mdsalutil/mdsalutil-api/src/main/java/org/opendaylight/genius/datastoreutils/AsyncDataTreeChangeListenerBase.java

   1 /*
   2  * Copyright (c) 2016 Ericsson India Global Services Pvt Ltd. 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.genius.datastoreutils;
  10
  11 import com.google.common.base.Preconditions;
  12 import java.util.Collection;
  13 import java.util.concurrent.ExecutorService;
  14 import javax.annotation.PostConstruct;
  15 import javax.annotation.PreDestroy;
  16 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  17 import org.opendaylight.controller.md.sal.binding.api.DataObjectModification;
  18 import org.opendaylight.controller.md.sal.binding.api.DataTreeChangeListener;
  19 import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
  20 import org.opendaylight.controller.md.sal.binding.api.DataTreeModification;
  21 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  22 import org.opendaylight.genius.utils.SuperTypeUtil;
  23 import org.opendaylight.infrautils.utils.concurrent.Executors;
  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 @Deprecated
  31 public abstract class AsyncDataTreeChangeListenerBase<T extends DataObject, K extends DataTreeChangeListener<T>>
  32         implements DataTreeChangeListener<T>, ChainableDataTreeChangeListener<T>, AutoCloseable {
  33
  34     private static final Logger LOG = LoggerFactory.getLogger(AsyncDataTreeChangeListenerBase.class);
  35
  36     private ListenerRegistration<K> listenerRegistration;
  37     private final ChainableDataTreeChangeListenerImpl<T> chainingDelegate = new ChainableDataTreeChangeListenerImpl<>();
  38
  39     private final ExecutorService dataTreeChangeHandlerExecutor =
  40             Executors.newSingleThreadExecutor("AsyncDataTreeChangeListenerBase-DataTreeChangeHandler", LOG);
  41     protected final Class<T> clazz;
  42
  43     protected AsyncDataTreeChangeListenerBase() {
  44         this.clazz = SuperTypeUtil.getTypeParameter(getClass(), 0);
  45     }
  46
  47     @Deprecated
  48     public AsyncDataTreeChangeListenerBase(Class<T> clazz, Class<K> eventClazz) {
  49         this.clazz = Preconditions.checkNotNull(clazz, "Class can not be null!");
  50     }
  51
  52     @Override
  53     public void addBeforeListener(DataTreeChangeListener<T> listener) {
  54         chainingDelegate.addBeforeListener(listener);
  55     }
  56
  57     @Override
  58     public void addAfterListener(DataTreeChangeListener<T> listener) {
  59         chainingDelegate.addAfterListener(listener);
  60     }
  61
  62     @Override
  63     public void onDataTreeChanged(Collection<DataTreeModification<T>> changes) {
  64         if (changes == null || changes.isEmpty()) {
  65             return;
  66         }
  67
  68         DataTreeChangeHandler dataTreeChangeHandler = new DataTreeChangeHandler(changes);
  69         dataTreeChangeHandlerExecutor.execute(dataTreeChangeHandler);
  70     }
  71
  72     public void registerListener(LogicalDatastoreType dsType, final DataBroker db) {
  73         final DataTreeIdentifier<T> treeId = new DataTreeIdentifier<>(dsType, getWildCardPath());
  74         listenerRegistration = db.registerDataTreeChangeListener(treeId, getDataTreeChangeListener());
  75     }
  76
  77     /**
  78      * Subclasses override this and place initialization logic here, notably
  79      * calls to registerListener(). Note that the overriding method MUST repeat
  80      * the PostConstruct annotation, because JSR 250 specifies that lifecycle
  81      * methods "are called unless a subclass of the declaring class overrides
  82      * the method without repeating the annotation".  (The blueprint-maven-plugin
  83      * would gen. XML which calls PostConstruct annotated methods even if they are
  84      * in a subclass without repeating the annotation, but this is wrong and not
  85      * JSR 250 compliant, and while working in BP, then causes issues e.g. when
  86      * wiring with Guice for tests, so do always repeat it.)
  87      */
  88     @PostConstruct
  89     protected void init() {
  90     }
  91
  92     @Override
  93     @PreDestroy
  94     public void close() {
  95         dataTreeChangeHandlerExecutor.shutdownNow();
  96
  97         if (listenerRegistration != null) {
  98             try {
  99                 listenerRegistration.close();
 100             } finally {
 101                 listenerRegistration = null;
 102             }
 103         }
 104     }
 105
 106     protected abstract InstanceIdentifier<T> getWildCardPath();
 107
 108     protected abstract void remove(InstanceIdentifier<T> key, T dataObjectModification);
 109
 110     protected abstract void update(InstanceIdentifier<T> key,
 111             T dataObjectModificationBefore, T dataObjectModificationAfter);
 112
 113     protected abstract void add(InstanceIdentifier<T> key, T dataObjectModification);
 114
 115     protected abstract K getDataTreeChangeListener();
 116
 117     public class DataTreeChangeHandler implements Runnable {
 118         private final Collection<DataTreeModification<T>> changes;
 119
 120         public DataTreeChangeHandler(Collection<DataTreeModification<T>> changes) {
 121             chainingDelegate.notifyBeforeOnDataTreeChanged(changes);
 122             this.changes = changes;
 123         }
 124
 125         @Override
 126         public void run() {
 127             for (DataTreeModification<T> change : changes) {
 128                 final InstanceIdentifier<T> key = change.getRootPath().getRootIdentifier();
 129                 final DataObjectModification<T> mod = change.getRootNode();
 130
 131                 switch (mod.getModificationType()) {
 132                     case DELETE:
 133                         remove(key, mod.getDataBefore());
 134                         break;
 135                     case SUBTREE_MODIFIED:
 136                         update(key, mod.getDataBefore(), mod.getDataAfter());
 137                         break;
 138                     case WRITE:
 139                         if (mod.getDataBefore() == null) {
 140                             add(key, mod.getDataAfter());
 141                         } else {
 142                             update(key, mod.getDataBefore(), mod.getDataAfter());
 143                         }
 144                         break;
 145                     default:
 146                         // FIXME: May be not a good idea to throw.
 147                         throw new IllegalArgumentException("Unhandled modification type " + mod.getModificationType());
 148                 }
 149             }
 150             chainingDelegate.notifyAfterOnDataTreeChanged(changes);
 151         }
 152     }
 153 }