opendaylight/md-sal/samples/l2switch/implementation/src/main/java/org/opendaylight/controller/sample/l2switch/md/topology/TopologyLinkDataChangeHandler.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. 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 package org.opendaylight.controller.sample.l2switch.md.topology;
   9
  10 import com.google.common.base.Preconditions;
  11 import org.opendaylight.controller.sample.l2switch.md.util.InstanceIdentifierUtils;
  12 import org.opendaylight.controller.md.sal.common.api.data.DataChangeEvent;
  13 import org.opendaylight.controller.sal.binding.api.data.DataBrokerService;
  14 import org.opendaylight.controller.sal.binding.api.data.DataChangeListener;
  15 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NetworkTopology;
  16 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.TopologyId;
  17 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.Topology;
  18 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.TopologyKey;
  19 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Link;
  20 import org.opendaylight.yangtools.yang.binding.DataObject;
  21 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.concurrent.Executors;
  28 import java.util.concurrent.ScheduledExecutorService;
  29 import java.util.concurrent.TimeUnit;
  30
  31 /**
  32  * Listens to data change events on topology links
  33  * {@link org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Link}
  34  * and maintains a topology graph using provided NetworkGraphService
  35  * {@link org.opendaylight.controller.sample.l2switch.md.topology.NetworkGraphService}.
  36  * It refreshes the graph after a delay(default 10 sec) to accommodate burst of change events if they come in bulk.
  37  * This is to avoid continuous refresh of graph on a series of change events in short time.
  38  */
  39 public class TopologyLinkDataChangeHandler implements DataChangeListener {
  40   private static final Logger _logger = LoggerFactory.getLogger(TopologyLinkDataChangeHandler.class);
  41   private static final String DEFAULT_TOPOLOGY_ID = "flow:1";
  42
  43   private boolean networkGraphRefreshScheduled = false;
  44   private final ScheduledExecutorService networkGraphRefreshScheduler = Executors.newScheduledThreadPool(1);
  45   private final long DEFAULT_GRAPH_REFRESH_DELAY = 10;
  46   private final long graphRefreshDelayInSec;
  47
  48   private final NetworkGraphService networkGraphService;
  49   private final DataBrokerService dataBrokerService;
  50
  51   /**
  52    * Uses default delay to refresh topology graph if this constructor is used.
  53    * @param dataBrokerService
  54    * @param networkGraphService
  55    */
  56   public TopologyLinkDataChangeHandler(DataBrokerService dataBrokerService, NetworkGraphService networkGraphService) {
  57     Preconditions.checkNotNull(dataBrokerService, "dataBrokerService should not be null.");
  58     Preconditions.checkNotNull(networkGraphService, "networkGraphService should not be null.");
  59     this.dataBrokerService = dataBrokerService;
  60     this.networkGraphService = networkGraphService;
  61     this.graphRefreshDelayInSec = DEFAULT_GRAPH_REFRESH_DELAY;
  62   }
  63
  64   /**
  65    *
  66    * @param dataBrokerService
  67    * @param networkGraphService
  68    * @param graphRefreshDelayInSec
  69    */
  70   public TopologyLinkDataChangeHandler(DataBrokerService dataBrokerService, NetworkGraphService networkGraphService,
  71                                        long graphRefreshDelayInSec) {
  72     Preconditions.checkNotNull(dataBrokerService, "dataBrokerService should not be null.");
  73     Preconditions.checkNotNull(networkGraphService, "networkGraphService should not be null.");
  74     this.dataBrokerService = dataBrokerService;
  75     this.networkGraphService = networkGraphService;
  76     this.graphRefreshDelayInSec = graphRefreshDelayInSec;
  77   }
  78
  79   /**
  80    * Based on if links have been added or removed in topology data store, schedules a refresh of network graph.
  81    * @param dataChangeEvent
  82    */
  83   @Override
  84   public void onDataChanged(DataChangeEvent<InstanceIdentifier<?>, DataObject> dataChangeEvent) {
  85     if(dataChangeEvent == null) {
  86       _logger.info("In onDataChanged: No Processing done as dataChangeEvent is null.");
  87     }
  88     Map<InstanceIdentifier<?>, DataObject> linkOriginalData = dataChangeEvent.getOriginalOperationalData();
  89     Map<InstanceIdentifier<?>, DataObject> linkUpdatedData = dataChangeEvent.getUpdatedOperationalData();
  90     // change this logic, once MD-SAL start populating DeletedOperationData Set
  91     if(linkOriginalData != null && linkUpdatedData != null
  92         && (linkOriginalData.size() != 0 || linkUpdatedData.size() != 0)
  93         && !networkGraphRefreshScheduled) {
  94       networkGraphRefreshScheduled = linkOriginalData.size() != linkUpdatedData.size();
  95       if(networkGraphRefreshScheduled) {
  96         networkGraphRefreshScheduler.schedule(new NetworkGraphRefresher(), graphRefreshDelayInSec, TimeUnit.SECONDS);
  97       }
  98     }
  99
 100   }
 101
 102   /**
 103    * Registers as a data listener to receive changes done to
 104    * {@link org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Link}
 105    * under {@link org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NetworkTopology}
 106    * operation data root.
 107    */
 108
 109   public void registerAsDataChangeListener() {
 110     InstanceIdentifier<Link> linkInstance = InstanceIdentifier.builder(NetworkTopology.class)
 111         .child(Topology.class, new TopologyKey(new TopologyId(DEFAULT_TOPOLOGY_ID))).child(Link.class).toInstance();
 112     dataBrokerService.registerDataChangeListener(linkInstance, this);
 113   }
 114
 115   /**
 116    *
 117    */
 118   private class NetworkGraphRefresher implements Runnable {
 119     /**
 120      *
 121      */
 122     @Override
 123     public void run() {
 124       networkGraphRefreshScheduled = false;
 125       //TODO: it should refer to changed links only from DataChangeEvent above.
 126       List<Link> links = getLinksFromTopology(DEFAULT_TOPOLOGY_ID);
 127       networkGraphService.clear();// can remove this once changed links are addressed
 128       if(links != null && !links.isEmpty()) {
 129         networkGraphService.addLinks(links);
 130       }
 131     }
 132
 133     /**
 134      * @param topologyId
 135      * @return
 136      */
 137     private List<Link> getLinksFromTopology(String topologyId) {
 138       InstanceIdentifier<Topology> topologyInstanceIdentifier = InstanceIdentifierUtils.generateTopologyInstanceIdentifier(topologyId);
 139       Topology topology = (Topology) dataBrokerService.readOperationalData(topologyInstanceIdentifier);
 140       return topology.getLink();
 141     }
 142   }
 143 }