bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/LocalMetaArea.java - platform/eclipse.platform.resources - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2016 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Francis Lynch (Wind River) - [301563] Save and load tree snapshots
  *     Broadcom Corporation - ongoing development
  *     Sergey Prigogin (Google) - [437005] Out-of-date .snap file prevents Eclipse from running
  *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
  *     Mickael Istria (Red Hat Inc.) - Bug 488937
  *******************************************************************************/
 package org.eclipse.core.internal.resources;

 import java.io.*;
 import java.net.URI;
 import java.util.HashMap;
 import java.util.Map;
 import org.eclipse.core.filesystem.URIUtil;
 import org.eclipse.core.internal.localstore.SafeChunkyInputStream;
 import org.eclipse.core.internal.localstore.SafeChunkyOutputStream;
 import org.eclipse.core.internal.utils.Messages;
 import org.eclipse.core.internal.utils.Policy;
 import org.eclipse.core.resources.*;
 import org.eclipse.core.runtime.*;
 import org.eclipse.osgi.util.NLS;

 public class LocalMetaArea implements ICoreConstants {
 	/* package */static final String F_BACKUP_FILE_EXTENSION = ".bak"; //$NON-NLS-1$
 	/* package */static final String F_DESCRIPTION = ".workspace"; //$NON-NLS-1$

 	/* package */static final String F_HISTORY_STORE = ".history"; //$NON-NLS-1$
 	/* package */static final String F_MARKERS = ".markers"; //$NON-NLS-1$
 	/* package */static final String F_OLD_PROJECT = ".prj"; //$NON-NLS-1$
 	/* package */static final String F_PROJECT_LOCATION = ".location"; //$NON-NLS-1$
 	/* package */static final String F_PROJECTS = ".projects"; //$NON-NLS-1$
 	/* package */static final String F_PROPERTIES = ".properties"; //$NON-NLS-1$
 	/* package */static final String F_REFRESH = ".refresh"; //$NON-NLS-1$
 	/* package */static final String F_ROOT = ".root"; //$NON-NLS-1$
 	/* package */static final String F_SAFE_TABLE = ".safetable"; //$NON-NLS-1$
 	/* package */static final String F_SNAP = ".snap"; //$NON-NLS-1$
 	/* package */static final String F_SNAP_EXTENSION = "snap"; //$NON-NLS-1$
 	/* package */static final String F_SYNCINFO = ".syncinfo"; //$NON-NLS-1$
 	/* package */static final String F_TREE = ".tree"; //$NON-NLS-1$
 	/* package */static final String URI_PREFIX = "URI//"; //$NON-NLS-1$
 	/* package */static final String F_METADATA = ".metadata"; //$NON-NLS-1$

 	protected final IPath metaAreaLocation;

 	/**
 	 * The project location is just stored as an optimization, to avoid recomputing it.
 	 */
 	protected final IPath projectMetaLocation;

 	public LocalMetaArea() {
 		super();
 		metaAreaLocation = ResourcesPlugin.getPlugin().getStateLocation();
 		projectMetaLocation = metaAreaLocation.append(F_PROJECTS);
 	}

 	/**
 	 * For backwards compatibility, if there is a project at the old project
 	 * description location, delete it.
 	 */
 	public void clearOldDescription(IProject target) {
 		Workspace.clear(getOldDescriptionLocationFor(target).toFile());
 	}

 	/**
 	 * Delete the refresh snapshot once it has been used to open a new project.
 	 */
 	public void clearRefresh(IProject target) {
 		Workspace.clear(getRefreshLocationFor(target).toFile());
 	}

 	public void create(IProject target) {
 		java.io.File file = locationFor(target).toFile();
 		//make sure area is empty
 		Workspace.clear(file);
 		file.mkdirs();
 	}

 	/**
 	 * Creates the meta area root directory.
 	 */
 	public synchronized void createMetaArea() throws CoreException {
 		java.io.File workspaceLocation = metaAreaLocation.toFile();
 		Workspace.clear(workspaceLocation);
 		if (!workspaceLocation.mkdirs()) {
 			String message = NLS.bind(Messages.resources_writeWorkspaceMeta, workspaceLocation);
 			throw new ResourceException(IResourceStatus.FAILED_WRITE_METADATA, null, message, null);
 		}
 	}

 	/**
 	 * The project is being deleted. Delete all meta-data associated with the
 	 * project.
 	 */
 	public void delete(IProject target) throws CoreException {
 		IPath path = locationFor(target);
 		if (!Workspace.clear(path.toFile()) && path.toFile().exists()) {
 			String message = NLS.bind(Messages.resources_deleteMeta, target.getFullPath());
 			throw new ResourceException(IResourceStatus.FAILED_DELETE_METADATA, target.getFullPath(), message, null);
 		}
 	}

 	public IPath getBackupLocationFor(IPath file) {
 		return file.removeLastSegments(1).append(file.lastSegment() + F_BACKUP_FILE_EXTENSION);
 	}

 	public IPath getHistoryStoreLocation() {
 		return metaAreaLocation.append(F_HISTORY_STORE);
 	}

 	/**
 	 * Returns the local file system location which contains the META data for
 	 * the resources plugin (i.e., the entire workspace).
 	 */
 	public IPath getLocation() {
 		return metaAreaLocation;
 	}

 	/**
 	 * Returns the path of the file in which to save markers for the given
 	 * resource. Should only be called for the workspace root and projects.
 	 */
 	public IPath getMarkersLocationFor(IResource resource) {
 		Assert.isNotNull(resource);
 		Assert.isLegal(resource.getType() == IResource.ROOT || resource.getType() == IResource.PROJECT);
 		return locationFor(resource).append(F_MARKERS);
 	}

 	/**
 	 * Returns the path of the file in which to snapshot markers for the given
 	 * resource. Should only be called for the workspace root and projects.
 	 */
 	public IPath getMarkersSnapshotLocationFor(IResource resource) {
 		return getMarkersLocationFor(resource).addFileExtension(F_SNAP_EXTENSION);
 	}

 	/**
 	 * The project description file is the only metadata file stored outside
 	 * the metadata area. It is stored as a file directly under the project
 	 * location. For backwards compatibility, we also have to check for a
 	 * project file at the old location in the metadata area.
 	 */
 	public IPath getOldDescriptionLocationFor(IProject target) {
 		return locationFor(target).append(F_OLD_PROJECT);
 	}

 	public IPath getOldWorkspaceDescriptionLocation() {
 		return metaAreaLocation.append(F_DESCRIPTION);
 	}

 	public IPath getPropertyStoreLocation(IResource resource) {
 		int type = resource.getType();
 		Assert.isTrue(type != IResource.FILE && type != IResource.FOLDER);
 		return locationFor(resource).append(F_PROPERTIES);
 	}

 	/**
 	 * Returns the path of the file in which to save the refresh snapshot for
 	 * the given project.
 	 */
 	public IPath getRefreshLocationFor(IProject project) {
 		Assert.isNotNull(project);
 		return locationFor(project).append(F_REFRESH);
 	}

 	public IPath getSafeTableLocationFor(String pluginId) {
 		IPath prefix = metaAreaLocation.append(F_SAFE_TABLE);
 		// if the plugin is the resources plugin, we return the master table
 		// location
 		if (pluginId.equals(ResourcesPlugin.PI_RESOURCES))
 			return prefix.append(pluginId); // master table
 		int saveNumber = getWorkspace().getSaveManager().getSaveNumber(pluginId);
 		return prefix.append(pluginId + "." + saveNumber); //$NON-NLS-1$
 	}

 	/**
 	 * Returns the path of the snapshot file. The name of the file is composed from a sequence
 	 * number corresponding to the sequence number of tree file and ".snap" extension. Should
 	 * only be called for the workspace root.
 	 */
 	public IPath getSnapshotLocationFor(IResource resource) {
 		Assert.isNotNull(resource);
 		Assert.isLegal(resource.getType() == IResource.ROOT);
 		IPath key = resource.getFullPath().append(F_TREE);
 		String sequenceNumber = getWorkspace().getSaveManager().getMasterTable().getProperty(key.toString());
 		if (sequenceNumber == null)
 			sequenceNumber = "0"; //$NON-NLS-1$
 		return metaAreaLocation.append(sequenceNumber + F_SNAP);
 	}

 	/**
 	 * Returns the legacy, pre-4.4.1, path of the snapshot file. The name of the legacy snapshot
 	 * file is ".snap". Should only be called for the workspace root.
 	 */
 	public IPath getLegacySnapshotLocationFor(IResource resource) {
 		Assert.isNotNull(resource);
 		Assert.isLegal(resource.getType() == IResource.ROOT);
 		return metaAreaLocation.append(F_SNAP);
 	}

 	/**
 	 * Returns the path of the file in which to save the sync information for
 	 * the given resource. Should only be called for the workspace root and
 	 * projects.
 	 */
 	public IPath getSyncInfoLocationFor(IResource resource) {
 		Assert.isNotNull(resource);
 		Assert.isLegal(resource.getType() == IResource.ROOT || resource.getType() == IResource.PROJECT);
 		return locationFor(resource).append(F_SYNCINFO);
 	}

 	/**
 	 * Returns the path of the file in which to snapshot the sync information
 	 * for the given resource. Should only be called for the workspace root and
 	 * projects.
 	 */
 	public IPath getSyncInfoSnapshotLocationFor(IResource resource) {
 		return getSyncInfoLocationFor(resource).addFileExtension(F_SNAP_EXTENSION);
 	}

 	/**
 	 * Returns the local file system location of the tree file for the given
 	 * resource. This file does not follow the same save number as its plug-in.
 	 * So, the number here is called "sequence number" and not "save number" to
 	 * avoid confusion.
 	 */
 	public IPath getTreeLocationFor(IResource target, boolean updateSequenceNumber) {
 		IPath key = target.getFullPath().append(F_TREE);
 		String sequenceNumber = getWorkspace().getSaveManager().getMasterTable().getProperty(key.toString());
 		if (sequenceNumber == null)
 			sequenceNumber = "0"; //$NON-NLS-1$
 		if (updateSequenceNumber) {
 			int n = Integer.parseInt(sequenceNumber) + 1;
 			n = n < 0 ? 1 : n;
 			sequenceNumber = Integer.toString(n);
 			getWorkspace().getSaveManager().getMasterTable().setProperty(key.toString(), sequenceNumber);
 		}
 		return locationFor(target).append(sequenceNumber + F_TREE);
 	}

 	public IPath getWorkingLocation(IResource resource, String id) {
 		return locationFor(resource).append(id);
 	}

 	protected Workspace getWorkspace() {
 		return (Workspace) ResourcesPlugin.getWorkspace();
 	}

 	public boolean hasSavedProject(IProject project) {
 		//if there is a location file, then the project exists
 		return getOldDescriptionLocationFor(project).toFile().exists() || locationFor(project).append(F_PROJECT_LOCATION).toFile().exists();
 	}

 	public boolean hasSavedWorkspace() {
 		return metaAreaLocation.toFile().exists() || getBackupLocationFor(metaAreaLocation).toFile().exists();
 	}

 	/**
 	 * Returns the local file system location in which the meta data for the
 	 * resource with the given path is stored.
 	 */
 	public IPath locationFor(IPath resourcePath) {
 		if (Path.ROOT.equals(resourcePath))
 			return metaAreaLocation.append(F_ROOT);
 		return projectMetaLocation.append(resourcePath.segment(0));
 	}

 	/**
 	 * Returns the local file system location in which the meta data for the
 	 * given resource is stored.
 	 */
 	public IPath locationFor(IResource resource) {
 		if (resource.getType() == IResource.ROOT)
 			return metaAreaLocation.append(F_ROOT);
 		return projectMetaLocation.append(resource.getProject().getName());
 	}

 	/**
 	 * Reads and returns the project description for the given project. Returns
 	 * null if there was no project description file on disk. Throws an
 	 * exception if there was any failure to read the project.
 	 */
 	public ProjectDescription readOldDescription(IProject project) throws CoreException {
 		IPath path = getOldDescriptionLocationFor(project);
 		if (!path.toFile().exists())
 			return null;
 		IPath tempPath = getBackupLocationFor(path);
 		ProjectDescription description = null;
 		try {
 			description = new ProjectDescriptionReader(project).read(path, tempPath);
 		} catch (IOException e) {
 			String msg = NLS.bind(Messages.resources_readMeta, project.getName());
 			throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, project.getFullPath(), msg, e);
 		}
 		if (description == null) {
 			String msg = NLS.bind(Messages.resources_readMeta, project.getName());
 			throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, project.getFullPath(), msg, null);
 		}
 		return description;
 	}

 	/**
 	 * Provides backward compatibility with existing workspaces based on
 	 * descriptions.
 	 */
 	public WorkspaceDescription readOldWorkspace() {
 		IPath path = getOldWorkspaceDescriptionLocation();
 		IPath tempPath = getBackupLocationFor(path);
 		try {
 			WorkspaceDescription oldDescription = (WorkspaceDescription) new WorkspaceDescriptionReader().read(path, tempPath);
 			// if one of those files exist, get rid of them
 			Workspace.clear(path.toFile());
 			Workspace.clear(tempPath.toFile());
 			return oldDescription;
 		} catch (IOException e) {
 			return null;
 		}
 	}

 	/**
 	 * Returns the portions of the project description that are private, and
 	 * adds them to the supplied project description. In particular, the
 	 * project location, the project's dynamic references and build configurations
 	 * are stored here.
 	 * The project location will be set to <code>null</code> if the default
 	 * location should be used. In the case of failure, log the exception and
 	 * return silently, thus reverting to using the default location and no
 	 * dynamic references. The current format of the location file is:
 	 *    UTF - project location
 	 *    int - number of dynamic project references
 	 *    UTF - project reference 1
 	 *    ... repeat for remaining references
 	 * since 3.7:
 	 *    int - number of build configurations
 	 *      UTF - configuration name in order
 	 *      ... repeated for N configurations
 	 *    UTF - active build configuration name
 	 *    int - number of build configurations with refs
 	 *      UTF - build configuration name
 	 *      int - number of referenced configuration
 	 *        UTF - project name
 	 *        bool - hasConfigName
 	 *        UTF - configName if hasConfigName
 	 *        ... repeat for number of referenced configurations
 	 *      ... repeat for number of build configurations with references
 	 */
 	public void readPrivateDescription(IProject target, ProjectDescription description) {
 		IPath locationFile = locationFor(target).append(F_PROJECT_LOCATION);
 		java.io.File file = locationFile.toFile();
 		if (!file.exists()) {
 			locationFile = getBackupLocationFor(locationFile);
 			file = locationFile.toFile();
 			if (!file.exists())
 				return;
 		}
 		try (DataInputStream dataIn = new DataInputStream(new SafeChunkyInputStream(file, 500))) {
 			try {
 				String location = dataIn.readUTF();
 				if (location.length() > 0) {
 					//location format < 3.2 was a local file system OS path
 					//location format >= 3.2 is: URI_PREFIX + uri.toString()
 					if (location.startsWith(URI_PREFIX))
 						description.setLocationURI(URI.create(location.substring(URI_PREFIX.length())));
 					else
 						description.setLocationURI(URIUtil.toURI(Path.fromOSString(location)));
 				}
 			} catch (Exception e) {
 				//don't allow failure to read the location to propagate
 				String msg = NLS.bind(Messages.resources_exReadProjectLocation, target.getName());
 				Policy.log(new ResourceStatus(IStatus.ERROR, IResourceStatus.FAILED_READ_METADATA, target.getFullPath(), msg, e));
 			}
 			//try to read the dynamic references - will fail for old location files
 			int numRefs = dataIn.readInt();
 			IProject[] references = new IProject[numRefs];
 			IWorkspaceRoot root = getWorkspace().getRoot();
 			for (int i = 0; i < numRefs; i++)
 				references[i] = root.getProject(dataIn.readUTF());
 			description.setDynamicReferences(references);

 			// Since 3.7 -  Build Configurations
 			String[] configs = new String[dataIn.readInt()];
 			for (int i = 0; i < configs.length; i++)
 				configs[i] = dataIn.readUTF();
 			if (configs.length > 0)
 				// In the future we may decide this is better stored in the
 				// .project, so only set if configs.length > 0
 				description.setBuildConfigs(configs);
 			// Active configuration name
 			description.setActiveBuildConfig(dataIn.readUTF());
 			// Build configuration references?
 			int numBuildConifgsWithRefs = dataIn.readInt();
 			HashMap<String, IBuildConfiguration[]> m = new HashMap<>(numBuildConifgsWithRefs);
 			for (int i = 0; i < numBuildConifgsWithRefs; i++) {
 				String configName = dataIn.readUTF();
 				numRefs = dataIn.readInt();
 				IBuildConfiguration[] refs = new IBuildConfiguration[numRefs];
 				for (int j = 0; j < numRefs; j++) {
 					String projName = dataIn.readUTF();
 					if (dataIn.readBoolean())
 						refs[j] = new BuildConfiguration(root.getProject(projName), dataIn.readUTF());
 					else
 						refs[j] = new BuildConfiguration(root.getProject(projName), null);
 				}
 				m.put(configName, refs);
 			}
 			description.setBuildConfigReferences(m);
 		} catch (IOException e) {
 			//ignore - this is an old location file or an exception occurred
 			// closing the stream
 		}
 	}

 	/**
 	 * Writes the workspace description to the local meta area. This method is
 	 * synchronized to prevent multiple current write attempts.
 	 *
 	 * @deprecated should not be called any more - workspace preferences are
 	 *                     now maintained in the plug-in's preferences
 	 */
 	@Deprecated
 	public synchronized void write(WorkspaceDescription description) throws CoreException {
 		IPath path = getOldWorkspaceDescriptionLocation();
 		path.toFile().getParentFile().mkdirs();
 		IPath tempPath = getBackupLocationFor(path);
 		try {
 			new ModelObjectWriter().write(description, path, tempPath, System.lineSeparator());
 		} catch (IOException e) {
 			String message = NLS.bind(Messages.resources_writeWorkspaceMeta, path);
 			throw new ResourceException(IResourceStatus.FAILED_WRITE_METADATA, null, message, e);
 		}
 	}

 	/**
 	 * Write the private project description information, including the location
 	 * and the dynamic project references.  See <tt>readPrivateDescription</tt>
 	 * for details on the file format.
 	 */
 	public void writePrivateDescription(IProject target) throws CoreException {
 		IPath location = locationFor(target).append(F_PROJECT_LOCATION);
 		java.io.File file = location.toFile();
 		//delete any old location file
 		Workspace.clear(file);
 		//don't write anything if there is no interesting private metadata
 		ProjectDescription desc = ((Project) target).internalGetDescription();
 		if (desc == null)
 			return;
 		final URI projectLocation = desc.getLocationURI();
 		final IProject[] prjRefs = desc.getDynamicReferences(false);
 		final String[] buildConfigs = desc.configNames;
 		final Map<String, IBuildConfiguration[]> configRefs = desc.getBuildConfigReferences(false);
 		if (projectLocation == null && prjRefs.length == 0 && buildConfigs.length == 0 && configRefs.isEmpty())
 			return;
 		//write the private metadata file
 		try (SafeChunkyOutputStream output = new SafeChunkyOutputStream(file); DataOutputStream dataOut = new DataOutputStream(output);) {
 			if (projectLocation == null)
 				dataOut.writeUTF(""); //$NON-NLS-1$
 			else
 				dataOut.writeUTF(URI_PREFIX + projectLocation);
 			dataOut.writeInt(prjRefs.length);
 			for (IProject prjRef : prjRefs)
 				dataOut.writeUTF(prjRef.getName());

 			// Since 3.7 - build configurations + references
 			// Write out the build configurations
 			dataOut.writeInt(buildConfigs.length);
 			for (String buildConfig : buildConfigs) {
 				dataOut.writeUTF(buildConfig);
 			}
 			// Write active configuration name
 			dataOut.writeUTF(desc.getActiveBuildConfig());
 			// Write out the configuration level references
 			dataOut.writeInt(configRefs.size());
 			for (Map.Entry<String, IBuildConfiguration[]> e : configRefs.entrySet()) {
 				String refdName = e.getKey();
 				IBuildConfiguration[] refs = e.getValue();

 				dataOut.writeUTF(refdName);
 				dataOut.writeInt(refs.length);
 				for (IBuildConfiguration ref : refs) {
 					dataOut.writeUTF(ref.getProject().getName());
 					if (ref.getName() == null) {
 						dataOut.writeBoolean(false);
 					} else {
 						dataOut.writeBoolean(true);
 						dataOut.writeUTF(ref.getName());
 					}
 				}
 			}
 			output.succeed();
 		} catch (IOException e) {
 			String message = NLS.bind(Messages.resources_exSaveProjectLocation, target.getName());
 			throw new ResourceException(IResourceStatus.INTERNAL_ERROR, null, message, e);
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2016 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Francis Lynch (Wind River) - [301563] Save and load tree snapshots
	* Broadcom Corporation - ongoing development
	* Sergey Prigogin (Google) - [437005] Out-of-date .snap file prevents Eclipse from running
	* Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
	* Mickael Istria (Red Hat Inc.) - Bug 488937
	*******************************************************************************/
	package org.eclipse.core.internal.resources;

	import java.io.*;
	import java.net.URI;
	import java.util.HashMap;
	import java.util.Map;
	import org.eclipse.core.filesystem.URIUtil;
	import org.eclipse.core.internal.localstore.SafeChunkyInputStream;
	import org.eclipse.core.internal.localstore.SafeChunkyOutputStream;
	import org.eclipse.core.internal.utils.Messages;
	import org.eclipse.core.internal.utils.Policy;
	import org.eclipse.core.resources.*;
	import org.eclipse.core.runtime.*;
	import org.eclipse.osgi.util.NLS;

	public class LocalMetaArea implements ICoreConstants {
	/* package */static final String F_BACKUP_FILE_EXTENSION = ".bak"; //$NON-NLS-1$
	/* package */static final String F_DESCRIPTION = ".workspace"; //$NON-NLS-1$

	/* package */static final String F_HISTORY_STORE = ".history"; //$NON-NLS-1$
	/* package */static final String F_MARKERS = ".markers"; //$NON-NLS-1$
	/* package */static final String F_OLD_PROJECT = ".prj"; //$NON-NLS-1$
	/* package */static final String F_PROJECT_LOCATION = ".location"; //$NON-NLS-1$
	/* package */static final String F_PROJECTS = ".projects"; //$NON-NLS-1$
	/* package */static final String F_PROPERTIES = ".properties"; //$NON-NLS-1$
	/* package */static final String F_REFRESH = ".refresh"; //$NON-NLS-1$
	/* package */static final String F_ROOT = ".root"; //$NON-NLS-1$
	/* package */static final String F_SAFE_TABLE = ".safetable"; //$NON-NLS-1$
	/* package */static final String F_SNAP = ".snap"; //$NON-NLS-1$
	/* package */static final String F_SNAP_EXTENSION = "snap"; //$NON-NLS-1$
	/* package */static final String F_SYNCINFO = ".syncinfo"; //$NON-NLS-1$
	/* package */static final String F_TREE = ".tree"; //$NON-NLS-1$
	/* package */static final String URI_PREFIX = "URI//"; //$NON-NLS-1$
	/* package */static final String F_METADATA = ".metadata"; //$NON-NLS-1$

	protected final IPath metaAreaLocation;

	/**
	* The project location is just stored as an optimization, to avoid recomputing it.
	*/
	protected final IPath projectMetaLocation;

	public LocalMetaArea() {
	super();
	metaAreaLocation = ResourcesPlugin.getPlugin().getStateLocation();
	projectMetaLocation = metaAreaLocation.append(F_PROJECTS);
	}

	/**
	* For backwards compatibility, if there is a project at the old project
	* description location, delete it.
	*/
	public void clearOldDescription(IProject target) {
	Workspace.clear(getOldDescriptionLocationFor(target).toFile());
	}

	/**
	* Delete the refresh snapshot once it has been used to open a new project.
	*/
	public void clearRefresh(IProject target) {
	Workspace.clear(getRefreshLocationFor(target).toFile());
	}

	public void create(IProject target) {
	java.io.File file = locationFor(target).toFile();
	//make sure area is empty
	Workspace.clear(file);
	file.mkdirs();
	}

	/**
	* Creates the meta area root directory.
	*/
	public synchronized void createMetaArea() throws CoreException {
	java.io.File workspaceLocation = metaAreaLocation.toFile();
	Workspace.clear(workspaceLocation);
	if (!workspaceLocation.mkdirs()) {
	String message = NLS.bind(Messages.resources_writeWorkspaceMeta, workspaceLocation);
	throw new ResourceException(IResourceStatus.FAILED_WRITE_METADATA, null, message, null);
	}
	}

	/**
	* The project is being deleted. Delete all meta-data associated with the
	* project.
	*/
	public void delete(IProject target) throws CoreException {
	IPath path = locationFor(target);
	if (!Workspace.clear(path.toFile()) && path.toFile().exists()) {
	String message = NLS.bind(Messages.resources_deleteMeta, target.getFullPath());
	throw new ResourceException(IResourceStatus.FAILED_DELETE_METADATA, target.getFullPath(), message, null);
	}
	}

	public IPath getBackupLocationFor(IPath file) {
	return file.removeLastSegments(1).append(file.lastSegment() + F_BACKUP_FILE_EXTENSION);
	}

	public IPath getHistoryStoreLocation() {
	return metaAreaLocation.append(F_HISTORY_STORE);
	}

	/**
	* Returns the local file system location which contains the META data for
	* the resources plugin (i.e., the entire workspace).
	*/
	public IPath getLocation() {
	return metaAreaLocation;
	}

	/**
	* Returns the path of the file in which to save markers for the given
	* resource. Should only be called for the workspace root and projects.
	*/
	public IPath getMarkersLocationFor(IResource resource) {
	Assert.isNotNull(resource);
	Assert.isLegal(resource.getType() == IResource.ROOT \|\| resource.getType() == IResource.PROJECT);
	return locationFor(resource).append(F_MARKERS);
	}

	/**
	* Returns the path of the file in which to snapshot markers for the given
	* resource. Should only be called for the workspace root and projects.
	*/
	public IPath getMarkersSnapshotLocationFor(IResource resource) {
	return getMarkersLocationFor(resource).addFileExtension(F_SNAP_EXTENSION);
	}

	/**
	* The project description file is the only metadata file stored outside
	* the metadata area. It is stored as a file directly under the project
	* location. For backwards compatibility, we also have to check for a
	* project file at the old location in the metadata area.
	*/
	public IPath getOldDescriptionLocationFor(IProject target) {
	return locationFor(target).append(F_OLD_PROJECT);
	}

	public IPath getOldWorkspaceDescriptionLocation() {
	return metaAreaLocation.append(F_DESCRIPTION);
	}

	public IPath getPropertyStoreLocation(IResource resource) {
	int type = resource.getType();
	Assert.isTrue(type != IResource.FILE && type != IResource.FOLDER);
	return locationFor(resource).append(F_PROPERTIES);
	}

	/**
	* Returns the path of the file in which to save the refresh snapshot for
	* the given project.
	*/
	public IPath getRefreshLocationFor(IProject project) {
	Assert.isNotNull(project);
	return locationFor(project).append(F_REFRESH);
	}

	public IPath getSafeTableLocationFor(String pluginId) {
	IPath prefix = metaAreaLocation.append(F_SAFE_TABLE);
	// if the plugin is the resources plugin, we return the master table
	// location
	if (pluginId.equals(ResourcesPlugin.PI_RESOURCES))
	return prefix.append(pluginId); // master table
	int saveNumber = getWorkspace().getSaveManager().getSaveNumber(pluginId);
	return prefix.append(pluginId + "." + saveNumber); //$NON-NLS-1$
	}

	/**
	* Returns the path of the snapshot file. The name of the file is composed from a sequence
	* number corresponding to the sequence number of tree file and ".snap" extension. Should
	* only be called for the workspace root.
	*/
	public IPath getSnapshotLocationFor(IResource resource) {
	Assert.isNotNull(resource);
	Assert.isLegal(resource.getType() == IResource.ROOT);
	IPath key = resource.getFullPath().append(F_TREE);
	String sequenceNumber = getWorkspace().getSaveManager().getMasterTable().getProperty(key.toString());
	if (sequenceNumber == null)
	sequenceNumber = "0"; //$NON-NLS-1$
	return metaAreaLocation.append(sequenceNumber + F_SNAP);
	}

	/**
	* Returns the legacy, pre-4.4.1, path of the snapshot file. The name of the legacy snapshot
	* file is ".snap". Should only be called for the workspace root.
	*/
	public IPath getLegacySnapshotLocationFor(IResource resource) {
	Assert.isNotNull(resource);
	Assert.isLegal(resource.getType() == IResource.ROOT);
	return metaAreaLocation.append(F_SNAP);
	}

	/**
	* Returns the path of the file in which to save the sync information for
	* the given resource. Should only be called for the workspace root and
	* projects.
	*/
	public IPath getSyncInfoLocationFor(IResource resource) {
	Assert.isNotNull(resource);
	Assert.isLegal(resource.getType() == IResource.ROOT \|\| resource.getType() == IResource.PROJECT);
	return locationFor(resource).append(F_SYNCINFO);
	}

	/**
	* Returns the path of the file in which to snapshot the sync information
	* for the given resource. Should only be called for the workspace root and
	* projects.
	*/
	public IPath getSyncInfoSnapshotLocationFor(IResource resource) {
	return getSyncInfoLocationFor(resource).addFileExtension(F_SNAP_EXTENSION);
	}

	/**
	* Returns the local file system location of the tree file for the given
	* resource. This file does not follow the same save number as its plug-in.
	* So, the number here is called "sequence number" and not "save number" to
	* avoid confusion.
	*/
	public IPath getTreeLocationFor(IResource target, boolean updateSequenceNumber) {
	IPath key = target.getFullPath().append(F_TREE);
	String sequenceNumber = getWorkspace().getSaveManager().getMasterTable().getProperty(key.toString());
	if (sequenceNumber == null)
	sequenceNumber = "0"; //$NON-NLS-1$
	if (updateSequenceNumber) {
	int n = Integer.parseInt(sequenceNumber) + 1;
	n = n < 0 ? 1 : n;
	sequenceNumber = Integer.toString(n);
	getWorkspace().getSaveManager().getMasterTable().setProperty(key.toString(), sequenceNumber);
	}
	return locationFor(target).append(sequenceNumber + F_TREE);
	}

	public IPath getWorkingLocation(IResource resource, String id) {
	return locationFor(resource).append(id);
	}

	protected Workspace getWorkspace() {
	return (Workspace) ResourcesPlugin.getWorkspace();
	}

	public boolean hasSavedProject(IProject project) {
	//if there is a location file, then the project exists
	return getOldDescriptionLocationFor(project).toFile().exists() \|\| locationFor(project).append(F_PROJECT_LOCATION).toFile().exists();
	}

	public boolean hasSavedWorkspace() {
	return metaAreaLocation.toFile().exists() \|\| getBackupLocationFor(metaAreaLocation).toFile().exists();
	}

	/**
	* Returns the local file system location in which the meta data for the
	* resource with the given path is stored.
	*/
	public IPath locationFor(IPath resourcePath) {
	if (Path.ROOT.equals(resourcePath))
	return metaAreaLocation.append(F_ROOT);
	return projectMetaLocation.append(resourcePath.segment(0));
	}

	/**
	* Returns the local file system location in which the meta data for the
	* given resource is stored.
	*/
	public IPath locationFor(IResource resource) {
	if (resource.getType() == IResource.ROOT)
	return metaAreaLocation.append(F_ROOT);
	return projectMetaLocation.append(resource.getProject().getName());
	}

	/**
	* Reads and returns the project description for the given project. Returns
	* null if there was no project description file on disk. Throws an
	* exception if there was any failure to read the project.
	*/
	public ProjectDescription readOldDescription(IProject project) throws CoreException {
	IPath path = getOldDescriptionLocationFor(project);
	if (!path.toFile().exists())
	return null;
	IPath tempPath = getBackupLocationFor(path);
	ProjectDescription description = null;
	try {
	description = new ProjectDescriptionReader(project).read(path, tempPath);
	} catch (IOException e) {
	String msg = NLS.bind(Messages.resources_readMeta, project.getName());
	throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, project.getFullPath(), msg, e);
	}
	if (description == null) {
	String msg = NLS.bind(Messages.resources_readMeta, project.getName());
	throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, project.getFullPath(), msg, null);
	}
	return description;
	}

	/**
	* Provides backward compatibility with existing workspaces based on
	* descriptions.
	*/
	public WorkspaceDescription readOldWorkspace() {
	IPath path = getOldWorkspaceDescriptionLocation();
	IPath tempPath = getBackupLocationFor(path);
	try {
	WorkspaceDescription oldDescription = (WorkspaceDescription) new WorkspaceDescriptionReader().read(path, tempPath);
	// if one of those files exist, get rid of them
	Workspace.clear(path.toFile());
	Workspace.clear(tempPath.toFile());
	return oldDescription;
	} catch (IOException e) {
	return null;
	}
	}

	/**
	* Returns the portions of the project description that are private, and
	* adds them to the supplied project description. In particular, the
	* project location, the project's dynamic references and build configurations
	* are stored here.
	* The project location will be set to <code>null</code> if the default
	* location should be used. In the case of failure, log the exception and
	* return silently, thus reverting to using the default location and no
	* dynamic references. The current format of the location file is:
	* UTF - project location
	* int - number of dynamic project references
	* UTF - project reference 1
	* ... repeat for remaining references
	* since 3.7:
	* int - number of build configurations
	* UTF - configuration name in order
	* ... repeated for N configurations
	* UTF - active build configuration name
	* int - number of build configurations with refs
	* UTF - build configuration name
	* int - number of referenced configuration
	* UTF - project name
	* bool - hasConfigName
	* UTF - configName if hasConfigName
	* ... repeat for number of referenced configurations
	* ... repeat for number of build configurations with references
	*/
	public void readPrivateDescription(IProject target, ProjectDescription description) {
	IPath locationFile = locationFor(target).append(F_PROJECT_LOCATION);
	java.io.File file = locationFile.toFile();
	if (!file.exists()) {
	locationFile = getBackupLocationFor(locationFile);
	file = locationFile.toFile();
	if (!file.exists())
	return;
	}
	try (DataInputStream dataIn = new DataInputStream(new SafeChunkyInputStream(file, 500))) {
	try {
	String location = dataIn.readUTF();
	if (location.length() > 0) {
	//location format < 3.2 was a local file system OS path
	//location format >= 3.2 is: URI_PREFIX + uri.toString()
	if (location.startsWith(URI_PREFIX))
	description.setLocationURI(URI.create(location.substring(URI_PREFIX.length())));
	else
	description.setLocationURI(URIUtil.toURI(Path.fromOSString(location)));
	}
	} catch (Exception e) {
	//don't allow failure to read the location to propagate
	String msg = NLS.bind(Messages.resources_exReadProjectLocation, target.getName());
	Policy.log(new ResourceStatus(IStatus.ERROR, IResourceStatus.FAILED_READ_METADATA, target.getFullPath(), msg, e));
	}
	//try to read the dynamic references - will fail for old location files
	int numRefs = dataIn.readInt();
	IProject[] references = new IProject[numRefs];
	IWorkspaceRoot root = getWorkspace().getRoot();
	for (int i = 0; i < numRefs; i++)
	references[i] = root.getProject(dataIn.readUTF());
	description.setDynamicReferences(references);

	// Since 3.7 - Build Configurations
	String[] configs = new String[dataIn.readInt()];
	for (int i = 0; i < configs.length; i++)
	configs[i] = dataIn.readUTF();
	if (configs.length > 0)
	// In the future we may decide this is better stored in the
	// .project, so only set if configs.length > 0
	description.setBuildConfigs(configs);
	// Active configuration name
	description.setActiveBuildConfig(dataIn.readUTF());
	// Build configuration references?
	int numBuildConifgsWithRefs = dataIn.readInt();
	HashMap<String, IBuildConfiguration[]> m = new HashMap<>(numBuildConifgsWithRefs);
	for (int i = 0; i < numBuildConifgsWithRefs; i++) {
	String configName = dataIn.readUTF();
	numRefs = dataIn.readInt();
	IBuildConfiguration[] refs = new IBuildConfiguration[numRefs];
	for (int j = 0; j < numRefs; j++) {
	String projName = dataIn.readUTF();
	if (dataIn.readBoolean())
	refs[j] = new BuildConfiguration(root.getProject(projName), dataIn.readUTF());
	else
	refs[j] = new BuildConfiguration(root.getProject(projName), null);
	}
	m.put(configName, refs);
	}
	description.setBuildConfigReferences(m);
	} catch (IOException e) {
	//ignore - this is an old location file or an exception occurred
	// closing the stream
	}
	}

	/**
	* Writes the workspace description to the local meta area. This method is
	* synchronized to prevent multiple current write attempts.
	*
	* @deprecated should not be called any more - workspace preferences are
	* now maintained in the plug-in's preferences
	*/
	@Deprecated
	public synchronized void write(WorkspaceDescription description) throws CoreException {
	IPath path = getOldWorkspaceDescriptionLocation();
	path.toFile().getParentFile().mkdirs();
	IPath tempPath = getBackupLocationFor(path);
	try {
	new ModelObjectWriter().write(description, path, tempPath, System.lineSeparator());
	} catch (IOException e) {
	String message = NLS.bind(Messages.resources_writeWorkspaceMeta, path);
	throw new ResourceException(IResourceStatus.FAILED_WRITE_METADATA, null, message, e);
	}
	}

	/**
	* Write the private project description information, including the location
	* and the dynamic project references. See <tt>readPrivateDescription</tt>
	* for details on the file format.
	*/
	public void writePrivateDescription(IProject target) throws CoreException {
	IPath location = locationFor(target).append(F_PROJECT_LOCATION);
	java.io.File file = location.toFile();
	//delete any old location file
	Workspace.clear(file);
	//don't write anything if there is no interesting private metadata
	ProjectDescription desc = ((Project) target).internalGetDescription();
	if (desc == null)
	return;
	final URI projectLocation = desc.getLocationURI();
	final IProject[] prjRefs = desc.getDynamicReferences(false);
	final String[] buildConfigs = desc.configNames;
	final Map<String, IBuildConfiguration[]> configRefs = desc.getBuildConfigReferences(false);
	if (projectLocation == null && prjRefs.length == 0 && buildConfigs.length == 0 && configRefs.isEmpty())
	return;
	//write the private metadata file
	try (SafeChunkyOutputStream output = new SafeChunkyOutputStream(file); DataOutputStream dataOut = new DataOutputStream(output);) {
	if (projectLocation == null)
	dataOut.writeUTF(""); //$NON-NLS-1$
	else
	dataOut.writeUTF(URI_PREFIX + projectLocation);
	dataOut.writeInt(prjRefs.length);
	for (IProject prjRef : prjRefs)
	dataOut.writeUTF(prjRef.getName());

	// Since 3.7 - build configurations + references
	// Write out the build configurations
	dataOut.writeInt(buildConfigs.length);
	for (String buildConfig : buildConfigs) {
	dataOut.writeUTF(buildConfig);
	}
	// Write active configuration name
	dataOut.writeUTF(desc.getActiveBuildConfig());
	// Write out the configuration level references
	dataOut.writeInt(configRefs.size());
	for (Map.Entry<String, IBuildConfiguration[]> e : configRefs.entrySet()) {
	String refdName = e.getKey();
	IBuildConfiguration[] refs = e.getValue();

	dataOut.writeUTF(refdName);
	dataOut.writeInt(refs.length);
	for (IBuildConfiguration ref : refs) {
	dataOut.writeUTF(ref.getProject().getName());
	if (ref.getName() == null) {
	dataOut.writeBoolean(false);
	} else {
	dataOut.writeBoolean(true);
	dataOut.writeUTF(ref.getName());
	}
	}
	}
	output.succeed();
	} catch (IOException e) {
	String message = NLS.bind(Messages.resources_exSaveProjectLocation, target.getName());
	throw new ResourceException(IResourceStatus.INTERNAL_ERROR, null, message, e);
	}
	}
	}