plugins/org.eclipse.sphinx.emf/src/org/eclipse/sphinx/emf/resource/ContextAwareProxyURIHelper.java - sphinx/org.eclipse.sphinx - Git at Google

 /**
  * <copyright>
  *
  * Copyright (c) 2013-2014 itemis 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:
  *     itemis - Initial API and implementation
  *     itemis - [409510] Enable resource scope-sensitive proxy resolutions without forcing metamodel implementations to subclass EObjectImpl
  *     itemis - [421205] Model descriptor registry does not return correct model descriptor for (shared) plugin resources
  *     itemis - [442342] Sphinx doen't trim context information from proxy URIs when serializing proxyfied cross-document references
  *
  * </copyright>
  */
 package org.eclipse.sphinx.emf.resource;

 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.sphinx.emf.metamodel.IMetaModelDescriptor;
 import org.eclipse.sphinx.emf.metamodel.MetaModelDescriptorRegistry;
 import org.eclipse.sphinx.emf.model.IModelDescriptor;
 import org.eclipse.sphinx.emf.model.ModelDescriptorRegistry;
 import org.eclipse.sphinx.emf.scoping.IResourceScope;

 /**
  * A helper class for creating and analyzing proxy {@link URI}s that carry the target {@link IMetaModelDescriptor
  * metamodel descriptor} and the context {@link URI} as context information.
  */
 public class ContextAwareProxyURIHelper {

 	private static final String CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR = "tgtMMD"; //$NON-NLS-1$
 	private static final Pattern CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_TARGET_METAMODEL_DESCRIPTOR = createURIQueryValuePattern(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR);

 	private static final String CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI = "ctxURI"; //$NON-NLS-1$
 	private static final Pattern CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_CONTEXT_URI = createURIQueryValuePattern(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI);

 	private static Pattern createURIQueryValuePattern(String key) {
 		String amp = ExtendedResource.URI_QUERY_FIELD_SEPARATOR;
 		String eq = ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR;

 		// Regular expression in clear text: ([^&]+&)*key=([^&]*)(&[^&]+)*
 		return Pattern.compile("([^" + amp + "]+" + amp + ")*" + key + eq + "([^" + amp + "]*)(" + amp + "[^" + amp + "]+)*"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$
 	}

 	private static final int CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX = 2;

 	/**
 	 * Augments given {@link InternalEObject proxy} to a context-aware proxy by adding key/value pairs that contain the
 	 * target {@link IMetaModelDescriptor metamodel descriptor} and a context {@link URI} to the {@link URI#query()
 	 * query string} of the proxy URI. Those are required to support the resolution of proxified references between
 	 * objects from different metamodels and to honor the {@link IResourceScope resource scope} of the proxy URI when it
 	 * is being resolved.
 	 *
 	 * @param proxy
 	 *            The proxy to be handled.
 	 * @param contextResource
 	 *            The resource that identifies the context of the proxy (typically the resource containing it).
 	 * @see #trimProxyContextInfo(URI)
 	 */
 	public void augmentToContextAwareProxy(EObject proxy, Resource contextResource) {
 		Assert.isNotNull(proxy);
 		Assert.isNotNull(contextResource);

 		// Build target metamodel descriptor query field
 		StringBuilder targetMMDescriptorQueryField = null;
 		IMetaModelDescriptor proxyMMDescriptor = MetaModelDescriptorRegistry.INSTANCE.getDescriptor(proxy);
 		if (proxyMMDescriptor != null) {
 			targetMMDescriptorQueryField = new StringBuilder();
 			targetMMDescriptorQueryField.append(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR);
 			targetMMDescriptorQueryField.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
 			targetMMDescriptorQueryField.append(proxyMMDescriptor.getIdentifier());
 		}

 		// Build context URI query field
 		URI contextURI = null;
 		IModelDescriptor contextModelDescriptor = ModelDescriptorRegistry.INSTANCE.getModel(contextResource);
 		if (contextModelDescriptor != null) {
 			/*
 			 * Performance optimization: Don't use URI of context resource itself but only the URI of the root of the
 			 * model that contains the context resource as context URI. The latter is sufficient for identifying the
 			 * context and indicating it to applications relying on it (e.g., resource scoping). As it is nearly all of
 			 * the time significantly shorter than the context resource URI it greatly helps to avoid that proxy URIs
 			 * grow too long.
 			 */
 			IPath rootPath = contextModelDescriptor.getRoot().getFullPath();
 			contextURI = URI.createPlatformResourceURI(rootPath.toString(), true);
 		} else {
 			contextURI = contextResource.getURI();
 		}
 		StringBuilder contextURIQueryField = new StringBuilder();
 		contextURIQueryField.append(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI);
 		contextURIQueryField.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
 		contextURIQueryField.append(contextURI);

 		// Augment existing proxy URI with target metamodel descriptor and context URI query fields
 		URI proxyURI = ((InternalEObject) proxy).eProxyURI();
 		StringBuilder newQuery = new StringBuilder();

 		String oldQuery = proxyURI.query();
 		if (oldQuery != null) {
 			newQuery.append(oldQuery);
 			newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
 		}

 		if (targetMMDescriptorQueryField != null) {
 			newQuery.append(targetMMDescriptorQueryField);
 			newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
 		}

 		newQuery.append(contextURIQueryField);

 		proxyURI = proxyURI.trimQuery().appendQuery(newQuery.toString());
 		((InternalEObject) proxy).eSetProxyURI(proxyURI);
 	}

 	/**
 	 * If given {@link URI proxy URI} contains proxy context-related key/value pairs on its {@link URI#query() query
 	 * string}, returns the URI formed by removing those key/value pairs or removing the query string entirely in case
 	 * that no other key/value pairs exist; returns given proxy URI unchanged, otherwise.
 	 *
 	 * @param proxyURI
 	 *            The context-aware proxy URI to be handled.
 	 * @return The trimmed proxy URI.
 	 * @see #augmentToContextAwareProxy(EObject)
 	 */
 	public URI trimProxyContextInfo(URI proxyURI) {
 		String oldQuery = proxyURI.query();
 		if (oldQuery == null) {
 			return proxyURI;
 		}

 		// Parse all query fields
 		StringBuilder newQuery = new StringBuilder();
 		Matcher matcher = ExtendedResource.URI_QUERY_FIELD_PATTERN.matcher(oldQuery);
 		while (matcher.find()) {
 			// Retrieve current query key
 			String key = matcher.group(ExtendedResource.URI_QUERY_FIELD_PATTERN_KEY_GROUP_IDX);

 			// Ignore context awareness-related query fields
 			if (CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR.equals(key)
 					|| CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI.equals(key)) {
 				continue;
 			}

 			// Append query field separator if required
 			if (newQuery.length() > 0) {
 				newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
 			}

 			// Append query key
 			newQuery.append(key);

 			// Retrieve and append query value if any
 			String value = matcher.group(ExtendedResource.URI_QUERY_FIELD_PATTERN_VALUE_GROUP_IDX);
 			if (!value.isEmpty()) {
 				newQuery.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
 				newQuery.append(value);
 			}
 		}

 		URI newURI = proxyURI.trimQuery();
 		if (newQuery.length() == 0) {
 			return newURI;
 		}

 		return newURI.appendQuery(newQuery.toString());
 	}

 	/**
 	 * Extracts the identifier of the target {@link IMetaModelDescriptor metamodel descriptor} carried by given
 	 * context-aware proxy {@link URI}.
 	 */
 	public String getTargetMetaModelDescriptorId(URI uri) {
 		Assert.isNotNull(uri);

 		String query = uri.query();
 		if (query != null) {
 			Matcher matcher = CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_TARGET_METAMODEL_DESCRIPTOR.matcher(query);
 			if (matcher.matches()) {
 				return matcher.group(CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX);
 			}
 		}

 		// No information about target metamodel descriptor available on proxy URI
 		return null;
 	}

 	/**
 	 * Extracts the context {@link URI} carried by given context-aware proxy {@link URI}.
 	 */
 	public URI getContextURI(URI uri) {
 		Assert.isNotNull(uri);

 		String query = uri.query();
 		if (query != null) {
 			Matcher matcher = CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_CONTEXT_URI.matcher(query);
 			if (matcher.matches()) {
 				String contextURI = matcher.group(CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX);
 				return URI.createURI(contextURI);
 			}
 		}

 		// No context information available on proxy URI; use workspace root as context URI to make sure that the whole
 		// workspace with all resources is used as context
 		IPath workspaceRootPath = ResourcesPlugin.getWorkspace().getRoot().getFullPath();
 		return URI.createPlatformResourceURI(workspaceRootPath.toString(), true);
 	}
 }
	/**
	* <copyright>
	*
	* Copyright (c) 2013-2014 itemis 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:
	* itemis - Initial API and implementation
	* itemis - [409510] Enable resource scope-sensitive proxy resolutions without forcing metamodel implementations to subclass EObjectImpl
	* itemis - [421205] Model descriptor registry does not return correct model descriptor for (shared) plugin resources
	* itemis - [442342] Sphinx doen't trim context information from proxy URIs when serializing proxyfied cross-document references
	*
	* </copyright>
	*/
	package org.eclipse.sphinx.emf.resource;

	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.emf.common.util.URI;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.InternalEObject;
	import org.eclipse.emf.ecore.resource.Resource;
	import org.eclipse.sphinx.emf.metamodel.IMetaModelDescriptor;
	import org.eclipse.sphinx.emf.metamodel.MetaModelDescriptorRegistry;
	import org.eclipse.sphinx.emf.model.IModelDescriptor;
	import org.eclipse.sphinx.emf.model.ModelDescriptorRegistry;
	import org.eclipse.sphinx.emf.scoping.IResourceScope;

	/**
	* A helper class for creating and analyzing proxy {@link URI}s that carry the target {@link IMetaModelDescriptor
	* metamodel descriptor} and the context {@link URI} as context information.
	*/
	public class ContextAwareProxyURIHelper {

	private static final String CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR = "tgtMMD"; //$NON-NLS-1$
	private static final Pattern CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_TARGET_METAMODEL_DESCRIPTOR = createURIQueryValuePattern(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR);

	private static final String CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI = "ctxURI"; //$NON-NLS-1$
	private static final Pattern CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_CONTEXT_URI = createURIQueryValuePattern(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI);

	private static Pattern createURIQueryValuePattern(String key) {
	String amp = ExtendedResource.URI_QUERY_FIELD_SEPARATOR;
	String eq = ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR;

	// Regular expression in clear text: ([^&]+&)key=([^&])(&[^&]+)*
	return Pattern.compile("([^" + amp + "]+" + amp + ")" + key + eq + "([^" + amp + "])(" + amp + "[^" + amp + "]+)*"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$
	}

	private static final int CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX = 2;

	/**
	* Augments given {@link InternalEObject proxy} to a context-aware proxy by adding key/value pairs that contain the
	* target {@link IMetaModelDescriptor metamodel descriptor} and a context {@link URI} to the {@link URI#query()
	* query string} of the proxy URI. Those are required to support the resolution of proxified references between
	* objects from different metamodels and to honor the {@link IResourceScope resource scope} of the proxy URI when it
	* is being resolved.
	*
	* @param proxy
	* The proxy to be handled.
	* @param contextResource
	* The resource that identifies the context of the proxy (typically the resource containing it).
	* @see #trimProxyContextInfo(URI)
	*/
	public void augmentToContextAwareProxy(EObject proxy, Resource contextResource) {
	Assert.isNotNull(proxy);
	Assert.isNotNull(contextResource);

	// Build target metamodel descriptor query field
	StringBuilder targetMMDescriptorQueryField = null;
	IMetaModelDescriptor proxyMMDescriptor = MetaModelDescriptorRegistry.INSTANCE.getDescriptor(proxy);
	if (proxyMMDescriptor != null) {
	targetMMDescriptorQueryField = new StringBuilder();
	targetMMDescriptorQueryField.append(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR);
	targetMMDescriptorQueryField.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
	targetMMDescriptorQueryField.append(proxyMMDescriptor.getIdentifier());
	}

	// Build context URI query field
	URI contextURI = null;
	IModelDescriptor contextModelDescriptor = ModelDescriptorRegistry.INSTANCE.getModel(contextResource);
	if (contextModelDescriptor != null) {
	/*
	* Performance optimization: Don't use URI of context resource itself but only the URI of the root of the
	* model that contains the context resource as context URI. The latter is sufficient for identifying the
	* context and indicating it to applications relying on it (e.g., resource scoping). As it is nearly all of
	* the time significantly shorter than the context resource URI it greatly helps to avoid that proxy URIs
	* grow too long.
	*/
	IPath rootPath = contextModelDescriptor.getRoot().getFullPath();
	contextURI = URI.createPlatformResourceURI(rootPath.toString(), true);
	} else {
	contextURI = contextResource.getURI();
	}
	StringBuilder contextURIQueryField = new StringBuilder();
	contextURIQueryField.append(CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI);
	contextURIQueryField.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
	contextURIQueryField.append(contextURI);

	// Augment existing proxy URI with target metamodel descriptor and context URI query fields
	URI proxyURI = ((InternalEObject) proxy).eProxyURI();
	StringBuilder newQuery = new StringBuilder();

	String oldQuery = proxyURI.query();
	if (oldQuery != null) {
	newQuery.append(oldQuery);
	newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
	}

	if (targetMMDescriptorQueryField != null) {
	newQuery.append(targetMMDescriptorQueryField);
	newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
	}

	newQuery.append(contextURIQueryField);

	proxyURI = proxyURI.trimQuery().appendQuery(newQuery.toString());
	((InternalEObject) proxy).eSetProxyURI(proxyURI);
	}

	/**
	* If given {@link URI proxy URI} contains proxy context-related key/value pairs on its {@link URI#query() query
	* string}, returns the URI formed by removing those key/value pairs or removing the query string entirely in case
	* that no other key/value pairs exist; returns given proxy URI unchanged, otherwise.
	*
	* @param proxyURI
	* The context-aware proxy URI to be handled.
	* @return The trimmed proxy URI.
	* @see #augmentToContextAwareProxy(EObject)
	*/
	public URI trimProxyContextInfo(URI proxyURI) {
	String oldQuery = proxyURI.query();
	if (oldQuery == null) {
	return proxyURI;
	}

	// Parse all query fields
	StringBuilder newQuery = new StringBuilder();
	Matcher matcher = ExtendedResource.URI_QUERY_FIELD_PATTERN.matcher(oldQuery);
	while (matcher.find()) {
	// Retrieve current query key
	String key = matcher.group(ExtendedResource.URI_QUERY_FIELD_PATTERN_KEY_GROUP_IDX);

	// Ignore context awareness-related query fields
	if (CONTEXT_AWARE_PROXY_URI_QUERY_KEY_TARGET_METAMODEL_DESCRIPTOR.equals(key)
	\|\| CONTEXT_AWARE_PROXY_URI_QUERY_KEY_CONTEXT_URI.equals(key)) {
	continue;
	}

	// Append query field separator if required
	if (newQuery.length() > 0) {
	newQuery.append(ExtendedResource.URI_QUERY_FIELD_SEPARATOR);
	}

	// Append query key
	newQuery.append(key);

	// Retrieve and append query value if any
	String value = matcher.group(ExtendedResource.URI_QUERY_FIELD_PATTERN_VALUE_GROUP_IDX);
	if (!value.isEmpty()) {
	newQuery.append(ExtendedResource.URI_QUERY_KEY_VALUE_SEPARATOR);
	newQuery.append(value);
	}
	}

	URI newURI = proxyURI.trimQuery();
	if (newQuery.length() == 0) {
	return newURI;
	}

	return newURI.appendQuery(newQuery.toString());
	}

	/**
	* Extracts the identifier of the target {@link IMetaModelDescriptor metamodel descriptor} carried by given
	* context-aware proxy {@link URI}.
	*/
	public String getTargetMetaModelDescriptorId(URI uri) {
	Assert.isNotNull(uri);

	String query = uri.query();
	if (query != null) {
	Matcher matcher = CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_TARGET_METAMODEL_DESCRIPTOR.matcher(query);
	if (matcher.matches()) {
	return matcher.group(CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX);
	}
	}

	// No information about target metamodel descriptor available on proxy URI
	return null;
	}

	/**
	* Extracts the context {@link URI} carried by given context-aware proxy {@link URI}.
	*/
	public URI getContextURI(URI uri) {
	Assert.isNotNull(uri);

	String query = uri.query();
	if (query != null) {
	Matcher matcher = CONTEXT_AWARE_PROXY_URI_QUERY_FIELD_PATTERN_CONTEXT_URI.matcher(query);
	if (matcher.matches()) {
	String contextURI = matcher.group(CONTEXT_AWARE_PROXY_URI_QUERY_VALUE_GROUP_IDX);
	return URI.createURI(contextURI);
	}
	}

	// No context information available on proxy URI; use workspace root as context URI to make sure that the whole
	// workspace with all resources is used as context
	IPath workspaceRootPath = ResourcesPlugin.getWorkspace().getRoot().getFullPath();
	return URI.createPlatformResourceURI(workspaceRootPath.toString(), true);
	}
	}