/*******************************************************************************
* Copyright (c) 2011-2014 Fernando Petrola
*
* This file is part of Dragome SDK.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the GNU Public License v3.0
* which accompanies this distribution, and is available at
* http://www.gnu.org/licenses/gpl.html
******************************************************************************/
package com.dragome.web.serverside.compile.watchers;
import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
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 static java.nio.file.StandardWatchEventKinds.OVERFLOW;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.nio.file.attribute.BasicFileAttributes;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.dragome.commons.compiler.classpath.Classpath;
import com.dragome.web.helpers.serverside.DragomeCompilerLauncher;
public class DirectoryWatcher
{
ReschedulableTimer reschedulableTimer= new ReschedulableTimer();
private final WatchService watcher;
private final Map<WatchKey, Path> keys;
private final boolean recursive;
private boolean trace= false;
public static long lastCompilation;
private Classpath classPath;
private String path;
private static String lines;
@SuppressWarnings("unchecked")
static <T> WatchEvent<T> cast(WatchEvent<?> event)
{
return (WatchEvent<T>) event;
}
/**
* Register the given directory with the WatchService
*/
private void register(Path dir) throws IOException
{
WatchKey key= dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
if (trace)
{
Path prev= keys.get(key);
if (prev == null)
{
System.out.format("register: %s\n", dir);
}
else
{
if (!dir.equals(prev))
{
System.out.format("update: %s -> %s\n", prev, dir);
}
}
}
keys.put(key, dir);
}
/**
* Register the given directory, and all its sub-directories, with the
* WatchService.
*/
private void registerAll(final Path start) throws IOException
{
// register directory and sub-directories
Files.walkFileTree(start, new SimpleFileVisitor<Path>()
{
@Override
public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException
{
register(dir);
return FileVisitResult.CONTINUE;
}
});
}
/**
* Creates a WatchService and registers the given directory
*/
DirectoryWatcher(Path dir, boolean recursive, Classpath classPath, String path) throws IOException
{
this.classPath= classPath;
this.path= path;
this.watcher= FileSystems.getDefault().newWatchService();
this.keys= new HashMap<WatchKey, Path>();
this.recursive= recursive;
if (recursive)
{
System.out.format("Scanning %s ...\n", dir);
registerAll(dir);
// System.out.println("Done.");
}
else
{
register(dir);
}
// enable trace after initial registration
this.trace= true;
}
/**
* Process all events for keys queued to the watcher
*/
void processEvents()
{
for (;;)
{
// wait for key to be signalled
WatchKey key;
try
{
key= watcher.take();
}
catch (InterruptedException x)
{
return;
}
System.out.print(lines);
lines= "";
Path dir= keys.get(key);
if (dir == null)
{
System.err.println("WatchKey not recognized!!");
continue;
}
for (WatchEvent<?> event : key.pollEvents())
{
WatchEvent.Kind kind= event.kind();
// TBD - provide example of how OVERFLOW event is handled
if (kind == OVERFLOW || kind == ENTRY_DELETE)
{
continue;
}
// Context for directory entry event is the file name of entry
WatchEvent<Path> ev= cast(event);
Path name= ev.context();
Path child= dir.resolve(name);
// print out event
System.out.format("%s: %s\n", humanReadable(event.kind().name()), child.getName(child.getNameCount() - 1));
if (reschedulableTimer.isScheduling())
reschedulableTimer.reschedule(500);
else
reschedulableTimer.schedule(new Runnable()
{
public void run()
{
compile(classPath, path);
}
}, 500);
// if directory is created, and watching recursively, then
// register it and its sub-directories
if (recursive && (kind == ENTRY_CREATE))
{
try
{
if (Files.isDirectory(child, NOFOLLOW_LINKS))
{
registerAll(child);
}
}
catch (IOException x)
{
// ignore to keep sample readbale
}
}
}
// reset key and remove from set if directory no longer accessible
boolean valid= key.reset();
if (!valid)
{
keys.remove(key);
// all directories are inaccessible
if (keys.isEmpty())
{
break;
}
}
}
}
private String humanReadable(String string)
{
return string.replace(ENTRY_MODIFY.name(), "file modified").replace(ENTRY_DELETE.name(), "file deleted").replace(ENTRY_CREATE.name(), "file created");
}
static void usage()
{
System.err.println("usage: java WatchDir [-r] dir");
System.exit(-1);
}
public static void startWatching(String[] args, Classpath classPath, String path)
{
try
{
if (args.length == 0 || args.length > 2)
usage();
boolean recursive= false;
int dirArg= 0;
if (args[0].equals("-r"))
{
if (args.length < 2)
usage();
recursive= true;
dirArg++;
}
compile(classPath, path);
Path dir= Paths.get(args[dirArg]);
new DirectoryWatcher(dir, recursive, classPath, path).processEvents();
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
private static void compile(Classpath classPath, String path)
{
System.out.println("");
System.out.println("----------------------------------------------------------------------");
DragomeCompilerLauncher.compileWithMainClass(classPath, path);
lastCompilation= System.currentTimeMillis();
System.out.println("----------------------------------------------------------------------");
System.out.println("DRAGOME BUILD SUCCESSFUL: js application ready");
System.out.println("----------------------------------------------------------------------");
System.out.println("Finished at: " + new SimpleDateFormat("EEE MMM d HH:mm:ss z YYYY").format(new Date()));
System.out.println("======================================================================");
lines= "\n\n\n\n==================Dragome has detected these changes==================\n";
}
}