Change DistributedShardedDOMDataTree's ctor signature
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / DelayedListenerRegistration.java
index 8f18cb74dc79c6cd7cb6c08b03640b9df173dcd8..8d73bc6155d2c664ba6448a1085bbf85850d9606 100644 (file)
@@ -7,25 +7,22 @@
  */
 package org.opendaylight.controller.cluster.datastore;
 
-import com.google.common.base.Optional;
 import java.util.EventListener;
-import java.util.Map.Entry;
 import javax.annotation.concurrent.GuardedBy;
 import org.opendaylight.yangtools.concepts.ListenerRegistration;
-import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
 
-abstract class DelayedListenerRegistration<L extends EventListener, R> implements ListenerRegistration<L> {
-    private final R registrationMessage;
+abstract class DelayedListenerRegistration<L extends EventListener, M> implements ListenerRegistration<L> {
+    private final M registrationMessage;
     private volatile ListenerRegistration<L> delegate;
 
     @GuardedBy("this")
     private boolean closed;
 
-    protected DelayedListenerRegistration(R registrationMessage) {
+    protected DelayedListenerRegistration(M registrationMessage) {
         this.registrationMessage = registrationMessage;
     }
 
-    R getRegistrationMessage() {
+    M getRegistrationMessage() {
         return registrationMessage;
     }
 
@@ -33,18 +30,22 @@ abstract class DelayedListenerRegistration<L extends EventListener, R> implement
         return delegate;
     }
 
-    synchronized <LR extends ListenerRegistration<L>> void createDelegate(
-            final LeaderLocalDelegateFactory<R, LR, Optional<DataTreeCandidate>> factory) {
+    synchronized <R extends ListenerRegistration<L>> void createDelegate(
+            final LeaderLocalDelegateFactory<M, R> factory) {
         if (!closed) {
-            final Entry<LR, Optional<DataTreeCandidate>> res = factory.createDelegate(registrationMessage);
-            this.delegate = res.getKey();
+            this.delegate = factory.createDelegate(registrationMessage);
         }
     }
 
     @Override
     public L getInstance() {
-        final ListenerRegistration<L> d = delegate;
-        return d == null ? null : (L)d.getInstance();
+        // ObjectRegistration annotates this method as @Nonnull but we could return null if the delegate is not set yet.
+        // In reality, we do not and should not ever call this method on DelayedListenerRegistration instances anyway
+        // but, since we have to provide an implementation to satisfy the interface, we throw
+        // UnsupportedOperationException to honor the API contract of not returning null and to avoid a FindBugs error
+        // for possibly returning null.
+        throw new UnsupportedOperationException(
+                "getInstance should not be called on this instance since it could be null");
     }
 
     @Override