bundles/org.eclipse.core.net/src/org/eclipse/core/internal/net/PreferenceManager.java - platform/eclipse.platform.team - Git at Google

 /*******************************************************************************
 * Copyright (c) 2010, 2017 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.internal.net;

 import org.eclipse.core.net.proxy.IProxyData;
 import org.eclipse.core.runtime.preferences.ConfigurationScope;
 import org.eclipse.core.runtime.preferences.DefaultScope;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences.INodeChangeListener;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.osgi.service.prefs.BackingStoreException;
 import org.osgi.service.prefs.Preferences;

 /**
  * Provides set of methods to operate on preferences
  */
 public class PreferenceManager {

 	public static final String ROOT = ""; //$NON-NLS-1$

 	private static final String PREF_HAS_MIGRATED = "org.eclipse.core.net.hasMigrated"; //$NON-NLS-1$

 	private static final int DEFAULT_INT = -1;
 	private static final String DEFAULT_STRING = null;
 	private static final boolean DEFAULT_BOOLEAN = false;

 	private static boolean migrated = false;

 	private IEclipsePreferences defaultScope;
 	private IEclipsePreferences currentScope;

 	private PreferenceManager(String id) {
 		this.defaultScope = DefaultScope.INSTANCE.getNode(id);
 	}

 	/**
 	 * Creates the preferences manager for the node defined by id
 	 * in configuration scope.
 	 * @param id node name for which node should be created in configuration scope
 	 * @return {@link PreferenceManager}
 	 */
 	public static PreferenceManager createConfigurationManager(String id) {
 		PreferenceManager manager = new PreferenceManager(id);
 		manager.currentScope = ConfigurationScope.INSTANCE.getNode(id);
 		return manager;
 	}

 	/**
 	 * Checks if preference migration was already performed.
 	 * @return <code>boolean</code>
 	 */
 	public boolean isMigrated() {
 		return migrated;
 	}

 	/**
 	 * Returns the <code>boolean</code> value associated with the specified <code>key</code>
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * <p>
 	 * Returns the value specified in the default scope if there is no value associated with the
 	 * <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
 	 * value is something that can not be parsed as an integer value.
 	 * Use {@link #putBoolean(String, String, boolean)} to set the value of this preference key.
 	 * </p>
 	 * @param node node
 	 * @param key key whose associated value is to be returned as an <code>boolean</code>.
 	 * @return the <code>boolean</code> value associated with <code>key</code>, or
 	 *         <code>false</code> if the associated value does not exist in either scope or cannot
 	 *         be interpreted as an <code>boolean</code>.
 	 * @see #putBoolean(String, String, boolean)
 	 */
 	public boolean getBoolean(String node, String key) {
 		return currentScope.node(node).getBoolean(key, defaultScope.node(node).getBoolean(key, DEFAULT_BOOLEAN));
 	}

 	/**
 	 * Returns the <code>int</code> value associated with the specified <code>key</code>
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * <p>
 	 * Returns the value specified in the default scope if there is no value associated with the
 	 * <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
 	 * value is something that can not be parsed as an integer value.
 	 * Use {@link #putInt(String, String, int)} to set the value of this preference key.
 	 * </p>
 	 * @param node node
 	 * @param key key whose associated value is to be returned as an <code>int</code>.
 	 * @return the <code>int</code> value associated with <code>key</code>, or
 	 *         <code>-1</code> if the associated value does not exist in either scope or cannot
 	 *         be interpreted as an <code>int</code>.
 	 * @see #putInt(String, String, int)
 	 */
 	public int getInt(String node, String key) {
 		return currentScope.node(node).getInt(key, defaultScope.node(node).getInt(key, DEFAULT_INT));
 	}

 	/**
 	 * Returns the <code>String</code> value associated with the specified <code>key</code>
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * <p>
 	 * Returns the value specified in the default scope if there is no value associated with the
 	 * <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
 	 * value is something that can not be parsed as an integer value.
 	 * Use {@link #putString(String, String, String)} to set the value of this preference key.
 	 * </p>
 	 * @param node node
 	 * @param key key whose associated value is to be returned as an <code>String</code>.
 	 * @return the <code>String</code> value associated with <code>key</code>, or
 	 *         <code>null</code> if the associated value does not exist in either scope or cannot
 	 *         be interpreted as an <code>String</code>.
 	 * @see #putString(String, String, String)
 	 */
 	public String getString(String node, String key) {
 		return currentScope.node(node).get(key, defaultScope.node(node).get(key, DEFAULT_STRING));
 	}

 	/**
 	 * Associates the specified <code>int</code> value with the specified key
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * @param node node
 	 * @param key <code>key</code> with which the string form of value is to be associated.
 	 * @param value <code>value</code> to be associated with <code>key</code>.
 	 * @see #getInt(String, String)
 	 */
 	public void putInt(String node, String key, int value) {
 		currentScope.node(node).putInt(key, value);
 	}

 	/**
 	 * Associates the specified <code>boolean</code> value with the specified key
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * @param node node
 	 * @param key <code>key</code> with which the string form of value is to be associated.
 	 * @param value <code>value</code> to be associated with <code>key</code>.
 	 * @see #getBoolean(String, String)
 	 */
 	public void putBoolean(String node, String key, boolean value) {
 		currentScope.node(node).putBoolean(key, value);
 	}

 	/**
 	 * Associates the specified <code>String</code> value with the specified key
 	 * for specified <code>node</code> in current scope.
 	 *
 	 * @param node node
 	 * @param key <code>key</code> with which the string form of value is to be associated.
 	 * @param value <code>value</code> to be associated with <code>key</code>.
 	 * @see #getString(String, String)
 	 */
 	public void putString(String node, String key, String value) {
 		currentScope.node(node).put(key, value);
 	}

 	/**
 	 * Register the given listener for notification of preference changes.
 	 * Calling this method multiple times with the same listener has no effect. The
 	 * given listener argument must not be <code>null</code>.
 	 *
 	 * @param node node
 	 * @param listener the preference change listener to register
 	 * @see #removePreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
 	 * @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
 	 */
 	public void addPreferenceChangeListener(String node, IPreferenceChangeListener listener) {
 		((IEclipsePreferences)currentScope.node(node)).addPreferenceChangeListener(listener);
 	}

 	/**
 	 * De-register the given listener from receiving notification of preference changes
 	 * Calling this method multiple times with the same listener has no
 	 * effect. The given listener argument must not be <code>null</code>.
 	 * @param node node
 	 * @param listener the preference change listener to remove
 	 * @see #addPreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
 	 * @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
 	 */
 	public void removePreferenceChangeListener(String node, IPreferenceChangeListener listener) {
 		((IEclipsePreferences)currentScope.node(node)).removePreferenceChangeListener(listener);
 	}

 	/**
 	 * Register the given listener for changes to this node.
 	 * Calling this method multiple times with the same listener has no effect. The
 	 * given listener argument must not be <code>null</code>.
 	 *
 	 * @param node node
 	 * @param listener the preference change listener to register
 	 * @see #removeNodeChangeListener(String, IEclipsePreferences.INodeChangeListener)
 	 * @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
 	 */
 	public void addNodeChangeListener(String node, INodeChangeListener listener) {
 		((IEclipsePreferences)currentScope.node(node)).addNodeChangeListener(listener);
 	}

 	/**
 	 * De-register the given listener from receiving event change notifications for this node.
 	 * Calling this method multiple times with the same listener has no
 	 * effect. The given listener argument must not be <code>null</code>.
 	 * @param node node
 	 * @param listener the preference change listener to remove
 	 * @see #addPreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
 	 * @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
 	 */
 	public void removeNodeChangeListener(String node, INodeChangeListener listener) {
 		((IEclipsePreferences)currentScope.node(node)).removeNodeChangeListener(listener);
 	}

 	/**
 	 * Removes this node and all of its descendants,
 	 * invalidating any properties contained in the removed nodes.
 	 * @param node name of a node which should be removed
 	 * @throws BackingStoreException - if this operation cannot be completed
 	 * due to a failure in the backing store, or inability to communicate with it.
 	 */
 	public void removeNode(String node) throws BackingStoreException {
 		currentScope.node(node).removeNode();
 	}

 	/**
 	 * Forces any changes in the contents of current scope
 	 * and its descendants to the persistent store.
 	 * @throws BackingStoreException - if this operation cannot be completed
 	 * due to a failure in the backing store, or inability to communicate with it.
 	 */
 	public void flush() throws BackingStoreException {
 		currentScope.flush();
 	}

 	/**
 	 * Migrate preferences from instance scope to current scope.
 	 * @param proxies proxy types for which migration should be performed {@link ProxyType}
 	 */
 	public void migrate(ProxyType[] proxies) {
 		migrated = true;
 		if (currentScope.getBoolean(PREF_HAS_MIGRATED, false)
 				|| currentScope.name().equals(InstanceScope.SCOPE)) {
 			return;
 		}
 		currentScope.putBoolean(PREF_HAS_MIGRATED, true);
 		migrateInstanceScopePreferences(InstanceScope.INSTANCE.getNode(Activator.ID), currentScope, proxies, true);
 	}

 	void migrateInstanceScopePreferences(Preferences instanceScope, Preferences configuration, ProxyType[] proxies, boolean isInitialize) {
 		migrateUpdateHttpProxy(instanceScope, proxies, isInitialize);

 		// migrate enabled status
 		if (configuration.get(ProxyManager.PREF_ENABLED, null) == null) {
 			String instanceEnabled = instanceScope.get(ProxyManager.PREF_ENABLED, null);
 			if (instanceEnabled != null)
 				configuration.put(ProxyManager.PREF_ENABLED, instanceEnabled);
 		}

 		// migrate enabled status
 		if (configuration.get(ProxyManager.PREF_OS, null) == null) {
 			String instanceEnabled = instanceScope.get(ProxyManager.PREF_OS, null);
 			if (instanceEnabled != null)
 				configuration.put(ProxyManager.PREF_OS, instanceEnabled);
 		}

 		// migrate non proxied hosts if not already set
 		if (configuration.get(ProxyManager.PREF_NON_PROXIED_HOSTS, null) == null) {
 			String instanceNonProxiedHosts = instanceScope.get(ProxyManager.PREF_NON_PROXIED_HOSTS, null);
 			if (instanceNonProxiedHosts != null) {
 				configuration.put(ProxyManager.PREF_NON_PROXIED_HOSTS, instanceNonProxiedHosts);
 			}
 		}

 		// migrate proxy data
 		PreferenceManager instanceManager = PreferenceManager.createInstanceManager(instanceScope);
 		for (int i = 0; i < proxies.length; i++) {
 			ProxyType type = proxies[i];
 			IProxyData data = type.getProxyData(ProxyType.DO_NOT_VERIFY);
 			if (data.getHost() == null) {
 				ProxyType instanceType = new ProxyType(type.getName(), instanceManager);
 				IProxyData instanceData = instanceType.getProxyData(ProxyType.DO_NOT_VERIFY);
 				if (instanceData.getHost() != null)
 					type.setProxyData(instanceData);
 			}
 		}

 		// if this an import we should remove the old node
 		if (!isInitialize) {
 			try {
 				instanceScope.removeNode();
 			} catch (BackingStoreException e) {
 				// ignore
 			}
 		}
 	}

 	private void migrateUpdateHttpProxy(Preferences instanceScope, ProxyType[] proxies, boolean isInitialize) {
 		if (!instanceScope.getBoolean(PREF_HAS_MIGRATED, false)) {
 			// Only set the migration bit when initializing
 			if (isInitialize)
 				instanceScope.putBoolean(PREF_HAS_MIGRATED, true);
 			String httpProxyHost = getHostToMigrate(isInitialize /* checkSystemProperties */);
 			int port = getPortToMigrate(isInitialize /* checkSystemProperties */);
 			boolean httpProxyEnable = getEnablementToMigrate(isInitialize /* checkSystemProperties */);
 			if (httpProxyHost != null) {
 				ProxyData proxyData = new ProxyData(IProxyData.HTTP_PROXY_TYPE,
 						httpProxyHost, port, false, null);
 				for (int i = 0; i < proxies.length; i++) {
 					ProxyType type = proxies[i];
 					if (type.getName().equals(proxyData.getType())) {
 						type.updatePreferencesIfMissing(proxyData);
 					}
 				}
 				if (httpProxyEnable) {
 					instanceScope.putBoolean(ProxyManager.PREF_ENABLED, true);
 				}
 			}
 		}
 	}

 	private String getHostToMigrate(boolean checkSystemProperties) {
 		String httpProxyHost = ""; //$NON-NLS-1$
 		if (checkSystemProperties && "".equals(httpProxyHost)) { //$NON-NLS-1$
 			httpProxyHost = System.getProperty("http.proxyHost", ""); //$NON-NLS-1$ //$NON-NLS-2$
 		}
 		if ("".equals(httpProxyHost)) //$NON-NLS-1$
 			httpProxyHost = null;
 		return httpProxyHost;
 	}

 	private int getPortToMigrate(boolean checkSystemProperties) {
 		String httpProxyPort = ""; //$NON-NLS-1$
 		if (checkSystemProperties && "".equals(httpProxyPort)) { //$NON-NLS-1$
 			httpProxyPort = System.getProperty("http.proxyPort", ""); //$NON-NLS-1$ //$NON-NLS-2$
 		}
 		int port = -1;
 		if (httpProxyPort != null && !"".equals(httpProxyPort)) //$NON-NLS-1$
 			try {
 				port = Integer.parseInt(httpProxyPort);
 			} catch (NumberFormatException e) {
 				// Ignore
 			}
 		return port;
 	}

 	private boolean getEnablementToMigrate(boolean checkSystemProperties) {
 		boolean httpProxyEnable = false;
 		if (checkSystemProperties) {
 			httpProxyEnable = Boolean.getBoolean("http.proxySet"); //$NON-NLS-1$
 		}
 		return httpProxyEnable;
 	}

 	private static PreferenceManager createInstanceManager(Preferences instance) {
 		PreferenceManager manager = new PreferenceManager(Activator.ID);
 		manager.currentScope = (IEclipsePreferences) instance;
 		return manager;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2010, 2017 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.internal.net;

	import org.eclipse.core.net.proxy.IProxyData;
	import org.eclipse.core.runtime.preferences.ConfigurationScope;
	import org.eclipse.core.runtime.preferences.DefaultScope;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences.INodeChangeListener;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener;
	import org.eclipse.core.runtime.preferences.InstanceScope;
	import org.osgi.service.prefs.BackingStoreException;
	import org.osgi.service.prefs.Preferences;

	/**
	* Provides set of methods to operate on preferences
	*/
	public class PreferenceManager {

	public static final String ROOT = ""; //$NON-NLS-1$

	private static final String PREF_HAS_MIGRATED = "org.eclipse.core.net.hasMigrated"; //$NON-NLS-1$

	private static final int DEFAULT_INT = -1;
	private static final String DEFAULT_STRING = null;
	private static final boolean DEFAULT_BOOLEAN = false;

	private static boolean migrated = false;

	private IEclipsePreferences defaultScope;
	private IEclipsePreferences currentScope;

	private PreferenceManager(String id) {
	this.defaultScope = DefaultScope.INSTANCE.getNode(id);
	}

	/**
	* Creates the preferences manager for the node defined by id
	* in configuration scope.
	* @param id node name for which node should be created in configuration scope
	* @return {@link PreferenceManager}
	*/
	public static PreferenceManager createConfigurationManager(String id) {
	PreferenceManager manager = new PreferenceManager(id);
	manager.currentScope = ConfigurationScope.INSTANCE.getNode(id);
	return manager;
	}

	/**
	* Checks if preference migration was already performed.
	* @return <code>boolean</code>
	*/
	public boolean isMigrated() {
	return migrated;
	}

	/**
	* Returns the <code>boolean</code> value associated with the specified <code>key</code>
	* for specified <code>node</code> in current scope.
	*
	* <p>
	* Returns the value specified in the default scope if there is no value associated with the
	* <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
	* value is something that can not be parsed as an integer value.
	* Use {@link #putBoolean(String, String, boolean)} to set the value of this preference key.
	* </p>
	* @param node node
	* @param key key whose associated value is to be returned as an <code>boolean</code>.
	* @return the <code>boolean</code> value associated with <code>key</code>, or
	* <code>false</code> if the associated value does not exist in either scope or cannot
	* be interpreted as an <code>boolean</code>.
	* @see #putBoolean(String, String, boolean)
	*/
	public boolean getBoolean(String node, String key) {
	return currentScope.node(node).getBoolean(key, defaultScope.node(node).getBoolean(key, DEFAULT_BOOLEAN));
	}

	/**
	* Returns the <code>int</code> value associated with the specified <code>key</code>
	* for specified <code>node</code> in current scope.
	*
	* <p>
	* Returns the value specified in the default scope if there is no value associated with the
	* <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
	* value is something that can not be parsed as an integer value.
	* Use {@link #putInt(String, String, int)} to set the value of this preference key.
	* </p>
	* @param node node
	* @param key key whose associated value is to be returned as an <code>int</code>.
	* @return the <code>int</code> value associated with <code>key</code>, or
	* <code>-1</code> if the associated value does not exist in either scope or cannot
	* be interpreted as an <code>int</code>.
	* @see #putInt(String, String, int)
	*/
	public int getInt(String node, String key) {
	return currentScope.node(node).getInt(key, defaultScope.node(node).getInt(key, DEFAULT_INT));
	}

	/**
	* Returns the <code>String</code> value associated with the specified <code>key</code>
	* for specified <code>node</code> in current scope.
	*
	* <p>
	* Returns the value specified in the default scope if there is no value associated with the
	* <code>key</code> in the current scope, the backing store is inaccessible, or if the associated
	* value is something that can not be parsed as an integer value.
	* Use {@link #putString(String, String, String)} to set the value of this preference key.
	* </p>
	* @param node node
	* @param key key whose associated value is to be returned as an <code>String</code>.
	* @return the <code>String</code> value associated with <code>key</code>, or
	* <code>null</code> if the associated value does not exist in either scope or cannot
	* be interpreted as an <code>String</code>.
	* @see #putString(String, String, String)
	*/
	public String getString(String node, String key) {
	return currentScope.node(node).get(key, defaultScope.node(node).get(key, DEFAULT_STRING));
	}

	/**
	* Associates the specified <code>int</code> value with the specified key
	* for specified <code>node</code> in current scope.
	*
	* @param node node
	* @param key <code>key</code> with which the string form of value is to be associated.
	* @param value <code>value</code> to be associated with <code>key</code>.
	* @see #getInt(String, String)
	*/
	public void putInt(String node, String key, int value) {
	currentScope.node(node).putInt(key, value);
	}

	/**
	* Associates the specified <code>boolean</code> value with the specified key
	* for specified <code>node</code> in current scope.
	*
	* @param node node
	* @param key <code>key</code> with which the string form of value is to be associated.
	* @param value <code>value</code> to be associated with <code>key</code>.
	* @see #getBoolean(String, String)
	*/
	public void putBoolean(String node, String key, boolean value) {
	currentScope.node(node).putBoolean(key, value);
	}

	/**
	* Associates the specified <code>String</code> value with the specified key
	* for specified <code>node</code> in current scope.
	*
	* @param node node
	* @param key <code>key</code> with which the string form of value is to be associated.
	* @param value <code>value</code> to be associated with <code>key</code>.
	* @see #getString(String, String)
	*/
	public void putString(String node, String key, String value) {
	currentScope.node(node).put(key, value);
	}

	/**
	* Register the given listener for notification of preference changes.
	* Calling this method multiple times with the same listener has no effect. The
	* given listener argument must not be <code>null</code>.
	*
	* @param node node
	* @param listener the preference change listener to register
	* @see #removePreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
	* @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
	*/
	public void addPreferenceChangeListener(String node, IPreferenceChangeListener listener) {
	((IEclipsePreferences)currentScope.node(node)).addPreferenceChangeListener(listener);
	}

	/**
	* De-register the given listener from receiving notification of preference changes
	* Calling this method multiple times with the same listener has no
	* effect. The given listener argument must not be <code>null</code>.
	* @param node node
	* @param listener the preference change listener to remove
	* @see #addPreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
	* @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
	*/
	public void removePreferenceChangeListener(String node, IPreferenceChangeListener listener) {
	((IEclipsePreferences)currentScope.node(node)).removePreferenceChangeListener(listener);
	}

	/**
	* Register the given listener for changes to this node.
	* Calling this method multiple times with the same listener has no effect. The
	* given listener argument must not be <code>null</code>.
	*
	* @param node node
	* @param listener the preference change listener to register
	* @see #removeNodeChangeListener(String, IEclipsePreferences.INodeChangeListener)
	* @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
	*/
	public void addNodeChangeListener(String node, INodeChangeListener listener) {
	((IEclipsePreferences)currentScope.node(node)).addNodeChangeListener(listener);
	}

	/**
	* De-register the given listener from receiving event change notifications for this node.
	* Calling this method multiple times with the same listener has no
	* effect. The given listener argument must not be <code>null</code>.
	* @param node node
	* @param listener the preference change listener to remove
	* @see #addPreferenceChangeListener(String, IEclipsePreferences.IPreferenceChangeListener)
	* @see org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener
	*/
	public void removeNodeChangeListener(String node, INodeChangeListener listener) {
	((IEclipsePreferences)currentScope.node(node)).removeNodeChangeListener(listener);
	}

	/**
	* Removes this node and all of its descendants,
	* invalidating any properties contained in the removed nodes.
	* @param node name of a node which should be removed
	* @throws BackingStoreException - if this operation cannot be completed
	* due to a failure in the backing store, or inability to communicate with it.
	*/
	public void removeNode(String node) throws BackingStoreException {
	currentScope.node(node).removeNode();
	}

	/**
	* Forces any changes in the contents of current scope
	* and its descendants to the persistent store.
	* @throws BackingStoreException - if this operation cannot be completed
	* due to a failure in the backing store, or inability to communicate with it.
	*/
	public void flush() throws BackingStoreException {
	currentScope.flush();
	}

	/**
	* Migrate preferences from instance scope to current scope.
	* @param proxies proxy types for which migration should be performed {@link ProxyType}
	*/
	public void migrate(ProxyType[] proxies) {
	migrated = true;
	if (currentScope.getBoolean(PREF_HAS_MIGRATED, false)
	\|\| currentScope.name().equals(InstanceScope.SCOPE)) {
	return;
	}
	currentScope.putBoolean(PREF_HAS_MIGRATED, true);
	migrateInstanceScopePreferences(InstanceScope.INSTANCE.getNode(Activator.ID), currentScope, proxies, true);
	}

	void migrateInstanceScopePreferences(Preferences instanceScope, Preferences configuration, ProxyType[] proxies, boolean isInitialize) {
	migrateUpdateHttpProxy(instanceScope, proxies, isInitialize);

	// migrate enabled status
	if (configuration.get(ProxyManager.PREF_ENABLED, null) == null) {
	String instanceEnabled = instanceScope.get(ProxyManager.PREF_ENABLED, null);
	if (instanceEnabled != null)
	configuration.put(ProxyManager.PREF_ENABLED, instanceEnabled);
	}

	// migrate enabled status
	if (configuration.get(ProxyManager.PREF_OS, null) == null) {
	String instanceEnabled = instanceScope.get(ProxyManager.PREF_OS, null);
	if (instanceEnabled != null)
	configuration.put(ProxyManager.PREF_OS, instanceEnabled);
	}

	// migrate non proxied hosts if not already set
	if (configuration.get(ProxyManager.PREF_NON_PROXIED_HOSTS, null) == null) {
	String instanceNonProxiedHosts = instanceScope.get(ProxyManager.PREF_NON_PROXIED_HOSTS, null);
	if (instanceNonProxiedHosts != null) {
	configuration.put(ProxyManager.PREF_NON_PROXIED_HOSTS, instanceNonProxiedHosts);
	}
	}

	// migrate proxy data
	PreferenceManager instanceManager = PreferenceManager.createInstanceManager(instanceScope);
	for (int i = 0; i < proxies.length; i++) {
	ProxyType type = proxies[i];
	IProxyData data = type.getProxyData(ProxyType.DO_NOT_VERIFY);
	if (data.getHost() == null) {
	ProxyType instanceType = new ProxyType(type.getName(), instanceManager);
	IProxyData instanceData = instanceType.getProxyData(ProxyType.DO_NOT_VERIFY);
	if (instanceData.getHost() != null)
	type.setProxyData(instanceData);
	}
	}

	// if this an import we should remove the old node
	if (!isInitialize) {
	try {
	instanceScope.removeNode();
	} catch (BackingStoreException e) {
	// ignore
	}
	}
	}

	private void migrateUpdateHttpProxy(Preferences instanceScope, ProxyType[] proxies, boolean isInitialize) {
	if (!instanceScope.getBoolean(PREF_HAS_MIGRATED, false)) {
	// Only set the migration bit when initializing
	if (isInitialize)
	instanceScope.putBoolean(PREF_HAS_MIGRATED, true);
	String httpProxyHost = getHostToMigrate(isInitialize /* checkSystemProperties */);
	int port = getPortToMigrate(isInitialize /* checkSystemProperties */);
	boolean httpProxyEnable = getEnablementToMigrate(isInitialize /* checkSystemProperties */);
	if (httpProxyHost != null) {
	ProxyData proxyData = new ProxyData(IProxyData.HTTP_PROXY_TYPE,
	httpProxyHost, port, false, null);
	for (int i = 0; i < proxies.length; i++) {
	ProxyType type = proxies[i];
	if (type.getName().equals(proxyData.getType())) {
	type.updatePreferencesIfMissing(proxyData);
	}
	}
	if (httpProxyEnable) {
	instanceScope.putBoolean(ProxyManager.PREF_ENABLED, true);
	}
	}
	}
	}

	private String getHostToMigrate(boolean checkSystemProperties) {
	String httpProxyHost = ""; //$NON-NLS-1$
	if (checkSystemProperties && "".equals(httpProxyHost)) { //$NON-NLS-1$
	httpProxyHost = System.getProperty("http.proxyHost", ""); //$NON-NLS-1$ //$NON-NLS-2$
	}
	if ("".equals(httpProxyHost)) //$NON-NLS-1$
	httpProxyHost = null;
	return httpProxyHost;
	}

	private int getPortToMigrate(boolean checkSystemProperties) {
	String httpProxyPort = ""; //$NON-NLS-1$
	if (checkSystemProperties && "".equals(httpProxyPort)) { //$NON-NLS-1$
	httpProxyPort = System.getProperty("http.proxyPort", ""); //$NON-NLS-1$ //$NON-NLS-2$
	}
	int port = -1;
	if (httpProxyPort != null && !"".equals(httpProxyPort)) //$NON-NLS-1$
	try {
	port = Integer.parseInt(httpProxyPort);
	} catch (NumberFormatException e) {
	// Ignore
	}
	return port;
	}

	private boolean getEnablementToMigrate(boolean checkSystemProperties) {
	boolean httpProxyEnable = false;
	if (checkSystemProperties) {
	httpProxyEnable = Boolean.getBoolean("http.proxySet"); //$NON-NLS-1$
	}
	return httpProxyEnable;
	}

	private static PreferenceManager createInstanceManager(Preferences instance) {
	PreferenceManager manager = new PreferenceManager(Activator.ID);
	manager.currentScope = (IEclipsePreferences) instance;
	return manager;
	}
	}