[jboss-cvs] JBossAS SVN: r76050 - trunk/cluster/src/main/org/jboss/ha/singleton.

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

Author: bstansberry at jboss.com
Date: 2008-07-21 01:46:13 -0400 (Mon, 21 Jul 2008)
New Revision: 76050

Added:
   trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElector.java
Modified:
   trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElectionPolicySimple.java
   trunk/cluster/src/main/org/jboss/ha/singleton/PreferredMasterElectionPolicy.java
Log:
[JBAS-5782] HASingletonElector interface

Modified: trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElectionPolicySimple.java
===================================================================
--- trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElectionPolicySimple.java	2008-07-21 05:11:42 UTC (rev 76049)
+++ trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElectionPolicySimple.java	2008-07-21 05:46:13 UTC (rev 76050)
@@ -47,7 +47,7 @@
  * <attribute name="Position">2</attribute>
  * 
  * If no election policy is defined, the oldest node in the cluster runs the 
- * singleton. This behaivour can be achieved with this policy when "position" 
+ * singleton. This behavior can be achieved with this policy when "position" 
  * is set to 0. 
  * 
  * @author <a href="mailto:Alex.Fu at novell.com">Alex Fu</a>
@@ -56,11 +56,13 @@
  */
 public class HASingletonElectionPolicySimple 
    extends HASingletonElectionPolicyBase 
-   implements HASingletonElectionPolicySimpleMBean
+   implements HASingletonElectionPolicySimpleMBean, HASingletonElector
 {
    // Attributes
    private int mPosition = 0; // Default
    
+   // -------------------------------------------------------------  Properties
+   
    /**
     * @see HASingletonElectionPolicySimpleMBean#setPosition(int)
     */
@@ -77,11 +79,14 @@
       return this.mPosition;
    }
 
-   protected ClusterNode elect(List<ClusterNode> candidates) 
+   // -----------------------------------------------------  HASingletonElector
+
+   public ClusterNode elect(List<ClusterNode> candidates) 
    {
       int size = candidates.size();
       int remainder = ((this.mPosition % size) + size) % size;
       
       return candidates.get(remainder);
    }
+   
 }

Added: trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElector.java
===================================================================
--- trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElector.java	                        (rev 0)
+++ trunk/cluster/src/main/org/jboss/ha/singleton/HASingletonElector.java	2008-07-21 05:46:13 UTC (rev 76050)
@@ -0,0 +1,44 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2008, 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.ha.singleton;
+
+import java.util.List;
+
+import org.jboss.ha.framework.interfaces.ClusterNode;
+
+/**
+ * Serves as an elector in an HASingleton master election by choosing a master
+ * node from a list of candidates.
+ * <p>
+ * Differs from {@link HASingletonElectionPolicy} in that an election policy
+ * is also responsible for identifying the list of candidates. An election
+ * policy implementation could potentially prepare the list of candidates and
+ * then delegate the actual election to an injected 
+ * <code>HASingletonElector</code>. 
+ * </p>
+ * @author Brian Stansberry
+ */
+public interface HASingletonElector
+{
+   ClusterNode elect(List<ClusterNode> candidates);
+}

Modified: trunk/cluster/src/main/org/jboss/ha/singleton/PreferredMasterElectionPolicy.java
===================================================================
--- trunk/cluster/src/main/org/jboss/ha/singleton/PreferredMasterElectionPolicy.java	2008-07-21 05:11:42 UTC (rev 76049)
+++ trunk/cluster/src/main/org/jboss/ha/singleton/PreferredMasterElectionPolicy.java	2008-07-21 05:46:13 UTC (rev 76050)
@@ -43,6 +43,8 @@
 {
    private String preferredMaster;
    
+   // -------------------------------------------------------------  Properties
+   
    /**
     * @see PreferredMasterElectionPolicyMBean#setPreferredMaster(String)
     */
@@ -59,8 +61,10 @@
       return preferredMaster;
    }
 
+   // -----------------------------------------------------  HASingletonElector
+   
    @Override
-   protected ClusterNode elect(List<ClusterNode> candidates)
+   public ClusterNode elect(List<ClusterNode> candidates)
    {
       // If preferred master is defined and contained in cluster, return it
       if (preferredMaster != null) 
@@ -107,6 +111,8 @@
       return super.elect(candidates);
    }
    
+   // --------------------------------------------------------------- Protected
+   
    /**
     * Create a URI instance from the given preferred master. 
     *