org.eclipse.jetty.util.PathWatcher Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2018 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 static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Field;
import java.nio.file.ClosedWatchServiceException;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EventListener;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Scanner;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.TimeUnit;
import java.util.function.Predicate;
import java.util.stream.Stream;
import org.eclipse.jetty.util.component.AbstractLifeCycle;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
/**
* Watch a Path (and sub directories) for Path changes.
*
* Suitable replacement for the old {@link Scanner} implementation.
*
* Allows for configured Excludes and Includes using {@link FileSystem#getPathMatcher(String)} syntax.
*
* Reports activity via registered {@link Listener}s
*/
public class PathWatcher extends AbstractLifeCycle implements Runnable
{
public static class Config implements Predicate
{
public static final int UNLIMITED_DEPTH = -9999;
private static final String PATTERN_SEP;
static
{
String sep = File.separator;
if (File.separatorChar == '\\')
{
sep = "\\\\";
}
PATTERN_SEP = sep;
}
protected final Config parent;
protected final Path path;
protected final IncludeExcludeSet includeExclude;
protected int recurseDepth = 0; // 0 means no sub-directories are scanned
protected boolean excludeHidden = false;
protected long pauseUntil;
public Config(Path path)
{
this(path,null);
}
public Config(Path path, Config parent)
{
this.parent = parent;
this.includeExclude = parent==null ? new IncludeExcludeSet<>(PathMatcherSet.class) : parent.includeExclude;
Path dir = path;
if (!Files.exists(path))
throw new IllegalStateException("Path does not exist: "+path);
if (!Files.isDirectory(path))
{
dir = path.getParent();
includeExclude.include(new ExactPathMatcher(path));
setRecurseDepth(0);
}
this.path = dir;
}
public Config getParent()
{
return parent;
}
public void setPauseUntil(long time)
{
if (time>pauseUntil)
pauseUntil=time;
}
public boolean isPaused(long now)
{
if (pauseUntil==0)
return false;
if (pauseUntil>now)
{
if (LOG.isDebugEnabled())
LOG.debug("PAUSED {}",this);
return true;
}
if (LOG.isDebugEnabled())
LOG.debug("unpaused {}",this);
pauseUntil = 0;
return false;
}
/**
* Add an exclude PathMatcher
*
* @param matcher
* the path matcher for this exclude
*/
public void addExclude(PathMatcher matcher)
{
includeExclude.exclude(matcher);
}
/**
* Add an exclude PathMatcher.
*
* Note: this pattern is FileSystem specific (so use "/" for Linux and OSX, and "\\" for Windows)
*
* @param syntaxAndPattern
* the PathMatcher syntax and pattern to use
* @see FileSystem#getPathMatcher(String) for detail on syntax and pattern
*/
public void addExclude(final String syntaxAndPattern)
{
if (LOG.isDebugEnabled())
LOG.debug("Adding exclude: [{}]",syntaxAndPattern);
addExclude(path.getFileSystem().getPathMatcher(syntaxAndPattern));
}
/**
* Add a glob: syntax pattern exclude reference in a directory relative, os neutral, pattern.
*
*
* On Linux:
* Config config = new Config(Path("/home/user/example"));
* config.addExcludeGlobRelative("*.war") => "glob:/home/user/example/*.war"
*
* On Windows
* Config config = new Config(Path("D:/code/examples"));
* config.addExcludeGlobRelative("*.war") => "glob:D:\\code\\examples\\*.war"
*
*
*
* @param pattern
* the pattern, in unixy format, relative to config.dir
*/
public void addExcludeGlobRelative(String pattern)
{
addExclude(toGlobPattern(path,pattern));
}
/**
* Exclude hidden files and hidden directories
*/
public void addExcludeHidden()
{
if (!excludeHidden)
{
if (LOG.isDebugEnabled())
{
LOG.debug("Adding hidden files and directories to exclusions");
}
excludeHidden = true;
}
}
/**
* Add multiple exclude PathMatchers
*
* @param syntaxAndPatterns
* the list of PathMatcher syntax and patterns to use
* @see FileSystem#getPathMatcher(String) for detail on syntax and pattern
*/
public void addExcludes(List syntaxAndPatterns)
{
for (String syntaxAndPattern : syntaxAndPatterns)
{
addExclude(syntaxAndPattern);
}
}
/**
* Add an include PathMatcher
*
* @param matcher
* the path matcher for this include
*/
public void addInclude(PathMatcher matcher)
{
includeExclude.include(matcher);
}
/**
* Add an include PathMatcher
*
* @param syntaxAndPattern
* the PathMatcher syntax and pattern to use
* @see FileSystem#getPathMatcher(String) for detail on syntax and pattern
*/
public void addInclude(String syntaxAndPattern)
{
if (LOG.isDebugEnabled())
{
LOG.debug("Adding include: [{}]",syntaxAndPattern);
}
addInclude(path.getFileSystem().getPathMatcher(syntaxAndPattern));
}
/**
* Add a glob: syntax pattern reference in a directory relative, os neutral, pattern.
*
*
* On Linux:
* Config config = new Config(Path("/home/user/example"));
* config.addIncludeGlobRelative("*.war") => "glob:/home/user/example/*.war"
*
* On Windows
* Config config = new Config(Path("D:/code/examples"));
* config.addIncludeGlobRelative("*.war") => "glob:D:\\code\\examples\\*.war"
*
*
*
* @param pattern
* the pattern, in unixy format, relative to config.dir
*/
public void addIncludeGlobRelative(String pattern)
{
addInclude(toGlobPattern(path,pattern));
}
/**
* Add multiple include PathMatchers
*
* @param syntaxAndPatterns
* the list of PathMatcher syntax and patterns to use
* @see FileSystem#getPathMatcher(String) for detail on syntax and pattern
*/
public void addIncludes(List syntaxAndPatterns)
{
for (String syntaxAndPattern : syntaxAndPatterns)
{
addInclude(syntaxAndPattern);
}
}
/**
* Build a new config from a this configuration.
*
* Useful for working with sub-directories that also need to be watched.
*
* @param dir
* the directory to build new Config from (using this config as source of includes/excludes)
* @return the new Config
*/
public Config asSubConfig(Path dir)
{
Config subconfig = new Config(dir,this);
if (dir == this.path)
throw new IllegalStateException("sub "+dir.toString()+" of "+this);
if (this.recurseDepth == UNLIMITED_DEPTH)
subconfig.recurseDepth = UNLIMITED_DEPTH;
else
subconfig.recurseDepth = this.recurseDepth - (dir.getNameCount() - this.path.getNameCount());
if (LOG.isDebugEnabled())
LOG.debug("subconfig {} of {}",subconfig,path);
return subconfig;
}
public int getRecurseDepth()
{
return recurseDepth;
}
public boolean isRecurseDepthUnlimited ()
{
return this.recurseDepth == UNLIMITED_DEPTH;
}
public Path getPath ()
{
return this.path;
}
public Path resolve(Path path)
{
if (Files.isDirectory(this.path))
return this.path.resolve(path);
if (Files.exists(this.path))
return this.path;
return path;
}
@Override
public boolean test(Path path)
{
if (excludeHidden && isHidden(path))
{
if (LOG.isDebugEnabled())
LOG.debug("test({}) -> [Hidden]", toShortPath(path));
return false;
}
if (!path.startsWith(this.path))
{
if (LOG.isDebugEnabled())
LOG.debug("test({}) -> [!child {}]", toShortPath(path), this.path);
return false;
}
if (recurseDepth!=UNLIMITED_DEPTH)
{
int depth = path.getNameCount() - this.path.getNameCount() - 1;
if (depth>recurseDepth)
{
if (LOG.isDebugEnabled())
LOG.debug("test({}) -> [depth {}>{}]",toShortPath(path),depth,recurseDepth);
return false;
}
}
boolean matched = includeExclude.test(path);
if (LOG.isDebugEnabled())
LOG.debug("test({}) -> {}", toShortPath(path), matched);
return matched;
}
/**
* Set the recurse depth for the directory scanning.
*
* -999 indicates arbitrarily deep recursion, 0 indicates no recursion, 1 is only one directory deep, and so on.
*
* @param depth
* the number of directories deep to recurse
*/
public void setRecurseDepth(int depth)
{
this.recurseDepth = depth;
}
private String toGlobPattern(Path path, String subPattern)
{
StringBuilder s = new StringBuilder();
s.append("glob:");
boolean needDelim = false;
// Add root (aka "C:\" for Windows)
Path root = path.getRoot();
if (root != null)
{
if (LOG.isDebugEnabled())
{
LOG.debug("Path: {} -> Root: {}", path, root);
}
for (char c : root.toString().toCharArray())
{
if (c == '\\')
{
s.append(PATTERN_SEP);
}
else
{
s.append(c);
}
}
}
else
{
needDelim = true;
}
// Add the individual path segments
for (Path segment : path)
{
if (needDelim)
{
s.append(PATTERN_SEP);
}
s.append(segment);
needDelim = true;
}
// Add the sub pattern (if specified)
if ((subPattern != null) && (subPattern.length() > 0))
{
if (needDelim)
{
s.append(PATTERN_SEP);
}
for (char c : subPattern.toCharArray())
{
if (c == '/')
{
s.append(PATTERN_SEP);
}
else
{
s.append(c);
}
}
}
return s.toString();
}
DirAction handleDir(Path path)
{
try
{
if (!Files.isDirectory(path))
return DirAction.IGNORE;
if (excludeHidden && isHidden(path))
return DirAction.IGNORE;
if (getRecurseDepth()==0)
return DirAction.WATCH;
return DirAction.ENTER;
}
catch(Exception e)
{
LOG.ignore(e);
return DirAction.IGNORE;
}
}
public boolean isHidden(Path path)
{
try
{
if (!path.startsWith(this.path))
return true;
for (int i=this.path.getNameCount(); i events);
}
/**
* PathWatchEvent
*
* Represents a file event. Reported to registered listeners.
*/
public class PathWatchEvent
{
private final Path path;
private final PathWatchEventType type;
private final Config config;
long checked;
long modified;
long length;
public PathWatchEvent(Path path, PathWatchEventType type, Config config)
{
this.path = path;
this.type = type;
this.config = config;
checked = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
check();
}
public Config getConfig()
{
return config;
}
public PathWatchEvent(Path path, WatchEvent event, Config config)
{
this.path = path;
if (event.kind() == ENTRY_CREATE)
{
this.type = PathWatchEventType.ADDED;
}
else if (event.kind() == ENTRY_DELETE)
{
this.type = PathWatchEventType.DELETED;
}
else if (event.kind() == ENTRY_MODIFY)
{
this.type = PathWatchEventType.MODIFIED;
}
else
{
this.type = PathWatchEventType.UNKNOWN;
}
this.config = config;
checked = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
check();
}
private void check()
{
if (Files.exists(path))
{
try
{
modified = Files.getLastModifiedTime(path).toMillis();
length = Files.size(path);
}
catch(IOException e)
{
modified = -1;
length = -1;
}
}
else
{
modified = -1;
length = -1;
}
}
public boolean isQuiet(long now, long quietTime)
{
long lastModified = modified;
long lastLength = length;
check();
if (lastModified == modified && lastLength == length)
return (now-checked)>=quietTime;
checked = now;
return false;
}
public long toQuietCheck(long now, long quietTime)
{
long check = quietTime - (now-checked);
if (check<=0)
return quietTime;
return check;
}
public void modified()
{
long now = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
checked = now;
check();
config.setPauseUntil(now+getUpdateQuietTimeMillis());
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (getClass() != obj.getClass())
{
return false;
}
PathWatchEvent other = (PathWatchEvent)obj;
if (path == null)
{
if (other.path != null)
{
return false;
}
}
else if (!path.equals(other.path))
{
return false;
}
if (type != other.type)
{
return false;
}
return true;
}
public Path getPath()
{
return path;
}
public PathWatchEventType getType()
{
return type;
}
@Deprecated
public int getCount()
{
return 1;
}
/**
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = (prime * result) + ((path == null)?0:path.hashCode());
result = (prime * result) + ((type == null)?0:type.hashCode());
return result;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
return String.format("PathWatchEvent[%8s|%s]",type,path);
}
}
/**
* PathWatchEventType
*
* Type of an event
*/
public static enum PathWatchEventType
{
ADDED, DELETED, MODIFIED, UNKNOWN;
}
private static final boolean IS_WINDOWS;
static
{
String os = System.getProperty("os.name");
if (os == null)
{
IS_WINDOWS = false;
}
else
{
String osl = os.toLowerCase(Locale.ENGLISH);
IS_WINDOWS = osl.contains("windows");
}
}
static final Logger LOG = Log.getLogger(PathWatcher.class);
@SuppressWarnings("unchecked")
protected static WatchEvent cast(WatchEvent event)
{
return (WatchEvent)event;
}
private static final WatchEvent.Kind WATCH_EVENT_KINDS[] = { ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY };
private static final WatchEvent.Kind WATCH_DIR_KINDS[] = { ENTRY_CREATE, ENTRY_DELETE };
private WatchService watchService;
private WatchEvent.Modifier watchModifiers[];
private boolean nativeWatchService;
private final List configs = new ArrayList<>();
private final Map keys = new HashMap<>();
private final List listeners = new CopyOnWriteArrayList<>(); //a listener may modify the listener list directly or by stopping the PathWatcher
private final Map pending = new LinkedHashMap<>(32,(float)0.75,false);
private final List events = new ArrayList<>();
/**
* Update Quiet Time - set to 1000 ms as default (a lower value in Windows is not supported)
*/
private long updateQuietTimeDuration = 1000;
private TimeUnit updateQuietTimeUnit = TimeUnit.MILLISECONDS;
private Thread thread;
private boolean _notifyExistingOnStart = true;
/**
* Construct new PathWatcher
*/
public PathWatcher()
{
}
public Collection getConfigs()
{
return configs;
}
/**
* Request watch on a the given path (either file or dir)
* using all Config defaults. In the case of a dir,
* the default is not to recurse into subdirs for watching.
*
* @param file the path to watch
*/
public void watch (final Path file)
{
//Make a config for the dir above it and
//include a match only for the given path
//using all defaults for the configuration
Path abs = file;
if (!abs.isAbsolute())
{
abs = file.toAbsolutePath();
}
//Check we don't already have a config for the parent directory.
//If we do, add in this filename.
Config config = null;
Path parent = abs.getParent();
for (Config c:configs)
{
if (c.getPath().equals(parent))
{
config = c;
break;
}
}
//Make a new config
if (config == null)
{
config = new Config(abs.getParent());
// the include for the directory itself
config.addIncludeGlobRelative("");
//add the include for the file
config.addIncludeGlobRelative(file.getFileName().toString());
watch(config);
}
else
//add the include for the file
config.addIncludeGlobRelative(file.getFileName().toString());
}
/**
* Request watch on a path with custom Config
* provided.
*
* @param config the configuration to watch
*/
public void watch (final Config config)
{
//Add a custom config
configs.add(config);
}
/**
* Add a listener for changes the watcher notices.
*
* @param listener change listener
*/
public void addListener(EventListener listener)
{
listeners.add(listener);
}
/**
* Append some info on the paths that we are watching.
*
* @param s
*/
private void appendConfigId(StringBuilder s)
{
List dirs = new ArrayList<>();
for (Config config : keys.values())
{
dirs.add(config.path);
}
Collections.sort(dirs);
s.append("[");
if (dirs.size() > 0)
{
s.append(dirs.get(0));
if (dirs.size() > 1)
{
s.append(" (+").append(dirs.size() - 1).append(")");
}
}
else
{
s.append("");
}
s.append("]");
}
/**
* @see org.eclipse.jetty.util.component.AbstractLifeCycle#doStart()
*/
@Override
protected void doStart() throws Exception
{
//create a new watchservice
createWatchService();
//ensure setting of quiet time is appropriate now we have a watcher
setUpdateQuietTime(getUpdateQuietTimeMillis(), TimeUnit.MILLISECONDS);
// Register all watched paths, walking dir hierarchies as needed, possibly generating
// fake add events if notifyExistingOnStart is true
for (Config c:configs)
registerTree(c.getPath(),c,isNotifyExistingOnStart());
// Start Thread for watcher take/pollKeys loop
StringBuilder threadId = new StringBuilder();
threadId.append("PathWatcher@");
threadId.append(Integer.toHexString(hashCode()));
if (LOG.isDebugEnabled())
LOG.debug("{} -> {}", this, threadId);
thread = new Thread(this,threadId.toString());
thread.setDaemon(true);
thread.start();
super.doStart();
}
/**
* @see org.eclipse.jetty.util.component.AbstractLifeCycle#doStop()
*/
@Override
protected void doStop() throws Exception
{
if (watchService != null)
watchService.close(); //will invalidate registered watch keys, interrupt thread in take or poll
watchService = null;
thread = null;
keys.clear();
pending.clear();
events.clear();
super.doStop();
}
/**
* Remove all current configs and listeners.
*/
public void reset ()
{
if (!isStopped())
throw new IllegalStateException("PathWatcher must be stopped before reset.");
configs.clear();
listeners.clear();
}
/**
* Create a fresh WatchService and determine if it is a
* native implementation or not.
*
* @throws IOException
*/
private void createWatchService () throws IOException
{
//create a watch service
this.watchService = FileSystems.getDefault().newWatchService();
WatchEvent.Modifier modifiers[] = null;
boolean nativeService = true;
// Try to determine native behavior
// See http://stackoverflow.com/questions/9588737/is-java-7-watchservice-slow-for-anyone-else
try
{
ClassLoader cl = Thread.currentThread().getContextClassLoader();
Class pollingWatchServiceClass = Class.forName("sun.nio.fs.PollingWatchService",false,cl);
if (pollingWatchServiceClass.isAssignableFrom(this.watchService.getClass()))
{
nativeService = false;
LOG.info("Using Non-Native Java {}",pollingWatchServiceClass.getName());
Class c = Class.forName("com.sun.nio.file.SensitivityWatchEventModifier");
Field f = c.getField("HIGH");
modifiers = new WatchEvent.Modifier[]
{
(WatchEvent.Modifier)f.get(c)
};
}
}
catch (Throwable t)
{
// Unknown JVM environment, assuming native.
LOG.ignore(t);
}
this.watchModifiers = modifiers;
this.nativeWatchService = nativeService;
}
/**
* Check to see if the watcher is in a state where it should generate
* watch events to the listeners. Used to determine if watcher should generate
* events for existing files and dirs on startup.
*
* @return true if the watcher should generate events to the listeners.
*/
protected boolean isNotifiable ()
{
return (isStarted() || (!isStarted() && isNotifyExistingOnStart()));
}
/**
* Get an iterator over the listeners.
*
* @return iterator over the listeners.
*/
public Iterator getListeners()
{
return listeners.iterator();
}
/**
* Change the quiet time.
*
* @return the quiet time in millis
*/
public long getUpdateQuietTimeMillis()
{
return TimeUnit.MILLISECONDS.convert(updateQuietTimeDuration,updateQuietTimeUnit);
}
private void registerTree(Path dir, Config config, boolean notify) throws IOException
{
if (LOG.isDebugEnabled())
LOG.debug("registerTree {} {} {}", dir, config, notify);
if (!Files.isDirectory(dir))
throw new IllegalArgumentException(dir.toString());
register(dir,config);
final MultiException me = new MultiException();
try (Stream stream = Files.list( dir))
{
stream.forEach( p -> {
if ( LOG.isDebugEnabled() )
LOG.debug( "registerTree? {}", p );
try
{
if ( notify && config.test( p ) )
pending.put( p, new PathWatchEvent( p, PathWatchEventType.ADDED, config ) );
switch ( config.handleDir( p ) )
{
case ENTER:
registerTree( p, config.asSubConfig( p ), notify );
break;
case WATCH:
registerDir( p, config );
break;
case IGNORE:
default:
break;
}
}
catch ( IOException e )
{
me.add( e );
}
} );
}
try
{
me.ifExceptionThrow();
}
catch(IOException e)
{
throw e;
}
catch(Throwable th)
{
throw new IOException(th);
}
}
private void registerDir(Path path, Config config) throws IOException
{
if (LOG.isDebugEnabled())
LOG.debug("registerDir {} {}", path, config);
if (!Files.isDirectory(path))
throw new IllegalArgumentException(path.toString());
register(path,config.asSubConfig(path),WATCH_DIR_KINDS);
}
protected void register(Path path, Config config) throws IOException
{
if (LOG.isDebugEnabled())
LOG.debug("Registering watch on {} {}",path,watchModifiers==null?null:Arrays.asList(watchModifiers));
register(path,config,WATCH_EVENT_KINDS);
}
private void register(Path path, Config config, WatchEvent.Kind[] kinds) throws IOException
{
if(watchModifiers != null)
{
// Java Watcher
WatchKey key = path.register(watchService,kinds,watchModifiers);
keys.put(key,config);
} else
{
// Native Watcher
WatchKey key = path.register(watchService,kinds);
keys.put(key,config);
}
}
/**
* Delete a listener
* @param listener the listener to remove
* @return true if the listener existed and was removed
*/
public boolean removeListener(Listener listener)
{
return listeners.remove(listener);
}
/**
* Forever loop.
*
* Wait for the WatchService to report some filesystem events for the
* watched paths.
*
* When an event for a path first occurs, it is subjected to a quiet time.
* Subsequent events that arrive for the same path during this quiet time are
* accumulated and the timer reset. Only when the quiet time has expired are
* the accumulated events sent. MODIFY events are handled slightly differently -
* multiple MODIFY events arriving within a quiet time are coalesced into a
* single MODIFY event. Both the accumulation of events and coalescing of MODIFY
* events reduce the number and frequency of event reporting for "noisy" files (ie
* those that are undergoing rapid change).
*
* @see java.lang.Runnable#run()
*/
@Override
public void run()
{
// Start the java.nio watching
if (LOG.isDebugEnabled())
{
LOG.debug("Starting java.nio file watching with {}",watchService);
}
long wait_time = getUpdateQuietTimeMillis();
WatchService watch = watchService;
while (isRunning() && thread == Thread.currentThread())
{
WatchKey key;
try
{
// Reset all keys before watching
long now = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
for (Map.Entry e : keys.entrySet())
{
WatchKey k = e.getKey();
Config c = e.getValue();
if (!c.isPaused(now) && !k.reset())
{
keys.remove(k);
if (keys.isEmpty())
{
return; // all done, no longer monitoring anything
}
}
}
if (LOG.isDebugEnabled())
LOG.debug("Waiting for poll({})", wait_time);
key = wait_time<0?watch.take():wait_time>0?watch.poll(wait_time,updateQuietTimeUnit):watch.poll();
// handle all active keys
while (key!=null)
{
handleKey(key);
key = watch.poll();
}
wait_time = processPending();
notifyEvents();
}
catch (ClosedWatchServiceException e)
{
// Normal shutdown of watcher
return;
}
catch (InterruptedException e)
{
if (isRunning())
{
LOG.warn(e);
}
else
{
LOG.ignore(e);
}
}
}
}
private void handleKey(WatchKey key)
{
Config config = keys.get(key);
if (config == null)
{
if (LOG.isDebugEnabled())
LOG.debug("WatchKey not recognized: {}",key);
return;
}
for (WatchEvent event : key.pollEvents())
{
WatchEvent ev = cast(event);
Path name = ev.context();
Path path = config.resolve(name);
if (LOG.isDebugEnabled())
LOG.debug("handleKey? {} {} {}", ev.kind(), config.toShortPath(path), config);
// Ignore modified events on directories. These are handled as create/delete events of their contents
if (ev.kind()==ENTRY_MODIFY && Files.exists(path) && Files.isDirectory(path))
continue;
if (config.test(path))
handleWatchEvent(path, new PathWatchEvent(path,ev,config));
else if (config.getRecurseDepth()==-1)
{
// Convert a watched directory into a modify event on its parent
Path parent = path.getParent();
Config parentConfig = config.getParent();
handleWatchEvent(parent, new PathWatchEvent(parent,PathWatchEventType.MODIFIED,parentConfig));
continue;
}
if (ev.kind() == ENTRY_CREATE)
{
try
{
switch(config.handleDir(path))
{
case ENTER:
registerTree(path,config.asSubConfig(path),true);
break;
case WATCH:
registerDir(path,config);
break;
case IGNORE:
default:
break;
}
}
catch(IOException e)
{
LOG.warn(e);
}
}
}
}
/**
* Add an event reported by the WatchService to list of pending events
* that will be sent after their quiet time has expired.
*
* @param path the path to add to the pending list
* @param event the pending event
*/
public void handleWatchEvent (Path path, PathWatchEvent event)
{
PathWatchEvent existing = pending.get(path);
if (LOG.isDebugEnabled())
LOG.debug("handleWatchEvent {} {} <= {}", path, event, existing);
switch(event.getType())
{
case ADDED:
if (existing!=null && existing.getType()==PathWatchEventType.MODIFIED)
events.add(new PathWatchEvent(path,PathWatchEventType.DELETED,existing.getConfig()));
pending.put(path,event);
break;
case MODIFIED:
if (existing==null)
pending.put(path,event);
else
existing.modified();
break;
case DELETED:
case UNKNOWN:
if (existing!=null)
pending.remove(path);
events.add(event);
break;
}
}
private long processPending()
{
if (LOG.isDebugEnabled())
LOG.debug("processPending> {}",pending.values());
long now = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
long wait = Long.MAX_VALUE;
// pending map is maintained in LRU order
for (PathWatchEvent event : new ArrayList<>(pending.values()))
{
Path path = event.getPath();
// for directories, wait until parent is quiet
if (pending.containsKey(path.getParent()))
continue;
// if the path is quiet move to events
if (event.isQuiet(now,getUpdateQuietTimeMillis()))
{
if (LOG.isDebugEnabled())
LOG.debug("isQuiet {}",event);
pending.remove(path);
events.add(event);
}
else
{
long ms_to_check = event.toQuietCheck(now,getUpdateQuietTimeMillis());
if (LOG.isDebugEnabled())
LOG.debug("pending {} {}",event, ms_to_check);
if (ms_to_check implements Predicate
{
@Override
public boolean test(Path path)
{
for (PathMatcher pm: this)
if (pm.matches(path))
return true;
return false;
}
}
}