[jboss-cvs] JBossAS SVN: r65957 - projects/ejb3/branches/cluster-dev/ejb3-cache/src/main/java/org/jboss/ejb3/cache/impl.

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

Author: bstansberry at jboss.com
Date: 2007-10-08 23:49:57 -0400 (Mon, 08 Oct 2007)
New Revision: 65957

Added:
   projects/ejb3/branches/cluster-dev/ejb3-cache/src/main/java/org/jboss/ejb3/cache/impl/SerializationGroupMemberImpl.java
Log:
Extract Entry from GroupedPassivatingCacheImpl2; becomes SerializationGroupMemberImpl

Added: projects/ejb3/branches/cluster-dev/ejb3-cache/src/main/java/org/jboss/ejb3/cache/impl/SerializationGroupMemberImpl.java
===================================================================
--- projects/ejb3/branches/cluster-dev/ejb3-cache/src/main/java/org/jboss/ejb3/cache/impl/SerializationGroupMemberImpl.java	                        (rev 0)
+++ projects/ejb3/branches/cluster-dev/ejb3-cache/src/main/java/org/jboss/ejb3/cache/impl/SerializationGroupMemberImpl.java	2007-10-09 03:49:57 UTC (rev 65957)
@@ -0,0 +1,161 @@
+package org.jboss.ejb3.cache.impl;
+
+import java.io.Serializable;
+
+import org.jboss.ejb3.cache.Cacheable;
+import org.jboss.ejb3.cache.PassivatingCache;
+import org.jboss.ejb3.cache.grouped.SerializationGroup;
+import org.jboss.ejb3.cache.grouped.SerializationGroupMember;
+
+/**
+ * Default implementation of {@link SerializationGroupMember}.
+ * 
+ * @author Brian Stansberry
+ * @version $Revision$
+ */
+public class SerializationGroupMemberImpl<T extends Cacheable & Serializable> 
+ implements Cacheable, SerializationGroupMember, Serializable
+{
+   private static final long serialVersionUID = 1L;
+   
+   private Object id;
+   /**
+    * The underlying object (e.g. bean context).
+    * Preferably, this field would be transient. It isn't now because it is 
+    * possible this entry will never be assigned to a PassivationGroup,
+    * in which case we need to serialize obj.
+    * TODO Relying on nulling this field is fragile. Can we make this
+    * field transient by ensuring we only use this cache class with bean 
+    * classes that are sure to be part of a group?
+    */
+   private T obj;
+   /**
+    * Hack. We hold two refs to our object; one we clear in prePassivate,
+    * one we keep, but it's transient.  getSerializableObject() returns
+    * whichever is available, making it available for passivation callbacks.
+    */
+   private transient T transientObj;
+   /** The group. Never serialize the group; only the groupCache does that */
+   private transient SerializationGroup group;
+   private Object groupId;
+   private long lastUsed;
+   /** The cache that's handling us */
+   private transient PassivatingCache<SerializationGroupMemberImpl<T>> delegate;
+   
+   SerializationGroupMemberImpl(T obj, PassivatingCache<SerializationGroupMemberImpl<T>> delegate)
+   {
+      assert obj != null : "obj is null";
+      assert delegate != null : "delegate is null";
+      
+      this.obj = transientObj = obj;
+      this.id = obj.getId();
+      this.delegate = delegate;
+   }
+   
+   public Object getId()
+   {
+      return id;
+   }
+   
+   public boolean isClustered()
+   {
+      // Value from the containing cache
+      return delegate.isClustered();
+   }
+   
+   @SuppressWarnings("unchecked")
+   public T getSerializableObject()
+   {      
+      return obj == null ? transientObj : obj;
+   }
+   
+   public void setSerializableObject(T obj)
+   {
+      this.obj = transientObj = obj;
+   }
+   
+   public SerializationGroup getGroup()
+   {
+      return group;
+   }
+
+   public void setGroup(SerializationGroup group)
+   {
+      this.group = group;
+   }
+
+   public Object getGroupId()
+   {
+      return groupId;
+   }
+
+   public void setGroupId(Object groupId)
+   {
+      this.groupId = groupId;
+   }
+
+   // Called by PassivationGroup prior to its passivating
+   public void prePassivate()
+   {
+      // make sure we don't passivate the group twice
+      group = null;
+      
+      // null out obj so when delegate passivates this entry
+      // we don't serialize it. It serializes with the PassivationGroup only  
+      // We still have a ref to transientObj, so it can be retrieved
+      // for passivation callbacks
+      obj = null;
+      
+      delegate.passivate(this.id);
+   }
+   
+   // Called by PassivationGroup prior to its replicating
+   public void preReplicate()
+   {
+      // make sure we don't replicate the group twice
+      group = null;
+      // null out obj so when delegate passivates this entry
+      // we don't serialize it. It serializes with the PassivationGroup only
+      obj = null;
+      
+      delegate.replicate(this.id);
+   }
+   
+   public long getLastUsed()
+   {
+      return obj == null ? lastUsed : obj.getLastUsed();
+   }
+
+   public boolean isInUse()
+   {
+      return obj == null ? false : obj.isInUse();
+   }
+
+   public void setInUse(boolean inUse)
+   {
+      if (obj != null)
+      {
+         obj.setInUse(inUse);
+         lastUsed = obj.getLastUsed();
+      }
+   }
+   
+   /**
+    * Allows our controlling {@link PassivatingCache} to provide
+    * us a reference after deserialization.
+    * 
+    * @param delegate
+    */
+   public void setPassivatingCache(PassivatingCache<SerializationGroupMemberImpl<T>> delegate)
+   {
+      assert delegate != null : "delegate is null";
+      
+      this.delegate = delegate;
+   }
+
+   @Override
+   public String toString()
+   {
+      return super.toString() + "{id=" + id + ",obj=" + obj + ",groupId=" + groupId + ",group=" + group + "}";
+   }
+}
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