[jboss-cvs] JBossAS SVN: r60698 - branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity.

jboss-cvs-commits at lists.jboss.org jboss-cvs-commits at lists.jboss.org
Tue Feb 20 00:10:07 EST 2007


Author: bstansberry at jboss.com
Date: 2007-02-20 00:10:07 -0500 (Tue, 20 Feb 2007)
New Revision: 60698

Added:
   branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticJBCCache.java
Modified:
   branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticTreeCacheProviderHook.java
Log:
[EJBTHREE-844] Support optimistic locking in replicated 2nd level cache

Added: branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticJBCCache.java
===================================================================
--- branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticJBCCache.java	                        (rev 0)
+++ branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticJBCCache.java	2007-02-20 05:10:07 UTC (rev 60698)
@@ -0,0 +1,449 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2006, Red Hat Middleware LLC, and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.jboss.ejb3.entity;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.util.Comparator;
+
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.hibernate.cache.CacheException;
+import org.hibernate.cache.OptimisticCache;
+import org.hibernate.cache.OptimisticCacheSource;
+import org.hibernate.cache.StandardQueryCache;
+import org.hibernate.cache.UpdateTimestampsCache;
+import org.jboss.cache.Fqn;
+import org.jboss.cache.optimistic.DataVersion;
+import org.jboss.cache.config.Option;
+import org.jboss.cache.lock.TimeoutException;
+
+/**
+ * Represents a particular region within the given JBossCache TreeCache
+ * utilizing TreeCache's optimistic locking capabilities.
+ *
+ * @see org.hibernate.cache.OptimisticTreeCacheProvider for more details
+ *
+ * @author Steve Ebersole
+ * @author Brian Stansberry
+ */
+public class OptimisticJBCCache implements OptimisticCache {
+
+	// todo : eventually merge this with TreeCache and just add optional opt-lock support there.
+
+	private static final Log log = LogFactory.getLog( OptimisticJBCCache.class);
+
+	private static final String ITEM = "item";
+
+	private org.jboss.cache.TreeCache cache;
+	private final String regionName;
+	private final Fqn regionFqn;
+	private OptimisticCacheSource source;
+    private boolean localWritesOnly;
+
+	public OptimisticJBCCache(org.jboss.cache.TreeCache cache, String regionName)
+	throws CacheException {
+		this.cache = cache;
+		this.regionName = regionName;
+		this.regionFqn = Fqn.fromString( regionName.replace( '.', '/' ) );
+        if (cache.getUseRegionBasedMarshalling())
+        {           
+           localWritesOnly = StandardQueryCache.class.getName().equals(regionName);
+           
+           boolean fetchState = cache.getFetchInMemoryState();
+           try
+           {
+              // We don't want a state transfer for the StandardQueryCache,
+              // as it can include classes from multiple scoped classloaders
+              if (localWritesOnly)
+                 cache.setFetchInMemoryState(false);
+              
+              // We always activate
+              activateCacheRegion(regionFqn.toString());
+           }
+           finally
+           {
+              // Restore the normal state transfer setting
+              if (localWritesOnly)
+                 cache.setFetchInMemoryState(fetchState);              
+           }
+        }
+        else
+        {
+           log.debug("TreeCache is not configured for region based marshalling");
+        }
+	}
+
+
+	// OptimisticCache impl ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+	public void setSource(OptimisticCacheSource source) {
+		this.source = source;
+	}
+
+	public void writeInsert(Object key, Object value, Object currentVersion) {
+		writeUpdate( key, value, currentVersion, null );
+	}
+
+	public void writeUpdate(Object key, Object value, Object currentVersion, Object previousVersion) {
+		try {
+			Option option = new Option();
+			DataVersion dv = ( source != null && source.isVersioned() )
+			                 ? new DataVersionAdapter( currentVersion, previousVersion, source.getVersionComparator(), source.toString() )
+			                 : NonLockingDataVersion.INSTANCE;
+			option.setDataVersion( dv );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.put( new Fqn( regionFqn, key ), ITEM, value, option );
+		}
+		catch ( Exception e ) {
+			throw new CacheException( e );
+		}
+	}
+
+	public void writeLoad(Object key, Object value, Object currentVersion) {
+		try {
+			Option option = new Option();
+			option.setFailSilently( true );
+			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.remove( new Fqn( regionFqn, key ), "ITEM", option );
+
+			option = new Option();
+			option.setFailSilently( true );
+			DataVersion dv = ( source != null && source.isVersioned() )
+			                 ? new DataVersionAdapter( currentVersion, currentVersion, source.getVersionComparator(), source.toString() )
+			                 : NonLockingDataVersion.INSTANCE;
+			option.setDataVersion( dv );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.put( new Fqn( regionFqn, key ), ITEM, value, option );
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+
+	// Cache impl ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+	public Object get(Object key) throws CacheException {
+		try {
+			Option option = new Option();
+			option.setFailSilently( true );
+//			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+			return cache.get( new Fqn( regionFqn, key ), ITEM, option );
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public Object read(Object key) throws CacheException {
+		try {
+			return cache.get( new Fqn( regionFqn, key ), ITEM );
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public void update(Object key, Object value) throws CacheException {
+		try {
+			Option option = new Option();
+			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.put( new Fqn( regionFqn, key ), ITEM, value, option );
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public void put(Object key, Object value) throws CacheException {
+		try {
+			log.trace( "performing put() into region [" + regionName + "]" );
+			// do the put outside the scope of the JTA txn
+			Option option = new Option();
+			option.setFailSilently( true );
+			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.put( new Fqn( regionFqn, key ), ITEM, value, option );
+		}
+		catch (TimeoutException te) {
+			//ignore!
+			log.debug("ignoring write lock acquisition failure");
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public void remove(Object key) throws CacheException {
+		try {
+			// tree cache in optimistic mode seems to have as very difficult
+			// time with remove calls on non-existent nodes (NPEs)...
+			if ( cache.get( new Fqn( regionFqn, key ), ITEM ) != null ) {
+				Option option = new Option();
+				option.setDataVersion( NonLockingDataVersion.INSTANCE );
+                option.setCacheModeLocal(localWritesOnly);
+				cache.remove( new Fqn( regionFqn, key ), option );
+			}
+			else {
+				log.trace( "skipping remove() call as the underlying node did not seem to exist" );
+			}
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public void clear() throws CacheException {
+		try {
+			Option option = new Option();
+			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+            option.setCacheModeLocal(localWritesOnly);
+			cache.remove( regionFqn, option );
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public void destroy() throws CacheException {
+		try {
+			Option option = new Option();
+			option.setCacheModeLocal( true );
+			option.setFailSilently( true );
+			option.setDataVersion( NonLockingDataVersion.INSTANCE );
+			cache.remove( regionFqn, option );
+            
+            if (cache.getUseRegionBasedMarshalling() && !isSharedClassLoaderRegion(regionName))
+            {
+               inactivateCacheRegion();
+            }
+		}
+		catch( Exception e ) {
+			throw new CacheException( e );
+		}
+	}
+
+	public void lock(Object key) throws CacheException {
+		throw new UnsupportedOperationException( "TreeCache is a fully transactional cache" + regionName );
+	}
+
+	public void unlock(Object key) throws CacheException {
+		throw new UnsupportedOperationException( "TreeCache is a fully transactional cache: " + regionName );
+	}
+
+	public long nextTimestamp() {
+		return System.currentTimeMillis() / 100;
+	}
+
+	public int getTimeout() {
+		return 600; //60 seconds
+	}
+
+	public String getRegionName() {
+		return regionName;
+	}
+
+	public long getSizeInMemory() {
+		return -1;
+	}
+
+	public long getElementCountInMemory() {
+		try {
+			Set children = cache.getChildrenNames( regionFqn );
+			return children == null ? 0 : children.size();
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public long getElementCountOnDisk() {
+		return 0;
+	}
+
+	public Map toMap() {
+		try {
+			Map result = new HashMap();
+			Set childrenNames = cache.getChildrenNames( regionFqn );
+			if (childrenNames != null) {
+				Iterator iter = childrenNames.iterator();
+				while ( iter.hasNext() ) {
+					Object key = iter.next();
+					result.put(
+							key,
+					        cache.get( new Fqn( regionFqn, key ), ITEM )
+						);
+				}
+			}
+			return result;
+		}
+		catch (Exception e) {
+			throw new CacheException(e);
+		}
+	}
+
+	public String toString() {
+		return "OptimisticTreeCache(" + regionName + ')';
+	}
+       
+    private boolean isSharedClassLoaderRegion(String regionName)
+    {
+       return (StandardQueryCache.class.getName().equals(regionName) 
+                || UpdateTimestampsCache.class.getName().equals(regionName));
+    }
+    
+    private void activateCacheRegion(String regionName) throws CacheException
+    {
+       String fqnString = regionFqn.toString();
+       // FIXME -- find a way that doesn't involve this API
+       if (cache.getMarshaller().isInactive(fqnString))
+       {
+          try
+          {
+             // Only register the classloader if it's not a shared region.  
+             // If it's shared, no single classloader is valid
+             if (!isSharedClassLoaderRegion(regionName))
+             {
+                cache.registerClassLoader(fqnString, Thread.currentThread().getContextClassLoader());
+             }
+             cache.activateRegion(fqnString);
+          }
+          catch (Exception e)
+          {
+             throw new CacheException("Problem activating region " + regionName, e);
+          }
+       }
+       else
+       {
+          log.debug("activateCacheRegion(): Region " + fqnString + " is already active");
+       }
+    }
+    
+    private void inactivateCacheRegion() throws CacheException
+    {
+       String fqnString = regionFqn.toString();
+       // FIXME -- find a way that doesn't involve this API
+       if (!cache.getMarshaller().isInactive(fqnString))
+       {
+          try
+          {
+             cache.inactivateRegion(fqnString);
+             cache.unregisterClassLoader(fqnString);
+          }
+          catch (Exception e)
+          {
+             throw new CacheException("Problem activating region " + fqnString, e);
+          }
+       }     
+       else
+       {
+          log.debug("inactivateCacheRegion(): Region " + fqnString + " is already inactive");
+       }
+    }   
+
+	public static class DataVersionAdapter implements DataVersion {
+		private final Object currentVersion;
+		private final Object previousVersion;
+		private final Comparator versionComparator;
+		private final String sourceIdentifer;
+
+		public DataVersionAdapter(Object currentVersion, Object previousVersion, Comparator versionComparator, String sourceIdentifer) {
+			this.currentVersion = currentVersion;
+			this.previousVersion = previousVersion;
+			this.versionComparator = versionComparator;
+			this.sourceIdentifer = sourceIdentifer;
+			log.trace( "created " + this );
+		}
+
+		/**
+		 * newerThan() call is dispatched against the DataVersion currently
+		 * associated with the node; the passed dataVersion param is the
+		 * DataVersion associated with the data we are trying to put into
+		 * the node.
+		 * <p/>
+		 * we are expected to return true in the case where we (the current
+		 * node DataVersion) are newer that then incoming value.  Returning
+		 * true here essentially means that a optimistic lock failure has
+		 * occured (because conversely, the value we are trying to put into
+		 * the node is "older than" the value already there...)
+		 */
+		public boolean newerThan(DataVersion dataVersion) {
+			log.trace( "checking [" + this + "] against [" + dataVersion + "]" );
+			if ( dataVersion instanceof CircumventChecksDataVersion ) {
+				log.trace( "skipping lock checks..." );
+				return false;
+			}
+			else if ( dataVersion instanceof NonLockingDataVersion ) {
+				// can happen because of the multiple ways Cache.remove()
+				// can be invoked :(
+				log.trace( "skipping lock checks..." );
+				return false;
+			}
+			DataVersionAdapter other = ( DataVersionAdapter ) dataVersion;
+			if ( other.previousVersion == null ) {
+				log.warn( "Unexpected optimistic lock check on inserting data" );
+				// work around the "feature" where tree cache is validating the
+				// inserted node during the next transaction.  no idea...
+				if ( this == dataVersion ) {
+					log.trace( "skipping lock checks due to same DV instance" );
+					return false;
+				}
+			}
+			return versionComparator.compare( currentVersion, other.previousVersion ) >= 1;
+		}
+
+		public String toString() {
+			return super.toString() + " [current=" + currentVersion + ", previous=" + previousVersion + ", src=" + sourceIdentifer + "]";
+		}
+	}
+
+	/**
+	 * Used in regions where no locking should ever occur.  This includes query-caches,
+	 * update-timestamps caches, collection caches, and entity caches where the entity
+	 * is not versioned.
+	 */
+	public static class NonLockingDataVersion implements DataVersion {
+		public static final DataVersion INSTANCE = new NonLockingDataVersion();
+		public boolean newerThan(DataVersion dataVersion) {
+			log.trace( "non locking lock check...");
+			return false;
+		}
+	}
+
+	/**
+	 * Used to signal to a DataVersionAdapter to simply not perform any checks.  This
+	 * is currently needed for proper handling of remove() calls for entity cache regions
+	 * (we do not know the version info...).
+	 */
+	public static class CircumventChecksDataVersion implements DataVersion {
+		public static final DataVersion INSTANCE = new CircumventChecksDataVersion();
+		public boolean newerThan(DataVersion dataVersion) {
+			throw new CacheException( "optimistic locking checks should never happen on CircumventChecksDataVersion" );
+		}
+	}
+}

Modified: branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticTreeCacheProviderHook.java
===================================================================
--- branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticTreeCacheProviderHook.java	2007-02-20 05:08:31 UTC (rev 60697)
+++ branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/OptimisticTreeCacheProviderHook.java	2007-02-20 05:10:07 UTC (rev 60698)
@@ -13,7 +13,6 @@
 import org.hibernate.cache.Cache;
 import org.hibernate.cache.CacheException;
 import org.hibernate.cache.CacheProvider;
-import org.hibernate.cache.OptimisticTreeCache;
 import org.jboss.cache.TreeCache;
 import org.jboss.cache.TreeCacheMBean;
 import org.jboss.logging.Logger;
@@ -33,8 +32,8 @@
    
    public Cache buildCache(String regionName, Properties properties) throws CacheException
    {
-      if (log.isDebugEnabled()) { log.debug("Building org.hibernate.cache.OptimisticTreeCache instance for region " + regionName); }
-      return new OptimisticTreeCache( cache, regionName );
+      if (log.isDebugEnabled()) { log.debug("Building org.jboss.ejb3.entity.OptimisticJBCCache instance for region " + regionName); }
+      return new OptimisticJBCCache( cache, regionName );
    }
 
    public boolean isMinimalPutsEnabledByDefault()




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