jsf/plugins/org.eclipse.jst.jsf.common/src/org/eclipse/jst/jsf/common/metadata/internal/MetaDataModelManager.java - jsf/webtools.jsf - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007 Oracle Corporation.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    Oracle - initial API and implementation
  *
  ********************************************************************************/
 package org.eclipse.jst.jsf.common.metadata.internal;

 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;

 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResourceChangeEvent;
 import org.eclipse.core.resources.IResourceChangeListener;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.ISafeRunnable;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.jface.util.SafeRunnable;
 import org.eclipse.jst.jsf.common.JSFCommonPlugin;
 import org.eclipse.jst.jsf.common.metadata.Model;
 import org.eclipse.jst.jsf.common.metadata.query.ITaglibDomainMetaDataModelContext;

 /**
  * Singleton instance for each IProject used to manage all standard metdata models for that project.
  *
  * Manager is responsible for loading and caching MetaDataModels.  Models are keyed by URI.
  *
  * The manager listens for project closing resource events so that the resources can be freed up.
  */
 public class MetaDataModelManager implements IResourceChangeListener{
 	/**
 	 * Key that is used for the IProject instance's session property that
 	 * holds a MetaDataModelManager instance.  Each project will have it's own instance of a model manager.
 	 */
 	public static final QualifiedName KEY_SESSIONPROPERTY =
 		new QualifiedName(null, "MetaDataModelManager"); //$NON-NLS-1$ FIX ME

 	private static MetaDataModelManager SHARED_INSTANCE;

 	// used to lock all instance calls for getModel
 	private static final Object  GLOBAL_INSTANCE_LOCK = new Object();
 	private final ModelMap models;
 	private final IProject project;


 	/**
 	 * @return instance that is project agnostic.   * may get removed *
 	 */
 	public synchronized static MetaDataModelManager getSharedInstance(){
 		if (SHARED_INSTANCE == null) {
 			SHARED_INSTANCE = new MetaDataModelManager(null);
 		}
 		return SHARED_INSTANCE;
 	}

 	/**
 	 * @param project
 	 * @return instance of the model manager for this project.  Shouldn't, but may, return null.
 	 */
 	public synchronized static MetaDataModelManager getInstance(final IProject project){
 		MetaDataModelManager repo = null;
 		repo = getFromSessionProperty(project);
 		if (repo == null) {
 			repo = new MetaDataModelManager(project);
 			ResourcesPlugin.getWorkspace().addResourceChangeListener(repo, IResourceChangeEvent.PRE_CLOSE);
 		}
 		return repo;
 	}
 	private MetaDataModelManager(final IProject project) {
 		this.project = project;
 		models = new ModelMap();
         setAsSessionProperty();
 	}

 	/**
 	 * @param project
 	 * @return MetaDataModelManager instance for the project
 	 */
 	private static MetaDataModelManager getFromSessionProperty(final IProject project) {
 		MetaDataModelManager repo = null;
 		try {
 			Object obj = project.getSessionProperty(KEY_SESSIONPROPERTY);
 			if (obj instanceof MetaDataModelManager) {
 				repo = (MetaDataModelManager)obj;
 			}
 		} catch(CoreException ce) {
 			JSFCommonPlugin.log(IStatus.ERROR, "Internal Error: Unable to recover MetaDataModelManager for: "+project.getName(), ce); //$NON-NLS-1$
 		}
 		return repo;
 	}

 	/**
 	 * Sets this MetaDataModelManager instance as a session property of its
 	 * IProject instance.
 	 */
 	private void setAsSessionProperty() {
 		if (project != null) {//&& project.isAccessible()) {
 			try {
 				project.setSessionProperty(KEY_SESSIONPROPERTY, this);
 			} catch(CoreException ce) {
 				JSFCommonPlugin.log(IStatus.ERROR, "Internal Error: Unable to store MetaDataModelManager for: "+project.getName(), ce); //$NON-NLS-1$		}
 			}
 		}
 	}

 	/**
 	 * Releases a project's MetaDataModelManager instance by removing from project session property
 	 * @param aProject
 	 */
 	private void removeAsSessionProperty(IProject aProject){
 		try {
 			ResourcesPlugin.getWorkspace().removeResourceChangeListener(this);
 			aProject.setSessionProperty(KEY_SESSIONPROPERTY, null);
 		} catch (CoreException e) {
             JSFCommonPlugin.log(e, "Error removing session property"); //$NON-NLS-1$
 		}
 	}

 	/**
      * Will locate the cached MetaDataModel. Sets the model context in the
      * model.
      *
      * @param modelContext
      * @return the MetaDataModel for the given ITaglibDomainMetaDataModelContext
      */
     public MetaDataModel getModel(
             final ITaglibDomainMetaDataModelContext modelContext) {
         synchronized (GLOBAL_INSTANCE_LOCK) {
             ModelKeyDescriptor modelKeyDescriptor = StandardModelFactory.getInstance().createModelKeyDescriptor(modelContext);

             StandardModelFactory.debug(">START getModel: "+modelKeyDescriptor, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$

             MetaDataModel model = models.get(modelKeyDescriptor);
             if (model == null || project == null) { //<---  why is the project == null test here?!?!
                 // long in = System.currentTimeMillis();
                 model = loadMetadata(modelKeyDescriptor);
                 //System.out.println("Time to load "+modelContext.getURI()+": "+
                 // String.valueOf(System.currentTimeMillis() - in));
             } else if (model.needsRefresh()) {
                 try {
                     model.reload();
                 } catch (ModelNotSetException e) {
                     // simply load it - should not get here
                     model = loadMetadata(modelKeyDescriptor);
                 }
             }
             if (model != null && model.getRoot() != null)
                 ((Model) model.getRoot())
                         .setCurrentModelContext(modelKeyDescriptor);

             StandardModelFactory.debug(">END getModel: "+modelKeyDescriptor, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$
             return model;
         }
     }

     /*
      * (non-Javadoc)
      *
      * @see
      * org.eclipse.core.resources.IResourceChangeListener#resourceChanged(org
      * .eclipse.core.resources.IResourceChangeEvent)
      */
     public void resourceChanged(IResourceChangeEvent event) {
         if (event.getType() == IResourceChangeEvent.PRE_CLOSE
                 || event.getType() == IResourceChangeEvent.PRE_DELETE) {
             // a project is closing - release and cleanup
             final IProject aProject = (IProject) event.getResource();
             if (aProject != null && aProject.equals(this.project)) {
                 SafeRunnable.run(new ISafeRunnable() {

                     public void handleException(Throwable exception) {
                         JSFCommonPlugin.log(exception);
                     }

                     public void run() throws Exception {
                         models.dispose();
                         removeAsSessionProperty(project);
                     }
                 });
             }
         }
     }

 	private MetaDataModel loadMetadata(ModelKeyDescriptor modelKeyDescriptor) {
         if (!Thread.holdsLock(GLOBAL_INSTANCE_LOCK)) {
             JSFCommonPlugin
                     .log(IStatus.ERROR,
                             "Internal Error: loadMetadata must not be called if class lock not held"); //$NON-NLS-1$
             return null;
         }

         IDomainLoadingStrategy strategy = DomainLoadingStrategyRegistry
                 .getInstance().getLoadingStrategy(
                         modelKeyDescriptor.getDomain());
         ;
         if (strategy == null) {
             JSFCommonPlugin
                     .log(
                             IStatus.ERROR,
                             "Internal Error: Unable to locate metadata loading strategy for: " + modelKeyDescriptor.toString()); //$NON-NLS-1$
             return null;
         }
         MetaDataModel model = StandardModelFactory.getInstance().createModel(
                 modelKeyDescriptor, strategy);// new MetaDataModel(modelKey,
                                               // strategy);
         model.load();
         addModel(model);

         return model;
     }

     private void addModel(MetaDataModel model) {
         if (model != null)
             models.put(model);
     }

     /**
      * Map of models keyed by ModelKeyDescriptor (.toString())
      *
      */
     private static class ModelMap
     {
         private final Map<String, MetaDataModel> map;
         private final AtomicBoolean _isDisposed = new AtomicBoolean(false);

         ModelMap() {
             map = new HashMap<String, MetaDataModel>();
         }

         /**
          * @param model
          *            adds model to the map using the given key descriptor
          */
         public void put(final MetaDataModel model) {
             assert !_isDisposed.get();
             final String key = calculateKey(model);
             synchronized (this) {
                 map.put(key, model);
             }
         }

         /**
          * @param modelKeyDescriptor
          * @return MetaDataModel for this ModelKeyDescriptor. May return null.
          */
         public MetaDataModel get(final ModelKeyDescriptor modelKeyDescriptor) {
             assert !_isDisposed.get();

             final String key = calculateKey(modelKeyDescriptor);

             synchronized (this)
             {
                 return map.get(key);
             }
         }

 //        /**
 //         * @param model
 //         *            from the map
 //         */
 //        public void remove(final MetaDataModel model) {
 //            assert !_isDisposed.get();
 //            final String key = calculateKey(model);
 //            synchronized(this)
 //            {
 //                map.remove(key);
 //            }
 //        }

         public void dispose() {
             if (_isDisposed.compareAndSet(false, true)) {
                 synchronized(this)
                 {
                     for (final Iterator<Map.Entry<String, MetaDataModel>> it = map.entrySet().iterator(); it.hasNext();)
                     {
                         // System.out.println("kill mmModel: "+model.toString());
                         final Map.Entry<String, MetaDataModel> entry = it.next();
                         final MetaDataModel model = entry.getValue();

                         if (model != null)
                         {
                             model.cleanup();
                         }
                         it.remove();
                     }
                 }
             }
         }

         private String calculateKey(final MetaDataModel model)
         {
             return calculateKey(model.getModelKey());
         }

         private String calculateKey(final ModelKeyDescriptor modelKeyDescriptor)
         {
             return modelKeyDescriptor.toString();
         }
     }
 }
	/*******************************************************************************
	* Copyright (c) 2007 Oracle Corporation.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Oracle - initial API and implementation
	*
	********************************************************************************/
	package org.eclipse.jst.jsf.common.metadata.internal;

	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.concurrent.atomic.AtomicBoolean;

	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResourceChangeEvent;
	import org.eclipse.core.resources.IResourceChangeListener;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.ISafeRunnable;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.QualifiedName;
	import org.eclipse.jface.util.SafeRunnable;
	import org.eclipse.jst.jsf.common.JSFCommonPlugin;
	import org.eclipse.jst.jsf.common.metadata.Model;
	import org.eclipse.jst.jsf.common.metadata.query.ITaglibDomainMetaDataModelContext;

	/**
	* Singleton instance for each IProject used to manage all standard metdata models for that project.
	*
	* Manager is responsible for loading and caching MetaDataModels. Models are keyed by URI.
	*
	* The manager listens for project closing resource events so that the resources can be freed up.
	*/
	public class MetaDataModelManager implements IResourceChangeListener{
	/**
	* Key that is used for the IProject instance's session property that
	* holds a MetaDataModelManager instance. Each project will have it's own instance of a model manager.
	*/
	public static final QualifiedName KEY_SESSIONPROPERTY =
	new QualifiedName(null, "MetaDataModelManager"); //$NON-NLS-1$ FIX ME

	private static MetaDataModelManager SHARED_INSTANCE;

	// used to lock all instance calls for getModel
	private static final Object GLOBAL_INSTANCE_LOCK = new Object();
	private final ModelMap models;
	private final IProject project;


	/**
	* @return instance that is project agnostic. * may get removed *
	*/
	public synchronized static MetaDataModelManager getSharedInstance(){
	if (SHARED_INSTANCE == null) {
	SHARED_INSTANCE = new MetaDataModelManager(null);
	}
	return SHARED_INSTANCE;
	}

	/**
	* @param project
	* @return instance of the model manager for this project. Shouldn't, but may, return null.
	*/
	public synchronized static MetaDataModelManager getInstance(final IProject project){
	MetaDataModelManager repo = null;
	repo = getFromSessionProperty(project);
	if (repo == null) {
	repo = new MetaDataModelManager(project);
	ResourcesPlugin.getWorkspace().addResourceChangeListener(repo, IResourceChangeEvent.PRE_CLOSE);
	}
	return repo;
	}
	private MetaDataModelManager(final IProject project) {
	this.project = project;
	models = new ModelMap();
	setAsSessionProperty();
	}

	/**
	* @param project
	* @return MetaDataModelManager instance for the project
	*/
	private static MetaDataModelManager getFromSessionProperty(final IProject project) {
	MetaDataModelManager repo = null;
	try {
	Object obj = project.getSessionProperty(KEY_SESSIONPROPERTY);
	if (obj instanceof MetaDataModelManager) {
	repo = (MetaDataModelManager)obj;
	}
	} catch(CoreException ce) {
	JSFCommonPlugin.log(IStatus.ERROR, "Internal Error: Unable to recover MetaDataModelManager for: "+project.getName(), ce); //$NON-NLS-1$
	}
	return repo;
	}

	/**
	* Sets this MetaDataModelManager instance as a session property of its
	* IProject instance.
	*/
	private void setAsSessionProperty() {
	if (project != null) {//&& project.isAccessible()) {
	try {
	project.setSessionProperty(KEY_SESSIONPROPERTY, this);
	} catch(CoreException ce) {
	JSFCommonPlugin.log(IStatus.ERROR, "Internal Error: Unable to store MetaDataModelManager for: "+project.getName(), ce); //$NON-NLS-1$ }
	}
	}
	}

	/**
	* Releases a project's MetaDataModelManager instance by removing from project session property
	* @param aProject
	*/
	private void removeAsSessionProperty(IProject aProject){
	try {
	ResourcesPlugin.getWorkspace().removeResourceChangeListener(this);
	aProject.setSessionProperty(KEY_SESSIONPROPERTY, null);
	} catch (CoreException e) {
	JSFCommonPlugin.log(e, "Error removing session property"); //$NON-NLS-1$
	}
	}

	/**
	* Will locate the cached MetaDataModel. Sets the model context in the
	* model.
	*
	* @param modelContext
	* @return the MetaDataModel for the given ITaglibDomainMetaDataModelContext
	*/
	public MetaDataModel getModel(
	final ITaglibDomainMetaDataModelContext modelContext) {
	synchronized (GLOBAL_INSTANCE_LOCK) {
	ModelKeyDescriptor modelKeyDescriptor = StandardModelFactory.getInstance().createModelKeyDescriptor(modelContext);

	StandardModelFactory.debug(">START getModel: "+modelKeyDescriptor, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$

	MetaDataModel model = models.get(modelKeyDescriptor);
	if (model == null \|\| project == null) { //<--- why is the project == null test here?!?!
	// long in = System.currentTimeMillis();
	model = loadMetadata(modelKeyDescriptor);
	//System.out.println("Time to load "+modelContext.getURI()+": "+
	// String.valueOf(System.currentTimeMillis() - in));
	} else if (model.needsRefresh()) {
	try {
	model.reload();
	} catch (ModelNotSetException e) {
	// simply load it - should not get here
	model = loadMetadata(modelKeyDescriptor);
	}
	}
	if (model != null && model.getRoot() != null)
	((Model) model.getRoot())
	.setCurrentModelContext(modelKeyDescriptor);

	StandardModelFactory.debug(">END getModel: "+modelKeyDescriptor, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$
	return model;
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see
	* org.eclipse.core.resources.IResourceChangeListener#resourceChanged(org
	* .eclipse.core.resources.IResourceChangeEvent)
	*/
	public void resourceChanged(IResourceChangeEvent event) {
	if (event.getType() == IResourceChangeEvent.PRE_CLOSE
	\|\| event.getType() == IResourceChangeEvent.PRE_DELETE) {
	// a project is closing - release and cleanup
	final IProject aProject = (IProject) event.getResource();
	if (aProject != null && aProject.equals(this.project)) {
	SafeRunnable.run(new ISafeRunnable() {

	public void handleException(Throwable exception) {
	JSFCommonPlugin.log(exception);
	}

	public void run() throws Exception {
	models.dispose();
	removeAsSessionProperty(project);
	}
	});
	}
	}
	}

	private MetaDataModel loadMetadata(ModelKeyDescriptor modelKeyDescriptor) {
	if (!Thread.holdsLock(GLOBAL_INSTANCE_LOCK)) {
	JSFCommonPlugin
	.log(IStatus.ERROR,
	"Internal Error: loadMetadata must not be called if class lock not held"); //$NON-NLS-1$
	return null;
	}

	IDomainLoadingStrategy strategy = DomainLoadingStrategyRegistry
	.getInstance().getLoadingStrategy(
	modelKeyDescriptor.getDomain());
	;
	if (strategy == null) {
	JSFCommonPlugin
	.log(
	IStatus.ERROR,
	"Internal Error: Unable to locate metadata loading strategy for: " + modelKeyDescriptor.toString()); //$NON-NLS-1$
	return null;
	}
	MetaDataModel model = StandardModelFactory.getInstance().createModel(
	modelKeyDescriptor, strategy);// new MetaDataModel(modelKey,
	// strategy);
	model.load();
	addModel(model);

	return model;
	}

	private void addModel(MetaDataModel model) {
	if (model != null)
	models.put(model);
	}

	/**
	* Map of models keyed by ModelKeyDescriptor (.toString())
	*
	*/
	private static class ModelMap
	{
	private final Map<String, MetaDataModel> map;
	private final AtomicBoolean _isDisposed = new AtomicBoolean(false);

	ModelMap() {
	map = new HashMap<String, MetaDataModel>();
	}

	/**
	* @param model
	* adds model to the map using the given key descriptor
	*/
	public void put(final MetaDataModel model) {
	assert !_isDisposed.get();
	final String key = calculateKey(model);
	synchronized (this) {
	map.put(key, model);
	}
	}

	/**
	* @param modelKeyDescriptor
	* @return MetaDataModel for this ModelKeyDescriptor. May return null.
	*/
	public MetaDataModel get(final ModelKeyDescriptor modelKeyDescriptor) {
	assert !_isDisposed.get();

	final String key = calculateKey(modelKeyDescriptor);

	synchronized (this)
	{
	return map.get(key);
	}
	}

	// /**
	// * @param model
	// * from the map
	// */
	// public void remove(final MetaDataModel model) {
	// assert !_isDisposed.get();
	// final String key = calculateKey(model);
	// synchronized(this)
	// {
	// map.remove(key);
	// }
	// }

	public void dispose() {
	if (_isDisposed.compareAndSet(false, true)) {
	synchronized(this)
	{
	for (final Iterator<Map.Entry<String, MetaDataModel>> it = map.entrySet().iterator(); it.hasNext();)
	{
	// System.out.println("kill mmModel: "+model.toString());
	final Map.Entry<String, MetaDataModel> entry = it.next();
	final MetaDataModel model = entry.getValue();

	if (model != null)
	{
	model.cleanup();
	}
	it.remove();
	}
	}
	}
	}

	private String calculateKey(final MetaDataModel model)
	{
	return calculateKey(model.getModelKey());
	}

	private String calculateKey(final ModelKeyDescriptor modelKeyDescriptor)
	{
	return modelKeyDescriptor.toString();
	}
	}
	}