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