FamilyClusterInfo


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22  package org.jboss.ha.framework.interfaces;
23  
24  import java.util.List  ;
25  
26  /**
27   * Maintain information for a given proxy family. Proxies can statically reference
28   * objects implementing this interface: only the content will change as the 
29   * cluster topology changes, not the FamilyClusterInfo object itself.
30   * Proxies or LoadBalancing policy implementations can use the cursor and object
31   * attribute to store arbitrary data that is then shared accross all proxies belonging
32   * to the same family. 
33   * Initial access to this object is done through the ClusteringTargetsRepository singleton.
34   *
35   * @see org.jboss.ha.framework.interfaces.FamilyClusterInfoImpl
36   * @see org.jboss.ha.framework.interfaces.ClusteringTargetsRepository
37   *
38   * @author  <a HREF="mailto:sacha.labourey@cogito-info.ch">Sacha Labourey</a>.
39   * @version $Revision: 56210 $
40   *
41   * <p><b>Revisions:</b>
42   *
43   * <p><b>2002/08/23, Sacha Labourey:</b>
44   * <ul>
45   * <li> First implementation </li>
46   * </ul>
47   */
48  
49  public interface FamilyClusterInfo
50  {
51     public String   getFamilyName ();
52     
53     /**
54      * Gets the list of targets for this family.
55      * 
56      * <strong>NOTE:</strong> Implementations should synchronize on themselves 
57      * when executing this method (see JBAS-2071).
58      */
59     public List   getTargets ();
60     public long getCurrentViewId ();
61     
62     /**
63      * Remove the given target from the list of targets.
64      * 
65      * <strong>NOTE:</strong> Implementations should synchronize on themselves 
66      * when executing this method (see JBAS-2071).
67      * 
68      * @param target the target
69      * @return the updated list of targets
70      */
71     public List   removeDeadTarget(Object   target);
72     
73     /**
74      * Updates the targets and the view id.
75      * 
76      * <strong>NOTE:</strong> Implementations should synchronize on themselves 
77      * when executing this method (see JBAS-2071).
78      */
79     public List   updateClusterInfo (List   targets, long viewId);
80     
81     public boolean currentMembershipInSyncWithViewId();
82     
83     /**
84      * Force a reload of the view at the next invocation.
85      * 
86      * <strong>NOTE:</strong> Implementations should synchronize on themselves 
87      * when executing this method (see JBAS-2071).
88      */
89     public void resetView ();
90     
91     // arbitrary usage by the LoadBalancePolicy implementation
92     // We could have used an HashMap but the lookup would have taken
93     // much more time and we probably don't need as much flexibility
94     // (+ it is slow for a simple int)
95     //
96     public int getCursor();
97     public int setCursor (int cursor);
98     public Object   getObject ();
99     public Object   setObject (Object   whatever);
100    
101    public final static int UNINITIALIZED_CURSOR = 999999999;
102 }
103
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