server-worker/src/main/java/org/taverna/server/localworker/impl/DirectoryDelegate.java

/*
 * Copyright (C) 2010-2011 The University of Manchester
 * 
 * See the file "LICENSE" for license terms.
 */
package org.taverna.server.localworker.impl;

import static org.apache.commons.io.FileUtils.forceDelete;
import static org.apache.commons.io.FileUtils.forceMkdir;
import static org.apache.commons.io.FileUtils.touch;
import static org.taverna.server.localworker.impl.utils.FilenameVerifier.getValidatedNewFile;

import java.io.File;
import java.io.IOException;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;

import javax.annotation.Nonnull;

import org.apache.commons.collections.MapIterator;
import org.apache.commons.collections.map.ReferenceMap;
import org.taverna.server.localworker.remote.RemoteDirectory;
import org.taverna.server.localworker.remote.RemoteDirectoryEntry;
import org.taverna.server.localworker.remote.RemoteFile;

/**
 * This class acts as a remote-aware delegate for the workflow run's working
 * directory and its subdirectories.
 * 
 * @author Donal Fellows
 * @see FileDelegate
 */
@SuppressWarnings("serial")
public class DirectoryDelegate extends UnicastRemoteObject implements
		RemoteDirectory {
	private File dir;
	private DirectoryDelegate parent;
	private ReferenceMap localCache;

	/**
	 * @param dir
	 * @param parent
	 * @throws RemoteException
	 *             If registration of the directory fails.
	 */
	public DirectoryDelegate(@Nonnull File dir,
			@Nonnull DirectoryDelegate parent) throws RemoteException {
		super();
		this.localCache = new ReferenceMap();
		this.dir = dir;
		this.parent = parent;
	}

	@Override
	public Collection<RemoteDirectoryEntry> getContents()
			throws RemoteException {
		List<RemoteDirectoryEntry> result = new ArrayList<>();
		for (String s : dir.list()) {
			if (s.equals(".") || s.equals(".."))
				continue;
			File f = new File(dir, s);
			RemoteDirectoryEntry entry;
			synchronized (localCache) {
				entry = (RemoteDirectoryEntry) localCache.get(s);
				if (f.isDirectory()) {
					if (entry == null || !(entry instanceof DirectoryDelegate)) {
						entry = new DirectoryDelegate(f, this);
						localCache.put(s, entry);
					}
				} else if (f.isFile()) {
					if (entry == null || !(entry instanceof FileDelegate)) {
						entry = new FileDelegate(f, this);
						localCache.put(s, entry);
					}
				} else {
					// not file or dir; skip...
					continue;
				}
			}
			result.add(entry);
		}
		return result;
	}

	@Override
	public RemoteFile makeEmptyFile(String name) throws IOException {
		File f = getValidatedNewFile(dir, name);
		touch(f);
		FileDelegate delegate = new FileDelegate(f, this);
		synchronized (localCache) {
			localCache.put(name, delegate);
		}
		return delegate;
	}

	@Override
	public RemoteDirectory makeSubdirectory(String name) throws IOException {
		File f = getValidatedNewFile(dir, name);
		forceMkdir(f);
		DirectoryDelegate delegate = new DirectoryDelegate(f, this);
		synchronized (localCache) {
			localCache.put(name, delegate);
		}
		return delegate;
	}

	@SuppressWarnings("unchecked")
	@Override
	public void destroy() throws IOException {
		if (parent == null)
			throw new IOException("tried to destroy main job working directory");
		Collection<RemoteDirectoryEntry> values;
		synchronized (localCache) {
			values = new ArrayList<>(localCache.values());
		}
		for (RemoteDirectoryEntry obj : values) {
			if (obj == null)
				continue;
			try {
				obj.destroy();
			} catch (IOException e) {
			}
		}
		forceDelete(dir);
		parent.forgetEntry(this);
	}

	@Override
	public RemoteDirectory getContainingDirectory() {
		return parent;
	}

	void forgetEntry(@Nonnull RemoteDirectoryEntry entry) {
		synchronized (localCache) {
			MapIterator i = localCache.mapIterator();
			while (i.hasNext()) {
				Object key = i.next();
				if (entry == i.getValue()) {
					localCache.remove(key);
					break;
				}
			}
		}
	}

	@Override
	public String getName() {
		if (parent == null)
			return "";
		return dir.getName();
	}

	@Override
	public Date getModificationDate() throws RemoteException {
		return new Date(dir.lastModified());
	}
}