opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/PingPongDataBroker.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.md.sal.dom.broker.impl;
   9
  10 import com.google.common.base.Preconditions;
  11 import javax.annotation.Nonnull;
  12 import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
  13 import org.opendaylight.controller.md.sal.dom.api.DOMDataBroker;
  14 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  15 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeService;
  16 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeIdentifier;
  17 import org.opendaylight.controller.md.sal.dom.spi.ForwardingDOMDataBroker;
  18 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  19
  20 /**
  21  * An implementation of a {@link DOMDataBroker}, which forwards most requests to a delegate.
  22  *
  23  * Its interpretation of the API contract is somewhat looser, specifically it does not
  24  * guarantee transaction ordering between transactions allocated directly from the broker
  25  * and its transaction chains.
  26  */
  27 public final class PingPongDataBroker extends ForwardingDOMDataBroker implements AutoCloseable, DOMDataTreeChangeService {
  28     private final DOMDataBroker delegate;
  29
  30     /**
  31      * Instantiate a new broker, backed by the the specified delegate
  32      * {@link DOMDataBroker}.
  33      *
  34      * @param delegate Backend broker, may not be null.
  35      */
  36     public PingPongDataBroker(@Nonnull final DOMDataBroker delegate) {
  37         this.delegate = Preconditions.checkNotNull(delegate);
  38     }
  39
  40     @Override
  41     protected DOMDataBroker delegate() {
  42         return delegate;
  43     }
  44
  45     @Override
  46     public PingPongTransactionChain createTransactionChain(final TransactionChainListener listener) {
  47         return new PingPongTransactionChain(delegate, listener);
  48     }
  49
  50     @Override
  51     public void close() {
  52         // intentionally NOOP
  53     }
  54
  55     @Override
  56     public <L extends DOMDataTreeChangeListener> ListenerRegistration<L> registerDataTreeChangeListener(final DOMDataTreeIdentifier treeId, final L listener) {
  57         final DOMDataTreeChangeService treeService =
  58                 (DOMDataTreeChangeService) delegate.getSupportedExtensions().get(DOMDataTreeChangeService.class);
  59         if (treeService != null) {
  60             return treeService.registerDataTreeChangeListener(treeId, listener);
  61         }
  62
  63         throw new UnsupportedOperationException("Delegate " + delegate + " does not support required functionality");
  64     }
  65 }