[jbosscache-commits] JBoss Cache SVN: r6251 - in core/trunk/src/main/java/org/jboss/cache: mvcc and 1 other directory.

[jbosscache-commits at lists.jboss.org]

Author: manik.surtani at jboss.com
Date: 2008-07-11 13:01:51 -0400 (Fri, 11 Jul 2008)
New Revision: 6251

Modified:
   core/trunk/src/main/java/org/jboss/cache/NodeFactory.java
   core/trunk/src/main/java/org/jboss/cache/mvcc/ReadCommittedNode.java
   core/trunk/src/main/java/org/jboss/cache/mvcc/RepeatableReadNode.java
Log:
Do we actualy need data versions with MVCC?

Modified: core/trunk/src/main/java/org/jboss/cache/NodeFactory.java
===================================================================
--- core/trunk/src/main/java/org/jboss/cache/NodeFactory.java	2008-07-11 15:46:23 UTC (rev 6250)
+++ core/trunk/src/main/java/org/jboss/cache/NodeFactory.java	2008-07-11 17:01:51 UTC (rev 6251)
@@ -125,6 +125,7 @@
     */
    public NodeSPI<K, V> createDataNode(Object childName, Fqn fqn, NodeSPI<K, V> parent, Map<K, V> data, boolean mapSafe)
    {
+      // TODO: See if data versions are needed with MVCC.  Should use cheaper UnversionedNode otherwise.
       UnversionedNode un = useVersionedNode ? new VersionedNode<K, V>(fqn, parent, data, cache) : new UnversionedNode<K, V>(childName, fqn, data, cache);
 
       // it is internal nodes that are wrapped in NIDs.

Modified: core/trunk/src/main/java/org/jboss/cache/mvcc/ReadCommittedNode.java
===================================================================
--- core/trunk/src/main/java/org/jboss/cache/mvcc/ReadCommittedNode.java	2008-07-11 15:46:23 UTC (rev 6250)
+++ core/trunk/src/main/java/org/jboss/cache/mvcc/ReadCommittedNode.java	2008-07-11 17:01:51 UTC (rev 6251)
@@ -52,6 +52,7 @@
          InternalNode backupDelegationTarget = ((NodeReference) backup).getDelegate();
          node = backupDelegationTarget.copy();
       }
+      // TODO: See if data versions are even needed in the first place!!
       // TODO: Make sure this works with custom versions as well!
 //      DataVersion newVersion = ((DefaultDataVersion) node.getVersion()).increment();
 //      node.setVersion(newVersion);

Modified: core/trunk/src/main/java/org/jboss/cache/mvcc/RepeatableReadNode.java
===================================================================
--- core/trunk/src/main/java/org/jboss/cache/mvcc/RepeatableReadNode.java	2008-07-11 15:46:23 UTC (rev 6250)
+++ core/trunk/src/main/java/org/jboss/cache/mvcc/RepeatableReadNode.java	2008-07-11 17:01:51 UTC (rev 6251)
@@ -8,7 +8,6 @@
 import org.jboss.cache.invocation.InvocationContext;
 import org.jboss.cache.optimistic.DataVersion;
 import org.jboss.cache.optimistic.DataVersioningException;
-import org.jboss.cache.optimistic.DefaultDataVersion;
 
 /**
  * A node delegate that encapsulates repeatable read semantics when writes are initiated, committed or rolled back.
@@ -36,9 +35,11 @@
       // check for write skew.
       NodeSPI underlyingNode = container.peek(fqn, false, true);  // even check for invalid nodes.  we should check tombstones too.
       DataVersion underlyingNodeVersion = underlyingNode == null ? null : underlyingNode.getVersion();
-      if (!allowWriteSkew && underlyingNode != null && !node.getVersion().equals(underlyingNodeVersion))
+      // TODO: See if data versions are even needed in the first place!!
+      //if (!allowWriteSkew && underlyingNode != null && !node.getVersion().equals(underlyingNodeVersion))
+      if (!allowWriteSkew && underlyingNode != null && underlyingNode != node)
       {
-         String errormsg = new StringBuilder().append("Detected write skew on Fqn [").append(fqn).append("].  Attempting to overwrite version ").append(node.getVersion()).append(" but current version has progressed to ").append(underlyingNodeVersion).toString();
+         String errormsg = new StringBuilder().append("Detected write skew on Fqn [").append(fqn).append("].  Another process has changed the node since we last read it!").toString();
          if (log.isWarnEnabled()) log.warn(errormsg + ".  Unable to copy node for update.");
          throw new DataVersioningException(errormsg);
       }
@@ -46,11 +47,11 @@
       // make a backup copy
       backup = node;
       node = backup.copy();
-
+      // TODO: See if data versions are even needed in the first place!!
       // update version on copy
       // TODO: Make sure this works with custom versions as well!
-      DataVersion newVersion = ((DefaultDataVersion) node.getVersion()).increment();
-      node.setVersion(newVersion);
+//      DataVersion newVersion = ((DefaultDataVersion) node.getVersion()).increment();
+//      node.setVersion(newVersion);
    }
 
    @Override