bundles/org.eclipse.osgi/eclipseAdaptor/src/org/eclipse/core/runtime/adaptor/LocationManager.java - equinox/rt.equinox.framework - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.runtime.adaptor;

 import java.io.*;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Properties;
 import org.eclipse.core.runtime.internal.adaptor.BasicLocation;
 import org.eclipse.osgi.framework.adaptor.FrameworkAdaptor;
 import org.eclipse.osgi.framework.internal.core.FrameworkProperties;
 import org.eclipse.osgi.service.datalocation.Location;

 /**
  * This class is used to manage the various Locations for Eclipse.
  * <p>
  * Clients may not extend this class.
  * </p>
  * @since 3.1
  */
 public class LocationManager {
 	private static Location installLocation = null;
 	private static Location configurationLocation = null;
 	private static Location userLocation = null;
 	private static Location instanceLocation = null;

 	public static final String READ_ONLY_AREA_SUFFIX = ".readOnly"; //$NON-NLS-1$
 	public static final String PROP_INSTALL_AREA = "osgi.install.area"; //$NON-NLS-1$
 	public static final String PROP_CONFIG_AREA = "osgi.configuration.area"; //$NON-NLS-1$
 	public static final String PROP_CONFIG_AREA_DEFAULT = "osgi.configuration.area.default"; //$NON-NLS-1$
 	public static final String PROP_SHARED_CONFIG_AREA = "osgi.sharedConfiguration.area"; //$NON-NLS-1$
 	public static final String PROP_INSTANCE_AREA = "osgi.instance.area"; //$NON-NLS-1$
 	public static final String PROP_INSTANCE_AREA_DEFAULT = "osgi.instance.area.default"; //$NON-NLS-1$
 	public static final String PROP_USER_AREA = "osgi.user.area"; //$NON-NLS-1$
 	public static final String PROP_USER_AREA_DEFAULT = "osgi.user.area.default"; //$NON-NLS-1$
 	public static final String PROP_MANIFEST_CACHE = "osgi.manifest.cache"; //$NON-NLS-1$
 	public static final String PROP_USER_HOME = "user.home"; //$NON-NLS-1$
 	public static final String PROP_USER_DIR = "user.dir"; //$NON-NLS-1$

 	// configuration area file/dir names
 	public static final String BUNDLES_DIR = "bundles"; //$NON-NLS-1$
 	public static final String STATE_FILE = ".state"; //$NON-NLS-1$
 	public static final String LAZY_FILE = ".lazy"; //$NON-NLS-1$
 	public static final String BUNDLE_DATA_FILE = ".bundledata"; //$NON-NLS-1$
 	public static final String MANIFESTS_DIR = "manifests"; //$NON-NLS-1$
 	public static final String CONFIG_FILE = "config.ini"; //$NON-NLS-1$
 	public static final String ECLIPSE_PROPERTIES = "eclipse.properties"; //$NON-NLS-1$

 	// Constants for configuration location discovery
 	private static final String ECLIPSE = "eclipse"; //$NON-NLS-1$
 	private static final String PRODUCT_SITE_MARKER = ".eclipseproduct"; //$NON-NLS-1$
 	private static final String PRODUCT_SITE_ID = "id"; //$NON-NLS-1$
 	private static final String PRODUCT_SITE_VERSION = "version"; //$NON-NLS-1$

 	private static final String CONFIG_DIR = "configuration"; //$NON-NLS-1$

 	// Data mode constants for user, configuration and data locations.
 	private static final String NONE = "@none"; //$NON-NLS-1$
 	private static final String NO_DEFAULT = "@noDefault"; //$NON-NLS-1$
 	private static final String USER_HOME = "@user.home"; //$NON-NLS-1$
 	private static final String USER_DIR = "@user.dir"; //$NON-NLS-1$

 	/**
 	 * Builds a URL with the given specification
 	 * @param spec the URL specification
 	 * @param trailingSlash flag to indicate a trailing slash on the spec
 	 * @return a URL
 	 */
 	public static URL buildURL(String spec, boolean trailingSlash) {
 		if (spec == null)
 			return null;
 		boolean isFile = spec.startsWith("file:"); //$NON-NLS-1$
 		try {
 			if (isFile)
 				return adjustTrailingSlash(new File(spec.substring(5)).toURL(), trailingSlash);
 			else
 				return new URL(spec);
 		} catch (MalformedURLException e) {
 			// if we failed and it is a file spec, there is nothing more we can do
 			// otherwise, try to make the spec into a file URL.
 			if (isFile)
 				return null;
 			try {
 				return adjustTrailingSlash(new File(spec).toURL(), trailingSlash);
 			} catch (MalformedURLException e1) {
 				return null;
 			}
 		}
 	}

 	private static URL adjustTrailingSlash(URL url, boolean trailingSlash) throws MalformedURLException {
 		String file = url.getFile();
 		if (trailingSlash == (file.endsWith("/"))) //$NON-NLS-1$
 			return url;
 		file = trailingSlash ? file + "/" : file.substring(0, file.length() - 1); //$NON-NLS-1$
 		return new URL(url.getProtocol(), url.getHost(), file);
 	}

 	private static void mungeConfigurationLocation() {
 		// if the config property was set, munge it for backwards compatibility.
 		String location = FrameworkProperties.getProperty(PROP_CONFIG_AREA);
 		if (location != null) {
 			location = buildURL(location, false).toExternalForm();
 			if (location.endsWith(".cfg")) { //$NON-NLS-1$
 				int index = location.lastIndexOf('/');
 				location = location.substring(0, index + 1);
 			}
 			if (!location.endsWith("/")) //$NON-NLS-1$
 				location += "/"; //$NON-NLS-1$
 			FrameworkProperties.setProperty(PROP_CONFIG_AREA, location);
 		}
 	}

 	/**
 	 * Initializes the Location objects for the LocationManager.
 	 */
 	public static void initializeLocations() {
 		// do install location initialization first since others may depend on it
 		// assumes that the property is already set
 		installLocation = buildLocation(PROP_INSTALL_AREA, null, null, true);

 		Location temp = buildLocation(PROP_USER_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
 		URL defaultLocation = temp == null ? null : temp.getURL();
 		if (defaultLocation == null)
 			defaultLocation = buildURL(new File(FrameworkProperties.getProperty(PROP_USER_HOME), "user").getAbsolutePath(), true); //$NON-NLS-1$
 		userLocation = buildLocation(PROP_USER_AREA, defaultLocation, "", false); //$NON-NLS-1$

 		temp = buildLocation(PROP_INSTANCE_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
 		defaultLocation = temp == null ? null : temp.getURL();
 		if (defaultLocation == null)
 			defaultLocation = buildURL(new File(FrameworkProperties.getProperty(PROP_USER_DIR), "workspace").getAbsolutePath(), true); //$NON-NLS-1$
 		instanceLocation = buildLocation(PROP_INSTANCE_AREA, defaultLocation, "", false); //$NON-NLS-1$

 		mungeConfigurationLocation();
 		// compute a default but it is very unlikely to be used since main will have computed everything
 		temp = buildLocation(PROP_CONFIG_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
 		defaultLocation = temp == null ? null : temp.getURL();
 		if (defaultLocation == null)
 			defaultLocation = buildURL(computeDefaultConfigurationLocation(), true);
 		configurationLocation = buildLocation(PROP_CONFIG_AREA, defaultLocation, "", false); //$NON-NLS-1$
 		// get the parent location based on the system property. This will have been set on the
 		// way in either by the caller/user or by main.  There will be no parent location if we are not
 		// cascaded.
 		URL parentLocation = computeSharedConfigurationLocation();
 		if (parentLocation != null && !parentLocation.equals(configurationLocation.getURL())) {
 			Location parent = new BasicLocation(null, parentLocation, true);
 			((BasicLocation) configurationLocation).setParent(parent);
 		}
 		initializeDerivedConfigurationLocations();
 	}

 	private static Location buildLocation(String property, URL defaultLocation, String userDefaultAppendage, boolean readOnlyDefault) {
 		String location = FrameworkProperties.clearProperty(property);
 		// the user/product may specify a non-default readOnly setting
 		String userReadOnlySetting = FrameworkProperties.getProperty(property + READ_ONLY_AREA_SUFFIX);
 		boolean readOnly = (userReadOnlySetting == null ? readOnlyDefault : Boolean.valueOf(userReadOnlySetting).booleanValue());
 		// if the instance location is not set, predict where the workspace will be and
 		// put the instance area inside the workspace meta area.
 		if (location == null)
 			return new BasicLocation(property, defaultLocation, readOnly);
 		String trimmedLocation = location.trim();
 		if (trimmedLocation.equalsIgnoreCase(NONE))
 			return null;
 		if (trimmedLocation.equalsIgnoreCase(NO_DEFAULT))
 			return new BasicLocation(property, null, readOnly);
 		if (trimmedLocation.startsWith(USER_HOME)) {
 			String base = substituteVar(location, USER_HOME, PROP_USER_HOME);
 			location = new File(base, userDefaultAppendage).getAbsolutePath();
 		} else if (trimmedLocation.startsWith(USER_DIR)) {
 			String base = substituteVar(location, USER_DIR, PROP_USER_DIR);
 			location = new File(base, userDefaultAppendage).getAbsolutePath();
 		}
 		URL url = buildURL(location, true);
 		BasicLocation result = null;
 		if (url != null) {
 			result = new BasicLocation(property, null, readOnly);
 			result.setURL(url, false);
 		}
 		return result;
 	}

 	private static String substituteVar(String source, String var, String prop) {
 		String value = FrameworkProperties.getProperty(prop, ""); //$NON-NLS-1$
 		return value + source.substring(var.length());
 	}

 	private static void initializeDerivedConfigurationLocations() {
 		if (FrameworkProperties.getProperty(PROP_MANIFEST_CACHE) == null)
 			FrameworkProperties.setProperty(PROP_MANIFEST_CACHE, getConfigurationFile(MANIFESTS_DIR).getAbsolutePath());
 	}

 	private static URL computeInstallConfigurationLocation() {
 		String property = FrameworkProperties.getProperty(PROP_INSTALL_AREA);
 		if (property != null) {
 			try {
 				return new URL(property);
 			} catch (MalformedURLException e) {
 				// do nothing here since it is basically impossible to get a bogus url
 			}
 		}
 		return null;
 	}

 	private static URL computeSharedConfigurationLocation() {
 		String property = FrameworkProperties.getProperty(PROP_SHARED_CONFIG_AREA);
 		if (property == null)
 			return null;
 		try {
 			URL sharedConfigurationURL = new URL(property);
 			if (sharedConfigurationURL.getPath().startsWith("/")) //$NON-NLS-1$
 				// absolute
 				return sharedConfigurationURL;
 			URL installURL = installLocation.getURL();
 			if (!sharedConfigurationURL.getProtocol().equals(installURL.getProtocol()))
 				// different protocol
 				return sharedConfigurationURL;
 			sharedConfigurationURL = new URL(installURL, sharedConfigurationURL.getPath());
 			FrameworkProperties.setProperty(PROP_SHARED_CONFIG_AREA, sharedConfigurationURL.toExternalForm());
 		} catch (MalformedURLException e) {
 			// do nothing here since it is basically impossible to get a bogus url
 		}
 		return null;
 	}

 	private static String computeDefaultConfigurationLocation() {
 		// 1) We store the config state relative to the 'eclipse' directory if possible
 		// 2) If this directory is read-only
 		//    we store the state in <user.home>/.eclipse/<application-id>_<version> where <user.home>
 		//    is unique for each local user, and <application-id> is the one
 		//    defined in .eclipseproduct marker file. If .eclipseproduct does not
 		//    exist, use "eclipse" as the application-id.

 		URL installURL = computeInstallConfigurationLocation();
 		if (installURL != null) {
 			File installDir = new File(installURL.getFile());
 			if ("file".equals(installURL.getProtocol()) && canWrite(installDir)) //$NON-NLS-1$
 				return new File(installDir, CONFIG_DIR).getAbsolutePath();
 		}
 		// We can't write in the eclipse install dir so try for some place in the user's home dir
 		return computeDefaultUserAreaLocation(CONFIG_DIR);
 	}

 	private static boolean canWrite(File installDir) {
 		if (installDir.canWrite() == false)
 			return false;

 		if (!installDir.isDirectory())
 			return false;

 		File fileTest = null;
 		try {
 			// we use the .dll suffix to properly test on Vista virtual directories
         	// on Vista you are not allowed to write executable files on virtual directories like "Program Files"
             fileTest = File.createTempFile("writtableArea", ".dll", installDir); //$NON-NLS-1$ //$NON-NLS-2$
 		} catch (IOException e) {
 			//If an exception occured while trying to create the file, it means that it is not writtable
 			return false;
 		} finally {
 			if (fileTest != null)
 				fileTest.delete();
 		}
 		return true;
 	}

 	private static String computeDefaultUserAreaLocation(String pathAppendage) {
 		//    we store the state in <user.home>/.eclipse/<application-id>_<version> where <user.home>
 		//    is unique for each local user, and <application-id> is the one
 		//    defined in .eclipseproduct marker file. If .eclipseproduct does not
 		//    exist, use "eclipse" as the application-id.
 		String installProperty = FrameworkProperties.getProperty(PROP_INSTALL_AREA);
 		URL installURL = buildURL(installProperty, true);
 		if (installURL == null)
 			return null;
 		File installDir = new File(installURL.getFile());
 		// compute an install dir hash to prevent configuration area collisions with other eclipse installs
         int hashCode;
         try {
         	hashCode = installDir.getCanonicalPath().hashCode();
         } catch (IOException ioe) {
         	// fall back to absolute path
         	hashCode = installDir.getAbsolutePath().hashCode();
         }
        	if (hashCode < 0)
        		hashCode = -(hashCode);
        	String installDirHash = String.valueOf(hashCode);

 		String appName = "." + ECLIPSE; //$NON-NLS-1$
 		File eclipseProduct = new File(installDir, PRODUCT_SITE_MARKER);
 		if (eclipseProduct.exists()) {
 			Properties props = new Properties();
 			try {
 				props.load(new FileInputStream(eclipseProduct));
 				String appId = props.getProperty(PRODUCT_SITE_ID);
 				if (appId == null || appId.trim().length() == 0)
 					appId = ECLIPSE;
 				String appVersion = props.getProperty(PRODUCT_SITE_VERSION);
 				if (appVersion == null || appVersion.trim().length() == 0)
 					appVersion = ""; //$NON-NLS-1$
 				appName += File.separator + appId + "_" + appVersion + "_" + installDirHash; //$NON-NLS-1$ //$NON-NLS-2$
 			} catch (IOException e) {
 				// Do nothing if we get an exception.  We will default to a standard location
 				// in the user's home dir.
             	// add the hash to help prevent collisions
             	appName += File.separator + installDirHash;
 			}
 		} else {
         	// add the hash to help prevent collisions
         	appName += File.separator + installDirHash;
         }
 		String userHome = FrameworkProperties.getProperty(PROP_USER_HOME);
 		return new File(userHome, appName + "/" + pathAppendage).getAbsolutePath(); //$NON-NLS-1$
 	}

 	/**
 	 * Returns the user Location object
 	 * @return the user Location object
 	 */
 	public static Location getUserLocation() {
 		return userLocation;
 	}

 	/**
 	 * Returns the configuration Location object
 	 * @return the configuration Location object
 	 */
 	public static Location getConfigurationLocation() {
 		return configurationLocation;
 	}

 	/**
 	 * Returns the install Location object
 	 * @return the install Location object
 	 */
 	public static Location getInstallLocation() {
 		return installLocation;
 	}

 	/**
 	 * Returns the instance Location object
 	 * @return the instance Location object
 	 */
 	public static Location getInstanceLocation() {
 		return instanceLocation;
 	}

 	/**
 	 * Returns the File object under the configuration location used for the OSGi configuration
 	 * @return the OSGi configuration directory
 	 */
 	public static File getOSGiConfigurationDir() {
 		// TODO assumes the URL is a file: url
 		return new File(configurationLocation.getURL().getFile(), FrameworkAdaptor.FRAMEWORK_SYMBOLICNAME);
 	}

 	/**
 	 * Returns a file from the configuration area that can be used by the framework
 	 * @param filename the filename
 	 * @return a file from the configuration area
 	 */
 	public static File getConfigurationFile(String filename) {
 		File dir = getOSGiConfigurationDir();
 		if (!dir.exists())
 			dir.mkdirs();
 		return new File(dir, filename);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2007 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.core.runtime.adaptor;

	import java.io.*;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.Properties;
	import org.eclipse.core.runtime.internal.adaptor.BasicLocation;
	import org.eclipse.osgi.framework.adaptor.FrameworkAdaptor;
	import org.eclipse.osgi.framework.internal.core.FrameworkProperties;
	import org.eclipse.osgi.service.datalocation.Location;

	/**
	* This class is used to manage the various Locations for Eclipse.
	* <p>
	* Clients may not extend this class.
	* </p>
	* @since 3.1
	*/
	public class LocationManager {
	private static Location installLocation = null;
	private static Location configurationLocation = null;
	private static Location userLocation = null;
	private static Location instanceLocation = null;

	public static final String READ_ONLY_AREA_SUFFIX = ".readOnly"; //$NON-NLS-1$
	public static final String PROP_INSTALL_AREA = "osgi.install.area"; //$NON-NLS-1$
	public static final String PROP_CONFIG_AREA = "osgi.configuration.area"; //$NON-NLS-1$
	public static final String PROP_CONFIG_AREA_DEFAULT = "osgi.configuration.area.default"; //$NON-NLS-1$
	public static final String PROP_SHARED_CONFIG_AREA = "osgi.sharedConfiguration.area"; //$NON-NLS-1$
	public static final String PROP_INSTANCE_AREA = "osgi.instance.area"; //$NON-NLS-1$
	public static final String PROP_INSTANCE_AREA_DEFAULT = "osgi.instance.area.default"; //$NON-NLS-1$
	public static final String PROP_USER_AREA = "osgi.user.area"; //$NON-NLS-1$
	public static final String PROP_USER_AREA_DEFAULT = "osgi.user.area.default"; //$NON-NLS-1$
	public static final String PROP_MANIFEST_CACHE = "osgi.manifest.cache"; //$NON-NLS-1$
	public static final String PROP_USER_HOME = "user.home"; //$NON-NLS-1$
	public static final String PROP_USER_DIR = "user.dir"; //$NON-NLS-1$

	// configuration area file/dir names
	public static final String BUNDLES_DIR = "bundles"; //$NON-NLS-1$
	public static final String STATE_FILE = ".state"; //$NON-NLS-1$
	public static final String LAZY_FILE = ".lazy"; //$NON-NLS-1$
	public static final String BUNDLE_DATA_FILE = ".bundledata"; //$NON-NLS-1$
	public static final String MANIFESTS_DIR = "manifests"; //$NON-NLS-1$
	public static final String CONFIG_FILE = "config.ini"; //$NON-NLS-1$
	public static final String ECLIPSE_PROPERTIES = "eclipse.properties"; //$NON-NLS-1$

	// Constants for configuration location discovery
	private static final String ECLIPSE = "eclipse"; //$NON-NLS-1$
	private static final String PRODUCT_SITE_MARKER = ".eclipseproduct"; //$NON-NLS-1$
	private static final String PRODUCT_SITE_ID = "id"; //$NON-NLS-1$
	private static final String PRODUCT_SITE_VERSION = "version"; //$NON-NLS-1$

	private static final String CONFIG_DIR = "configuration"; //$NON-NLS-1$

	// Data mode constants for user, configuration and data locations.
	private static final String NONE = "@none"; //$NON-NLS-1$
	private static final String NO_DEFAULT = "@noDefault"; //$NON-NLS-1$
	private static final String USER_HOME = "@user.home"; //$NON-NLS-1$
	private static final String USER_DIR = "@user.dir"; //$NON-NLS-1$

	/**
	* Builds a URL with the given specification
	* @param spec the URL specification
	* @param trailingSlash flag to indicate a trailing slash on the spec
	* @return a URL
	*/
	public static URL buildURL(String spec, boolean trailingSlash) {
	if (spec == null)
	return null;
	boolean isFile = spec.startsWith("file:"); //$NON-NLS-1$
	try {
	if (isFile)
	return adjustTrailingSlash(new File(spec.substring(5)).toURL(), trailingSlash);
	else
	return new URL(spec);
	} catch (MalformedURLException e) {
	// if we failed and it is a file spec, there is nothing more we can do
	// otherwise, try to make the spec into a file URL.
	if (isFile)
	return null;
	try {
	return adjustTrailingSlash(new File(spec).toURL(), trailingSlash);
	} catch (MalformedURLException e1) {
	return null;
	}
	}
	}

	private static URL adjustTrailingSlash(URL url, boolean trailingSlash) throws MalformedURLException {
	String file = url.getFile();
	if (trailingSlash == (file.endsWith("/"))) //$NON-NLS-1$
	return url;
	file = trailingSlash ? file + "/" : file.substring(0, file.length() - 1); //$NON-NLS-1$
	return new URL(url.getProtocol(), url.getHost(), file);
	}

	private static void mungeConfigurationLocation() {
	// if the config property was set, munge it for backwards compatibility.
	String location = FrameworkProperties.getProperty(PROP_CONFIG_AREA);
	if (location != null) {
	location = buildURL(location, false).toExternalForm();
	if (location.endsWith(".cfg")) { //$NON-NLS-1$
	int index = location.lastIndexOf('/');
	location = location.substring(0, index + 1);
	}
	if (!location.endsWith("/")) //$NON-NLS-1$
	location += "/"; //$NON-NLS-1$
	FrameworkProperties.setProperty(PROP_CONFIG_AREA, location);
	}
	}

	/**
	* Initializes the Location objects for the LocationManager.
	*/
	public static void initializeLocations() {
	// do install location initialization first since others may depend on it
	// assumes that the property is already set
	installLocation = buildLocation(PROP_INSTALL_AREA, null, null, true);

	Location temp = buildLocation(PROP_USER_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
	URL defaultLocation = temp == null ? null : temp.getURL();
	if (defaultLocation == null)
	defaultLocation = buildURL(new File(FrameworkProperties.getProperty(PROP_USER_HOME), "user").getAbsolutePath(), true); //$NON-NLS-1$
	userLocation = buildLocation(PROP_USER_AREA, defaultLocation, "", false); //$NON-NLS-1$

	temp = buildLocation(PROP_INSTANCE_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
	defaultLocation = temp == null ? null : temp.getURL();
	if (defaultLocation == null)
	defaultLocation = buildURL(new File(FrameworkProperties.getProperty(PROP_USER_DIR), "workspace").getAbsolutePath(), true); //$NON-NLS-1$
	instanceLocation = buildLocation(PROP_INSTANCE_AREA, defaultLocation, "", false); //$NON-NLS-1$

	mungeConfigurationLocation();
	// compute a default but it is very unlikely to be used since main will have computed everything
	temp = buildLocation(PROP_CONFIG_AREA_DEFAULT, null, "", false); //$NON-NLS-1$
	defaultLocation = temp == null ? null : temp.getURL();
	if (defaultLocation == null)
	defaultLocation = buildURL(computeDefaultConfigurationLocation(), true);
	configurationLocation = buildLocation(PROP_CONFIG_AREA, defaultLocation, "", false); //$NON-NLS-1$
	// get the parent location based on the system property. This will have been set on the
	// way in either by the caller/user or by main. There will be no parent location if we are not
	// cascaded.
	URL parentLocation = computeSharedConfigurationLocation();
	if (parentLocation != null && !parentLocation.equals(configurationLocation.getURL())) {
	Location parent = new BasicLocation(null, parentLocation, true);
	((BasicLocation) configurationLocation).setParent(parent);
	}
	initializeDerivedConfigurationLocations();
	}

	private static Location buildLocation(String property, URL defaultLocation, String userDefaultAppendage, boolean readOnlyDefault) {
	String location = FrameworkProperties.clearProperty(property);
	// the user/product may specify a non-default readOnly setting
	String userReadOnlySetting = FrameworkProperties.getProperty(property + READ_ONLY_AREA_SUFFIX);
	boolean readOnly = (userReadOnlySetting == null ? readOnlyDefault : Boolean.valueOf(userReadOnlySetting).booleanValue());
	// if the instance location is not set, predict where the workspace will be and
	// put the instance area inside the workspace meta area.
	if (location == null)
	return new BasicLocation(property, defaultLocation, readOnly);
	String trimmedLocation = location.trim();
	if (trimmedLocation.equalsIgnoreCase(NONE))
	return null;
	if (trimmedLocation.equalsIgnoreCase(NO_DEFAULT))
	return new BasicLocation(property, null, readOnly);
	if (trimmedLocation.startsWith(USER_HOME)) {
	String base = substituteVar(location, USER_HOME, PROP_USER_HOME);
	location = new File(base, userDefaultAppendage).getAbsolutePath();
	} else if (trimmedLocation.startsWith(USER_DIR)) {
	String base = substituteVar(location, USER_DIR, PROP_USER_DIR);
	location = new File(base, userDefaultAppendage).getAbsolutePath();
	}
	URL url = buildURL(location, true);
	BasicLocation result = null;
	if (url != null) {
	result = new BasicLocation(property, null, readOnly);
	result.setURL(url, false);
	}
	return result;
	}

	private static String substituteVar(String source, String var, String prop) {
	String value = FrameworkProperties.getProperty(prop, ""); //$NON-NLS-1$
	return value + source.substring(var.length());
	}

	private static void initializeDerivedConfigurationLocations() {
	if (FrameworkProperties.getProperty(PROP_MANIFEST_CACHE) == null)
	FrameworkProperties.setProperty(PROP_MANIFEST_CACHE, getConfigurationFile(MANIFESTS_DIR).getAbsolutePath());
	}

	private static URL computeInstallConfigurationLocation() {
	String property = FrameworkProperties.getProperty(PROP_INSTALL_AREA);
	if (property != null) {
	try {
	return new URL(property);
	} catch (MalformedURLException e) {
	// do nothing here since it is basically impossible to get a bogus url
	}
	}
	return null;
	}

	private static URL computeSharedConfigurationLocation() {
	String property = FrameworkProperties.getProperty(PROP_SHARED_CONFIG_AREA);
	if (property == null)
	return null;
	try {
	URL sharedConfigurationURL = new URL(property);
	if (sharedConfigurationURL.getPath().startsWith("/")) //$NON-NLS-1$
	// absolute
	return sharedConfigurationURL;
	URL installURL = installLocation.getURL();
	if (!sharedConfigurationURL.getProtocol().equals(installURL.getProtocol()))
	// different protocol
	return sharedConfigurationURL;
	sharedConfigurationURL = new URL(installURL, sharedConfigurationURL.getPath());
	FrameworkProperties.setProperty(PROP_SHARED_CONFIG_AREA, sharedConfigurationURL.toExternalForm());
	} catch (MalformedURLException e) {
	// do nothing here since it is basically impossible to get a bogus url
	}
	return null;
	}

	private static String computeDefaultConfigurationLocation() {
	// 1) We store the config state relative to the 'eclipse' directory if possible
	// 2) If this directory is read-only
	// we store the state in <user.home>/.eclipse/<application-id>_<version> where <user.home>
	// is unique for each local user, and <application-id> is the one
	// defined in .eclipseproduct marker file. If .eclipseproduct does not
	// exist, use "eclipse" as the application-id.

	URL installURL = computeInstallConfigurationLocation();
	if (installURL != null) {
	File installDir = new File(installURL.getFile());
	if ("file".equals(installURL.getProtocol()) && canWrite(installDir)) //$NON-NLS-1$
	return new File(installDir, CONFIG_DIR).getAbsolutePath();
	}
	// We can't write in the eclipse install dir so try for some place in the user's home dir
	return computeDefaultUserAreaLocation(CONFIG_DIR);
	}

	private static boolean canWrite(File installDir) {
	if (installDir.canWrite() == false)
	return false;

	if (!installDir.isDirectory())
	return false;

	File fileTest = null;
	try {
	// we use the .dll suffix to properly test on Vista virtual directories
	// on Vista you are not allowed to write executable files on virtual directories like "Program Files"
	fileTest = File.createTempFile("writtableArea", ".dll", installDir); //$NON-NLS-1$ //$NON-NLS-2$
	} catch (IOException e) {
	//If an exception occured while trying to create the file, it means that it is not writtable
	return false;
	} finally {
	if (fileTest != null)
	fileTest.delete();
	}
	return true;
	}

	private static String computeDefaultUserAreaLocation(String pathAppendage) {
	// we store the state in <user.home>/.eclipse/<application-id>_<version> where <user.home>
	// is unique for each local user, and <application-id> is the one
	// defined in .eclipseproduct marker file. If .eclipseproduct does not
	// exist, use "eclipse" as the application-id.
	String installProperty = FrameworkProperties.getProperty(PROP_INSTALL_AREA);
	URL installURL = buildURL(installProperty, true);
	if (installURL == null)
	return null;
	File installDir = new File(installURL.getFile());
	// compute an install dir hash to prevent configuration area collisions with other eclipse installs
	int hashCode;
	try {
	hashCode = installDir.getCanonicalPath().hashCode();
	} catch (IOException ioe) {
	// fall back to absolute path
	hashCode = installDir.getAbsolutePath().hashCode();
	}
	if (hashCode < 0)
	hashCode = -(hashCode);
	String installDirHash = String.valueOf(hashCode);

	String appName = "." + ECLIPSE; //$NON-NLS-1$
	File eclipseProduct = new File(installDir, PRODUCT_SITE_MARKER);
	if (eclipseProduct.exists()) {
	Properties props = new Properties();
	try {
	props.load(new FileInputStream(eclipseProduct));
	String appId = props.getProperty(PRODUCT_SITE_ID);
	if (appId == null \|\| appId.trim().length() == 0)
	appId = ECLIPSE;
	String appVersion = props.getProperty(PRODUCT_SITE_VERSION);
	if (appVersion == null \|\| appVersion.trim().length() == 0)
	appVersion = ""; //$NON-NLS-1$
	appName += File.separator + appId + "_" + appVersion + "_" + installDirHash; //$NON-NLS-1$ //$NON-NLS-2$
	} catch (IOException e) {
	// Do nothing if we get an exception. We will default to a standard location
	// in the user's home dir.
	// add the hash to help prevent collisions
	appName += File.separator + installDirHash;
	}
	} else {
	// add the hash to help prevent collisions
	appName += File.separator + installDirHash;
	}
	String userHome = FrameworkProperties.getProperty(PROP_USER_HOME);
	return new File(userHome, appName + "/" + pathAppendage).getAbsolutePath(); //$NON-NLS-1$
	}

	/**
	* Returns the user Location object
	* @return the user Location object
	*/
	public static Location getUserLocation() {
	return userLocation;
	}

	/**
	* Returns the configuration Location object
	* @return the configuration Location object
	*/
	public static Location getConfigurationLocation() {
	return configurationLocation;
	}

	/**
	* Returns the install Location object
	* @return the install Location object
	*/
	public static Location getInstallLocation() {
	return installLocation;
	}

	/**
	* Returns the instance Location object
	* @return the instance Location object
	*/
	public static Location getInstanceLocation() {
	return instanceLocation;
	}

	/**
	* Returns the File object under the configuration location used for the OSGi configuration
	* @return the OSGi configuration directory
	*/
	public static File getOSGiConfigurationDir() {
	// TODO assumes the URL is a file: url
	return new File(configurationLocation.getURL().getFile(), FrameworkAdaptor.FRAMEWORK_SYMBOLICNAME);
	}

	/**
	* Returns a file from the configuration area that can be used by the framework
	* @param filename the filename
	* @return a file from the configuration area
	*/
	public static File getConfigurationFile(String filename) {
	File dir = getOSGiConfigurationDir();
	if (!dir.exists())
	dir.mkdirs();
	return new File(dir, filename);
	}
	}