Java tutorial
/* * Copyright (c) 2012-2018 Red Hat, Inc. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Red Hat, Inc. - initial API and implementation */ package org.eclipse.che.api.watcher.server.detectors; import static com.google.common.io.Files.hash; import static java.nio.charset.Charset.defaultCharset; import static org.eclipse.che.api.project.shared.dto.event.FileWatcherEventType.DELETED; import static org.eclipse.che.api.project.shared.dto.event.FileWatcherEventType.MODIFIED; import static org.eclipse.che.dto.server.DtoFactory.newDto; import static org.slf4j.LoggerFactory.getLogger; import com.google.common.hash.Hashing; import java.io.File; import java.io.IOException; import java.nio.file.Files; import java.util.HashMap; import java.util.Map; import java.util.Objects; import java.util.Timer; import java.util.TimerTask; import java.util.function.Consumer; import javax.annotation.PreDestroy; import javax.inject.Inject; import javax.inject.Named; import javax.inject.Singleton; import org.eclipse.che.api.core.jsonrpc.commons.RequestTransmitter; import org.eclipse.che.api.core.notification.EventService; import org.eclipse.che.api.core.notification.EventSubscriber; import org.eclipse.che.api.fs.server.FsManager; import org.eclipse.che.api.project.shared.dto.event.FileStateUpdateDto; import org.eclipse.che.api.project.shared.dto.event.FileTrackingOperationDto; import org.eclipse.che.api.project.shared.dto.event.FileTrackingOperationDto.Type; import org.eclipse.che.api.watcher.server.FileWatcherManager; import org.eclipse.che.api.watcher.server.impl.FileWatcherUtils; import org.slf4j.Logger; /** * Receive a file tracking operation call from client. There are several type of such calls: * * <ul> * <li>START/STOP - tells to start/stop tracking specific file * <li>SUSPEND/RESUME - tells to start/stop tracking all files registered for specific endpoint * <li>MOVE - tells that file that is being tracked should be moved (renamed) * </ul> * * @author Dmitry Kuleshov */ @Singleton public class EditorFileTracker { private static final Logger LOG = getLogger(EditorFileTracker.class); private static final String OUTGOING_METHOD = "event:file-state-changed"; private final Map<String, String> hashRegistry = new HashMap<>(); private final Map<String, Integer> watchIdRegistry = new HashMap<>(); private final RequestTransmitter transmitter; private final FileWatcherManager fileWatcherManager; private final FsManager fsManager; private final EventService eventService; private final EventSubscriber<FileTrackingOperationEvent> fileOperationEventSubscriber; private File root; @Inject public EditorFileTracker(@Named("che.user.workspaces.storage") File root, FileWatcherManager fileWatcherManager, RequestTransmitter transmitter, FsManager fsManager, EventService eventService) { this.root = root; this.fileWatcherManager = fileWatcherManager; this.transmitter = transmitter; this.fsManager = fsManager; this.eventService = eventService; fileOperationEventSubscriber = new EventSubscriber<FileTrackingOperationEvent>() { @Override public void onEvent(FileTrackingOperationEvent event) { onFileTrackingOperationReceived(event.getEndpointId(), event.getFileTrackingOperation()); } }; eventService.subscribe(fileOperationEventSubscriber); } private void onFileTrackingOperationReceived(String endpointId, FileTrackingOperationDto operation) { Type type = operation.getType(); String path = operation.getPath(); String oldPath = operation.getOldPath(); switch (type) { case START: { String key = path + endpointId; LOG.debug("Received file tracking operation START trigger key : {}", key); if (watchIdRegistry.containsKey(key)) { LOG.debug("Already registered {}", key); return; } int id = fileWatcherManager.registerByPath(path, getCreateConsumer(endpointId, path), getModifyConsumer(endpointId, path), getDeleteConsumer(endpointId, path)); watchIdRegistry.put(key, id); break; } case STOP: { LOG.debug("Received file tracking operation STOP trigger."); Integer id = watchIdRegistry.remove(path + endpointId); if (id != null) { fileWatcherManager.unRegisterByPath(id); } break; } case SUSPEND: { LOG.debug("Received file tracking operation SUSPEND trigger."); break; } case RESUME: { LOG.debug("Received file tracking operation RESUME trigger."); break; } case MOVE: { LOG.debug("Received file tracking operation MOVE trigger."); Integer oldId = watchIdRegistry.remove(oldPath + endpointId); if (oldId != null) { fileWatcherManager.unRegisterByPath(oldId); } int newId = fileWatcherManager.registerByPath(path, getCreateConsumer(endpointId, path), getModifyConsumer(endpointId, path), getDeleteConsumer(endpointId, path)); watchIdRegistry.put(path + endpointId, newId); break; } default: { LOG.error("Received file tracking operation UNKNOWN trigger."); break; } } } private Consumer<String> getCreateConsumer(String endpointId, String path) { // for case when file is updated through recreation return getModifyConsumer(endpointId, path); } private Consumer<String> getModifyConsumer(String endpointId, String path) { return it -> { String newHash = hashFile(path); String oldHash = hashRegistry.getOrDefault(path + endpointId, null); if (Objects.equals(newHash, oldHash)) { return; } hashRegistry.put(path + endpointId, newHash); FileStateUpdateDto params = newDto(FileStateUpdateDto.class).withPath(path).withType(MODIFIED) .withHashCode(newHash); transmitter.newRequest().endpointId(endpointId).methodName(OUTGOING_METHOD).paramsAsDto(params) .sendAndSkipResult(); }; } private Consumer<String> getDeleteConsumer(String endpointId, String path) { return it -> new Timer().schedule(new TimerTask() { @Override public void run() { if (!Files.exists(FileWatcherUtils.toNormalPath(root.toPath(), it))) { hashRegistry.remove(path + endpointId); FileStateUpdateDto params = newDto(FileStateUpdateDto.class).withPath(path).withType(DELETED); transmitter.newRequest().endpointId(endpointId).methodName(OUTGOING_METHOD).paramsAsDto(params) .sendAndSkipResult(); } } }, 1_000L); } private String hashFile(String wsPath) { try { File file = fsManager.toIoFile(wsPath); return file == null ? Hashing.md5().hashString("", defaultCharset()).toString() : hash(file, Hashing.md5()).toString(); } catch (IOException e) { LOG.error("Error trying to read {} file and broadcast it", wsPath, e); } return null; } @PreDestroy private void unsubscribe() { eventService.unsubscribe(fileOperationEventSubscriber); } }