netvirt/src/main/java/org/opendaylight/unimgr/mef/netvirt/DataWaitListener.java

   1 /*
   2  * Copyright (c) 2016 Hewlett Packard Enterprise, Co. 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.unimgr.mef.netvirt;
  10
  11 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  12 import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
  13 import org.opendaylight.controller.md.sal.binding.api.DataTreeModification;
  14 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  15 import org.opendaylight.unimgr.api.UnimgrDataTreeChangeListener;
  16 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  17 import org.opendaylight.yangtools.yang.binding.DataObject;
  18 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 import com.google.common.base.Optional;
  23
  24 @SuppressWarnings("rawtypes")
  25 public class DataWaitListener<D extends DataObject> extends UnimgrDataTreeChangeListener<D> {
  26     private static final Logger Log = LoggerFactory.getLogger(DataWaitListener.class);
  27     InstanceIdentifier<D> objectIdentifierId;
  28     private ListenerRegistration<DataWaitListener> dataWaitListenerRegistration;
  29     Boolean dataAvailable = false;
  30     private int maxRetries;
  31     LogicalDatastoreType logicalDatastoreType;
  32     DataWaitGetter<D> getData;
  33     private final long waitMillisec = 1000;
  34
  35     public DataWaitListener(final DataBroker dataBroker, final InstanceIdentifier<D> objectIdentifierId,
  36             int maxRetiries, LogicalDatastoreType logicalDatastoreType, final DataWaitGetter<D> getData) {
  37         super(dataBroker);
  38         this.objectIdentifierId = objectIdentifierId;
  39         this.maxRetries = maxRetiries;
  40         this.logicalDatastoreType = logicalDatastoreType;
  41         this.getData = getData;
  42         registerListener();
  43     }
  44
  45     @SuppressWarnings("unchecked")
  46     public void registerListener() {
  47         try {
  48             final DataTreeIdentifier<D> dataTreeIid = new DataTreeIdentifier<D>(logicalDatastoreType,
  49                     objectIdentifierId);
  50             dataWaitListenerRegistration = dataBroker.registerDataTreeChangeListener(dataTreeIid, this);
  51             Log.info("DataWaitListener created and registered");
  52         } catch (final Exception e) {
  53             Log.error("DataWaitListener DataChange listener registration failed !", e);
  54             throw new IllegalStateException("DataWaitListener registration Listener failed.", e);
  55         }
  56     }
  57
  58     @Override
  59     public void close() throws Exception {
  60         dataWaitListenerRegistration.close();
  61     }
  62
  63     @Override
  64     public void add(DataTreeModification<D> newDataObject) {
  65         if (newDataObject.getRootPath() != null && newDataObject.getRootNode() != null) {
  66             Log.info("data {} created", newDataObject.getRootNode().getIdentifier());
  67         }
  68         synchronized (dataAvailable) {
  69             dataAvailable.notifyAll();
  70         }
  71     }
  72
  73     @Override
  74     public void remove(DataTreeModification<D> removedDataObject) {
  75     }
  76
  77     @Override
  78     public void update(DataTreeModification<D> modifiedDataObject) {
  79         if (modifiedDataObject.getRootPath() != null && modifiedDataObject.getRootNode() != null) {
  80             Log.info("data {} updated", modifiedDataObject.getRootNode().getIdentifier());
  81         }
  82         synchronized (dataAvailable) {
  83             dataAvailable.notifyAll();
  84         }
  85     }
  86
  87     private boolean dataAvailable() {
  88         if (getData() != null) {
  89             return true;
  90         }
  91         return false;
  92     }
  93
  94     public boolean waitForData() {
  95         return waitForData(maxRetries);
  96     }
  97
  98     public Object getData() {
  99         Optional<D> objectInstance = MdsalUtils.read(dataBroker, logicalDatastoreType, objectIdentifierId);
 100         if (!objectInstance.isPresent()) {
 101             Log.debug("Data for {} doesn't exist, waiting more", objectIdentifierId);
 102             return null;
 103         }
 104         return getData.get(objectInstance.get());
 105     }
 106
 107     public boolean waitForData(int retry) {
 108         synchronized (dataAvailable) {
 109             dataAvailable = dataAvailable();
 110             if (dataAvailable == true) {
 111                 return true;
 112             } else if (retry <= 0) {
 113                 return false;
 114             }
 115             try {
 116                 dataAvailable.wait(waitMillisec);
 117             } catch (InterruptedException e1) {
 118             }
 119         }
 120         return waitForData(--retry);
 121     }
 122 }