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     private Boolean dataAvailable = false;
  30     private final Object lockDataAvailable = new Object();
  31     private int maxRetries;
  32     LogicalDatastoreType logicalDatastoreType;
  33     DataWaitGetter<D> getData;
  34     private final long waitMillisec = 1000;
  35
  36     public DataWaitListener(final DataBroker dataBroker, final InstanceIdentifier<D> objectIdentifierId,
  37             int maxRetiries, LogicalDatastoreType logicalDatastoreType, final DataWaitGetter<D> getData) {
  38         super(dataBroker);
  39         this.objectIdentifierId = objectIdentifierId;
  40         this.maxRetries = maxRetiries;
  41         this.logicalDatastoreType = logicalDatastoreType;
  42         this.getData = getData;
  43         registerListener();
  44     }
  45
  46     @SuppressWarnings("unchecked")
  47     public void registerListener() {
  48         try {
  49             final DataTreeIdentifier<D> dataTreeIid = new DataTreeIdentifier<D>(logicalDatastoreType,
  50                     objectIdentifierId);
  51             dataWaitListenerRegistration = dataBroker.registerDataTreeChangeListener(dataTreeIid, this);
  52             Log.info("DataWaitListener created and registered");
  53         } catch (final Exception e) {
  54             Log.error("DataWaitListener DataChange listener registration failed !", e);
  55             throw new IllegalStateException("DataWaitListener registration Listener failed.", e);
  56         }
  57     }
  58
  59     @Override
  60     public void close() throws Exception {
  61         dataWaitListenerRegistration.close();
  62     }
  63
  64     @Override
  65     public void add(DataTreeModification<D> newDataObject) {
  66         if (newDataObject.getRootPath() != null && newDataObject.getRootNode() != null) {
  67             Log.info("data {} created", newDataObject.getRootNode().getIdentifier());
  68         }
  69         synchronized (lockDataAvailable) {
  70             lockDataAvailable.notifyAll();
  71         }
  72     }
  73
  74     @Override
  75     public void remove(DataTreeModification<D> removedDataObject) {
  76     }
  77
  78     @Override
  79     public void update(DataTreeModification<D> modifiedDataObject) {
  80         if (modifiedDataObject.getRootPath() != null && modifiedDataObject.getRootNode() != null) {
  81             Log.info("data {} updated", modifiedDataObject.getRootNode().getIdentifier());
  82         }
  83         synchronized (lockDataAvailable) {
  84             lockDataAvailable.notifyAll();
  85         }
  86     }
  87
  88     private boolean dataAvailable() {
  89         if (getData() != null) {
  90             return true;
  91         }
  92         return false;
  93     }
  94
  95     public boolean waitForData() {
  96         return waitForData(maxRetries);
  97     }
  98
  99     public Object getData() {
 100         Optional<D> objectInstance = MdsalUtils.read(dataBroker, logicalDatastoreType, objectIdentifierId);
 101         if (!objectInstance.isPresent()) {
 102             Log.debug("Data for {} doesn't exist, waiting more", objectIdentifierId);
 103             return null;
 104         }
 105         return getData.get(objectInstance.get());
 106     }
 107
 108     public boolean waitForData(int retry) {
 109         synchronized (lockDataAvailable) {
 110             dataAvailable = dataAvailable();
 111             if (dataAvailable == true) {
 112                 return true;
 113             } else if (retry <= 0) {
 114                 return false;
 115             }
 116             try {
 117                 lockDataAvailable.wait(waitMillisec);
 118             } catch (InterruptedException e1) {
 119             }
 120         }
 121         return waitForData(--retry);
 122     }
 123 }