Copyright (c) 2004, 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
/*******************************************************************************
 * Copyright (c) 2004, 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
 *******************************************************************************/
package org.eclipse.core.internal.preferences;

import org.eclipse.core.runtime.*;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.osgi.service.prefs.BackingStoreException;
import org.osgi.service.prefs.Preferences;

Since:
3.0/**
 * @since 3.0
 */
public class RootPreferences extends EclipsePreferences {

	
Default constructor.
/**
	 * Default constructor.
	 */
	public RootPreferences() {
		super(null, ""); //$NON-NLS-1$
	}


	@Override
	public void flush() throws BackingStoreException {
		// flush all children
		BackingStoreException exception = null;
		String[] names = childrenNames();
		for (String n : names) {
			try {
				node(n).flush();
			}catch (BackingStoreException e) {
				// store the first exception we get and still try and flush
				// the rest of the children.
				if (exception == null)
					exception = e;
			}
		}
		if (exception != null)
			throw exception;
	}


	protected synchronized IEclipsePreferences getChild(String key, Object context) {
		if (children == null)
			return null;
		Object value = children.get(key);
		if (value == null)
			return null;
		if (value instanceof IEclipsePreferences)
			return (IEclipsePreferences) value;
		//lazy initialization
		IEclipsePreferences child = PreferencesService.getDefault().createNode(key);
		addChild(key, child);
		return child;
	}


	protected synchronized IEclipsePreferences[] getChildren() {
		//must perform lazy initialization of child nodes
		String[] childNames = new String[0];
		try {
			childNames = childrenNames();
		} catch (BackingStoreException e) {
			log(new Status(IStatus.ERROR, Activator.PI_PREFERENCES, PrefsMessages.childrenNames, e));
			return new IEclipsePreferences[0];
		}
		IEclipsePreferences[] childNodes = new IEclipsePreferences[childNames.length];
		for (int i = 0; i < childNames.length; i++)
			childNodes[i] = getChild(childNames[i], null);
		return childNodes;
	}


	@Override
	public Preferences node(String path) {
		return getNode(path, true); // create if not found
	}

	public Preferences getNode(String path, boolean create) {
		if (path.length() == 0 || (path.length() == 1 && path.charAt(0) == IPath.SEPARATOR))
			return this;
		int startIndex = path.charAt(0) == IPath.SEPARATOR ? 1 : 0;
		int endIndex = path.indexOf(IPath.SEPARATOR, startIndex + 1);
		String scope = path.substring(startIndex, endIndex == -1 ? path.length() : endIndex);
		IEclipsePreferences child;
		if (create) {
			child = getChild(scope, null);
			if (child == null) {
				child = new EclipsePreferences(this, scope);
				addChild(scope, child);
			}
		} else {
			child = getChild(scope, null, false);
			if (child == null)
				return null;
		}
		return child.node(endIndex == -1 ? "" : path.substring(endIndex + 1)); //$NON-NLS-1$
	}


	@Override
	public void sync() throws BackingStoreException {
		// sync all children
		BackingStoreException exception = null;
		String[] names = childrenNames();
		for (String n : names) {
			try {
				node(n).sync();
			}catch (BackingStoreException e) {
				// store the first exception we get and still try and sync
				// the rest of the children.
				if (exception == null)
					exception = e;
			}
		}
		if (exception != null)
			throw exception;
	}
}