[jboss-cvs] JBossAS SVN: r60705 - branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity.

[jboss-cvs-commits at lists.jboss.org]

Author: bstansberry at jboss.com
Date: 2007-02-20 01:04:29 -0500 (Tue, 20 Feb 2007)
New Revision: 60705

Modified:
   branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/TreeCacheProviderHook.java
Log:
Support both optimistic and pessimistic locking.

Modified: branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/TreeCacheProviderHook.java
===================================================================
--- branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/TreeCacheProviderHook.java	2007-02-20 05:18:06 UTC (rev 60704)
+++ branches/Branch_4_2/ejb3/src/main/org/jboss/ejb3/entity/TreeCacheProviderHook.java	2007-02-20 06:04:29 UTC (rev 60705)
@@ -30,33 +30,64 @@
 import org.hibernate.cache.CacheProvider;
 import org.jboss.cache.TreeCacheMBean;
 import org.jboss.ejb3.tx.TxUtil;
+import org.jboss.logging.Logger;
 import org.jboss.mx.util.MBeanProxyExt;
 import org.jboss.mx.util.MBeanServerLocator;
 
 /**
- * Support for a standalone JBossCache (TreeCache) instance.  The JBossCache is configured
- * via a local config resource.
- *
+ * Support for integration as a 2nd level cache with an already existing 
+ * JBoss Cache (TreeCache) instance.  The ObjectName of the cache is 
+ * provided via the <code>hibernate.treecache.mbean.object_name</code>
+ * configuration property.
+ * <p/>
+ * This class supports both optimistic and pessimistic locking, providing
+ * instances of <code>org.hibernate.cache.OptimisticCache</code> if the 
+ * underlying JBoss Cache is configured for optimistic locking.
+ * 
  * @author Gavin King
  * @author Brian Stansberry
  */
 public class TreeCacheProviderHook implements CacheProvider
 {
-
+   /**
+    * Name of the Hibernate configuration property used to provide
+    * the ObjectName of the JBoss Cache instance.
+    */
+   public static final String HIBERNATE_CACHE_OBJECT_NAME_PROPERTY = 
+      "hibernate.treecache.mbean.object_name";
+   
+   /**
+    * Default ObjectName for the JBoss Cache instance that will be used
+    * if {@link HIBERNATE_CACHE_OBJECT_NAME_PROPERTY} is not provided.
+    */
+   public static final String DEFAULT_MBEAN_OBJECT_NAME = "jboss.cache:service=EJB3EntityTreeCache";
+   
+   protected Logger log = Logger.getLogger(getClass());
+   
    private org.jboss.cache.TreeCache cache;
-
+   private boolean optimistic;
+   
    /**
     * Construct and configure the Cache representation of a named cache region.
     *
     * @param regionName the name of the cache region
     * @param properties configuration settings
-    * @return The Cache representation of the named cache region.
+    * @return The Cache representation of the named cache region.  If the
+    *         underlying JBoss Cache is configured for optimistic locking,
+    *         the returned object will also implement org.hibernate.cache.OptimisticCache.
     * @throws org.hibernate.cache.CacheException
     *          Indicates an error building the cache region.
     */
    public Cache buildCache(String regionName, Properties properties) throws CacheException
    {
-      return new JBCCache(cache, regionName, TxUtil.getTransactionManager());
+      if (optimistic)
+      {
+         return new OptimisticJBCCache(cache, regionName);
+      }
+      else
+      {
+         return new JBCCache(cache, regionName, TxUtil.getTransactionManager());
+      }
    }
 
    public boolean isMinimalPutsEnabledByDefault()
@@ -70,9 +101,12 @@
    }
 
    /**
-    * Prepare the underlying JBossCache TreeCache instance.
+    * Find the underlying JBoss Cache TreeCache instance.
     *
-    * @param properties All current config settings.
+    * @param properties  All current config settings. 
+    *                    If {@link #HIBERNATE_CACHE_OBJECT_NAME_PROPERTY} is provided,
+    *                    the value will be the expected name of the cache; otherwise
+    *                    {@link #DEFAULT_MBEAN_OBJECT_NAME} will be used.
     * @throws org.hibernate.cache.CacheException
     *          Indicates a problem preparing cache for use.
     */
@@ -80,9 +114,20 @@
    {
       try
       {
-         ObjectName mbeanObjectName = new ObjectName((String) properties.get("hibernate.treecache.mbean.object_name"));
+         String cacheName = (String) properties.get(HIBERNATE_CACHE_OBJECT_NAME_PROPERTY);
+         if (cacheName == null)
+         {
+            cacheName = DEFAULT_MBEAN_OBJECT_NAME;
+         }
+         ObjectName mbeanObjectName = new ObjectName(cacheName);
          TreeCacheMBean mbean = (TreeCacheMBean) MBeanProxyExt.create(TreeCacheMBean.class, mbeanObjectName, MBeanServerLocator.locateJBoss());
          cache = mbean.getInstance();
+         if ("OPTIMISTIC".equals(cache.getNodeLockingScheme()))
+         {
+            optimistic = true;
+            log.debug("JBoss Cache is configured for optimistic locking; " +
+                    "provided Cache implementations will also implement OptimisticCache");
+         }
       }
       catch (Exception e)
       {
@@ -93,5 +138,10 @@
    public void stop()
    {
    }
+   
+   public boolean isOptimistic()
+   {
+      return optimistic;
+   }
 
 }