Copyright (c) 2000, 2015 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
    James Blackburn (Broadcom Corp.) - ongoing development
/*******************************************************************************
 * Copyright (c) 2000, 2015 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
 *     James Blackburn (Broadcom Corp.) - ongoing development
 *******************************************************************************/
package org.eclipse.core.internal.resources;

import java.net.URI;
import java.util.*;
import org.eclipse.core.filesystem.URIUtil;
import org.eclipse.core.internal.utils.FileUtil;
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 WorkspaceRoot extends Container implements IWorkspaceRoot {
	
As an optimization, we store a table of project handles
that have been requested from this root.  This maps project
name strings to project handles.
/**
	 * As an optimization, we store a table of project handles
	 * that have been requested from this root.  This maps project
	 * name strings to project handles.
	 */
	private final Map<String, Project> projectTable = Collections.synchronizedMap(new HashMap<>(16));

	
Cache of the canonicalized platform location.
/**
	 * Cache of the canonicalized platform location.
	 */
	private final IPath workspaceLocation;

	protected WorkspaceRoot(IPath path, Workspace container) {
		super(path, container);
		Assert.isTrue(path.equals(Path.ROOT));
		workspaceLocation = FileUtil.canonicalPath(Platform.getLocation());
		Assert.isNotNull(workspaceLocation);
	}

	@Override
	public void delete(boolean deleteContent, boolean force, IProgressMonitor monitor) throws CoreException {
		int updateFlags = force ? IResource.FORCE : IResource.NONE;
		updateFlags |= deleteContent ? IResource.ALWAYS_DELETE_PROJECT_CONTENT : IResource.NEVER_DELETE_PROJECT_CONTENT;
		delete(updateFlags, monitor);
	}

	@Override
	public void delete(boolean force, IProgressMonitor monitor) throws CoreException {
		int updateFlags = force ? IResource.FORCE : IResource.NONE;
		delete(updateFlags, monitor);
	}

	@Override
	public boolean exists(int flags, boolean checkType) {
		return true;
	}

	@Deprecated
	@Override
	public IContainer[] findContainersForLocation(IPath location) {
		return findContainersForLocationURI(URIUtil.toURI(location.makeAbsolute()));
	}

	@Override
	public IContainer[] findContainersForLocationURI(URI location) {
		return findContainersForLocationURI(location, NONE);
	}

	@Override
	public IContainer[] findContainersForLocationURI(URI location, int memberFlags) {
		if (!location.isAbsolute())
			throw new IllegalArgumentException();
		return (IContainer[]) getLocalManager().allResourcesFor(location, false, memberFlags);
	}

	@Deprecated
	@Override
	public IFile[] findFilesForLocation(IPath location) {
		return findFilesForLocationURI(URIUtil.toURI(location.makeAbsolute()));
	}

	@Override
	public IFile[] findFilesForLocationURI(URI location) {
		return findFilesForLocationURI(location, NONE);
	}

	@Override
	public IFile[] findFilesForLocationURI(URI location, int memberFlags) {
		if (!location.isAbsolute())
			throw new IllegalArgumentException();
		return (IFile[]) getLocalManager().allResourcesFor(location, true, memberFlags);
	}

	@Override
	public IContainer getContainerForLocation(IPath location) {
		return getLocalManager().containerForLocation(location);
	}

	@Override
	public String getDefaultCharset(boolean checkImplicit) {
		if (checkImplicit)
			return ResourcesPlugin.getEncoding();
		String enc = ResourcesPlugin.getPlugin().getPluginPreferences().getString(ResourcesPlugin.PREF_ENCODING);
		return enc == null || enc.length() == 0 ? null : enc;
	}

	@Override
	public IFile getFileForLocation(IPath location) {
		return getLocalManager().fileForLocation(location);
	}

	@Override
	public long getLocalTimeStamp() {
		return IResource.NULL_STAMP;
	}

	@Override
	public IPath getLocation() {
		return workspaceLocation;
	}

	@Override
	public String getName() {
		return ""; //$NON-NLS-1$
	}

	@Override
	public IContainer getParent() {
		return null;
	}

	@Override
	public IProject getProject() {
		return null;
	}

	@Override
	public IProject getProject(String name) {
		//first check our project cache
		Project result = projectTable.get(name);
		if (result == null) {
			IPath projectPath = new Path(null, name).makeAbsolute();
			String message = "Path for project must have only one segment."; //$NON-NLS-1$
			Assert.isLegal(projectPath.segmentCount() == ICoreConstants.PROJECT_SEGMENT_LENGTH, message);
			//try to get the project using a canonical name
			String canonicalName = projectPath.lastSegment();
			result = projectTable.get(canonicalName);
			if (result != null)
				return result;
			result = new Project(projectPath, workspace);
			projectTable.put(canonicalName, result);
		}
		return result;
	}

	@Override
	public IPath getProjectRelativePath() {
		return Path.EMPTY;
	}

	@Override
	public IProject[] getProjects() {
		return getProjects(IResource.NONE);
	}

	@Override
	public IProject[] getProjects(int memberFlags) {
		IResource[] roots = getChildren(memberFlags);
		IProject[] result = new IProject[roots.length];
		try {
			System.arraycopy(roots, 0, result, 0, roots.length);
		} catch (ArrayStoreException ex) {
			// Shouldn't happen since only projects should be children of the workspace root
			for (IResource root2 : roots) {
				if (root2.getType() != IResource.PROJECT)
					Policy.log(IStatus.ERROR, NLS.bind("{0} is an invalid child of the workspace root.", //$NON-NLS-1$
							root2), null);

			}
			throw ex;
		}
		return result;
	}

	@Override
	public int getType() {
		return IResource.ROOT;
	}

	@Override
	public void internalSetLocal(boolean flag, int depth) throws CoreException {
		// do nothing for the root, but call for its children
		if (depth == IResource.DEPTH_ZERO)
			return;
		if (depth == IResource.DEPTH_ONE)
			depth = IResource.DEPTH_ZERO;
		// get the children via the workspace since we know that this
		// resource exists (it is local).
		IResource[] children = getChildren(IResource.NONE);
		for (IResource element : children)
			((Resource) element).internalSetLocal(flag, depth);
	}

	@Override
	public boolean isDerived(int options) {
		return false;//the root is never derived
	}

	@Override
	public boolean isHidden() {
		return false;//the root is never hidden
	}

	@Override
	public boolean isHidden(int options) {
		return false;//the root is never hidden
	}

	@Override
	public boolean isTeamPrivateMember(int options) {
		return false;//the root is never a team private member
	}

	@Override
	public boolean isLinked(int options) {
		return false;//the root is never linked
	}

	@Deprecated
	@Override
	public boolean isLocal(int depth) {
		// the flags parameter is ignored for the workspace root so pass anything
		return isLocal(-1, depth);
	}

	@Deprecated
	@Override
	public boolean isLocal(int flags, int depth) {
		// don't check the flags....workspace root is always local
		if (depth == DEPTH_ZERO)
			return true;
		if (depth == DEPTH_ONE)
			depth = DEPTH_ZERO;
		// get the children via the workspace since we know that this
		// resource exists (it is local).
		IResource[] children = getChildren(IResource.NONE);
		for (IResource c : children) {
			if (!c.isLocal(depth)) {
				return false;
			}
		}
		return true;
	}

	@Override
	public boolean isPhantom() {
		return false;
	}

	@Deprecated
	@Override
	public void setDefaultCharset(String charset) {
		// directly change the Resource plugin's preference for encoding
		Preferences resourcesPreferences = ResourcesPlugin.getPlugin().getPluginPreferences();
		if (charset != null)
			resourcesPreferences.setValue(ResourcesPlugin.PREF_ENCODING, charset);
		else
			resourcesPreferences.setToDefault(ResourcesPlugin.PREF_ENCODING);
	}

	@Override
	public void setHidden(boolean isHidden) {
		//workspace root cannot be set hidden
	}

	@Override
	public long setLocalTimeStamp(long value) {
		if (value < 0)
			throw new IllegalArgumentException("Illegal time stamp: " + value); //$NON-NLS-1$
		//can't set local time for root
		return value;
	}

	@Deprecated
	@Override
	public void setReadOnly(boolean readonly) {
		//can't set the root read only
	}

	@Override
	public void touch(IProgressMonitor monitor) {
		// do nothing for the workspace root
	}
}