apitools/org.eclipse.pde.api.tools/src/org/eclipse/pde/api/tools/internal/ApiDescriptionManager.java - pde/eclipse.pde.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008, 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
  *******************************************************************************/
 package org.eclipse.pde.api.tools.internal;

 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.jar.JarFile;

 import org.eclipse.core.resources.ISaveContext;
 import org.eclipse.core.resources.ISaveParticipant;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragment;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.osgi.service.resolver.BundleDescription;
 import org.eclipse.pde.api.tools.internal.ApiDescription.ManifestNode;
 import org.eclipse.pde.api.tools.internal.ProjectApiDescription.TypeNode;
 import org.eclipse.pde.api.tools.internal.model.ApiModelCache;
 import org.eclipse.pde.api.tools.internal.model.ProjectComponent;
 import org.eclipse.pde.api.tools.internal.provisional.ApiPlugin;
 import org.eclipse.pde.api.tools.internal.provisional.Factory;
 import org.eclipse.pde.api.tools.internal.provisional.IApiDescription;
 import org.eclipse.pde.api.tools.internal.provisional.descriptors.IElementDescriptor;
 import org.eclipse.pde.api.tools.internal.provisional.descriptors.IReferenceTypeDescriptor;
 import org.eclipse.pde.api.tools.internal.provisional.model.IApiElement;
 import org.eclipse.pde.api.tools.internal.provisional.scanner.ScannerMessages;
 import org.eclipse.pde.api.tools.internal.util.Util;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 import com.ibm.icu.text.MessageFormat;

 /**
  * Manages a cache of API descriptions for Java projects. Descriptions are
  * re-used between API components for the same project.
  *
  * @since 1.0
  */
 public final class ApiDescriptionManager implements ISaveParticipant {

 	/**
 	 * Singleton
 	 */
 	private static ApiDescriptionManager fgDefault;

 	/**
 	 * Maps Java projects to API descriptions
 	 */
 	private Map<IJavaProject, IApiDescription> fDescriptions = new HashMap<>();

 	/**
 	 * Path to the local directory where API descriptions are cached per
 	 * project.
 	 */
 	public static final IPath API_DESCRIPTIONS_CONTAINER_PATH = ApiPlugin.getDefault().getStateLocation();

 	/**
 	 * Constructs an API description manager.
 	 */
 	private ApiDescriptionManager() {
 		ApiPlugin.getDefault().addSaveParticipant(this);
 	}

 	/**
 	 * Cleans up Java element listener
 	 */
 	public static void shutdown() {
 		if (fgDefault != null) {
 			ApiPlugin.getDefault().removeSaveParticipant(fgDefault);
 		}
 	}

 	/**
 	 * Returns the singleton API description manager.
 	 *
 	 * @return API description manager
 	 */
 	public synchronized static ApiDescriptionManager getManager() {
 		if (fgDefault == null) {
 			fgDefault = new ApiDescriptionManager();
 		}
 		return fgDefault;
 	}

 	/**
 	 * Returns an API description for the given project component and connect it
 	 * to the given bundle description.
 	 *
 	 * @param project Java project
 	 * @param bundle
 	 *
 	 * @return API description
 	 */
 	public synchronized IApiDescription getApiDescription(ProjectComponent component, BundleDescription bundle) {
 		IJavaProject project = component.getJavaProject();
 		ProjectApiDescription description = (ProjectApiDescription) fDescriptions.get(project);
 		if (description == null) {
 			if (Util.isApiProject(project)) {
 				description = new ProjectApiDescription(project);
 			} else {
 				description = new NonApiProjectDescription(project);
 			}
 			try {
 				restoreDescription(project, description);
 			} catch (CoreException e) {
 				ApiPlugin.log(e.getStatus());
 				description = new ProjectApiDescription(project);
 			}
 			fDescriptions.put(project, description);
 		}
 		return description;
 	}

 	/**
 	 * Cleans the API description for the given project.
 	 *
 	 * @param project
 	 * @param delete whether to delete the file on disk
 	 * @param remove whether to remove the cached API description
 	 */
 	public synchronized void clean(IJavaProject project, boolean delete, boolean remove) {
 		ProjectApiDescription desc = null;
 		if (remove) {
 			desc = (ProjectApiDescription) fDescriptions.remove(project);
 		} else {
 			desc = (ProjectApiDescription) fDescriptions.get(project);
 		}
 		if (desc != null) {
 			desc.clean();
 		}
 		if (delete) {
 			File file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).append(IApiCoreConstants.API_DESCRIPTION_XML_NAME).toFile();
 			if (file.exists()) {
 				file.delete();
 			}
 			file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).toFile();
 			if (file.exists() && file.isDirectory()) {
 				file.delete();
 			}
 		}
 	}

 	/**
 	 * Notifies the API description that the underlying project has changed.
 	 *
 	 * @param project
 	 */
 	synchronized void projectChanged(IJavaProject project) {
 		ProjectApiDescription desc = (ProjectApiDescription) fDescriptions.get(project);
 		if (desc != null) {
 			desc.projectChanged();
 		}
 	}

 	/**
 	 * Notifies the API description that the underlying project classpath has
 	 * changed.
 	 *
 	 * @param project
 	 */
 	synchronized void projectClasspathChanged(IJavaProject project) {
 		ProjectApiDescription desc = (ProjectApiDescription) fDescriptions.get(project);
 		if (desc != null) {
 			desc.projectClasspathChanged();
 		}
 	}

 	/**
 	 * Flushes the changed element from the model cache
 	 *
 	 * @param element
 	 */
 	void flushElementCache(IJavaElement element) {
 		switch (element.getElementType()) {
 			case IJavaElement.COMPILATION_UNIT: {
 				ICompilationUnit unit = (ICompilationUnit) element;
 				IType type = unit.findPrimaryType();
 				if (type != null) {
 					ApiModelCache.getCache().removeElementInfo(ApiBaselineManager.WORKSPACE_API_BASELINE_ID, element.getJavaProject().getElementName(), type.getFullyQualifiedName(), IApiElement.TYPE);
 				}
 				break;
 			}
 			case IJavaElement.JAVA_PROJECT: {
 				ApiModelCache.getCache().removeElementInfo(ApiBaselineManager.WORKSPACE_API_BASELINE_ID, element.getElementName(), null, IApiElement.COMPONENT);
 				break;
 			}
 			default:
 				break;
 		}
 	}

 	@Override
 	public void doneSaving(ISaveContext context) {
 		//
 	}

 	@Override
 	public void prepareToSave(ISaveContext context) throws CoreException {
 		//
 	}

 	@Override
 	public void rollback(ISaveContext context) {
 		//
 	}

 	@Override
 	public synchronized void saving(ISaveContext context) throws CoreException {
 		if (context.getKind() == ISaveContext.PROJECT_SAVE && !Util.isJavaProject(context.getProject())) {
 			return;
 		}

 		Iterator<Entry<IJavaProject, IApiDescription>> entries = fDescriptions.entrySet().iterator();
 		while (entries.hasNext()) {
 			Entry<IJavaProject, IApiDescription> entry = entries.next();
 			IJavaProject project = entry.getKey();
 			ProjectApiDescription desc = (ProjectApiDescription) entry.getValue();
 			if (desc.isModified()) {
 				File dir = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).toFile();
 				dir.mkdirs();
 				String xml = desc.getXML();
 				try {
 					Util.saveFile(new File(dir, IApiCoreConstants.API_DESCRIPTION_XML_NAME), xml);
 					desc.setModified(false);
 				} catch (IOException e) {
 					abort(MessageFormat.format(ScannerMessages.ApiDescriptionManager_0, project.getElementName()), e);
 				}
 			}
 		}
 	}

 	/**
 	 * Restores the API description from its saved file, if any and returns true
 	 * if successful.
 	 *
 	 * @param project
 	 * @param description
 	 * @return whether the restore succeeded
 	 * @throws CoreException
 	 */
 	private boolean restoreDescription(IJavaProject project, ProjectApiDescription description) throws CoreException {
 		File file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).append(IApiCoreConstants.API_DESCRIPTION_XML_NAME).toFile();
 		if (file.exists()) {
 			BufferedInputStream stream = null;
 			try {
 				stream = new BufferedInputStream(new FileInputStream(file));
 				String xml = new String(Util.getInputStreamAsCharArray(stream, -1, StandardCharsets.UTF_8));
 				Element root = Util.parseDocument(xml);
 				if (!root.getNodeName().equals(IApiXmlConstants.ELEMENT_COMPONENT)) {
 					abort(ScannerMessages.ComponentXMLScanner_0, null);
 				}
 				long timestamp = getLong(root, IApiXmlConstants.ATTR_MODIFICATION_STAMP);
 				String version = root.getAttribute(IApiXmlConstants.ATTR_VERSION);
 				description.setEmbeddedVersion(version);
 				if (IApiXmlConstants.API_DESCRIPTION_CURRENT_VERSION.equals(version)) {
 					description.fPackageTimeStamp = timestamp;
 					description.fManifestFile = project.getProject().getFile(JarFile.MANIFEST_NAME);
 					restoreChildren(description, root, null, description.fPackageMap);
 					return true;
 				}
 			} catch (IOException e) {
 				abort(MessageFormat.format(ScannerMessages.ApiDescriptionManager_1, project.getElementName()), e);
 			} finally {
 				if (stream != null) {
 					try {
 						stream.close();
 					} catch (IOException e) {
 						// ignore
 					}
 				}
 			}
 		}
 		return false;
 	}

 	private void restoreChildren(ProjectApiDescription apiDesc, Element element, ManifestNode parentNode, Map<IElementDescriptor, ManifestNode> childrenMap) throws CoreException {
 		NodeList children = element.getChildNodes();
 		for (int i = 0; i < children.getLength(); i++) {
 			Node child = children.item(i);
 			if (child.getNodeType() == Node.ELEMENT_NODE) {
 				restoreNode(apiDesc, (Element) child, parentNode, childrenMap);
 			}
 		}
 	}

 	private void restoreNode(ProjectApiDescription apiDesc, Element element, ManifestNode parentNode, Map<IElementDescriptor, ManifestNode> childrenMap) throws CoreException {
 		ManifestNode node = null;
 		IElementDescriptor elementDesc = null;
 		if (element.getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE)) {
 			int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
 			int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
 			// collect fragments
 			List<IJavaElement> fragments = new ArrayList<>();
 			NodeList childNodes = element.getChildNodes();
 			String pkgName = null;
 			for (int i = 0; i < childNodes.getLength(); i++) {
 				Node child = childNodes.item(i);
 				if (child.getNodeType() == Node.ELEMENT_NODE) {
 					if (((Element) child).getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE_FRAGMENT)) {
 						Element fragment = (Element) child;
 						String handle = fragment.getAttribute(IApiXmlConstants.ATTR_HANDLE);
 						IJavaElement je = JavaCore.create(handle);
 						if (je.getElementType() != IJavaElement.PACKAGE_FRAGMENT) {
 							abort(ScannerMessages.ApiDescriptionManager_2 + handle, null);
 						}
 						pkgName = je.getElementName();
 						fragments.add(je);
 					}
 				}
 			}
 			if (!fragments.isEmpty()) {
 				elementDesc = Factory.packageDescriptor(pkgName);
 				node = apiDesc.newPackageNode(fragments.toArray(new IPackageFragment[fragments.size()]), parentNode, elementDesc, vis, res);
 			} else {
 				abort(ScannerMessages.ApiDescriptionManager_2, null);
 			}
 		} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE_FRAGMENT)) {
 			return; // nothing to do
 		} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_TYPE)) {
 			String handle = element.getAttribute(IApiXmlConstants.ATTR_HANDLE);
 			int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
 			int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
 			IJavaElement je = JavaCore.create(handle);
 			if (je.getElementType() != IJavaElement.TYPE) {
 				abort(ScannerMessages.ApiDescriptionManager_3 + handle, null);
 			}
 			IType type = (IType) je;
 			elementDesc = Factory.typeDescriptor(type.getFullyQualifiedName('$'));
 			TypeNode tn = apiDesc.newTypeNode(type, parentNode, elementDesc, vis, res);
 			node = tn;
 			tn.fTimeStamp = getLong(element, IApiXmlConstants.ATTR_MODIFICATION_STAMP);
 		} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_FIELD)) {
 			if (parentNode.element instanceof IReferenceTypeDescriptor) {
 				IReferenceTypeDescriptor type = (IReferenceTypeDescriptor) parentNode.element;
 				int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
 				int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
 				String name = element.getAttribute(IApiXmlConstants.ATTR_NAME);
 				elementDesc = type.getField(name);
 				node = apiDesc.newNode(parentNode, elementDesc, vis, res);
 			}
 		} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_METHOD)) {
 			if (parentNode.element instanceof IReferenceTypeDescriptor) {
 				IReferenceTypeDescriptor type = (IReferenceTypeDescriptor) parentNode.element;
 				int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
 				int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
 				String name = element.getAttribute(IApiXmlConstants.ATTR_NAME);
 				String sig = element.getAttribute(IApiXmlConstants.ATTR_SIGNATURE);
 				if (sig.indexOf('.') != -1) {
 					// old files might use '.' instead of '/'
 					sig = sig.replace('.', '/');
 				}
 				elementDesc = type.getMethod(name, sig);
 				node = apiDesc.newNode(parentNode, elementDesc, vis, res);
 			}
 		}
 		if (node != null) {
 			childrenMap.put(elementDesc, node);
 			restoreChildren(apiDesc, element, node, node.children);
 		} else {
 			abort(ScannerMessages.ApiDescriptionManager_4, null);
 		}
 	}

 	/**
 	 * Returns an integer attribute.
 	 *
 	 * @param element element with the integer
 	 * @param attr attribute name
 	 * @return attribute value as an integer
 	 */
 	private int getInt(Element element, String attr) {
 		String attribute = element.getAttribute(attr);
 		try {
 			return Integer.parseInt(attribute);
 		} catch (NumberFormatException e) {
 			// ignore
 		}
 		return 0;
 	}

 	/**
 	 * Returns a long attribute.
 	 *
 	 * @param element element with the long
 	 * @param attr attribute name
 	 * @return attribute value as an long
 	 */
 	private long getLong(Element element, String attr) {
 		String attribute = element.getAttribute(attr);
 		if (attribute != null) {
 			try {
 				return Long.parseLong(attribute);
 			} catch (NumberFormatException e) {
 				// ignore
 			}
 		}
 		return 0L;
 	}

 	/**
 	 * Throws an exception with the given message and underlying exception.
 	 *
 	 * @param message error message
 	 * @param exception underlying exception, or <code>null</code>
 	 * @throws CoreException
 	 */
 	private static void abort(String message, Throwable exception) throws CoreException {
 		IStatus status = new Status(IStatus.ERROR, ApiPlugin.PLUGIN_ID, message, exception);
 		throw new CoreException(status);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008, 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
	*******************************************************************************/
	package org.eclipse.pde.api.tools.internal;

	import java.io.BufferedInputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.nio.charset.StandardCharsets;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.jar.JarFile;

	import org.eclipse.core.resources.ISaveContext;
	import org.eclipse.core.resources.ISaveParticipant;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.IJavaProject;
	import org.eclipse.jdt.core.IPackageFragment;
	import org.eclipse.jdt.core.IType;
	import org.eclipse.jdt.core.JavaCore;
	import org.eclipse.osgi.service.resolver.BundleDescription;
	import org.eclipse.pde.api.tools.internal.ApiDescription.ManifestNode;
	import org.eclipse.pde.api.tools.internal.ProjectApiDescription.TypeNode;
	import org.eclipse.pde.api.tools.internal.model.ApiModelCache;
	import org.eclipse.pde.api.tools.internal.model.ProjectComponent;
	import org.eclipse.pde.api.tools.internal.provisional.ApiPlugin;
	import org.eclipse.pde.api.tools.internal.provisional.Factory;
	import org.eclipse.pde.api.tools.internal.provisional.IApiDescription;
	import org.eclipse.pde.api.tools.internal.provisional.descriptors.IElementDescriptor;
	import org.eclipse.pde.api.tools.internal.provisional.descriptors.IReferenceTypeDescriptor;
	import org.eclipse.pde.api.tools.internal.provisional.model.IApiElement;
	import org.eclipse.pde.api.tools.internal.provisional.scanner.ScannerMessages;
	import org.eclipse.pde.api.tools.internal.util.Util;
	import org.w3c.dom.Element;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;

	import com.ibm.icu.text.MessageFormat;

	/**
	* Manages a cache of API descriptions for Java projects. Descriptions are
	* re-used between API components for the same project.
	*
	* @since 1.0
	*/
	public final class ApiDescriptionManager implements ISaveParticipant {

	/**
	* Singleton
	*/
	private static ApiDescriptionManager fgDefault;

	/**
	* Maps Java projects to API descriptions
	*/
	private Map<IJavaProject, IApiDescription> fDescriptions = new HashMap<>();

	/**
	* Path to the local directory where API descriptions are cached per
	* project.
	*/
	public static final IPath API_DESCRIPTIONS_CONTAINER_PATH = ApiPlugin.getDefault().getStateLocation();

	/**
	* Constructs an API description manager.
	*/
	private ApiDescriptionManager() {
	ApiPlugin.getDefault().addSaveParticipant(this);
	}

	/**
	* Cleans up Java element listener
	*/
	public static void shutdown() {
	if (fgDefault != null) {
	ApiPlugin.getDefault().removeSaveParticipant(fgDefault);
	}
	}

	/**
	* Returns the singleton API description manager.
	*
	* @return API description manager
	*/
	public synchronized static ApiDescriptionManager getManager() {
	if (fgDefault == null) {
	fgDefault = new ApiDescriptionManager();
	}
	return fgDefault;
	}

	/**
	* Returns an API description for the given project component and connect it
	* to the given bundle description.
	*
	* @param project Java project
	* @param bundle
	*
	* @return API description
	*/
	public synchronized IApiDescription getApiDescription(ProjectComponent component, BundleDescription bundle) {
	IJavaProject project = component.getJavaProject();
	ProjectApiDescription description = (ProjectApiDescription) fDescriptions.get(project);
	if (description == null) {
	if (Util.isApiProject(project)) {
	description = new ProjectApiDescription(project);
	} else {
	description = new NonApiProjectDescription(project);
	}
	try {
	restoreDescription(project, description);
	} catch (CoreException e) {
	ApiPlugin.log(e.getStatus());
	description = new ProjectApiDescription(project);
	}
	fDescriptions.put(project, description);
	}
	return description;
	}

	/**
	* Cleans the API description for the given project.
	*
	* @param project
	* @param delete whether to delete the file on disk
	* @param remove whether to remove the cached API description
	*/
	public synchronized void clean(IJavaProject project, boolean delete, boolean remove) {
	ProjectApiDescription desc = null;
	if (remove) {
	desc = (ProjectApiDescription) fDescriptions.remove(project);
	} else {
	desc = (ProjectApiDescription) fDescriptions.get(project);
	}
	if (desc != null) {
	desc.clean();
	}
	if (delete) {
	File file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).append(IApiCoreConstants.API_DESCRIPTION_XML_NAME).toFile();
	if (file.exists()) {
	file.delete();
	}
	file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).toFile();
	if (file.exists() && file.isDirectory()) {
	file.delete();
	}
	}
	}

	/**
	* Notifies the API description that the underlying project has changed.
	*
	* @param project
	*/
	synchronized void projectChanged(IJavaProject project) {
	ProjectApiDescription desc = (ProjectApiDescription) fDescriptions.get(project);
	if (desc != null) {
	desc.projectChanged();
	}
	}

	/**
	* Notifies the API description that the underlying project classpath has
	* changed.
	*
	* @param project
	*/
	synchronized void projectClasspathChanged(IJavaProject project) {
	ProjectApiDescription desc = (ProjectApiDescription) fDescriptions.get(project);
	if (desc != null) {
	desc.projectClasspathChanged();
	}
	}

	/**
	* Flushes the changed element from the model cache
	*
	* @param element
	*/
	void flushElementCache(IJavaElement element) {
	switch (element.getElementType()) {
	case IJavaElement.COMPILATION_UNIT: {
	ICompilationUnit unit = (ICompilationUnit) element;
	IType type = unit.findPrimaryType();
	if (type != null) {
	ApiModelCache.getCache().removeElementInfo(ApiBaselineManager.WORKSPACE_API_BASELINE_ID, element.getJavaProject().getElementName(), type.getFullyQualifiedName(), IApiElement.TYPE);
	}
	break;
	}
	case IJavaElement.JAVA_PROJECT: {
	ApiModelCache.getCache().removeElementInfo(ApiBaselineManager.WORKSPACE_API_BASELINE_ID, element.getElementName(), null, IApiElement.COMPONENT);
	break;
	}
	default:
	break;
	}
	}

	@Override
	public void doneSaving(ISaveContext context) {
	//
	}

	@Override
	public void prepareToSave(ISaveContext context) throws CoreException {
	//
	}

	@Override
	public void rollback(ISaveContext context) {
	//
	}

	@Override
	public synchronized void saving(ISaveContext context) throws CoreException {
	if (context.getKind() == ISaveContext.PROJECT_SAVE && !Util.isJavaProject(context.getProject())) {
	return;
	}

	Iterator<Entry<IJavaProject, IApiDescription>> entries = fDescriptions.entrySet().iterator();
	while (entries.hasNext()) {
	Entry<IJavaProject, IApiDescription> entry = entries.next();
	IJavaProject project = entry.getKey();
	ProjectApiDescription desc = (ProjectApiDescription) entry.getValue();
	if (desc.isModified()) {
	File dir = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).toFile();
	dir.mkdirs();
	String xml = desc.getXML();
	try {
	Util.saveFile(new File(dir, IApiCoreConstants.API_DESCRIPTION_XML_NAME), xml);
	desc.setModified(false);
	} catch (IOException e) {
	abort(MessageFormat.format(ScannerMessages.ApiDescriptionManager_0, project.getElementName()), e);
	}
	}
	}
	}

	/**
	* Restores the API description from its saved file, if any and returns true
	* if successful.
	*
	* @param project
	* @param description
	* @return whether the restore succeeded
	* @throws CoreException
	*/
	private boolean restoreDescription(IJavaProject project, ProjectApiDescription description) throws CoreException {
	File file = API_DESCRIPTIONS_CONTAINER_PATH.append(project.getElementName()).append(IApiCoreConstants.API_DESCRIPTION_XML_NAME).toFile();
	if (file.exists()) {
	BufferedInputStream stream = null;
	try {
	stream = new BufferedInputStream(new FileInputStream(file));
	String xml = new String(Util.getInputStreamAsCharArray(stream, -1, StandardCharsets.UTF_8));
	Element root = Util.parseDocument(xml);
	if (!root.getNodeName().equals(IApiXmlConstants.ELEMENT_COMPONENT)) {
	abort(ScannerMessages.ComponentXMLScanner_0, null);
	}
	long timestamp = getLong(root, IApiXmlConstants.ATTR_MODIFICATION_STAMP);
	String version = root.getAttribute(IApiXmlConstants.ATTR_VERSION);
	description.setEmbeddedVersion(version);
	if (IApiXmlConstants.API_DESCRIPTION_CURRENT_VERSION.equals(version)) {
	description.fPackageTimeStamp = timestamp;
	description.fManifestFile = project.getProject().getFile(JarFile.MANIFEST_NAME);
	restoreChildren(description, root, null, description.fPackageMap);
	return true;
	}
	} catch (IOException e) {
	abort(MessageFormat.format(ScannerMessages.ApiDescriptionManager_1, project.getElementName()), e);
	} finally {
	if (stream != null) {
	try {
	stream.close();
	} catch (IOException e) {
	// ignore
	}
	}
	}
	}
	return false;
	}

	private void restoreChildren(ProjectApiDescription apiDesc, Element element, ManifestNode parentNode, Map<IElementDescriptor, ManifestNode> childrenMap) throws CoreException {
	NodeList children = element.getChildNodes();
	for (int i = 0; i < children.getLength(); i++) {
	Node child = children.item(i);
	if (child.getNodeType() == Node.ELEMENT_NODE) {
	restoreNode(apiDesc, (Element) child, parentNode, childrenMap);
	}
	}
	}

	private void restoreNode(ProjectApiDescription apiDesc, Element element, ManifestNode parentNode, Map<IElementDescriptor, ManifestNode> childrenMap) throws CoreException {
	ManifestNode node = null;
	IElementDescriptor elementDesc = null;
	if (element.getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE)) {
	int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
	int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
	// collect fragments
	List<IJavaElement> fragments = new ArrayList<>();
	NodeList childNodes = element.getChildNodes();
	String pkgName = null;
	for (int i = 0; i < childNodes.getLength(); i++) {
	Node child = childNodes.item(i);
	if (child.getNodeType() == Node.ELEMENT_NODE) {
	if (((Element) child).getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE_FRAGMENT)) {
	Element fragment = (Element) child;
	String handle = fragment.getAttribute(IApiXmlConstants.ATTR_HANDLE);
	IJavaElement je = JavaCore.create(handle);
	if (je.getElementType() != IJavaElement.PACKAGE_FRAGMENT) {
	abort(ScannerMessages.ApiDescriptionManager_2 + handle, null);
	}
	pkgName = je.getElementName();
	fragments.add(je);
	}
	}
	}
	if (!fragments.isEmpty()) {
	elementDesc = Factory.packageDescriptor(pkgName);
	node = apiDesc.newPackageNode(fragments.toArray(new IPackageFragment[fragments.size()]), parentNode, elementDesc, vis, res);
	} else {
	abort(ScannerMessages.ApiDescriptionManager_2, null);
	}
	} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_PACKAGE_FRAGMENT)) {
	return; // nothing to do
	} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_TYPE)) {
	String handle = element.getAttribute(IApiXmlConstants.ATTR_HANDLE);
	int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
	int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
	IJavaElement je = JavaCore.create(handle);
	if (je.getElementType() != IJavaElement.TYPE) {
	abort(ScannerMessages.ApiDescriptionManager_3 + handle, null);
	}
	IType type = (IType) je;
	elementDesc = Factory.typeDescriptor(type.getFullyQualifiedName('$'));
	TypeNode tn = apiDesc.newTypeNode(type, parentNode, elementDesc, vis, res);
	node = tn;
	tn.fTimeStamp = getLong(element, IApiXmlConstants.ATTR_MODIFICATION_STAMP);
	} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_FIELD)) {
	if (parentNode.element instanceof IReferenceTypeDescriptor) {
	IReferenceTypeDescriptor type = (IReferenceTypeDescriptor) parentNode.element;
	int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
	int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
	String name = element.getAttribute(IApiXmlConstants.ATTR_NAME);
	elementDesc = type.getField(name);
	node = apiDesc.newNode(parentNode, elementDesc, vis, res);
	}
	} else if (element.getTagName().equals(IApiXmlConstants.ELEMENT_METHOD)) {
	if (parentNode.element instanceof IReferenceTypeDescriptor) {
	IReferenceTypeDescriptor type = (IReferenceTypeDescriptor) parentNode.element;
	int vis = getInt(element, IApiXmlConstants.ATTR_VISIBILITY);
	int res = getInt(element, IApiXmlConstants.ATTR_RESTRICTIONS);
	String name = element.getAttribute(IApiXmlConstants.ATTR_NAME);
	String sig = element.getAttribute(IApiXmlConstants.ATTR_SIGNATURE);
	if (sig.indexOf('.') != -1) {
	// old files might use '.' instead of '/'
	sig = sig.replace('.', '/');
	}
	elementDesc = type.getMethod(name, sig);
	node = apiDesc.newNode(parentNode, elementDesc, vis, res);
	}
	}
	if (node != null) {
	childrenMap.put(elementDesc, node);
	restoreChildren(apiDesc, element, node, node.children);
	} else {
	abort(ScannerMessages.ApiDescriptionManager_4, null);
	}
	}

	/**
	* Returns an integer attribute.
	*
	* @param element element with the integer
	* @param attr attribute name
	* @return attribute value as an integer
	*/
	private int getInt(Element element, String attr) {
	String attribute = element.getAttribute(attr);
	try {
	return Integer.parseInt(attribute);
	} catch (NumberFormatException e) {
	// ignore
	}
	return 0;
	}

	/**
	* Returns a long attribute.
	*
	* @param element element with the long
	* @param attr attribute name
	* @return attribute value as an long
	*/
	private long getLong(Element element, String attr) {
	String attribute = element.getAttribute(attr);
	if (attribute != null) {
	try {
	return Long.parseLong(attribute);
	} catch (NumberFormatException e) {
	// ignore
	}
	}
	return 0L;
	}

	/**
	* Throws an exception with the given message and underlying exception.
	*
	* @param message error message
	* @param exception underlying exception, or <code>null</code>
	* @throws CoreException
	*/
	private static void abort(String message, Throwable exception) throws CoreException {
	IStatus status = new Status(IStatus.ERROR, ApiPlugin.PLUGIN_ID, message, exception);
	throw new CoreException(status);
	}
	}