sfc/translator/src/main/java/org/opendaylight/netvirt/sfc/translator/DelegatingDataTreeListener.java

   1 /*
   2  * Copyright (c) 2016, 2017 Brocade Communications 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
   9 package org.opendaylight.netvirt.sfc.translator;
  10
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.util.concurrent.ThreadFactoryBuilder;
  13 import java.util.Collection;
  14 import java.util.concurrent.ExecutorService;
  15 import java.util.concurrent.Executors;
  16 import java.util.concurrent.ThreadFactory;
  17 import javax.annotation.Nonnull;
  18 import javax.annotation.Nullable;
  19 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  20 import org.opendaylight.controller.md.sal.binding.api.DataObjectModification;
  21 import org.opendaylight.controller.md.sal.binding.api.DataTreeChangeListener;
  22 import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
  23 import org.opendaylight.controller.md.sal.binding.api.DataTreeModification;
  24 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  25 import org.opendaylight.yangtools.yang.binding.DataObject;
  26 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 /**
  31  * Data-tree listener which delegates data processing to a {@link INeutronSfcDataProcessor}.
  32  */
  33 public abstract class DelegatingDataTreeListener<T extends DataObject> implements AutoCloseable,
  34         DataTreeChangeListener<T>,
  35         INeutronSfcDataProcessor<T> {
  36     private static final Logger LOG = LoggerFactory.getLogger(DelegatingDataTreeListener.class);
  37     private static final ThreadFactory THREAD_FACTORY = new ThreadFactoryBuilder()
  38         .setNameFormat("NeutronSfcListener-%d").build();
  39     private final ExecutorService executorService = Executors.newFixedThreadPool(1, THREAD_FACTORY);
  40     private final INeutronSfcDataProcessor<T> dataProcessor;
  41     @Nullable
  42     private ListenerRegistration<DelegatingDataTreeListener<T>> listenerRegistration;
  43
  44     public DelegatingDataTreeListener(DataBroker db, DataTreeIdentifier<T> treeId) {
  45         this.dataProcessor = Preconditions.checkNotNull(this, "Data processor can not be null!");
  46         registerListener(Preconditions.checkNotNull(db, "Data broker can not be null!"),
  47                 Preconditions.checkNotNull(treeId, "Tree identifier can not be null!"));
  48     }
  49
  50     // TODO Clean up the exception handling
  51     @SuppressWarnings("checkstyle:IllegalCatch")
  52     private void registerListener(final DataBroker db, DataTreeIdentifier<T> treeId) {
  53         try {
  54             LOG.info("Registering Data Change Listener for {}", getClass().getSimpleName());
  55             listenerRegistration = db.registerDataTreeChangeListener(treeId, this);
  56         } catch (final Exception e) {
  57             LOG.warn("{} DataChange listener registration fail!", getClass().getSimpleName(), e);
  58             throw new IllegalStateException("DataTreeListener startup fail! System needs restart.", e);
  59         }
  60     }
  61
  62     private void processChanges(Collection<DataTreeModification<T>> changes) {
  63         LOG.info("onDataTreeChanged: Received Data Tree Changed {}", changes);
  64         for (DataTreeModification<T> change : changes) {
  65             final InstanceIdentifier<T> key = change.getRootPath().getRootIdentifier();
  66             final DataObjectModification<T> mod = change.getRootNode();
  67             LOG.info("onDataTreeChanged: Received Data Tree Changed Update of Type={} for Key={}",
  68                     mod.getModificationType(), key);
  69             switch (mod.getModificationType()) {
  70                 case DELETE:
  71                     dataProcessor.remove(mod.getDataBefore());
  72                     break;
  73                 case SUBTREE_MODIFIED:
  74                     dataProcessor.update(mod.getDataBefore(), mod.getDataAfter());
  75                     break;
  76                 case WRITE:
  77                     if (mod.getDataBefore() == null) {
  78                         dataProcessor.add(mod.getDataAfter());
  79                     } else {
  80                         dataProcessor.update(mod.getDataBefore(), mod.getDataAfter());
  81                     }
  82                     break;
  83                 default:
  84                     throw new IllegalArgumentException("Unhandled modification type " + mod.getModificationType());
  85             }
  86         }
  87     }
  88
  89     @Override
  90     public void onDataTreeChanged(@Nonnull final Collection<DataTreeModification<T>> changes) {
  91         Preconditions.checkNotNull(changes, "Changes may not be null!");
  92         executorService.execute(() -> processChanges(changes));
  93     }
  94
  95     @Override
  96     public void close() {
  97         if (listenerRegistration != null) {
  98             listenerRegistration.close();
  99             listenerRegistration = null;
 100         }
 101         executorService.shutdownNow();
 102     }
 103 }