bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/CacheManager.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.metadata.repository;

 import java.io.*;
 import java.net.URL;
 import java.util.EventObject;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.p2.core.helpers.*;
 import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
 import org.eclipse.equinox.internal.provisional.p2.core.eventbus.IProvisioningEventBus;
 import org.eclipse.equinox.internal.provisional.p2.core.eventbus.SynchronousProvisioningListener;
 import org.eclipse.equinox.internal.provisional.p2.core.location.AgentLocation;
 import org.eclipse.equinox.internal.provisional.p2.core.repository.IRepository;
 import org.eclipse.equinox.internal.provisional.p2.core.repository.RepositoryEvent;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.ServiceReference;

 /**
  * A class to manage metadata cache files. Creating the cache files will place
  * the file in the AgentData location in a cache directory.
  *
  * Using the bus listeners will allow the manager to listen for repository
  * events. When a repository is removed, it will remove the cache file if one
  * was created for the repository.
  */
 public class CacheManager {
 	private static SynchronousProvisioningListener busListener;
 	private static final String CONTENT_FILENAME = "content"; //$NON-NLS-1$
 	private static final String JAR_EXTENSION = ".jar"; //$NON-NLS-1$
 	private static final String XML_EXTENSION = ".xml"; //$NON-NLS-1$

 	/**
 	 * Returns a hash of the URL.
 	 */
 	private int computeHash(URL repositoryLocation) {
 		//don't use URL#hashCode because it performs DNS lookups
 		return repositoryLocation.toExternalForm().hashCode();
 	}

 	/**
 	 * Returns a local cache file with the contents of the given remote location,
 	 * or <code>null</code> if a local cache could not be created.
 	 *
 	 * @param repositoryLocation
 	 * @param monitor - a progress monitor
 	 * @return A {@link File} object pointing to the cache file or <code>null</code>
 	 * if the location is not a repository.
 	 * @throws IOException
 	 * @throws ProvisionException
 	 */
 	public File createCache(URL repositoryLocation, IProgressMonitor monitor) throws IOException, ProvisionException {
 		File cacheFile = getCache(repositoryLocation);
 		URL jarLocation = URLMetadataRepository.getActualLocation(repositoryLocation, JAR_EXTENSION);
 		URL xmlLocation = URLMetadataRepository.getActualLocation(repositoryLocation, XML_EXTENSION);
 		AgentLocation agentLocation = (AgentLocation) ServiceHelper.getService(Activator.getContext(), AgentLocation.class.getName());
 		URL dataArea = agentLocation.getDataArea(Activator.ID + "/cache/"); //$NON-NLS-1$
 		File dataAreaFile = URLUtil.toFile(dataArea);
 		int hashCode = computeHash(repositoryLocation);
 		if (cacheFile == null || isCacheStale(repositoryLocation, cacheFile)) {
 			long lastModifiedRemote = getTransport().getLastModified(jarLocation);
 			URL remoteFile;
 			if (lastModifiedRemote != 0) {
 				cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + JAR_EXTENSION);
 				remoteFile = jarLocation;
 			} else {
 				lastModifiedRemote = getTransport().getLastModified(xmlLocation);
 				if (lastModifiedRemote == 0)
 					// no jar or xml file found
 					return null;
 				cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + XML_EXTENSION);
 				remoteFile = xmlLocation;
 			}
 			cacheFile.getParentFile().mkdirs();
 			OutputStream metadata = new BufferedOutputStream(new FileOutputStream(cacheFile));
 			try {
 				IStatus result = getTransport().download(remoteFile.toExternalForm(), metadata, monitor);
 				if (!result.isOK()) {
 					throw new ProvisionException(result);
 				}
 			} finally {
 				metadata.close();
 			}
 		}
 		return cacheFile;
 	}

 	/**
 	 * Deletes the local cache file for the given repository
 	 * @param repositoryLocation
 	 */
 	void deleteCache(URL repositoryLocation) {
 		File cacheFile = getCache(repositoryLocation);
 		if (cacheFile != null)
 			safeDelete(cacheFile);
 	}

 	/**
 	 * Determines the local filepath of the repository's cache file.
 	 * @param repositoryLocation
 	 * @return A {@link File} pointing to the cache file or <code>null</code> if
 	 * the cache file does not exist.
 	 */
 	private File getCache(URL repositoryLocation) {
 		AgentLocation agentLocation = (AgentLocation) ServiceHelper.getService(Activator.getContext(), AgentLocation.class.getName());
 		URL dataArea = agentLocation.getDataArea(Activator.ID + "/cache/"); //$NON-NLS-1$
 		File dataAreaFile = URLUtil.toFile(dataArea);
 		int hashCode = computeHash(repositoryLocation);
 		File cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + JAR_EXTENSION);
 		if (!cacheFile.exists()) {
 			cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + XML_EXTENSION);
 			if (!cacheFile.exists())
 				return null;
 		}
 		return cacheFile;
 	}

 	private Object getService(BundleContext ctx, String name) {
 		ServiceReference reference = ctx.getServiceReference(name);
 		if (reference == null)
 			return null;
 		Object result = ctx.getService(reference);
 		ctx.ungetService(reference);
 		return result;
 	}

 	private ECFMetadataTransport getTransport() {
 		return ECFMetadataTransport.getInstance();
 	}

 	/**
 	 * Checks if the repository's local cache file is out of date.
 	 * @param repositoryLocation The remote location of the file
 	 * @param cacheFile The current local cache of the remote location
 	 * @return <code>true</code> if the cache file is out of date, <code>false</code>
 	 * if the cache file is in sync with the repository. The cache file is
 	 * considered stale if there is no local cache file.
 	 */
 	private boolean isCacheStale(URL repositoryLocation, File cacheFile) {
 		long lastModified = cacheFile.lastModified();
 		String name = cacheFile.getName();
 		URL metadataLocation = null;
 		if (name.endsWith(XML_EXTENSION)) {
 			metadataLocation = URLMetadataRepository.getActualLocation(repositoryLocation, XML_EXTENSION);
 		} else if (name.endsWith(JAR_EXTENSION)) {
 			metadataLocation = URLMetadataRepository.getActualLocation(repositoryLocation, JAR_EXTENSION);
 		}
 		long lastModifiedRemote = 0;
 		try {
 			lastModifiedRemote = getTransport().getLastModified(metadataLocation);
 		} catch (ProvisionException e) {
 			// cache is stale
 			return true;
 		}
 		return lastModifiedRemote > lastModified ? true : false;
 	}

 	/**
 	 * Adds a {@link SynchronousProvisioningListener} to the event bus for
 	 * deleting cache files when the corresponding repository is deleted.
 	 */
 	public void registerRepoEventListener() {
 		IProvisioningEventBus eventBus = (IProvisioningEventBus) getService(Activator.getContext(), IProvisioningEventBus.SERVICE_NAME);
 		if (eventBus == null) {
 			LogHelper.log(new Status(IStatus.ERROR, Activator.ID, "ProvisioningEventBus could not be obtained. Metadata caches may not be cleaned up properly.")); //$NON-NLS-1$
 			return;
 		}
 		if (busListener == null) {
 			busListener = new SynchronousProvisioningListener() {
 				public void notify(EventObject o) {
 					if (o instanceof RepositoryEvent) {
 						RepositoryEvent event = (RepositoryEvent) o;
 						if (RepositoryEvent.REMOVED == event.getKind() && IRepository.TYPE_METADATA == event.getRepositoryType()) {
 							deleteCache(event.getRepositoryLocation());
 						}
 					}
 				}
 			};
 			eventBus.addListener(busListener);
 		}
 	}

 	private boolean safeDelete(File file) {
 		if (file.exists()) {
 			if (!file.delete()) {
 				file.deleteOnExit();
 				return true;
 			}
 		}
 		return false;
 	}

 	/**
 	 * Removes the {@link SynchronousProvisioningListener} that cleans up the
 	 * cache file from the event bus.
 	 */
 	public void unregisterRepoEventListener() {
 		IProvisioningEventBus eventBus = (IProvisioningEventBus) getService(Activator.getContext(), IProvisioningEventBus.SERVICE_NAME);
 		if (eventBus != null && busListener != null) {
 			eventBus.removeListener(busListener);
 			busListener = null;
 		}
 	}
 }
	/*******************************************************************************
	* 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.metadata.repository;

	import java.io.*;
	import java.net.URL;
	import java.util.EventObject;
	import org.eclipse.core.runtime.*;
	import org.eclipse.equinox.internal.p2.core.helpers.*;
	import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
	import org.eclipse.equinox.internal.provisional.p2.core.eventbus.IProvisioningEventBus;
	import org.eclipse.equinox.internal.provisional.p2.core.eventbus.SynchronousProvisioningListener;
	import org.eclipse.equinox.internal.provisional.p2.core.location.AgentLocation;
	import org.eclipse.equinox.internal.provisional.p2.core.repository.IRepository;
	import org.eclipse.equinox.internal.provisional.p2.core.repository.RepositoryEvent;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.ServiceReference;

	/**
	* A class to manage metadata cache files. Creating the cache files will place
	* the file in the AgentData location in a cache directory.
	*
	* Using the bus listeners will allow the manager to listen for repository
	* events. When a repository is removed, it will remove the cache file if one
	* was created for the repository.
	*/
	public class CacheManager {
	private static SynchronousProvisioningListener busListener;
	private static final String CONTENT_FILENAME = "content"; //$NON-NLS-1$
	private static final String JAR_EXTENSION = ".jar"; //$NON-NLS-1$
	private static final String XML_EXTENSION = ".xml"; //$NON-NLS-1$

	/**
	* Returns a hash of the URL.
	*/
	private int computeHash(URL repositoryLocation) {
	//don't use URL#hashCode because it performs DNS lookups
	return repositoryLocation.toExternalForm().hashCode();
	}

	/**
	* Returns a local cache file with the contents of the given remote location,
	* or <code>null</code> if a local cache could not be created.
	*
	* @param repositoryLocation
	* @param monitor - a progress monitor
	* @return A {@link File} object pointing to the cache file or <code>null</code>
	* if the location is not a repository.
	* @throws IOException
	* @throws ProvisionException
	*/
	public File createCache(URL repositoryLocation, IProgressMonitor monitor) throws IOException, ProvisionException {
	File cacheFile = getCache(repositoryLocation);
	URL jarLocation = URLMetadataRepository.getActualLocation(repositoryLocation, JAR_EXTENSION);
	URL xmlLocation = URLMetadataRepository.getActualLocation(repositoryLocation, XML_EXTENSION);
	AgentLocation agentLocation = (AgentLocation) ServiceHelper.getService(Activator.getContext(), AgentLocation.class.getName());
	URL dataArea = agentLocation.getDataArea(Activator.ID + "/cache/"); //$NON-NLS-1$
	File dataAreaFile = URLUtil.toFile(dataArea);
	int hashCode = computeHash(repositoryLocation);
	if (cacheFile == null \|\| isCacheStale(repositoryLocation, cacheFile)) {
	long lastModifiedRemote = getTransport().getLastModified(jarLocation);
	URL remoteFile;
	if (lastModifiedRemote != 0) {
	cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + JAR_EXTENSION);
	remoteFile = jarLocation;
	} else {
	lastModifiedRemote = getTransport().getLastModified(xmlLocation);
	if (lastModifiedRemote == 0)
	// no jar or xml file found
	return null;
	cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + XML_EXTENSION);
	remoteFile = xmlLocation;
	}
	cacheFile.getParentFile().mkdirs();
	OutputStream metadata = new BufferedOutputStream(new FileOutputStream(cacheFile));
	try {
	IStatus result = getTransport().download(remoteFile.toExternalForm(), metadata, monitor);
	if (!result.isOK()) {
	throw new ProvisionException(result);
	}
	} finally {
	metadata.close();
	}
	}
	return cacheFile;
	}

	/**
	* Deletes the local cache file for the given repository
	* @param repositoryLocation
	*/
	void deleteCache(URL repositoryLocation) {
	File cacheFile = getCache(repositoryLocation);
	if (cacheFile != null)
	safeDelete(cacheFile);
	}

	/**
	* Determines the local filepath of the repository's cache file.
	* @param repositoryLocation
	* @return A {@link File} pointing to the cache file or <code>null</code> if
	* the cache file does not exist.
	*/
	private File getCache(URL repositoryLocation) {
	AgentLocation agentLocation = (AgentLocation) ServiceHelper.getService(Activator.getContext(), AgentLocation.class.getName());
	URL dataArea = agentLocation.getDataArea(Activator.ID + "/cache/"); //$NON-NLS-1$
	File dataAreaFile = URLUtil.toFile(dataArea);
	int hashCode = computeHash(repositoryLocation);
	File cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + JAR_EXTENSION);
	if (!cacheFile.exists()) {
	cacheFile = new File(dataAreaFile, CONTENT_FILENAME + hashCode + XML_EXTENSION);
	if (!cacheFile.exists())
	return null;
	}
	return cacheFile;
	}

	private Object getService(BundleContext ctx, String name) {
	ServiceReference reference = ctx.getServiceReference(name);
	if (reference == null)
	return null;
	Object result = ctx.getService(reference);
	ctx.ungetService(reference);
	return result;
	}

	private ECFMetadataTransport getTransport() {
	return ECFMetadataTransport.getInstance();
	}

	/**
	* Checks if the repository's local cache file is out of date.
	* @param repositoryLocation The remote location of the file
	* @param cacheFile The current local cache of the remote location
	* @return <code>true</code> if the cache file is out of date, <code>false</code>
	* if the cache file is in sync with the repository. The cache file is
	* considered stale if there is no local cache file.
	*/
	private boolean isCacheStale(URL repositoryLocation, File cacheFile) {
	long lastModified = cacheFile.lastModified();
	String name = cacheFile.getName();
	URL metadataLocation = null;
	if (name.endsWith(XML_EXTENSION)) {
	metadataLocation = URLMetadataRepository.getActualLocation(repositoryLocation, XML_EXTENSION);
	} else if (name.endsWith(JAR_EXTENSION)) {
	metadataLocation = URLMetadataRepository.getActualLocation(repositoryLocation, JAR_EXTENSION);
	}
	long lastModifiedRemote = 0;
	try {
	lastModifiedRemote = getTransport().getLastModified(metadataLocation);
	} catch (ProvisionException e) {
	// cache is stale
	return true;
	}
	return lastModifiedRemote > lastModified ? true : false;
	}

	/**
	* Adds a {@link SynchronousProvisioningListener} to the event bus for
	* deleting cache files when the corresponding repository is deleted.
	*/
	public void registerRepoEventListener() {
	IProvisioningEventBus eventBus = (IProvisioningEventBus) getService(Activator.getContext(), IProvisioningEventBus.SERVICE_NAME);
	if (eventBus == null) {
	LogHelper.log(new Status(IStatus.ERROR, Activator.ID, "ProvisioningEventBus could not be obtained. Metadata caches may not be cleaned up properly.")); //$NON-NLS-1$
	return;
	}
	if (busListener == null) {
	busListener = new SynchronousProvisioningListener() {
	public void notify(EventObject o) {
	if (o instanceof RepositoryEvent) {
	RepositoryEvent event = (RepositoryEvent) o;
	if (RepositoryEvent.REMOVED == event.getKind() && IRepository.TYPE_METADATA == event.getRepositoryType()) {
	deleteCache(event.getRepositoryLocation());
	}
	}
	}
	};
	eventBus.addListener(busListener);
	}
	}

	private boolean safeDelete(File file) {
	if (file.exists()) {
	if (!file.delete()) {
	file.deleteOnExit();
	return true;
	}
	}
	return false;
	}

	/**
	* Removes the {@link SynchronousProvisioningListener} that cleans up the
	* cache file from the event bus.
	*/
	public void unregisterRepoEventListener() {
	IProvisioningEventBus eventBus = (IProvisioningEventBus) getService(Activator.getContext(), IProvisioningEventBus.SERVICE_NAME);
	if (eventBus != null && busListener != null) {
	eventBus.removeListener(busListener);
	busListener = null;
	}
	}
	}