| while (itor.hasNext()) |
| { |
| Object l = itor.next(); |
| try |
| { |
| if (l instanceof DiscreteListener) |
| ((DiscreteListener)l).fileRemoved(filename); |
| } |
| catch (Exception e) |
| { |
| warn(l,filename,e); |
| } |
| catch (Error e) |
| { |
| warn(l,filename,e); |
| } |
| } |
| } |
| |
| |
| /** |
| * Report a file change to the FileChangedListeners |
| * @param filename |
| */ |
| private void reportChange (String filename) |
| { |
| Iterator<Listener> itor = _listeners.iterator(); |
| while (itor.hasNext()) |
| { |
| Listener l = itor.next(); |
| try |
| { |
| if (l instanceof DiscreteListener) |
| ((DiscreteListener)l).fileChanged(filename); |
| } |
| catch (Exception e) |
| { |
| warn(l,filename,e); |
| } |
| catch (Error e) |
| { |
| warn(l,filename,e); |
| } |
| } |
| } |
| |
| private void reportBulkChanges (List<String> filenames) |
| { |
| Iterator<Listener> itor = _listeners.iterator(); |
| while (itor.hasNext()) |
| { |
| Listener l = itor.next(); |
| try |
| { |
| if (l instanceof BulkListener) |
| ((BulkListener)l).filesChanged(filenames); |
| } |
| catch (Exception e) |
| { |
| warn(l,filenames.toString(),e); |
| } |
| catch (Error e) |
| { |
| warn(l,filenames.toString(),e); |
| } |
| } |
| } |
| |
| /** |
| * signal any scan cycle listeners that a scan has started |
| */ |
| private void reportScanStart(int cycle) |
| { |
| for (Listener listener : _listeners) |
| { |
| try |
| { |
| if (listener instanceof ScanCycleListener) |
| { |
| ((ScanCycleListener)listener).scanStarted(cycle); |
| } |
| } |
| catch (Exception e) |
| { |
| LOG.warn(listener + " failed on scan start for cycle " + cycle, e); |
| } |
| } |
| } |
| |
| /** |
| * sign |
| */ |
| private void reportScanEnd(int cycle) |
| { |
| for (Listener listener : _listeners) |
| { |
| try |
| { |
| if (listener instanceof ScanCycleListener) |
| { |
| ((ScanCycleListener)listener).scanEnded(cycle); |
| } |
| } |
| catch (Exception e) |
| { |
| LOG.warn(listener + " failed on scan end for cycle " + cycle, e); |
| } |
| } |
| } |
| |
| } |