bundles/org.eclipse.equinox.p2.updatesite/src/org/eclipse/equinox/internal/p2/updatesite/UpdateSite.java - equinox/rt.equinox.p2 - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008 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.equinox.internal.p2.updatesite;

 import java.io.*;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.zip.*;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
 import org.eclipse.equinox.internal.p2.core.helpers.URLUtil;
 import org.eclipse.equinox.internal.p2.publisher.eclipse.FeatureParser;
 import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
 import org.eclipse.equinox.p2.publisher.eclipse.*;
 import org.eclipse.osgi.util.NLS;
 import org.xml.sax.SAXException;

 /**
  * @since 1.0
  */
 public class UpdateSite {

 	private static final String VERSION_SEPARATOR = "_"; //$NON-NLS-1$
 	private static final String JAR_EXTENSION = ".jar"; //$NON-NLS-1$
 	private static final String FEATURE_DIR = "features/"; //$NON-NLS-1$
 	private static final String PLUGIN_DIR = "plugins/"; //$NON-NLS-1$
 	private static final String FEATURE_TEMP_FILE = "feature"; //$NON-NLS-1$
 	private static final String SITE_FILE = "site.xml"; //$NON-NLS-1$
 	private static final String DIR_SEPARATOR = "/"; //$NON-NLS-1$
 	private static final String PROTOCOL_FILE = "file"; //$NON-NLS-1$
 	private static final int RETRY_COUNT = 2;
 	private static final String DOT_XML = ".xml"; //$NON-NLS-1$
 	private static final String SITE = "site"; //$NON-NLS-1$
 	private String checksum;
 	private URL location;
 	private SiteModel site;

 	/*
 	 * Some variables for caching.
 	 */
 	// map of String (URL.toExternalForm()) to UpdateSite
 	private static Map siteCache = new HashMap();
 	// map of String (featureID_featureVersion) to Feature
 	private Map featureCache = new HashMap();

 	/*
 	 * Return a new URL for the given file which is based from the specified root.
 	 */
 	public static URL getFileURL(URL root, String fileName) throws MalformedURLException {
 		String path = root.getPath();
 		if (path.endsWith(fileName))
 			return root;

 		if (constainsUpdateSiteFileName(path))
 			return new URL(root, fileName);

 		if (path.endsWith(DIR_SEPARATOR))
 			return new URL(root.toExternalForm() + fileName);
 		return new URL(root.toExternalForm() + DIR_SEPARATOR + fileName);
 	}

 	/*
 	 * Return a URL based on the given URL, which points to a site.xml file.
 	 */
 	private static URL getSiteURL(URL url) throws MalformedURLException {
 		String path = url.getPath();
 		if (constainsUpdateSiteFileName(path))
 			return url;

 		if (path.endsWith(DIR_SEPARATOR))
 			return new URL(url.toExternalForm() + SITE_FILE);
 		return new URL(url.toExternalForm() + DIR_SEPARATOR + SITE_FILE);
 	}

 	private static boolean constainsUpdateSiteFileName(String path) {
 		if (path.endsWith(DOT_XML)) {
 			int lastSlash = path.lastIndexOf('/');
 			String lastSegment = lastSlash == -1 ? path : path.substring(lastSlash + 1);
 			if (lastSegment.indexOf(SITE) != -1)
 				return true;
 		}
 		return false;
 	}

 	/*
 	 * Load and return an update site object from the given location.
 	 */
 	public static synchronized UpdateSite load(URL location, IProgressMonitor monitor) throws ProvisionException {
 		if (location == null)
 			return null;
 		UpdateSite result = (UpdateSite) siteCache.get(location.toExternalForm());
 		if (result != null)
 			return result;
 		InputStream input = null;
 		File siteFile = loadSiteFile(location, monitor);
 		try {
 			DefaultSiteParser siteParser = new DefaultSiteParser();
 			Checksum checksum = new CRC32();
 			input = new CheckedInputStream(new BufferedInputStream(new FileInputStream(siteFile)), checksum);
 			SiteModel siteModel = siteParser.parse(input);
 			String checksumString = Long.toString(checksum.getValue());
 			result = new UpdateSite(siteModel, getSiteURL(location), checksumString);
 			siteCache.put(location.toExternalForm(), result);
 			return result;
 		} catch (SAXException e) {
 			String msg = NLS.bind(Messages.ErrorReadingSite, location);
 			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
 		} catch (IOException e) {
 			String msg = NLS.bind(Messages.ErrorReadingSite, location);
 			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
 		} finally {
 			try {
 				if (input != null)
 					input.close();
 			} catch (IOException e) {
 				// ignore
 			}
 			if (!PROTOCOL_FILE.equals(location.getProtocol()))
 				siteFile.delete();
 		}
 	}

 	/**
 	 * Returns a local file containing the contents of the update site at the given location.
 	 */
 	private static File loadSiteFile(URL location, IProgressMonitor monitor) throws ProvisionException {
 		Throwable failure;
 		File siteFile = null;
 		IStatus transferResult;
 		boolean deleteSiteFile = false;
 		try {
 			URL actualLocation = getSiteURL(location);
 			if (PROTOCOL_FILE.equals(actualLocation.getProtocol())) {
 				siteFile = new File(actualLocation.getPath());
 				if (siteFile.exists())
 					transferResult = Status.OK_STATUS;
 				else {
 					String msg = NLS.bind(Messages.ErrorReadingSite, location);
 					transferResult = new Status(IStatus.ERROR, Activator.ID, msg, new FileNotFoundException(siteFile.getAbsolutePath()));
 				}
 			} else {
 				// creating a temp file. In the event of an error we want to delete it.
 				deleteSiteFile = true;
 				siteFile = File.createTempFile("site", ".xml"); //$NON-NLS-1$//$NON-NLS-2$
 				OutputStream destination = new BufferedOutputStream(new FileOutputStream(siteFile));
 				transferResult = getTransport().download(actualLocation.toExternalForm(), destination, monitor);
 			}
 			if (monitor.isCanceled())
 				throw new OperationCanceledException();
 			if (transferResult.isOK()) {
 				// successful. If the siteFile is the download of a remote site.xml it will get cleaned up later
 				deleteSiteFile = false;
 				return siteFile;
 			}
 			failure = transferResult.getException();
 		} catch (IOException e) {
 			failure = e;
 		} finally {
 			if (deleteSiteFile && siteFile != null)
 				siteFile.delete();
 		}
 		int code = (failure instanceof FileNotFoundException) ? ProvisionException.REPOSITORY_NOT_FOUND : ProvisionException.REPOSITORY_FAILED_READ;
 		String msg = NLS.bind(Messages.ErrorReadingSite, location);
 		throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, code, msg, failure));
 	}

 	/*
 	 * Parse the feature.xml specified by the given input stream and return the feature object.
 	 * In case of failure, the failure is logged and null is returned
 	 */
 	private static Feature parseFeature(FeatureParser featureParser, URL featureURL, IProgressMonitor monitor) {
 		File featureFile = null;
 		if (PROTOCOL_FILE.equals(featureURL.getProtocol())) {
 			featureFile = new File(featureURL.getPath());
 			return featureParser.parse(featureFile);
 		}
 		try {
 			featureFile = File.createTempFile(FEATURE_TEMP_FILE, JAR_EXTENSION);
 			IStatus transferResult = null;
 			//try the download twice in case of transient network problems
 			for (int i = 0; i < RETRY_COUNT; i++) {
 				if (monitor.isCanceled())
 					throw new OperationCanceledException();
 				OutputStream destination = new BufferedOutputStream(new FileOutputStream(featureFile));
 				transferResult = getTransport().download(featureURL.toExternalForm(), destination, monitor);
 				if (transferResult.isOK())
 					break;
 			}
 			if (monitor.isCanceled())
 				throw new OperationCanceledException();
 			if (!transferResult.isOK()) {
 				LogHelper.log(new ProvisionException(transferResult));
 				return null;
 			}
 			return featureParser.parse(featureFile);
 		} catch (IOException e) {
 			LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, featureURL), e));
 		} finally {
 			if (featureFile != null)
 				featureFile.delete();
 		}
 		return null;
 	}

 	/*
 	 * Throw an exception if the site pointed to by the given URL is not valid.
 	 */
 	public static void validate(URL url, IProgressMonitor monitor) throws ProvisionException {
 		try {
 			URL siteURL = getSiteURL(url);
 			long lastModified = getTransport().getLastModified(siteURL);
 			if (lastModified == 0) {
 				String msg = NLS.bind(Messages.ErrorReadingSite, url);
 				throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, null));
 			}
 		} catch (MalformedURLException e) {
 			String msg = NLS.bind(Messages.ErrorReadingSite, url);
 			throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
 		}
 	}

 	/*
 	 * Constructor for the class.
 	 */
 	private UpdateSite(SiteModel site, URL location, String checksum) {
 		super();
 		this.site = site;
 		this.location = location;
 		this.checksum = checksum;
 	}

 	/*
 	 * Iterate over the archive entries in this site and return the matching URL string for
 	 * the given identifier, if there is one.
 	 */
 	private URL getArchiveURL(URL base, String identifier) {
 		URLEntry[] archives = site.getArchives();
 		for (int i = 0; archives != null && i < archives.length; i++) {
 			URLEntry entry = archives[i];
 			if (identifier.equals(entry.getAnnotation()))
 				return internalGetURL(base, entry.getURL());
 		}
 		return null;
 	}

 	/*
 	 * Return the checksum for this site.
 	 */
 	public String getChecksum() {
 		return checksum;
 	}

 	/*
 	 * Return a URL which represents the location of the given feature.
 	 */
 	public URL getSiteFeatureURL(SiteFeature siteFeature) {
 		URL url = siteFeature.getURL();
 		if (url != null)
 			return url;

 		URL base = getBaseURL();
 		String featureURLString = siteFeature.getURLString();
 		return internalGetURL(base, featureURLString);
 	}

 	/*
 	 * Return a URL which represents the location of the given feature.
 	 */
 	public URL getFeatureURL(String id, String version) {
 		SiteFeature[] entries = site.getFeatures();
 		for (int i = 0; i < entries.length; i++) {
 			if (id.equals(entries[i].getFeatureIdentifier()) && version.equals(entries[i].getFeatureVersion())) {
 				return getSiteFeatureURL(entries[i]);
 			}
 		}

 		URL base = getBaseURL();
 		URL url = getArchiveURL(base, FEATURE_DIR + id + VERSION_SEPARATOR + version + JAR_EXTENSION);
 		if (url != null)
 			return url;

 		// fall through to default URL
 		try {
 			return getFileURL(base, FEATURE_DIR + id + VERSION_SEPARATOR + version + JAR_EXTENSION);
 		} catch (MalformedURLException e) {
 			// shouldn't happen
 		}
 		return null;
 	}

 	/*
 	 * Return the location of this site.
 	 */
 	public URL getLocation() {
 		return location;
 	}

 	public String getMirrorsURL() {
 		//copy mirror information from update site to p2 repositories
 		String mirrors = site.getMirrorsURL();
 		if (mirrors == null)
 			return null;
 		//remove site.xml file reference
 		int index = mirrors.indexOf("site.xml"); //$NON-NLS-1$
 		if (index != -1)
 			mirrors = mirrors.substring(0, index) + mirrors.substring(index + "site.xml".length()); //$NON-NLS-1$
 		return mirrors;
 	}

 	/*
 	 * Return a URL which represents the location of the given plug-in.
 	 */
 	public URL getPluginURL(FeatureEntry plugin) {
 		URL base = getBaseURL();
 		String path = PLUGIN_DIR + plugin.getId() + VERSION_SEPARATOR + plugin.getVersion() + JAR_EXTENSION;
 		URL url = getArchiveURL(base, path);
 		if (url != null)
 			return url;
 		try {
 			return getFileURL(base, path);
 		} catch (MalformedURLException e) {
 			// shouldn't happen
 		}
 		return null;
 	}

 	private URL getBaseURL() {
 		URL base = null;
 		String siteURLString = site.getLocationURLString();
 		if (siteURLString != null) {
 			if (!siteURLString.endsWith("/")) //$NON-NLS-1$
 				siteURLString += "/"; //$NON-NLS-1$
 			base = internalGetURL(location, siteURLString);
 		}
 		if (base == null)
 			base = location;
 		return base;
 	}

 	/*
 	 * Return the site model.
 	 */
 	public SiteModel getSite() {
 		return site;
 	}

 	/*
 	 * The trailing parameter can be either null, relative or absolute. If it is null,
 	 * then return null. If it is absolute, then create a new url and return it. If it is
 	 * relative, then make it relative to the given base url.
 	 */
 	private URL internalGetURL(URL base, String trailing) {
 		if (trailing == null)
 			return null;
 		try {
 			return new URL(trailing);
 		} catch (MalformedURLException e) {
 			try {
 				return new URL(base, trailing);
 			} catch (MalformedURLException e2) {
 				// shouldn't happen
 			}
 		}
 		return null;
 	}

 	/*
 	 * Load and return the features references in this update site.
 	 */
 	public synchronized Feature[] loadFeatures(IProgressMonitor monitor) throws ProvisionException {
 		if (!featureCache.isEmpty())
 			return (Feature[]) featureCache.values().toArray(new Feature[featureCache.size()]);
 		Feature[] result = loadFeaturesFromDigest(monitor);
 		return result == null ? loadFeaturesFromSite(monitor) : result;
 	}

 	/*
 	 * Try and load the feature information from the update site's
 	 * digest file, if it exists.
 	 */
 	private Feature[] loadFeaturesFromDigest(IProgressMonitor monitor) {
 		File digestFile = null;
 		boolean local = false;
 		try {
 			URL digestURL = getDigestURL();
 			if (PROTOCOL_FILE.equals(digestURL.getProtocol())) {
 				digestFile = URLUtil.toFile(digestURL);
 				if (!digestFile.exists())
 					return null;
 				local = true;
 			} else {
 				digestFile = File.createTempFile("digest", ".zip"); //$NON-NLS-1$ //$NON-NLS-2$
 				BufferedOutputStream destination = new BufferedOutputStream(new FileOutputStream(digestFile));
 				IStatus result = getTransport().download(digestURL.toExternalForm(), destination, monitor);
 				if (result.getSeverity() == IStatus.CANCEL || monitor.isCanceled())
 					throw new OperationCanceledException();
 				if (!result.isOK())
 					return null;
 			}
 			Feature[] features = new DigestParser().parse(digestFile);
 			if (features == null)
 				return null;
 			Map tmpFeatureCache = new HashMap(features.length);
 			for (int i = 0; i < features.length; i++) {
 				String key = features[i].getId() + VERSION_SEPARATOR + features[i].getVersion();
 				tmpFeatureCache.put(key, features[i]);
 			}
 			featureCache = tmpFeatureCache;
 			return features;
 		} catch (FileNotFoundException fnfe) {
 			// we do not track FNF exceptions as we will fall back to the
 			// standard feature parsing from the site itself, see bug 225587.
 		} catch (MalformedURLException e) {
 			String msg = NLS.bind(Messages.InvalidRepositoryLocation, location);
 			LogHelper.log(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_INVALID_LOCATION, msg, e));
 		} catch (IOException e) {
 			LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingDigest, location), e));
 		} finally {
 			if (!local && digestFile != null)
 				digestFile.delete();
 		}
 		return null;
 	}

 	private URL getDigestURL() throws MalformedURLException {
 		URL digestBase = location;
 		String digestURLString = site.getDigestURLString();
 		if (digestURLString != null) {
 			if (!digestURLString.endsWith("/")) //$NON-NLS-1$
 				digestURLString += "/"; //$NON-NLS-1$
 			digestBase = internalGetURL(location, digestURLString);
 		}

 		return getFileURL(digestBase, "digest.zip"); //$NON-NLS-1$
 	}

 	/*
 	 * Load and return the features that are referenced by this update site. Note this
 	 * requires downloading and parsing the feature manifest locally.
 	 */
 	private Feature[] loadFeaturesFromSite(IProgressMonitor monitor) throws ProvisionException {
 		SiteFeature[] siteFeatures = site.getFeatures();
 		FeatureParser featureParser = new FeatureParser();
 		Map tmpFeatureCache = new HashMap(siteFeatures.length);

 		for (int i = 0; i < siteFeatures.length; i++) {
 			if (monitor.isCanceled()) {
 				throw new OperationCanceledException();
 			}
 			SiteFeature siteFeature = siteFeatures[i];
 			String key = null;
 			if (siteFeature.getFeatureIdentifier() != null && siteFeature.getFeatureVersion() != null) {
 				key = siteFeature.getFeatureIdentifier() + VERSION_SEPARATOR + siteFeature.getFeatureVersion();
 				if (tmpFeatureCache.containsKey(key))
 					continue;
 			}
 			URL featureURL = getSiteFeatureURL(siteFeature);
 			Feature feature = parseFeature(featureParser, featureURL, monitor);
 			if (feature == null) {
 				LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, featureURL)));
 			} else {
 				if (key == null) {
 					siteFeature.setFeatureIdentifier(feature.getId());
 					siteFeature.setFeatureVersion(feature.getVersion());
 					key = siteFeature.getFeatureIdentifier() + VERSION_SEPARATOR + siteFeature.getFeatureVersion();
 				}
 				tmpFeatureCache.put(key, feature);
 				loadIncludedFeatures(feature, featureParser, tmpFeatureCache, monitor);
 			}
 		}
 		featureCache = tmpFeatureCache;
 		return (Feature[]) featureCache.values().toArray(new Feature[featureCache.size()]);
 	}

 	/*
 	 * Load the features that are included by the given feature.
 	 */
 	private void loadIncludedFeatures(Feature feature, FeatureParser featureParser, Map features, IProgressMonitor monitor) throws ProvisionException {
 		FeatureEntry[] featureEntries = feature.getEntries();
 		for (int i = 0; i < featureEntries.length; i++) {
 			if (monitor.isCanceled())
 				throw new OperationCanceledException();
 			FeatureEntry entry = featureEntries[i];
 			if (entry.isRequires() || entry.isPlugin())
 				continue;
 			String key = entry.getId() + VERSION_SEPARATOR + entry.getVersion();
 			if (features.containsKey(key))
 				continue;

 			URL includedFeatureURL = getFeatureURL(entry.getId(), entry.getVersion());
 			Feature includedFeature = parseFeature(featureParser, includedFeatureURL, monitor);
 			if (includedFeature == null) {
 				LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, includedFeatureURL)));
 			} else {
 				features.put(key, includedFeature);
 				loadIncludedFeatures(includedFeature, featureParser, features, monitor);
 			}
 		}
 	}

 	private static ECFTransport getTransport() {
 		return ECFTransport.getInstance();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008 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.equinox.internal.p2.updatesite;

	import java.io.*;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.zip.*;
	import org.eclipse.core.runtime.*;
	import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
	import org.eclipse.equinox.internal.p2.core.helpers.URLUtil;
	import org.eclipse.equinox.internal.p2.publisher.eclipse.FeatureParser;
	import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
	import org.eclipse.equinox.p2.publisher.eclipse.*;
	import org.eclipse.osgi.util.NLS;
	import org.xml.sax.SAXException;

	/**
	* @since 1.0
	*/
	public class UpdateSite {

	private static final String VERSION_SEPARATOR = "_"; //$NON-NLS-1$
	private static final String JAR_EXTENSION = ".jar"; //$NON-NLS-1$
	private static final String FEATURE_DIR = "features/"; //$NON-NLS-1$
	private static final String PLUGIN_DIR = "plugins/"; //$NON-NLS-1$
	private static final String FEATURE_TEMP_FILE = "feature"; //$NON-NLS-1$
	private static final String SITE_FILE = "site.xml"; //$NON-NLS-1$
	private static final String DIR_SEPARATOR = "/"; //$NON-NLS-1$
	private static final String PROTOCOL_FILE = "file"; //$NON-NLS-1$
	private static final int RETRY_COUNT = 2;
	private static final String DOT_XML = ".xml"; //$NON-NLS-1$
	private static final String SITE = "site"; //$NON-NLS-1$
	private String checksum;
	private URL location;
	private SiteModel site;

	/*
	* Some variables for caching.
	*/
	// map of String (URL.toExternalForm()) to UpdateSite
	private static Map siteCache = new HashMap();
	// map of String (featureID_featureVersion) to Feature
	private Map featureCache = new HashMap();

	/*
	* Return a new URL for the given file which is based from the specified root.
	*/
	public static URL getFileURL(URL root, String fileName) throws MalformedURLException {
	String path = root.getPath();
	if (path.endsWith(fileName))
	return root;

	if (constainsUpdateSiteFileName(path))
	return new URL(root, fileName);

	if (path.endsWith(DIR_SEPARATOR))
	return new URL(root.toExternalForm() + fileName);
	return new URL(root.toExternalForm() + DIR_SEPARATOR + fileName);
	}

	/*
	* Return a URL based on the given URL, which points to a site.xml file.
	*/
	private static URL getSiteURL(URL url) throws MalformedURLException {
	String path = url.getPath();
	if (constainsUpdateSiteFileName(path))
	return url;

	if (path.endsWith(DIR_SEPARATOR))
	return new URL(url.toExternalForm() + SITE_FILE);
	return new URL(url.toExternalForm() + DIR_SEPARATOR + SITE_FILE);
	}

	private static boolean constainsUpdateSiteFileName(String path) {
	if (path.endsWith(DOT_XML)) {
	int lastSlash = path.lastIndexOf('/');
	String lastSegment = lastSlash == -1 ? path : path.substring(lastSlash + 1);
	if (lastSegment.indexOf(SITE) != -1)
	return true;
	}
	return false;
	}

	/*
	* Load and return an update site object from the given location.
	*/
	public static synchronized UpdateSite load(URL location, IProgressMonitor monitor) throws ProvisionException {
	if (location == null)
	return null;
	UpdateSite result = (UpdateSite) siteCache.get(location.toExternalForm());
	if (result != null)
	return result;
	InputStream input = null;
	File siteFile = loadSiteFile(location, monitor);
	try {
	DefaultSiteParser siteParser = new DefaultSiteParser();
	Checksum checksum = new CRC32();
	input = new CheckedInputStream(new BufferedInputStream(new FileInputStream(siteFile)), checksum);
	SiteModel siteModel = siteParser.parse(input);
	String checksumString = Long.toString(checksum.getValue());
	result = new UpdateSite(siteModel, getSiteURL(location), checksumString);
	siteCache.put(location.toExternalForm(), result);
	return result;
	} catch (SAXException e) {
	String msg = NLS.bind(Messages.ErrorReadingSite, location);
	throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
	} catch (IOException e) {
	String msg = NLS.bind(Messages.ErrorReadingSite, location);
	throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
	} finally {
	try {
	if (input != null)
	input.close();
	} catch (IOException e) {
	// ignore
	}
	if (!PROTOCOL_FILE.equals(location.getProtocol()))
	siteFile.delete();
	}
	}

	/**
	* Returns a local file containing the contents of the update site at the given location.
	*/
	private static File loadSiteFile(URL location, IProgressMonitor monitor) throws ProvisionException {
	Throwable failure;
	File siteFile = null;
	IStatus transferResult;
	boolean deleteSiteFile = false;
	try {
	URL actualLocation = getSiteURL(location);
	if (PROTOCOL_FILE.equals(actualLocation.getProtocol())) {
	siteFile = new File(actualLocation.getPath());
	if (siteFile.exists())
	transferResult = Status.OK_STATUS;
	else {
	String msg = NLS.bind(Messages.ErrorReadingSite, location);
	transferResult = new Status(IStatus.ERROR, Activator.ID, msg, new FileNotFoundException(siteFile.getAbsolutePath()));
	}
	} else {
	// creating a temp file. In the event of an error we want to delete it.
	deleteSiteFile = true;
	siteFile = File.createTempFile("site", ".xml"); //$NON-NLS-1$//$NON-NLS-2$
	OutputStream destination = new BufferedOutputStream(new FileOutputStream(siteFile));
	transferResult = getTransport().download(actualLocation.toExternalForm(), destination, monitor);
	}
	if (monitor.isCanceled())
	throw new OperationCanceledException();
	if (transferResult.isOK()) {
	// successful. If the siteFile is the download of a remote site.xml it will get cleaned up later
	deleteSiteFile = false;
	return siteFile;
	}
	failure = transferResult.getException();
	} catch (IOException e) {
	failure = e;
	} finally {
	if (deleteSiteFile && siteFile != null)
	siteFile.delete();
	}
	int code = (failure instanceof FileNotFoundException) ? ProvisionException.REPOSITORY_NOT_FOUND : ProvisionException.REPOSITORY_FAILED_READ;
	String msg = NLS.bind(Messages.ErrorReadingSite, location);
	throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, code, msg, failure));
	}

	/*
	* Parse the feature.xml specified by the given input stream and return the feature object.
	* In case of failure, the failure is logged and null is returned
	*/
	private static Feature parseFeature(FeatureParser featureParser, URL featureURL, IProgressMonitor monitor) {
	File featureFile = null;
	if (PROTOCOL_FILE.equals(featureURL.getProtocol())) {
	featureFile = new File(featureURL.getPath());
	return featureParser.parse(featureFile);
	}
	try {
	featureFile = File.createTempFile(FEATURE_TEMP_FILE, JAR_EXTENSION);
	IStatus transferResult = null;
	//try the download twice in case of transient network problems
	for (int i = 0; i < RETRY_COUNT; i++) {
	if (monitor.isCanceled())
	throw new OperationCanceledException();
	OutputStream destination = new BufferedOutputStream(new FileOutputStream(featureFile));
	transferResult = getTransport().download(featureURL.toExternalForm(), destination, monitor);
	if (transferResult.isOK())
	break;
	}
	if (monitor.isCanceled())
	throw new OperationCanceledException();
	if (!transferResult.isOK()) {
	LogHelper.log(new ProvisionException(transferResult));
	return null;
	}
	return featureParser.parse(featureFile);
	} catch (IOException e) {
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, featureURL), e));
	} finally {
	if (featureFile != null)
	featureFile.delete();
	}
	return null;
	}

	/*
	* Throw an exception if the site pointed to by the given URL is not valid.
	*/
	public static void validate(URL url, IProgressMonitor monitor) throws ProvisionException {
	try {
	URL siteURL = getSiteURL(url);
	long lastModified = getTransport().getLastModified(siteURL);
	if (lastModified == 0) {
	String msg = NLS.bind(Messages.ErrorReadingSite, url);
	throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, null));
	}
	} catch (MalformedURLException e) {
	String msg = NLS.bind(Messages.ErrorReadingSite, url);
	throw new ProvisionException(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_FAILED_READ, msg, e));
	}
	}

	/*
	* Constructor for the class.
	*/
	private UpdateSite(SiteModel site, URL location, String checksum) {
	super();
	this.site = site;
	this.location = location;
	this.checksum = checksum;
	}

	/*
	* Iterate over the archive entries in this site and return the matching URL string for
	* the given identifier, if there is one.
	*/
	private URL getArchiveURL(URL base, String identifier) {
	URLEntry[] archives = site.getArchives();
	for (int i = 0; archives != null && i < archives.length; i++) {
	URLEntry entry = archives[i];
	if (identifier.equals(entry.getAnnotation()))
	return internalGetURL(base, entry.getURL());
	}
	return null;
	}

	/*
	* Return the checksum for this site.
	*/
	public String getChecksum() {
	return checksum;
	}

	/*
	* Return a URL which represents the location of the given feature.
	*/
	public URL getSiteFeatureURL(SiteFeature siteFeature) {
	URL url = siteFeature.getURL();
	if (url != null)
	return url;

	URL base = getBaseURL();
	String featureURLString = siteFeature.getURLString();
	return internalGetURL(base, featureURLString);
	}

	/*
	* Return a URL which represents the location of the given feature.
	*/
	public URL getFeatureURL(String id, String version) {
	SiteFeature[] entries = site.getFeatures();
	for (int i = 0; i < entries.length; i++) {
	if (id.equals(entries[i].getFeatureIdentifier()) && version.equals(entries[i].getFeatureVersion())) {
	return getSiteFeatureURL(entries[i]);
	}
	}

	URL base = getBaseURL();
	URL url = getArchiveURL(base, FEATURE_DIR + id + VERSION_SEPARATOR + version + JAR_EXTENSION);
	if (url != null)
	return url;

	// fall through to default URL
	try {
	return getFileURL(base, FEATURE_DIR + id + VERSION_SEPARATOR + version + JAR_EXTENSION);
	} catch (MalformedURLException e) {
	// shouldn't happen
	}
	return null;
	}

	/*
	* Return the location of this site.
	*/
	public URL getLocation() {
	return location;
	}

	public String getMirrorsURL() {
	//copy mirror information from update site to p2 repositories
	String mirrors = site.getMirrorsURL();
	if (mirrors == null)
	return null;
	//remove site.xml file reference
	int index = mirrors.indexOf("site.xml"); //$NON-NLS-1$
	if (index != -1)
	mirrors = mirrors.substring(0, index) + mirrors.substring(index + "site.xml".length()); //$NON-NLS-1$
	return mirrors;
	}

	/*
	* Return a URL which represents the location of the given plug-in.
	*/
	public URL getPluginURL(FeatureEntry plugin) {
	URL base = getBaseURL();
	String path = PLUGIN_DIR + plugin.getId() + VERSION_SEPARATOR + plugin.getVersion() + JAR_EXTENSION;
	URL url = getArchiveURL(base, path);
	if (url != null)
	return url;
	try {
	return getFileURL(base, path);
	} catch (MalformedURLException e) {
	// shouldn't happen
	}
	return null;
	}

	private URL getBaseURL() {
	URL base = null;
	String siteURLString = site.getLocationURLString();
	if (siteURLString != null) {
	if (!siteURLString.endsWith("/")) //$NON-NLS-1$
	siteURLString += "/"; //$NON-NLS-1$
	base = internalGetURL(location, siteURLString);
	}
	if (base == null)
	base = location;
	return base;
	}

	/*
	* Return the site model.
	*/
	public SiteModel getSite() {
	return site;
	}

	/*
	* The trailing parameter can be either null, relative or absolute. If it is null,
	* then return null. If it is absolute, then create a new url and return it. If it is
	* relative, then make it relative to the given base url.
	*/
	private URL internalGetURL(URL base, String trailing) {
	if (trailing == null)
	return null;
	try {
	return new URL(trailing);
	} catch (MalformedURLException e) {
	try {
	return new URL(base, trailing);
	} catch (MalformedURLException e2) {
	// shouldn't happen
	}
	}
	return null;
	}

	/*
	* Load and return the features references in this update site.
	*/
	public synchronized Feature[] loadFeatures(IProgressMonitor monitor) throws ProvisionException {
	if (!featureCache.isEmpty())
	return (Feature[]) featureCache.values().toArray(new Feature[featureCache.size()]);
	Feature[] result = loadFeaturesFromDigest(monitor);
	return result == null ? loadFeaturesFromSite(monitor) : result;
	}

	/*
	* Try and load the feature information from the update site's
	* digest file, if it exists.
	*/
	private Feature[] loadFeaturesFromDigest(IProgressMonitor monitor) {
	File digestFile = null;
	boolean local = false;
	try {
	URL digestURL = getDigestURL();
	if (PROTOCOL_FILE.equals(digestURL.getProtocol())) {
	digestFile = URLUtil.toFile(digestURL);
	if (!digestFile.exists())
	return null;
	local = true;
	} else {
	digestFile = File.createTempFile("digest", ".zip"); //$NON-NLS-1$ //$NON-NLS-2$
	BufferedOutputStream destination = new BufferedOutputStream(new FileOutputStream(digestFile));
	IStatus result = getTransport().download(digestURL.toExternalForm(), destination, monitor);
	if (result.getSeverity() == IStatus.CANCEL \|\| monitor.isCanceled())
	throw new OperationCanceledException();
	if (!result.isOK())
	return null;
	}
	Feature[] features = new DigestParser().parse(digestFile);
	if (features == null)
	return null;
	Map tmpFeatureCache = new HashMap(features.length);
	for (int i = 0; i < features.length; i++) {
	String key = features[i].getId() + VERSION_SEPARATOR + features[i].getVersion();
	tmpFeatureCache.put(key, features[i]);
	}
	featureCache = tmpFeatureCache;
	return features;
	} catch (FileNotFoundException fnfe) {
	// we do not track FNF exceptions as we will fall back to the
	// standard feature parsing from the site itself, see bug 225587.
	} catch (MalformedURLException e) {
	String msg = NLS.bind(Messages.InvalidRepositoryLocation, location);
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, ProvisionException.REPOSITORY_INVALID_LOCATION, msg, e));
	} catch (IOException e) {
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingDigest, location), e));
	} finally {
	if (!local && digestFile != null)
	digestFile.delete();
	}
	return null;
	}

	private URL getDigestURL() throws MalformedURLException {
	URL digestBase = location;
	String digestURLString = site.getDigestURLString();
	if (digestURLString != null) {
	if (!digestURLString.endsWith("/")) //$NON-NLS-1$
	digestURLString += "/"; //$NON-NLS-1$
	digestBase = internalGetURL(location, digestURLString);
	}

	return getFileURL(digestBase, "digest.zip"); //$NON-NLS-1$
	}

	/*
	* Load and return the features that are referenced by this update site. Note this
	* requires downloading and parsing the feature manifest locally.
	*/
	private Feature[] loadFeaturesFromSite(IProgressMonitor monitor) throws ProvisionException {
	SiteFeature[] siteFeatures = site.getFeatures();
	FeatureParser featureParser = new FeatureParser();
	Map tmpFeatureCache = new HashMap(siteFeatures.length);

	for (int i = 0; i < siteFeatures.length; i++) {
	if (monitor.isCanceled()) {
	throw new OperationCanceledException();
	}
	SiteFeature siteFeature = siteFeatures[i];
	String key = null;
	if (siteFeature.getFeatureIdentifier() != null && siteFeature.getFeatureVersion() != null) {
	key = siteFeature.getFeatureIdentifier() + VERSION_SEPARATOR + siteFeature.getFeatureVersion();
	if (tmpFeatureCache.containsKey(key))
	continue;
	}
	URL featureURL = getSiteFeatureURL(siteFeature);
	Feature feature = parseFeature(featureParser, featureURL, monitor);
	if (feature == null) {
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, featureURL)));
	} else {
	if (key == null) {
	siteFeature.setFeatureIdentifier(feature.getId());
	siteFeature.setFeatureVersion(feature.getVersion());
	key = siteFeature.getFeatureIdentifier() + VERSION_SEPARATOR + siteFeature.getFeatureVersion();
	}
	tmpFeatureCache.put(key, feature);
	loadIncludedFeatures(feature, featureParser, tmpFeatureCache, monitor);
	}
	}
	featureCache = tmpFeatureCache;
	return (Feature[]) featureCache.values().toArray(new Feature[featureCache.size()]);
	}

	/*
	* Load the features that are included by the given feature.
	*/
	private void loadIncludedFeatures(Feature feature, FeatureParser featureParser, Map features, IProgressMonitor monitor) throws ProvisionException {
	FeatureEntry[] featureEntries = feature.getEntries();
	for (int i = 0; i < featureEntries.length; i++) {
	if (monitor.isCanceled())
	throw new OperationCanceledException();
	FeatureEntry entry = featureEntries[i];
	if (entry.isRequires() \|\| entry.isPlugin())
	continue;
	String key = entry.getId() + VERSION_SEPARATOR + entry.getVersion();
	if (features.containsKey(key))
	continue;

	URL includedFeatureURL = getFeatureURL(entry.getId(), entry.getVersion());
	Feature includedFeature = parseFeature(featureParser, includedFeatureURL, monitor);
	if (includedFeature == null) {
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, NLS.bind(Messages.ErrorReadingFeature, includedFeatureURL)));
	} else {
	features.put(key, includedFeature);
	loadIncludedFeatures(includedFeature, featureParser, features, monitor);
	}
	}
	}

	private static ECFTransport getTransport() {
	return ECFTransport.getInstance();
	}
	}