bundles/org.eclipse.core.runtime/src/org/eclipse/core/internal/runtime/DataArea.java

/**********************************************************************
 * Copyright (c) 2004 IBM Corporation and others.
 * All rights reserved.   This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors: 
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.internal.runtime;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import org.eclipse.core.runtime.*;
import org.eclipse.osgi.service.datalocation.Location;
import org.osgi.framework.Bundle;

public class DataArea {
	/* package */static final String F_META_AREA = ".metadata"; //$NON-NLS-1$
	/* package */static final String F_PLUGIN_DATA = ".plugins"; //$NON-NLS-1$
	/* package */static final String F_LOG = ".log"; //$NON-NLS-1$
	/* package */static final String F_BACKUP = ".bak"; //$NON-NLS-1$
	/**
	 * Internal name of the preference storage file (value <code>"pref_store.ini"</code>) in this plug-in's (read-write) state area.
	 */
	/* package */static final String PREFERENCES_FILE_NAME = "pref_store.ini"; //$NON-NLS-1$

	private IPath location; //The location of the instance data
	private boolean initialized = false;

	protected void assertLocationInitialized() throws IllegalStateException {
		if (location != null && initialized)
			return;
		Location service = InternalPlatform.getDefault().getInstanceLocation();
		if (service == null)
			throw new IllegalStateException(Policy.bind("meta.noDataModeSpecified")); //$NON-NLS-1$
		try {
			URL url = service.getURL();
			if (url == null)
				throw new IllegalStateException(Policy.bind("meta.instanceDataUnspecified")); //$NON-NLS-1$
			// TODO assume the URL is a file: 
			// Use the new File technique to ensure that the resultant string is 
			// in the right format (e.g., leading / removed from /c:/foo etc)
			location = new Path(new File(url.getFile()).toString());
			initializeLocation();
		} catch (CoreException e) {
			throw new IllegalStateException(e.getMessage());
		}
	}

	public IPath getBackupFilePathFor(IPath file) throws IllegalStateException { //TODO Does not seems to be used
		assertLocationInitialized();
		return file.removeLastSegments(1).append(file.lastSegment() + F_BACKUP);
	}

	public IPath getMetadataLocation() throws IllegalStateException {
		assertLocationInitialized();
		return location.append(F_META_AREA);
	}

	public IPath getInstanceDataLocation() throws IllegalStateException {
		assertLocationInitialized();
		return location;
	}

	public IPath getLogLocation() throws IllegalStateException {
		return new Path(InternalPlatform.getDefault().getFrameworkLog().getFile().getAbsolutePath());
	}

	/**
	 * Returns the read/write location in which the given bundle can manage private state.
	 */
	public IPath getStateLocation(Bundle bundle) throws IllegalStateException {
		assertLocationInitialized();
		return getStateLocation(bundle.getSymbolicName());
	}

	public IPath getStateLocation(String bundleName) throws IllegalStateException {
		assertLocationInitialized();
		return getMetadataLocation().append(F_PLUGIN_DATA).append(bundleName);
	}

	/**
	 * Returns the read/write location of the file for storing plugin preferences.
	 */
	public IPath getPreferenceLocation(Bundle bundle, boolean create) throws IllegalStateException {
		assertLocationInitialized();
		return getPreferenceLocation(bundle.getSymbolicName(), create);
	}

	public IPath getPreferenceLocation(String bundleName, boolean create) throws IllegalStateException {
		IPath result = getStateLocation(bundleName);
		if (create)
			result.toFile().mkdirs();
		return result.append(PREFERENCES_FILE_NAME);
	}

	private void initializeLocation() throws CoreException {
		// check if the location can be created
		if (location.toFile().exists()) {
			if (!location.toFile().isDirectory()) {
				String message = Policy.bind("meta.notDir", location.toString()); //$NON-NLS-1$
				throw new CoreException(new Status(IStatus.ERROR, Platform.PI_RUNTIME, Platform.FAILED_WRITE_METADATA, message, null));
			}
		}
		//try infer the device if there isn't one (windows)
		if (location.getDevice() == null)
			location = new Path(location.toFile().getAbsolutePath());
		createLocation();
		initialized = true;
	}

	private void createLocation() throws CoreException {
		// append on the metadata location so that the whole structure is created.  
		File file = location.append(F_META_AREA).toFile();
		try {
			file.mkdirs();
		} catch (Exception e) {
			String message = Policy.bind("meta.couldNotCreate", file.getAbsolutePath()); //$NON-NLS-1$
			throw new CoreException(new Status(IStatus.ERROR, Platform.PI_RUNTIME, Platform.FAILED_WRITE_METADATA, message, e));
		}
		if (!file.canWrite()) {
			String message = Policy.bind("meta.readonly", file.getAbsolutePath()); //$NON-NLS-1$
			throw new CoreException(new Status(IStatus.ERROR, Platform.PI_RUNTIME, Platform.FAILED_WRITE_METADATA, message, null));
		}
		// set the log file location now that we created the data area
		IPath path = location.append(F_META_AREA).append(F_LOG);
		try {
			InternalPlatform.getDefault().getFrameworkLog().setFile(path.toFile(), true);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}