plugins/org.eclipse.sphinx.emf/src/org/eclipse/sphinx/emf/scoping/ResourceScopeProviderRegistry.java - sphinx/org.eclipse.sphinx - Git at Google

 /**
  * <copyright>
  *
  * Copyright (c) 2008-2012 See4sys, BMW Car IT and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
  *
  * Contributors:
  *     See4sys - Initial API and implementation
  *     BMW Car IT - [373481] Performance optimizations for model loading
  *
  * </copyright>
  */
 package org.eclipse.sphinx.emf.scoping;

 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.sphinx.emf.Activator;
 import org.eclipse.sphinx.emf.internal.messages.Messages;
 import org.eclipse.sphinx.emf.metamodel.IMetaModelDescriptor;
 import org.eclipse.sphinx.emf.metamodel.MetaModelDescriptorRegistry;
 import org.eclipse.sphinx.platform.util.PlatformLogUtil;

 public class ResourceScopeProviderRegistry {

 	/**
 	 * The singleton instance of this registry.
 	 */
 	public static ResourceScopeProviderRegistry INSTANCE = new ResourceScopeProviderRegistry();

 	private static final String EXTP_MODEL_SCOPE_PROVIDER = "org.eclipse.sphinx.emf.resourceScopeProviders";//$NON-NLS-1$
 	private static final String NODE_APPLICABLEFOR = "applicableFor";//$NON-NLS-1$
 	private static final String NODE_PROVIDER = "provider";//$NON-NLS-1$
 	private static final String ATTR_ID = "id"; //$NON-NLS-1$
 	private static final String ATTR_CLASS = "class"; //$NON-NLS-1$
 	private static final String ATTR_OVERRIDE = "override"; //$NON-NLS-1$
 	private static final String ATTR_META_MODEL_DESCRIPTOR_ID_PATTERN = "metaModelDescriptorIdPattern";//$NON-NLS-1$

 	private Map<IMetaModelDescriptor, IResourceScopeProvider> fContributedResourceScopeProviders = new HashMap<IMetaModelDescriptor, IResourceScopeProvider>();

 	private Map<IResourceScopeProvider, Collection<IMetaModelDescriptor>> fMetaModelDescriptorsForResourceScopeProviders = new HashMap<IResourceScopeProvider, Collection<IMetaModelDescriptor>>();

 	private IResourceScopeProvider defaultResourceScopeProvider = null;

 	/**
 	 * Private constructor for the singleton pattern that prevents from instantiation by clients.
 	 */
 	private ResourceScopeProviderRegistry() {
 		readContributedResourceScopeProviders();
 		contributeDefaultResourceScopeProvider();

 	}

 	private void readContributedResourceScopeProviders() {
 		IExtension[] extensions = Platform.getExtensionRegistry().getExtensionPoint(EXTP_MODEL_SCOPE_PROVIDER).getExtensions();
 		Set<String> overriddenIds = new HashSet<String>();
 		// We retrieve overriden ids
 		for (IExtension extension : extensions) {
 			IConfigurationElement[] configElements = extension.getConfigurationElements();
 			overriddenIds.addAll(getOverriddenResourceScopeProviderIds(configElements));
 		}
 		// we contribute extension points excluding overriden ids
 		for (IExtension extension : extensions) {
 			IConfigurationElement[] configElements = extension.getConfigurationElements();
 			readContributedResourceScopeProviders(configElements, overriddenIds);
 		}
 	}

 	/**
 	 * Reads contributions to <em>Meta-Model Descriptor</em> extension point.
 	 * <p>
 	 * <table>
 	 * <tr valign=top>
 	 * <td><b>Note</b>&nbsp;&nbsp;</td>
 	 * <td>It is recommended to call this method inside a block <tt><b>synchronized</b></tt> on the encapsulated
 	 * <code>fMetaModelDescriptors</code> field in order to avoid inconsistencies in registered meta-model
 	 * {@linkplain IMetaModelDescriptor descriptor}s in case of concurrent read/adds.</td>
 	 * </tr>
 	 * </table>
 	 */
 	private void readContributedResourceScopeProviders(IConfigurationElement[] configElements, Set<String> overriddenIds) {
 		for (IConfigurationElement configElement : configElements) {
 			try {
 				String id = configElement.getAttribute(ATTR_ID);
 				IResourceScopeProvider resourceScopeProvider = null;
 				if (!overriddenIds.contains(id)) {
 					resourceScopeProvider = (IResourceScopeProvider) configElement.createExecutableExtension(ATTR_CLASS);
 					IConfigurationElement[] childrenConfigElements = configElement.getChildren();
 					for (IConfigurationElement childConfigElement : childrenConfigElements) {
 						if (NODE_APPLICABLEFOR.equals(childConfigElement.getName())) {
 							String metaModelDescriptorIdPattern = childConfigElement.getAttribute(ATTR_META_MODEL_DESCRIPTOR_ID_PATTERN);
 							addResourceScopeProvider(metaModelDescriptorIdPattern, resourceScopeProvider);
 						}
 					}
 				}
 			} catch (Exception ex) {
 				PlatformLogUtil.logAsError(Activator.getDefault(), ex);
 			}
 		}
 	}

 	private void contributeDefaultResourceScopeProvider() {
 		List<IMetaModelDescriptor> orphanMMDescriptors = MetaModelDescriptorRegistry.INSTANCE.getDescriptors(MetaModelDescriptorRegistry.ANY_MM);
 		Set<IMetaModelDescriptor> alreadyRegisteredMMdescriptors = fContributedResourceScopeProviders.keySet();
 		orphanMMDescriptors.removeAll(alreadyRegisteredMMdescriptors);
 		addResourceScopeProvider(orphanMMDescriptors, getDefaultResourceScopeProvider());
 	}

 	private Set<String> getOverriddenResourceScopeProviderIds(IConfigurationElement[] configElements) {
 		Assert.isNotNull(configElements);
 		Set<String> overriddenIds = new HashSet<String>();
 		for (IConfigurationElement configElement : configElements) {
 			if (NODE_PROVIDER.equals(configElement.getName())) {
 				String overriddenResourceScopePolicyId = configElement.getAttribute(ATTR_OVERRIDE);
 				if (overriddenResourceScopePolicyId != null) {
 					if (!overriddenIds.contains(overriddenResourceScopePolicyId)) {
 						overriddenIds.add(overriddenResourceScopePolicyId);
 					} else {
 						PlatformLogUtil.logAsWarning(
 								Activator.getPlugin(),
 								new RuntimeException(NLS.bind(Messages.warning_multipleOverridesForSameResourceScopeProvider,
 										overriddenResourceScopePolicyId)));
 					}
 				}
 			}
 		}
 		return overriddenIds;
 	}

 	/**
 	 * Register a new {@link IResourceScopeProvider resource scope provider} for the provided
 	 * {@link IMetaModelDescriptor meta model descriptor}.
 	 *
 	 * @param mmDescIdPattern
 	 *            The {@link IMetaModelDescriptor meta model descriptor provider} to register a
 	 *            {@link IResourceScopeProvider resource scope provider} for.
 	 * @param contributedProvider
 	 *            The instance of {@link IResourceScopeProvider resource scope provider} to register.
 	 */
 	private void addResourceScopeProvider(String mmDescIdPattern, IResourceScopeProvider resourceScopeProvider) {
 		Collection<IMetaModelDescriptor> matchingMMDescriptors = getMetaModelDescriptors(mmDescIdPattern);
 		addResourceScopeProvider(matchingMMDescriptors, resourceScopeProvider);
 	}

 	private void addResourceScopeProvider(Collection<IMetaModelDescriptor> mmDescriptors, IResourceScopeProvider resourceScopeProvider) {
 		for (IMetaModelDescriptor mmDescriptor : mmDescriptors) {
 			if (fContributedResourceScopeProviders.get(mmDescriptor) == null) {
 				fContributedResourceScopeProviders.put(mmDescriptor, resourceScopeProvider);

 				Collection<IMetaModelDescriptor> mmDescriptorsOfResourceScopeProvider = fMetaModelDescriptorsForResourceScopeProviders
 						.get(resourceScopeProvider);
 				if (mmDescriptorsOfResourceScopeProvider == null) {
 					mmDescriptorsOfResourceScopeProvider = new HashSet<IMetaModelDescriptor>();
 					fMetaModelDescriptorsForResourceScopeProviders.put(resourceScopeProvider, mmDescriptorsOfResourceScopeProvider);
 				}
 				mmDescriptorsOfResourceScopeProvider.add(mmDescriptor);
 			} else {
 				PlatformLogUtil.logAsWarning(
 						Activator.getPlugin(),
 						new RuntimeException(NLS.bind(Messages.warning_multipleResourceScopeProvidersContributedForSameMetaModelDescriptor,
 								mmDescriptor.getIdentifier())));
 			}
 		}
 	}

 	private Collection<IMetaModelDescriptor> getMetaModelDescriptors(String mmDescIdPattern) {
 		HashSet<IMetaModelDescriptor> metaModelDescriptors = new HashSet<IMetaModelDescriptor>();
 		if (".*".equals(mmDescIdPattern) || ".+".equals(mmDescIdPattern)) { //$NON-NLS-1$ //$NON-NLS-2$
 			metaModelDescriptors.add(MetaModelDescriptorRegistry.ANY_MM);
 		}
 		metaModelDescriptors.addAll(MetaModelDescriptorRegistry.INSTANCE.getDescriptors(mmDescIdPattern));
 		return Collections.unmodifiableCollection(metaModelDescriptors);
 	}

 	/**
 	 * Retrieves all the {@link IMetaModelDescriptor meta model descriptors} registering the provided instance of
 	 * {@link IResourceScopeProvider resource scope provider}.
 	 *
 	 * @param resourceScopeProvider
 	 *            The {@link IResourceScopeProvider resource scope provider} used to investigate.
 	 * @return the {@link IMetaModelDescriptor meta model descriptors} the {@link IResourceScopeProvider resource scope
 	 *         provider} is registered for.
 	 */
 	public Collection<IMetaModelDescriptor> getMetaModelDescriptorsFor(IResourceScopeProvider resourceScopeProvider) {
 		Collection<IMetaModelDescriptor> metaModelDescriptorsForProvider = fMetaModelDescriptorsForResourceScopeProviders.get(resourceScopeProvider);
 		if (metaModelDescriptorsForProvider != null) {
 			return Collections.unmodifiableCollection(metaModelDescriptorsForProvider);
 		}
 		return Collections.emptySet();
 	}

 	/**
 	 * Returns the default instance of {@link IResourceScopeProvider resource scope provider}.
 	 *
 	 * @return IResourceScopeProvider the default instance of {@link IResourceScopeProvider resource scope provider}.
 	 */
 	public IResourceScopeProvider getDefaultResourceScopeProvider() {
 		if (defaultResourceScopeProvider == null) {
 			defaultResourceScopeProvider = new ProjectResourceScopeProvider();
 		}
 		return defaultResourceScopeProvider;
 	}

 	/**
 	 * Tests if given {@link IFile file} does not belong to any {@link IResourceScope resource scope}. This can be the
 	 * case if given {@link IFile file} is an obvious non-model file (e.g., a *.txt file), a model file based on a
 	 * metamodel that is not described by a {@link IMetaModelDescriptor metamodel descriptor}, or a model file which is
 	 * out of scope.
 	 * <p>
 	 * This method is guaranteed to have a very little performance overhead. It can be used by clients to optimize the
 	 * retrieval of the {@link IResourceScope resource scope}s for large amounts of model and/or non-model {@link IFile
 	 * file}s (e.g., after new {@link IFile file}s have been imported into the workspace). Clients therefore should call
 	 * this method of {@link #hasApplicableFileExtension(IFile)} prior to actually retrieving the {@link IResourceScope
 	 * resource scope} for a {@link IFile file} using {@link #getResourceScopeProvider(IMetaModelDescriptor)} and
 	 * {@link IResourceScopeProvider#getScope(org.eclipse.core.resources.IResource)}. This makes sure that irrelevant
 	 * {@link IFile file}s get filtered out in an efficient way and useless but potentially costly attempts of
 	 * retrieving the {@link IResourceScope resource scope} for such {@link IFile file}s are avoided.
 	 * </p>
 	 *
 	 * @param file
 	 *            The {@link IFile file} to be investigated.
 	 * @return <code>true</code> if given {@link IFile file} does not belong to any {@link IResourceScope resource
 	 *         scope}, <code>false</code> otherwise.
 	 * @see #hasApplicableFileExtension(IFile)
 	 */
 	public boolean isNotInAnyScope(IFile file) {
 		if (file != null) {
 			/*
 			 * Performance optimization: Create a separate HashSet for all contributed ResourceScopeProviders instead of
 			 * directly iterating over fContributedResourceScopeProviders.values() in order to avoid repeated processing
 			 * of same ResourceScopeProvider.
 			 */
 			Set<IResourceScopeProvider> allResourceScopeProviders = new HashSet<IResourceScopeProvider>(fContributedResourceScopeProviders.values());
 			for (IResourceScopeProvider provider : allResourceScopeProviders) {
 				if (provider.isApplicableTo(file)) {
 					return false;
 				}
 			}
 		}
 		return true;
 	}

 	/**
 	 * Tests if the given {@link IFile file}'s extension corresponds to a file type which is subject to some
 	 * {@link IResourceScopeProvider resource scope provider}. This is automatically the case if given {@link IFile
 	 * file} is a model file based on a metamodel that is described by a {@link IMetaModelDescriptor metamodel
 	 * descriptor}. The applicable {@link IResourceScopeProvider resource scope provider} for such model files is either
 	 * one that has been specifically contributed to the underlying {@link IMetaModelDescriptor metamodel descriptor}
 	 * via the org.eclipse.sphinx.emf.resourceScopeProviders extension point or a
 	 * {@link #getDefaultResourceScopeProvider() default resource scope provider}.
 	 * <p>
 	 * This method is guaranteed to have a very little performance overhead. It can be used by clients to optimize the
 	 * retrieval of the {@link IResourceScope resource scope}s for large amounts of model and/or non-model {@link IFile
 	 * file}s (e.g., after new {@link IFile file}s have been imported into the workspace). Clients therefore should call
 	 * this method or {@link #isNotInAnyScope(IFile)} prior to actually retrieving the {@link IResourceScope resource
 	 * scope} for a {@link IFile file} using {@link #getResourceScopeProvider(IMetaModelDescriptor)} and
 	 * {@link IResourceScopeProvider#getScope(org.eclipse.core.resources.IResource)}. This makes sure that irrelevant
 	 * {@link IFile file}s get filtered out in an efficient way and useless but potentially costly attempts of
 	 * retrieving the {@link IResourceScope resource scope} for such {@link IFile file}s are avoided.
 	 * </p>
 	 *
 	 * @param file
 	 *            The {@link IFile file} to be investigated.
 	 * @return <code>true</code> if some {@link IResourceScopeProvider resource scope provider} is applicable to
 	 *         {@link IFile file}s having the extension of the given {@link IFile file}, <code>false</code> otherwise.
 	 * @see #isNotInAnyScope(IFile)
 	 */
 	public boolean hasApplicableFileExtension(IFile file) {
 		if (file != null) {
 			for (IResourceScopeProvider provider : fMetaModelDescriptorsForResourceScopeProviders.keySet()) {
 				if (provider.hasApplicableFileExtension(file)) {
 					return true;
 				}
 			}
 		}
 		return false;
 	}

 	/**
 	 * Returns the {@link IResourceScopeProvider resource scope provider} registered for the provided
 	 * {@link IMetaModelDescriptor meta model descriptor}.
 	 *
 	 * @param mmDescriptor
 	 *            The {@link IMetaModelDescriptor meta model descriptor} use to investigate.
 	 * @return the {@link IResourceScopeProvider resource scope provider} registered for the provided
 	 *         {@link IMetaModelDescriptor meta model descriptor} or <code>null</code> if none has been registered.
 	 */
 	public IResourceScopeProvider getResourceScopeProvider(IMetaModelDescriptor mmDescriptor) {
 		if (mmDescriptor != null) {
 			return fContributedResourceScopeProviders.get(mmDescriptor);
 		}
 		return null;
 	}
 }
	/**
	* <copyright>
	*
	* Copyright (c) 2008-2012 See4sys, BMW Car IT and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
	*
	* Contributors:
	* See4sys - Initial API and implementation
	* BMW Car IT - [373481] Performance optimizations for model loading
	*
	* </copyright>
	*/
	package org.eclipse.sphinx.emf.scoping;

	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.sphinx.emf.Activator;
	import org.eclipse.sphinx.emf.internal.messages.Messages;
	import org.eclipse.sphinx.emf.metamodel.IMetaModelDescriptor;
	import org.eclipse.sphinx.emf.metamodel.MetaModelDescriptorRegistry;
	import org.eclipse.sphinx.platform.util.PlatformLogUtil;

	public class ResourceScopeProviderRegistry {

	/**
	* The singleton instance of this registry.
	*/
	public static ResourceScopeProviderRegistry INSTANCE = new ResourceScopeProviderRegistry();

	private static final String EXTP_MODEL_SCOPE_PROVIDER = "org.eclipse.sphinx.emf.resourceScopeProviders";//$NON-NLS-1$
	private static final String NODE_APPLICABLEFOR = "applicableFor";//$NON-NLS-1$
	private static final String NODE_PROVIDER = "provider";//$NON-NLS-1$
	private static final String ATTR_ID = "id"; //$NON-NLS-1$
	private static final String ATTR_CLASS = "class"; //$NON-NLS-1$
	private static final String ATTR_OVERRIDE = "override"; //$NON-NLS-1$
	private static final String ATTR_META_MODEL_DESCRIPTOR_ID_PATTERN = "metaModelDescriptorIdPattern";//$NON-NLS-1$

	private Map<IMetaModelDescriptor, IResourceScopeProvider> fContributedResourceScopeProviders = new HashMap<IMetaModelDescriptor, IResourceScopeProvider>();

	private Map<IResourceScopeProvider, Collection<IMetaModelDescriptor>> fMetaModelDescriptorsForResourceScopeProviders = new HashMap<IResourceScopeProvider, Collection<IMetaModelDescriptor>>();

	private IResourceScopeProvider defaultResourceScopeProvider = null;

	/**
	* Private constructor for the singleton pattern that prevents from instantiation by clients.
	*/
	private ResourceScopeProviderRegistry() {
	readContributedResourceScopeProviders();
	contributeDefaultResourceScopeProvider();

	}

	private void readContributedResourceScopeProviders() {
	IExtension[] extensions = Platform.getExtensionRegistry().getExtensionPoint(EXTP_MODEL_SCOPE_PROVIDER).getExtensions();
	Set<String> overriddenIds = new HashSet<String>();
	// We retrieve overriden ids
	for (IExtension extension : extensions) {
	IConfigurationElement[] configElements = extension.getConfigurationElements();
	overriddenIds.addAll(getOverriddenResourceScopeProviderIds(configElements));
	}
	// we contribute extension points excluding overriden ids
	for (IExtension extension : extensions) {
	IConfigurationElement[] configElements = extension.getConfigurationElements();
	readContributedResourceScopeProviders(configElements, overriddenIds);
	}
	}

	/**
	* Reads contributions to <em>Meta-Model Descriptor</em> extension point.
	* <p>
	* <table>
	* <tr valign=top>
	* <td><b>Note</b>  </td>
	* <td>It is recommended to call this method inside a block <tt><b>synchronized</b></tt> on the encapsulated
	* <code>fMetaModelDescriptors</code> field in order to avoid inconsistencies in registered meta-model
	* {@linkplain IMetaModelDescriptor descriptor}s in case of concurrent read/adds.</td>
	* </tr>
	* </table>
	*/
	private void readContributedResourceScopeProviders(IConfigurationElement[] configElements, Set<String> overriddenIds) {
	for (IConfigurationElement configElement : configElements) {
	try {
	String id = configElement.getAttribute(ATTR_ID);
	IResourceScopeProvider resourceScopeProvider = null;
	if (!overriddenIds.contains(id)) {
	resourceScopeProvider = (IResourceScopeProvider) configElement.createExecutableExtension(ATTR_CLASS);
	IConfigurationElement[] childrenConfigElements = configElement.getChildren();
	for (IConfigurationElement childConfigElement : childrenConfigElements) {
	if (NODE_APPLICABLEFOR.equals(childConfigElement.getName())) {
	String metaModelDescriptorIdPattern = childConfigElement.getAttribute(ATTR_META_MODEL_DESCRIPTOR_ID_PATTERN);
	addResourceScopeProvider(metaModelDescriptorIdPattern, resourceScopeProvider);
	}
	}
	}
	} catch (Exception ex) {
	PlatformLogUtil.logAsError(Activator.getDefault(), ex);
	}
	}
	}

	private void contributeDefaultResourceScopeProvider() {
	List<IMetaModelDescriptor> orphanMMDescriptors = MetaModelDescriptorRegistry.INSTANCE.getDescriptors(MetaModelDescriptorRegistry.ANY_MM);
	Set<IMetaModelDescriptor> alreadyRegisteredMMdescriptors = fContributedResourceScopeProviders.keySet();
	orphanMMDescriptors.removeAll(alreadyRegisteredMMdescriptors);
	addResourceScopeProvider(orphanMMDescriptors, getDefaultResourceScopeProvider());
	}

	private Set<String> getOverriddenResourceScopeProviderIds(IConfigurationElement[] configElements) {
	Assert.isNotNull(configElements);
	Set<String> overriddenIds = new HashSet<String>();
	for (IConfigurationElement configElement : configElements) {
	if (NODE_PROVIDER.equals(configElement.getName())) {
	String overriddenResourceScopePolicyId = configElement.getAttribute(ATTR_OVERRIDE);
	if (overriddenResourceScopePolicyId != null) {
	if (!overriddenIds.contains(overriddenResourceScopePolicyId)) {
	overriddenIds.add(overriddenResourceScopePolicyId);
	} else {
	PlatformLogUtil.logAsWarning(
	Activator.getPlugin(),
	new RuntimeException(NLS.bind(Messages.warning_multipleOverridesForSameResourceScopeProvider,
	overriddenResourceScopePolicyId)));
	}
	}
	}
	}
	return overriddenIds;
	}

	/**
	* Register a new {@link IResourceScopeProvider resource scope provider} for the provided
	* {@link IMetaModelDescriptor meta model descriptor}.
	*
	* @param mmDescIdPattern
	* The {@link IMetaModelDescriptor meta model descriptor provider} to register a
	* {@link IResourceScopeProvider resource scope provider} for.
	* @param contributedProvider
	* The instance of {@link IResourceScopeProvider resource scope provider} to register.
	*/
	private void addResourceScopeProvider(String mmDescIdPattern, IResourceScopeProvider resourceScopeProvider) {
	Collection<IMetaModelDescriptor> matchingMMDescriptors = getMetaModelDescriptors(mmDescIdPattern);
	addResourceScopeProvider(matchingMMDescriptors, resourceScopeProvider);
	}

	private void addResourceScopeProvider(Collection<IMetaModelDescriptor> mmDescriptors, IResourceScopeProvider resourceScopeProvider) {
	for (IMetaModelDescriptor mmDescriptor : mmDescriptors) {
	if (fContributedResourceScopeProviders.get(mmDescriptor) == null) {
	fContributedResourceScopeProviders.put(mmDescriptor, resourceScopeProvider);

	Collection<IMetaModelDescriptor> mmDescriptorsOfResourceScopeProvider = fMetaModelDescriptorsForResourceScopeProviders
	.get(resourceScopeProvider);
	if (mmDescriptorsOfResourceScopeProvider == null) {
	mmDescriptorsOfResourceScopeProvider = new HashSet<IMetaModelDescriptor>();
	fMetaModelDescriptorsForResourceScopeProviders.put(resourceScopeProvider, mmDescriptorsOfResourceScopeProvider);
	}
	mmDescriptorsOfResourceScopeProvider.add(mmDescriptor);
	} else {
	PlatformLogUtil.logAsWarning(
	Activator.getPlugin(),
	new RuntimeException(NLS.bind(Messages.warning_multipleResourceScopeProvidersContributedForSameMetaModelDescriptor,
	mmDescriptor.getIdentifier())));
	}
	}
	}

	private Collection<IMetaModelDescriptor> getMetaModelDescriptors(String mmDescIdPattern) {
	HashSet<IMetaModelDescriptor> metaModelDescriptors = new HashSet<IMetaModelDescriptor>();
	if (".*".equals(mmDescIdPattern) \|\| ".+".equals(mmDescIdPattern)) { //$NON-NLS-1$ //$NON-NLS-2$
	metaModelDescriptors.add(MetaModelDescriptorRegistry.ANY_MM);
	}
	metaModelDescriptors.addAll(MetaModelDescriptorRegistry.INSTANCE.getDescriptors(mmDescIdPattern));
	return Collections.unmodifiableCollection(metaModelDescriptors);
	}

	/**
	* Retrieves all the {@link IMetaModelDescriptor meta model descriptors} registering the provided instance of
	* {@link IResourceScopeProvider resource scope provider}.
	*
	* @param resourceScopeProvider
	* The {@link IResourceScopeProvider resource scope provider} used to investigate.
	* @return the {@link IMetaModelDescriptor meta model descriptors} the {@link IResourceScopeProvider resource scope
	* provider} is registered for.
	*/
	public Collection<IMetaModelDescriptor> getMetaModelDescriptorsFor(IResourceScopeProvider resourceScopeProvider) {
	Collection<IMetaModelDescriptor> metaModelDescriptorsForProvider = fMetaModelDescriptorsForResourceScopeProviders.get(resourceScopeProvider);
	if (metaModelDescriptorsForProvider != null) {
	return Collections.unmodifiableCollection(metaModelDescriptorsForProvider);
	}
	return Collections.emptySet();
	}

	/**
	* Returns the default instance of {@link IResourceScopeProvider resource scope provider}.
	*
	* @return IResourceScopeProvider the default instance of {@link IResourceScopeProvider resource scope provider}.
	*/
	public IResourceScopeProvider getDefaultResourceScopeProvider() {
	if (defaultResourceScopeProvider == null) {
	defaultResourceScopeProvider = new ProjectResourceScopeProvider();
	}
	return defaultResourceScopeProvider;
	}

	/**
	* Tests if given {@link IFile file} does not belong to any {@link IResourceScope resource scope}. This can be the
	* case if given {@link IFile file} is an obvious non-model file (e.g., a *.txt file), a model file based on a
	* metamodel that is not described by a {@link IMetaModelDescriptor metamodel descriptor}, or a model file which is
	* out of scope.
	* <p>
	* This method is guaranteed to have a very little performance overhead. It can be used by clients to optimize the
	* retrieval of the {@link IResourceScope resource scope}s for large amounts of model and/or non-model {@link IFile
	* file}s (e.g., after new {@link IFile file}s have been imported into the workspace). Clients therefore should call
	* this method of {@link #hasApplicableFileExtension(IFile)} prior to actually retrieving the {@link IResourceScope
	* resource scope} for a {@link IFile file} using {@link #getResourceScopeProvider(IMetaModelDescriptor)} and
	* {@link IResourceScopeProvider#getScope(org.eclipse.core.resources.IResource)}. This makes sure that irrelevant
	* {@link IFile file}s get filtered out in an efficient way and useless but potentially costly attempts of
	* retrieving the {@link IResourceScope resource scope} for such {@link IFile file}s are avoided.
	* </p>
	*
	* @param file
	* The {@link IFile file} to be investigated.
	* @return <code>true</code> if given {@link IFile file} does not belong to any {@link IResourceScope resource
	* scope}, <code>false</code> otherwise.
	* @see #hasApplicableFileExtension(IFile)
	*/
	public boolean isNotInAnyScope(IFile file) {
	if (file != null) {
	/*
	* Performance optimization: Create a separate HashSet for all contributed ResourceScopeProviders instead of
	* directly iterating over fContributedResourceScopeProviders.values() in order to avoid repeated processing
	* of same ResourceScopeProvider.
	*/
	Set<IResourceScopeProvider> allResourceScopeProviders = new HashSet<IResourceScopeProvider>(fContributedResourceScopeProviders.values());
	for (IResourceScopeProvider provider : allResourceScopeProviders) {
	if (provider.isApplicableTo(file)) {
	return false;
	}
	}
	}
	return true;
	}

	/**
	* Tests if the given {@link IFile file}'s extension corresponds to a file type which is subject to some
	* {@link IResourceScopeProvider resource scope provider}. This is automatically the case if given {@link IFile
	* file} is a model file based on a metamodel that is described by a {@link IMetaModelDescriptor metamodel
	* descriptor}. The applicable {@link IResourceScopeProvider resource scope provider} for such model files is either
	* one that has been specifically contributed to the underlying {@link IMetaModelDescriptor metamodel descriptor}
	* via the org.eclipse.sphinx.emf.resourceScopeProviders extension point or a
	* {@link #getDefaultResourceScopeProvider() default resource scope provider}.
	* <p>
	* This method is guaranteed to have a very little performance overhead. It can be used by clients to optimize the
	* retrieval of the {@link IResourceScope resource scope}s for large amounts of model and/or non-model {@link IFile
	* file}s (e.g., after new {@link IFile file}s have been imported into the workspace). Clients therefore should call
	* this method or {@link #isNotInAnyScope(IFile)} prior to actually retrieving the {@link IResourceScope resource
	* scope} for a {@link IFile file} using {@link #getResourceScopeProvider(IMetaModelDescriptor)} and
	* {@link IResourceScopeProvider#getScope(org.eclipse.core.resources.IResource)}. This makes sure that irrelevant
	* {@link IFile file}s get filtered out in an efficient way and useless but potentially costly attempts of
	* retrieving the {@link IResourceScope resource scope} for such {@link IFile file}s are avoided.
	* </p>
	*
	* @param file
	* The {@link IFile file} to be investigated.
	* @return <code>true</code> if some {@link IResourceScopeProvider resource scope provider} is applicable to
	* {@link IFile file}s having the extension of the given {@link IFile file}, <code>false</code> otherwise.
	* @see #isNotInAnyScope(IFile)
	*/
	public boolean hasApplicableFileExtension(IFile file) {
	if (file != null) {
	for (IResourceScopeProvider provider : fMetaModelDescriptorsForResourceScopeProviders.keySet()) {
	if (provider.hasApplicableFileExtension(file)) {
	return true;
	}
	}
	}
	return false;
	}

	/**
	* Returns the {@link IResourceScopeProvider resource scope provider} registered for the provided
	* {@link IMetaModelDescriptor meta model descriptor}.
	*
	* @param mmDescriptor
	* The {@link IMetaModelDescriptor meta model descriptor} use to investigate.
	* @return the {@link IResourceScopeProvider resource scope provider} registered for the provided
	* {@link IMetaModelDescriptor meta model descriptor} or <code>null</code> if none has been registered.
	*/
	public IResourceScopeProvider getResourceScopeProvider(IMetaModelDescriptor mmDescriptor) {
	if (mmDescriptor != null) {
	return fContributedResourceScopeProviders.get(mmDescriptor);
	}
	return null;
	}
	}