| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.meecrowave.watching; |
| |
| import org.apache.catalina.Context; |
| import org.apache.meecrowave.logging.tomcat.LogFacade; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.FileVisitResult; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.nio.file.SimpleFileVisitor; |
| import java.nio.file.StandardWatchEventKinds; |
| import java.nio.file.WatchEvent; |
| import java.nio.file.WatchKey; |
| import java.nio.file.WatchService; |
| import java.nio.file.attribute.BasicFileAttributes; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.TimeUnit; |
| |
| import static java.util.Arrays.asList; |
| |
| public class ReloadOnChangeController implements AutoCloseable, Runnable { |
| private final Context context; |
| private final long bouncing; |
| private final Collection<Path> paths = new ArrayList<>(); |
| private WatchService watchService; |
| private Thread bouncer; |
| private Thread watcher; |
| private volatile boolean running = true; |
| private volatile long redeployMarker = System.nanoTime(); |
| |
| public ReloadOnChangeController(final Context context, final int watcherBouncing) { |
| this.context = context; |
| this.bouncing = (long) watcherBouncing; |
| } |
| |
| public void register(final File folder) { |
| paths.add(folder.toPath()); |
| } |
| |
| public void start() { |
| if (paths.isEmpty()) { |
| return; |
| } |
| try { |
| watchService = paths.iterator().next().getFileSystem().newWatchService(); // assuming all share the same FS |
| for (final Path p : paths) { |
| p.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, |
| StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE); |
| } |
| } catch (final IOException ex) { |
| new LogFacade(ReloadOnChangeController.class.getName()) |
| .warn("Hot reloading will not be available", ex); |
| } |
| |
| watcher = new Thread(this); |
| watcher.setName("meecrowave-watcher-controller"); |
| watcher.start(); |
| } |
| |
| protected synchronized void redeploy() { |
| context.reload(); |
| } |
| |
| @Override |
| public void close() { |
| if (!running) { |
| return; |
| } |
| running = false; |
| final long waitMs = bouncing * 2 + 5000 /*margin if redeploying, we can make it configurable later*/; |
| if (bouncer != null) { |
| try { |
| bouncer.join(waitMs); |
| } catch (final InterruptedException e) { |
| Thread.interrupted(); |
| } |
| } |
| if (watcher != null) { |
| try { |
| watcher.join(waitMs); |
| } catch (final InterruptedException e) { |
| Thread.interrupted(); |
| } |
| } |
| } |
| |
| public boolean shouldRun() { |
| return !paths.isEmpty(); |
| } |
| |
| @Override |
| public void run() { |
| if (watchService == null) { |
| return; |
| } |
| |
| final CountDownLatch latch = new CountDownLatch(1); |
| bouncer = new Thread(() -> { // simple bouncing impl |
| long last = redeployMarker; |
| latch.countDown(); |
| |
| boolean needsRedeploy = false; |
| long antepenultiem = -1; |
| while (running) { |
| if (redeployMarker > last) { |
| antepenultiem = last; |
| last = redeployMarker; |
| needsRedeploy = true; |
| } else if (needsRedeploy) { |
| antepenultiem = last; |
| } |
| |
| try { |
| Thread.sleep(bouncing); |
| } catch (final InterruptedException e) { |
| Thread.interrupted(); |
| break; |
| } |
| |
| if (needsRedeploy && last == antepenultiem) { |
| new LogFacade(ReloadOnChangeController.class.getName()).info("Redeploying " + context.getName()); |
| redeploy(); |
| } |
| } |
| }); |
| bouncer.setName("meecrowave-watcher-redeployer"); |
| bouncer.start(); |
| try { |
| latch.await(1, TimeUnit.MINUTES); |
| } catch (final InterruptedException e) { |
| Thread.interrupted(); |
| return; |
| } |
| |
| paths.forEach(p -> { |
| try { |
| Files.walkFileTree(p, new SimpleFileVisitor<Path>() { |
| @Override |
| public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException { |
| dir.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY); |
| return FileVisitResult.CONTINUE; |
| } |
| }); |
| } catch (final IOException e) { |
| new LogFacade(ReloadOnChangeController.class.getName()).warn(e.getMessage()); |
| } |
| }); |
| |
| try { |
| while (running) { |
| final WatchKey watchKey = watchService.poll(bouncing, TimeUnit.MILLISECONDS); |
| if (watchKey == null) { |
| Thread.sleep(bouncing); |
| continue; |
| } |
| |
| boolean foundNew = false; |
| for (final WatchEvent<?> event : watchKey.pollEvents()) { |
| final Path path = Path.class.cast(event.context()); |
| final WatchEvent.Kind<?> kind = event.kind(); |
| if (!isIgnored(kind, path)) { |
| foundNew = true; |
| |
| final File file = path.toAbsolutePath().toFile(); |
| if (file.isDirectory()) { |
| if (kind == StandardWatchEventKinds.ENTRY_CREATE) { |
| try { |
| path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, |
| StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE); |
| } catch (final IOException e) { |
| new LogFacade(ReloadOnChangeController.class.getName()).warn(e.getMessage()); |
| } |
| } |
| } |
| break; |
| } |
| } |
| |
| if (foundNew) { |
| new LogFacade(ReloadOnChangeController.class.getName()).info("Marking to redeploy " + context.getName()); |
| redeployMarker = System.nanoTime(); |
| } |
| |
| if (!watchKey.reset()) { // deletion |
| watchKey.cancel(); |
| } |
| } |
| } catch (final InterruptedException ie) { |
| Thread.interrupted(); |
| } |
| } |
| |
| private boolean isIgnored(final WatchEvent.Kind<?> kind, final Path path) { |
| final String pathStr = path.toString(); |
| return pathStr.endsWith("___jb_tmp___") || pathStr.endsWith("___jb_old___") || pathStr.endsWith("~") || isResource(pathStr); |
| } |
| |
| private boolean isResource(final String pathStr) { |
| final int idx = pathStr.lastIndexOf('.'); |
| return idx > 0 && asList(".html", ".xhtml", ".js", ".ts", ".css", ".png", ".svg", ".jpg", ".jpeg").contains(pathStr.substring(idx)); |
| } |
| } |