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.LinkedBlockingQueue;
  14 import java.util.concurrent.ThreadPoolExecutor;
  15 import java.util.concurrent.TimeUnit;
  16 import javax.annotation.PostConstruct;
  17 import javax.annotation.PreDestroy;
  18 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  19 import org.opendaylight.controller.md.sal.binding.api.DataObjectModification;
  20 import org.opendaylight.controller.md.sal.binding.api.DataTreeChangeListener;
  21 import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
  22 import org.opendaylight.controller.md.sal.binding.api.DataTreeModification;
  23 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  24 import org.opendaylight.genius.utils.SuperTypeUtil;
  25 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  26 import org.opendaylight.yangtools.yang.binding.DataObject;
  27 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  28
  29 @Deprecated
  30 public abstract class AsyncDataTreeChangeListenerBase<T extends DataObject, K extends DataTreeChangeListener<T>>
  31         implements DataTreeChangeListener<T>, ChainableDataTreeChangeListener<T>, AutoCloseable {
  32
  33     private static final int DATATREE_CHANGE_HANDLER_THREAD_POOL_CORE_SIZE = 1;
  34     private static final int DATATREE_CHANGE_HANDLER_THREAD_POOL_MAX_SIZE = 1;
  35     private static final int DATATREE_CHANGE_HANDLER_THREAD_POOL_KEEP_ALIVE_TIME_SECS = 300;
  36
  37     private ListenerRegistration<K> listenerRegistration;
  38     private final ChainableDataTreeChangeListenerImpl<T> chainingDelegate = new ChainableDataTreeChangeListenerImpl<>();
  39
  40     private final ThreadPoolExecutor dataTreeChangeHandlerExecutor = new ThreadPoolExecutor(
  41             DATATREE_CHANGE_HANDLER_THREAD_POOL_CORE_SIZE,
  42             DATATREE_CHANGE_HANDLER_THREAD_POOL_MAX_SIZE,
  43             DATATREE_CHANGE_HANDLER_THREAD_POOL_KEEP_ALIVE_TIME_SECS,
  44             TimeUnit.SECONDS,
  45             new LinkedBlockingQueue<>());
  46
  47     protected final Class<T> clazz;
  48
  49     protected AsyncDataTreeChangeListenerBase() {
  50         this.clazz = SuperTypeUtil.getTypeParameter(getClass(), 0);
  51     }
  52
  53     @Deprecated
  54     public AsyncDataTreeChangeListenerBase(Class<T> clazz, Class<K> eventClazz) {
  55         this.clazz = Preconditions.checkNotNull(clazz, "Class can not be null!");
  56     }
  57
  58     @Override
  59     public void addBeforeListener(DataTreeChangeListener<T> listener) {
  60         chainingDelegate.addBeforeListener(listener);
  61     }
  62
  63     @Override
  64     public void addAfterListener(DataTreeChangeListener<T> listener) {
  65         chainingDelegate.addAfterListener(listener);
  66     }
  67
  68     @Override
  69     public void onDataTreeChanged(Collection<DataTreeModification<T>> changes) {
  70         if (changes == null || changes.isEmpty()) {
  71             return;
  72         }
  73
  74         DataTreeChangeHandler dataTreeChangeHandler = new DataTreeChangeHandler(changes);
  75         dataTreeChangeHandlerExecutor.execute(dataTreeChangeHandler);
  76     }
  77
  78     public void registerListener(LogicalDatastoreType dsType, final DataBroker db) {
  79         final DataTreeIdentifier<T> treeId = new DataTreeIdentifier<>(dsType, getWildCardPath());
  80         listenerRegistration = db.registerDataTreeChangeListener(treeId, getDataTreeChangeListener());
  81     }
  82
  83     /**
  84      * Subclasses override this and place initialization logic here, notably
  85      * calls to registerListener(). Note that the overriding method MUST repeat
  86      * the PostConstruct annotation, because JSR 250 specifies that lifecycle
  87      * methods "are called unless a subclass of the declaring class overrides
  88      * the method without repeating the annotation".  (The blueprint-maven-plugin
  89      * would gen. XML which calls PostConstruct annotated methods even if they are
  90      * in a subclass without repeating the annotation, but this is wrong and not
  91      * JSR 250 compliant, and while working in BP, then causes issues e.g. when
  92      * wiring with Guice for tests, so do always repeat it.)
  93      */
  94     @PostConstruct
  95     protected void init() {
  96     }
  97
  98     @Override
  99     @PreDestroy
 100     public void close() {
 101         if (listenerRegistration != null) {
 102             try {
 103                 listenerRegistration.close();
 104             } finally {
 105                 listenerRegistration = null;
 106             }
 107         }
 108     }
 109
 110     protected abstract InstanceIdentifier<T> getWildCardPath();
 111
 112     protected abstract void remove(InstanceIdentifier<T> key, T dataObjectModification);
 113
 114     protected abstract void update(InstanceIdentifier<T> key,
 115             T dataObjectModificationBefore, T dataObjectModificationAfter);
 116
 117     protected abstract void add(InstanceIdentifier<T> key, T dataObjectModification);
 118
 119     protected abstract K getDataTreeChangeListener();
 120
 121     public class DataTreeChangeHandler implements Runnable {
 122         private final Collection<DataTreeModification<T>> changes;
 123
 124         public DataTreeChangeHandler(Collection<DataTreeModification<T>> changes) {
 125             chainingDelegate.notifyBeforeOnDataTreeChanged(changes);
 126             this.changes = changes;
 127         }
 128
 129         @Override
 130         public void run() {
 131             for (DataTreeModification<T> change : changes) {
 132                 final InstanceIdentifier<T> key = change.getRootPath().getRootIdentifier();
 133                 final DataObjectModification<T> mod = change.getRootNode();
 134
 135                 switch (mod.getModificationType()) {
 136                     case DELETE:
 137                         remove(key, mod.getDataBefore());
 138                         break;
 139                     case SUBTREE_MODIFIED:
 140                         update(key, mod.getDataBefore(), mod.getDataAfter());
 141                         break;
 142                     case WRITE:
 143                         if (mod.getDataBefore() == null) {
 144                             add(key, mod.getDataAfter());
 145                         } else {
 146                             update(key, mod.getDataBefore(), mod.getDataAfter());
 147                         }
 148                         break;
 149                     default:
 150                         // FIXME: May be not a good idea to throw.
 151                         throw new IllegalArgumentException("Unhandled modification type " + mod.getModificationType());
 152                 }
 153             }
 154             chainingDelegate.notifyAfterOnDataTreeChanged(changes);
 155         }
 156     }
 157 }