--- /dev/null
+//
+// ========================================================================
+// 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 synchronized 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();
+ }
+
+ 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;
+ }
+ }
+
+ /**
+ * @return true if the path exists in one of the scandirs
+ */
+ public boolean exists(String path)
+ {
+ for (File dir : _scanDirs)
+ if (new File(dir,path).exists())
+ return true;
+ return false;
+ }
+
+
+ /**
+ * 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())))
+ {
+ LOG.debug("scan accepted {}",f);
+ String name = f.getCanonicalPath();
+ scanInfoMap.put(name, new TimeNSize(f.lastModified(),f.length()));
+ }
+ else
+ LOG.debug("scan rejected {}",f);
+ }
+
+ // 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);
+ }
+ }
+ }
+
+}
projects / gigi.git / blobdiff