| /******************************************************************************* |
| * 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.TimeUnit; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantLock; |
| |
| import org.eclipse.core.resources.IProject; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.core.runtime.jobs.Job; |
| import org.eclipse.jst.jsf.common.JSFCommonPlugin; |
| import org.eclipse.jst.jsf.common.metadata.Model; |
| |
| /** |
| * 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 final class MetaDataModelManager extends AbstractMetaDataModelManager { |
| |
| private static IMetaDataModelManager SHARED_INSTANCE; |
| |
| // used to lock all instance calls for getModel |
| private static final Lock GLOBAL_INSTANCE_LOCK = new ReentrantLock(); |
| private final ModelMap models; |
| |
| |
| /** |
| * @return instance that is project agnostic. |
| */ |
| public synchronized static IMetaDataModelManager getSharedInstance(){ |
| if (SHARED_INSTANCE == null) { |
| SHARED_INSTANCE = new MetaDataModelManager(null); |
| } |
| return SHARED_INSTANCE; |
| } |
| |
| /** |
| * @param project |
| */ |
| MetaDataModelManager(final IProject project) { |
| // this.project = project; |
| models = new ModelMap(); |
| } |
| |
| public Model getModel( |
| final IMetaDataModelContext modelContext) |
| { |
| boolean gotLock = false; |
| try |
| { |
| final int maxTries = 6; |
| int numTries = 0; |
| final Job currentJob = Job.getJobManager().currentJob(); |
| while (numTries < maxTries && |
| !(gotLock = GLOBAL_INSTANCE_LOCK.tryLock(5000, TimeUnit.MILLISECONDS))) |
| { |
| numTries++; |
| if (currentJob != null) |
| { |
| currentJob.yieldRule(null); |
| } |
| } |
| |
| if (!gotLock) |
| { |
| return null; |
| } |
| StandardModelFactory.debug(">START getModel: "+modelContext, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$ |
| |
| MetaDataModel model = models.get(modelContext); |
| if (model == null) { |
| // long in = System.currentTimeMillis(); |
| model = loadMetadata(modelContext); |
| //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(modelContext); |
| } |
| } |
| |
| // if (model != null && model.getRoot() != null) |
| // ((Model) model.getRoot()) |
| // .setCurrentModelContext(modelContext); |
| |
| StandardModelFactory.debug(">END getModel: "+modelContext, StandardModelFactory.DEBUG_MD_GET); //$NON-NLS-1$ |
| if (model != null && !model.isEmpty()){ |
| return (Model)model.getRoot(); |
| } |
| return null; |
| } |
| catch (final InterruptedException e) |
| { |
| return null; |
| } |
| finally |
| { |
| if (gotLock) |
| { |
| GLOBAL_INSTANCE_LOCK.unlock(); |
| } |
| } |
| } |
| |
| private MetaDataModel loadMetadata(final IMetaDataModelContext context) { |
| // 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; |
| // } |
| |
| final IDomainLoadingStrategy strategy = DomainLoadingStrategyRegistry |
| .getInstance().getLoadingStrategy( |
| context.getDomainId()); |
| ; |
| if (strategy == null) { |
| JSFCommonPlugin |
| .log( |
| IStatus.ERROR, |
| "Internal Error: Unable to locate metadata loading strategy for: " + context.toString()); //$NON-NLS-1$ |
| return null; |
| } |
| final MetaDataModel model = StandardModelFactory.getInstance().createModel( |
| context, strategy);// new MetaDataModel(modelKey, |
| // strategy); |
| model.load(); |
| addModel(model); |
| |
| return model; |
| } |
| |
| private void addModel(final MetaDataModel model) { |
| if (model != null) |
| models.put(model); |
| } |
| |
| @Override |
| public void dispose() { |
| super.dispose(); |
| models.dispose(); |
| } |
| |
| @Override |
| public void destroy() { |
| // no persistent data to cleanup. just call dispose |
| dispose(); |
| } |
| |
| /** |
| * Map of models keyed by DOMAIN_ID:MODEL_ID from the context. Project is not part of key. |
| * |
| */ |
| private static class ModelMap |
| { |
| 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 context |
| * @return MetaDataModel for this context. May return null. |
| */ |
| public MetaDataModel get(final IMetaDataModelContext context) { |
| assert !_isDisposed.get(); |
| |
| final String key = calculateKey(context); |
| |
| synchronized (this) |
| { |
| return map.get(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.getModelContext()); |
| } |
| |
| private String calculateKey(final IMetaDataModelContext context) { |
| final StringBuffer buf = new StringBuffer(context.getDomainId()).append(":").append(context.getModelIdentifier()); //$NON-NLS-1$; |
| return buf.toString(); |
| } |
| } |
| } |