/*******************************************************************************
* Copyright (c) 2010 IBM Corporation and others.
* 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:
* IBM Corporation - initial API and implementation
*
*******************************************************************************/
package org.eclipse.wst.xml.core.internal.contentmodel.modelqueryimpl;
import java.lang.ref.SoftReference;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.wst.sse.core.internal.util.AbstractMemoryListener;
import org.eclipse.wst.xml.core.internal.Logger;
import org.eclipse.wst.xml.core.internal.XMLCorePlugin;
import org.eclipse.wst.xml.core.internal.catalog.provisional.ICatalog;
import org.eclipse.wst.xml.core.internal.catalog.provisional.ICatalogEntry;
import org.eclipse.wst.xml.core.internal.catalog.provisional.INextCatalog;
import org.eclipse.wst.xml.core.internal.contentmodel.CMDocument;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
public class GlobalCMDocumentCache {
private static GlobalCMDocumentCache globalDocumentCache = new GlobalCMDocumentCache();
private Map systemCatalogEntries = getSystemCatalogEntries();
private MemoryListener memoryListener;
private final static String CATEGORY = "CMDocumentGlobalCache"; //$NON-NLS-1$
protected GlobalCMDocumentCache() {
Logger.trace(CATEGORY, "Cache initialized"); //$NON-NLS-1$
memoryListener = new MemoryListener();
memoryListener.connect();
}
public static GlobalCMDocumentCache getInstance() {
return globalDocumentCache;
}
public synchronized GlobalCacheQueryResponse getCMDocument(String grammarURI) {
//Logger.trace(CATEGORY, "Query for: " + grammarURI); //$NON-NLS-1$
Object systemCatalogEntry = systemCatalogEntries.get(grammarURI);
if(systemCatalogEntry != null) {
//Logger.trace(CATEGORY, "Document " + grammarURI + " is in system catalog"); //$NON-NLS-1$ //$NON-NLS-2$
Object object = ((SoftReference)systemCatalogEntry).get();
if(object != null) {
//Logger.trace(CATEGORY, "Document " + grammarURI + "is in cache, returning cached version"); //$NON-NLS-1$ //$NON-NLS-2$
return new GlobalCacheQueryResponse((CMDocument)object, true);
} else {
//Logger.trace(CATEGORY, "Document " + grammarURI + " is not in cache"); //$NON-NLS-1$ //$NON-NLS-2$
return new GlobalCacheQueryResponse(null, true);
}
}
//Logger.trace(CATEGORY, "Document " + grammarURI + " is not in system catalog, not cached"); //$NON-NLS-1$ //$NON-NLS-2$
return new GlobalCacheQueryResponse(null, false);
}
public synchronized void putCMDocument(String grammarURI, CMDocument cmDocument) {
//Logger.trace(CATEGORY, "Document: " + grammarURI + " added to global cache"); //$NON-NLS-1$ //$NON-NLS-2$
systemCatalogEntries.put(grammarURI, new SoftReference(cmDocument));
}
private synchronized static HashMap getSystemCatalogEntries(){
HashMap systemCatalogURIs = new HashMap();
ICatalog systemCatalog = null;
ICatalog defaultCatalog = XMLCorePlugin.getDefault().getDefaultXMLCatalog();
INextCatalog[] nextCatalogs = defaultCatalog.getNextCatalogs();
for (int i = 0; i < nextCatalogs.length; i++) {
INextCatalog catalog = nextCatalogs[i];
ICatalog referencedCatalog = catalog.getReferencedCatalog();
if (referencedCatalog != null) {
if (XMLCorePlugin.SYSTEM_CATALOG_ID.equals(referencedCatalog.getId())) {
systemCatalog = referencedCatalog;
}
}
}
if(systemCatalog != null) {
ICatalogEntry[] catalogEntries = systemCatalog.getCatalogEntries();
for (int i = 0; i < catalogEntries.length; i++) {
systemCatalogURIs.put(catalogEntries[i].getURI(), new SoftReference(null));
}
}
return systemCatalogURIs;
}
public class GlobalCacheQueryResponse {
private CMDocument cachedDocument;
private boolean documentCacheable;
public GlobalCacheQueryResponse(CMDocument cachedCMDocument, boolean documentCacheable) {
this.cachedDocument = cachedCMDocument;
this.documentCacheable = documentCacheable;
}
public CMDocument getCachedCMDocument() {
return cachedDocument;
}
public boolean isDocumentCacheable() {
return documentCacheable;
}
}
private class MemoryListener extends AbstractMemoryListener {
protected void handleMemoryEvent(Event event) {
Object topic = event.getProperty(EventConstants.EVENT_TOPIC);
if(SEV_SERIOUS.equals(topic) || SEV_CRITICAL.equals(topic)) {
Logger.trace(CATEGORY, "Serious severity low memory event received, flushing global CMDocument cache."); //$NON-NLS-1$
systemCatalogEntries = getSystemCatalogEntries();
}
}
}
}