bundles/org.eclipse.equinox.p2.console/src/org/eclipse/equinox/internal/p2/console/ProvisioningHelper.java - equinox/rt.equinox.p2 - Git at Google

 /*******************************************************************************
  *  Copyright (c) 2007, 2017 IBM Corporation and others.
  *
  *  This program and the accompanying materials
  *  are made available under the terms of the Eclipse Public License 2.0
  *  which accompanies this distribution, and is available at
  *  https://www.eclipse.org/legal/epl-2.0/
  *
  *  SPDX-License-Identifier: EPL-2.0
  *
  *  Contributors:
  *     IBM Corporation - initial API and implementation
  *     Sonatype, Inc. - ongoing development
  *     Red Hat Inc. - Bug 460967
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.console;

 import java.net.URI;
 import java.util.HashMap;
 import java.util.Map;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.p2.core.helpers.ServiceHelper;
 import org.eclipse.equinox.internal.provisional.p2.director.PlanExecutionHelper;
 import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.core.ProvisionException;
 import org.eclipse.equinox.p2.engine.*;
 import org.eclipse.equinox.p2.metadata.IInstallableUnit;
 import org.eclipse.equinox.p2.metadata.Version;
 import org.eclipse.equinox.p2.planner.IPlanner;
 import org.eclipse.equinox.p2.planner.IProfileChangeRequest;
 import org.eclipse.equinox.p2.query.*;
 import org.eclipse.equinox.p2.repository.IRepositoryManager;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactRepository;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
 import org.eclipse.equinox.p2.repository.metadata.IMetadataRepository;
 import org.eclipse.equinox.p2.repository.metadata.IMetadataRepositoryManager;
 import org.eclipse.osgi.service.environment.EnvironmentInfo;

 public class ProvisioningHelper {

 	static IMetadataRepository addMetadataRepository(IProvisioningAgent agent, URI location) {
 		IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
 		boolean createRepo = "file".equals(location.getScheme()); //$NON-NLS-1$

 		if (manager == null)
 			throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
 		try {
 			return manager.loadRepository(location, null);
 		} catch (ProvisionException e) {
 			if (!createRepo)
 				return null;
 		}

 		// for convenience create and add a repository here
 		String repositoryName = location + " - metadata"; //$NON-NLS-1$
 		try {
 			return manager.createRepository(location, repositoryName, IMetadataRepositoryManager.TYPE_SIMPLE_REPOSITORY, null);
 		} catch (ProvisionException e) {
 			return null;
 		}
 	}

 	static IMetadataRepository getMetadataRepository(IProvisioningAgent agent, URI location) {
 		IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
 		if (manager == null)
 			throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
 		try {
 			return manager.loadRepository(location, null);
 		} catch (ProvisionException e) {
 			return null;
 		}
 	}

 	static void removeMetadataRepository(IProvisioningAgent agent, URI location) {
 		IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
 		if (manager == null)
 			throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
 		manager.removeRepository(location);
 	}

 	static IArtifactRepository addArtifactRepository(IProvisioningAgent agent, URI location) {
 		IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
 		boolean createRepo = "file".equals(location.getScheme()); //$NON-NLS-1$

 		if (manager == null)
 			throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$

 		try {
 			return manager.loadRepository(location, null);
 		} catch (ProvisionException e) {
 			//fall through and create a new repository
 			if (!createRepo)
 				return null;
 		}
 		// could not load a repo at that location so create one as a convenience
 		String repositoryName = location + " - artifacts"; //$NON-NLS-1$
 		try {
 			return manager.createRepository(location, repositoryName, IArtifactRepositoryManager.TYPE_SIMPLE_REPOSITORY, null);
 		} catch (ProvisionException e) {
 			return null;
 		}
 	}

 	static void removeArtifactRepository(IProvisioningAgent agent, URI location) {
 		IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
 		if (manager == null)
 			// TODO log here
 			return;
 		manager.removeRepository(location);
 	}

 	static IProfile addProfile(IProvisioningAgent agent, String profileId, Map<String, String> properties) throws ProvisionException {
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			return null;
 		IProfile profile = profileRegistry.getProfile(profileId);
 		if (profile != null)
 			return profile;

 		Map<String, String> profileProperties = new HashMap<>(properties);
 		if (profileProperties.get(IProfile.PROP_ENVIRONMENTS) == null) {
 			EnvironmentInfo info = ServiceHelper.getService(Activator.getContext(), EnvironmentInfo.class);
 			if (info != null)
 				profileProperties.put(IProfile.PROP_ENVIRONMENTS, "osgi.os=" + info.getOS() + ",osgi.ws=" + info.getWS() + ",osgi.arch=" + info.getOSArch()); //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 			else
 				profileProperties.put(IProfile.PROP_ENVIRONMENTS, ""); //$NON-NLS-1$
 		}

 		return profileRegistry.addProfile(profileId, profileProperties);
 	}

 	static void removeProfile(IProvisioningAgent agent, String profileId) {
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			return;
 		profileRegistry.removeProfile(profileId);
 	}

 	static IProfile[] getProfiles(IProvisioningAgent agent) {
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			return new IProfile[0];
 		return profileRegistry.getProfiles();
 	}

 	static IProfile getProfile(IProvisioningAgent agent, String id) {
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			return null;
 		return profileRegistry.getProfile(id);
 	}

 	/**
 	 * Returns the installable units that match the given query
 	 * in the given metadata repository.
 	 *
 	 * @param location The location of the metadata repo to search.  <code>null</code> indicates
 	 *        search all known repos.
 	 * @param query The query to perform
 	 * @param monitor A progress monitor, or <code>null</code>
 	 * @return The IUs that match the query
 	 */
 	static IQueryResult<IInstallableUnit> getInstallableUnits(IProvisioningAgent agent, URI location, IQuery<IInstallableUnit> query, IProgressMonitor monitor) {
 		IQueryable<IInstallableUnit> queryable = null;
 		if (location == null) {
 			queryable = agent.getService(IMetadataRepositoryManager.class);
 		} else {
 			queryable = getMetadataRepository(agent, location);
 		}
 		if (queryable != null)
 			return queryable.query(query, monitor);
 		return Collector.emptyCollector();
 	}

 	static URI[] getMetadataRepositories(IProvisioningAgent agent) {
 		IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
 		if (manager == null)
 			// TODO log here
 			return null;
 		URI[] repos = manager.getKnownRepositories(IRepositoryManager.REPOSITORIES_ALL);
 		if (repos.length > 0)
 			return repos;
 		return null;
 	}

 	/**
 	 * Install the described IU
 	 */
 	static IStatus install(IProvisioningAgent agent, String unitId, String version, IProfile profile, IProgressMonitor progress) throws ProvisionException {
 		if (profile == null)
 			return null;
 		IQueryResult<IInstallableUnit> units = getInstallableUnits(agent, (URI) null, QueryUtil.createIUQuery(unitId, Version.create(version)), progress);
 		if (units.isEmpty()) {
 			StringBuilder error = new StringBuilder();
 			error.append("Installable unit not found: " + unitId + ' ' + version + '\n'); //$NON-NLS-1$
 			error.append("Repositories searched:\n");//$NON-NLS-1$
 			URI[] repos = getMetadataRepositories(agent);
 			if (repos != null) {
 				for (URI repo : repos)
 					error.append(repo + "\n");//$NON-NLS-1$
 			}
 			throw new ProvisionException(error.toString());
 		}

 		IPlanner planner = agent.getService(IPlanner.class);
 		if (planner == null)
 			throw new ProvisionException("No planner service found.");//$NON-NLS-1$

 		IEngine engine = agent.getService(IEngine.class);
 		if (engine == null)
 			throw new ProvisionException("No director service found."); //$NON-NLS-1$
 		ProvisioningContext context = new ProvisioningContext(agent);
 		IProfileChangeRequest request = planner.createChangeRequest(profile);
 		request.addAll(units.toUnmodifiableSet());
 		IProvisioningPlan result = planner.getProvisioningPlan(request, context, progress);
 		return PlanExecutionHelper.executePlan(result, engine, context, progress);
 	}

 	static URI[] getArtifactRepositories(IProvisioningAgent agent) {
 		IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
 		if (manager == null)
 			throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
 		URI[] repos = manager.getKnownRepositories(IRepositoryManager.REPOSITORIES_ALL);
 		if (repos.length > 0)
 			return repos;
 		return null;
 	}

 	static IArtifactRepository getArtifactRepository(IProvisioningAgent agent, URI repoURL) {
 		IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
 		try {
 			if (manager != null)
 				return manager.loadRepository(repoURL, null);
 		} catch (ProvisionException e) {
 			//for console, just ignore repositories that can't be read
 		}
 		return null;
 	}

 	static long[] getProfileTimestamps(IProvisioningAgent agent, String profileId) {
 		if (profileId == null) {
 			profileId = IProfileRegistry.SELF;
 		}
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			return null;
 		return profileRegistry.listProfileTimestamps(profileId);
 	}

 	static IStatus revertToPreviousState(IProvisioningAgent agent, IProfile profile, long revertToPreviousState) throws ProvisionException {
 		IEngine engine = agent.getService(IEngine.class);
 		if (engine == null)
 			throw new ProvisionException("No p2 engine found."); //$NON-NLS-1$
 		IPlanner planner = agent.getService(IPlanner.class);
 		if (planner == null)
 			throw new ProvisionException("No planner found."); //$NON-NLS-1$
 		IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
 		if (profileRegistry == null)
 			throw new ProvisionException("profile registry cannot be null"); //$NON-NLS-1$
 		// If given profile is null, then get/use the self profile
 		if (profile == null) {
 			profile = getProfile(agent, IProfileRegistry.SELF);
 		}
 		IProfile targetProfile = null;
 		if (revertToPreviousState == 0) {
 			long[] profiles = profileRegistry.listProfileTimestamps(profile.getProfileId());
 			if (profiles.length == 0)
 				// Nothing to do, as the profile does not have any previous timestamps
 				return Status.OK_STATUS;
 			targetProfile = profileRegistry.getProfile(profile.getProfileId(), profiles[profiles.length - 1]);
 		} else {
 			targetProfile = profileRegistry.getProfile(profile.getProfileId(), revertToPreviousState);
 		}
 		if (targetProfile == null)
 			throw new ProvisionException("target profile with timestamp=" + revertToPreviousState + " not found"); //$NON-NLS-1$//$NON-NLS-2$
 		URI[] artifactRepos = getArtifactRepositories(agent);
 		URI[] metadataRepos = getMetadataRepositories(agent);
 		IProvisioningPlan plan = planner.getDiffPlan(profile, targetProfile, new NullProgressMonitor());
 		ProvisioningContext context = new ProvisioningContext(agent);
 		context.setMetadataRepositories(metadataRepos);
 		context.setArtifactRepositories(artifactRepos);
 		return PlanExecutionHelper.executePlan(plan, engine, context, new NullProgressMonitor());
 	}

 	/**
 	 * Install the described IU
 	 */
 	static IStatus uninstall(IProvisioningAgent agent, String unitId, String version, IProfile profile, IProgressMonitor progress) throws ProvisionException {
 		if (profile == null)
 			return null;
 		IQueryResult<IInstallableUnit> units = profile.query(QueryUtil.createIUQuery(unitId, Version.create(version)), progress);
 		if (units.isEmpty()) {
 			StringBuilder error = new StringBuilder();
 			error.append("Installable unit not found: " + unitId + ' ' + version + '\n'); //$NON-NLS-1$
 			error.append("Repositories searched:\n"); //$NON-NLS-1$
 			URI[] repos = getMetadataRepositories(agent);
 			if (repos != null) {
 				for (URI repo : repos)
 					error.append(repo + "\n"); //$NON-NLS-1$
 			}
 			throw new ProvisionException(error.toString());
 		}

 		IPlanner planner = agent.getService(IPlanner.class);
 		if (planner == null)
 			throw new ProvisionException("No planner service found."); //$NON-NLS-1$

 		IEngine engine = agent.getService(IEngine.class);
 		if (engine == null)
 			throw new ProvisionException("No engine service found."); //$NON-NLS-1$
 		ProvisioningContext context = new ProvisioningContext(agent);
 		IProfileChangeRequest request = planner.createChangeRequest(profile);
 		request.removeAll(units.toUnmodifiableSet());
 		IProvisioningPlan result = planner.getProvisioningPlan(request, context, progress);
 		return PlanExecutionHelper.executePlan(result, engine, context, progress);
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2007, 2017 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Sonatype, Inc. - ongoing development
	* Red Hat Inc. - Bug 460967
	*******************************************************************************/
	package org.eclipse.equinox.internal.p2.console;

	import java.net.URI;
	import java.util.HashMap;
	import java.util.Map;
	import org.eclipse.core.runtime.*;
	import org.eclipse.equinox.internal.p2.core.helpers.ServiceHelper;
	import org.eclipse.equinox.internal.provisional.p2.director.PlanExecutionHelper;
	import org.eclipse.equinox.p2.core.IProvisioningAgent;
	import org.eclipse.equinox.p2.core.ProvisionException;
	import org.eclipse.equinox.p2.engine.*;
	import org.eclipse.equinox.p2.metadata.IInstallableUnit;
	import org.eclipse.equinox.p2.metadata.Version;
	import org.eclipse.equinox.p2.planner.IPlanner;
	import org.eclipse.equinox.p2.planner.IProfileChangeRequest;
	import org.eclipse.equinox.p2.query.*;
	import org.eclipse.equinox.p2.repository.IRepositoryManager;
	import org.eclipse.equinox.p2.repository.artifact.IArtifactRepository;
	import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
	import org.eclipse.equinox.p2.repository.metadata.IMetadataRepository;
	import org.eclipse.equinox.p2.repository.metadata.IMetadataRepositoryManager;
	import org.eclipse.osgi.service.environment.EnvironmentInfo;

	public class ProvisioningHelper {

	static IMetadataRepository addMetadataRepository(IProvisioningAgent agent, URI location) {
	IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
	boolean createRepo = "file".equals(location.getScheme()); //$NON-NLS-1$

	if (manager == null)
	throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
	try {
	return manager.loadRepository(location, null);
	} catch (ProvisionException e) {
	if (!createRepo)
	return null;
	}

	// for convenience create and add a repository here
	String repositoryName = location + " - metadata"; //$NON-NLS-1$
	try {
	return manager.createRepository(location, repositoryName, IMetadataRepositoryManager.TYPE_SIMPLE_REPOSITORY, null);
	} catch (ProvisionException e) {
	return null;
	}
	}

	static IMetadataRepository getMetadataRepository(IProvisioningAgent agent, URI location) {
	IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
	if (manager == null)
	throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
	try {
	return manager.loadRepository(location, null);
	} catch (ProvisionException e) {
	return null;
	}
	}

	static void removeMetadataRepository(IProvisioningAgent agent, URI location) {
	IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
	if (manager == null)
	throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
	manager.removeRepository(location);
	}

	static IArtifactRepository addArtifactRepository(IProvisioningAgent agent, URI location) {
	IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
	boolean createRepo = "file".equals(location.getScheme()); //$NON-NLS-1$

	if (manager == null)
	throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$

	try {
	return manager.loadRepository(location, null);
	} catch (ProvisionException e) {
	//fall through and create a new repository
	if (!createRepo)
	return null;
	}
	// could not load a repo at that location so create one as a convenience
	String repositoryName = location + " - artifacts"; //$NON-NLS-1$
	try {
	return manager.createRepository(location, repositoryName, IArtifactRepositoryManager.TYPE_SIMPLE_REPOSITORY, null);
	} catch (ProvisionException e) {
	return null;
	}
	}

	static void removeArtifactRepository(IProvisioningAgent agent, URI location) {
	IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
	if (manager == null)
	// TODO log here
	return;
	manager.removeRepository(location);
	}

	static IProfile addProfile(IProvisioningAgent agent, String profileId, Map<String, String> properties) throws ProvisionException {
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	return null;
	IProfile profile = profileRegistry.getProfile(profileId);
	if (profile != null)
	return profile;

	Map<String, String> profileProperties = new HashMap<>(properties);
	if (profileProperties.get(IProfile.PROP_ENVIRONMENTS) == null) {
	EnvironmentInfo info = ServiceHelper.getService(Activator.getContext(), EnvironmentInfo.class);
	if (info != null)
	profileProperties.put(IProfile.PROP_ENVIRONMENTS, "osgi.os=" + info.getOS() + ",osgi.ws=" + info.getWS() + ",osgi.arch=" + info.getOSArch()); //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
	else
	profileProperties.put(IProfile.PROP_ENVIRONMENTS, ""); //$NON-NLS-1$
	}

	return profileRegistry.addProfile(profileId, profileProperties);
	}

	static void removeProfile(IProvisioningAgent agent, String profileId) {
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	return;
	profileRegistry.removeProfile(profileId);
	}

	static IProfile[] getProfiles(IProvisioningAgent agent) {
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	return new IProfile[0];
	return profileRegistry.getProfiles();
	}

	static IProfile getProfile(IProvisioningAgent agent, String id) {
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	return null;
	return profileRegistry.getProfile(id);
	}

	/**
	* Returns the installable units that match the given query
	* in the given metadata repository.
	*
	* @param location The location of the metadata repo to search. <code>null</code> indicates
	* search all known repos.
	* @param query The query to perform
	* @param monitor A progress monitor, or <code>null</code>
	* @return The IUs that match the query
	*/
	static IQueryResult<IInstallableUnit> getInstallableUnits(IProvisioningAgent agent, URI location, IQuery<IInstallableUnit> query, IProgressMonitor monitor) {
	IQueryable<IInstallableUnit> queryable = null;
	if (location == null) {
	queryable = agent.getService(IMetadataRepositoryManager.class);
	} else {
	queryable = getMetadataRepository(agent, location);
	}
	if (queryable != null)
	return queryable.query(query, monitor);
	return Collector.emptyCollector();
	}

	static URI[] getMetadataRepositories(IProvisioningAgent agent) {
	IMetadataRepositoryManager manager = agent.getService(IMetadataRepositoryManager.class);
	if (manager == null)
	// TODO log here
	return null;
	URI[] repos = manager.getKnownRepositories(IRepositoryManager.REPOSITORIES_ALL);
	if (repos.length > 0)
	return repos;
	return null;
	}

	/**
	* Install the described IU
	*/
	static IStatus install(IProvisioningAgent agent, String unitId, String version, IProfile profile, IProgressMonitor progress) throws ProvisionException {
	if (profile == null)
	return null;
	IQueryResult<IInstallableUnit> units = getInstallableUnits(agent, (URI) null, QueryUtil.createIUQuery(unitId, Version.create(version)), progress);
	if (units.isEmpty()) {
	StringBuilder error = new StringBuilder();
	error.append("Installable unit not found: " + unitId + ' ' + version + '\n'); //$NON-NLS-1$
	error.append("Repositories searched:\n");//$NON-NLS-1$
	URI[] repos = getMetadataRepositories(agent);
	if (repos != null) {
	for (URI repo : repos)
	error.append(repo + "\n");//$NON-NLS-1$
	}
	throw new ProvisionException(error.toString());
	}

	IPlanner planner = agent.getService(IPlanner.class);
	if (planner == null)
	throw new ProvisionException("No planner service found.");//$NON-NLS-1$

	IEngine engine = agent.getService(IEngine.class);
	if (engine == null)
	throw new ProvisionException("No director service found."); //$NON-NLS-1$
	ProvisioningContext context = new ProvisioningContext(agent);
	IProfileChangeRequest request = planner.createChangeRequest(profile);
	request.addAll(units.toUnmodifiableSet());
	IProvisioningPlan result = planner.getProvisioningPlan(request, context, progress);
	return PlanExecutionHelper.executePlan(result, engine, context, progress);
	}

	static URI[] getArtifactRepositories(IProvisioningAgent agent) {
	IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
	if (manager == null)
	throw new IllegalStateException("No metadata repository manager found"); //$NON-NLS-1$
	URI[] repos = manager.getKnownRepositories(IRepositoryManager.REPOSITORIES_ALL);
	if (repos.length > 0)
	return repos;
	return null;
	}

	static IArtifactRepository getArtifactRepository(IProvisioningAgent agent, URI repoURL) {
	IArtifactRepositoryManager manager = agent.getService(IArtifactRepositoryManager.class);
	try {
	if (manager != null)
	return manager.loadRepository(repoURL, null);
	} catch (ProvisionException e) {
	//for console, just ignore repositories that can't be read
	}
	return null;
	}

	static long[] getProfileTimestamps(IProvisioningAgent agent, String profileId) {
	if (profileId == null) {
	profileId = IProfileRegistry.SELF;
	}
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	return null;
	return profileRegistry.listProfileTimestamps(profileId);
	}

	static IStatus revertToPreviousState(IProvisioningAgent agent, IProfile profile, long revertToPreviousState) throws ProvisionException {
	IEngine engine = agent.getService(IEngine.class);
	if (engine == null)
	throw new ProvisionException("No p2 engine found."); //$NON-NLS-1$
	IPlanner planner = agent.getService(IPlanner.class);
	if (planner == null)
	throw new ProvisionException("No planner found."); //$NON-NLS-1$
	IProfileRegistry profileRegistry = agent.getService(IProfileRegistry.class);
	if (profileRegistry == null)
	throw new ProvisionException("profile registry cannot be null"); //$NON-NLS-1$
	// If given profile is null, then get/use the self profile
	if (profile == null) {
	profile = getProfile(agent, IProfileRegistry.SELF);
	}
	IProfile targetProfile = null;
	if (revertToPreviousState == 0) {
	long[] profiles = profileRegistry.listProfileTimestamps(profile.getProfileId());
	if (profiles.length == 0)
	// Nothing to do, as the profile does not have any previous timestamps
	return Status.OK_STATUS;
	targetProfile = profileRegistry.getProfile(profile.getProfileId(), profiles[profiles.length - 1]);
	} else {
	targetProfile = profileRegistry.getProfile(profile.getProfileId(), revertToPreviousState);
	}
	if (targetProfile == null)
	throw new ProvisionException("target profile with timestamp=" + revertToPreviousState + " not found"); //$NON-NLS-1$//$NON-NLS-2$
	URI[] artifactRepos = getArtifactRepositories(agent);
	URI[] metadataRepos = getMetadataRepositories(agent);
	IProvisioningPlan plan = planner.getDiffPlan(profile, targetProfile, new NullProgressMonitor());
	ProvisioningContext context = new ProvisioningContext(agent);
	context.setMetadataRepositories(metadataRepos);
	context.setArtifactRepositories(artifactRepos);
	return PlanExecutionHelper.executePlan(plan, engine, context, new NullProgressMonitor());
	}

	/**
	* Install the described IU
	*/
	static IStatus uninstall(IProvisioningAgent agent, String unitId, String version, IProfile profile, IProgressMonitor progress) throws ProvisionException {
	if (profile == null)
	return null;
	IQueryResult<IInstallableUnit> units = profile.query(QueryUtil.createIUQuery(unitId, Version.create(version)), progress);
	if (units.isEmpty()) {
	StringBuilder error = new StringBuilder();
	error.append("Installable unit not found: " + unitId + ' ' + version + '\n'); //$NON-NLS-1$
	error.append("Repositories searched:\n"); //$NON-NLS-1$
	URI[] repos = getMetadataRepositories(agent);
	if (repos != null) {
	for (URI repo : repos)
	error.append(repo + "\n"); //$NON-NLS-1$
	}
	throw new ProvisionException(error.toString());
	}

	IPlanner planner = agent.getService(IPlanner.class);
	if (planner == null)
	throw new ProvisionException("No planner service found."); //$NON-NLS-1$

	IEngine engine = agent.getService(IEngine.class);
	if (engine == null)
	throw new ProvisionException("No engine service found."); //$NON-NLS-1$
	ProvisioningContext context = new ProvisioningContext(agent);
	IProfileChangeRequest request = planner.createChangeRequest(profile);
	request.removeAll(units.toUnmodifiableSet());
	IProvisioningPlan result = planner.getProvisioningPlan(request, context, progress);
	return PlanExecutionHelper.executePlan(result, engine, context, progress);
	}

	}