Java tutorial
/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.bgpcep.bgp.topology.provider; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.concurrent.ExecutionException; import org.opendaylight.controller.md.sal.binding.api.DataBroker; import org.opendaylight.controller.md.sal.binding.api.ReadTransaction; import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction; import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType; import org.opendaylight.protocol.bgp.rib.RibReference; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpPrefix; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.path.attributes.Attributes; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.Route; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.CNextHop; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv4NextHopCase; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.Ipv6NextHopCase; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.ipv4.next.hop._case.Ipv4NextHop; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.next.hop.c.next.hop.ipv6.next.hop._case.Ipv6NextHop; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NodeId; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.TopologyId; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Node; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.NodeBuilder; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.NodeKey; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.TopologyTypes; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.Node1; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.Node1Builder; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.igp.node.attributes.IgpNodeAttributes; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.igp.node.attributes.IgpNodeAttributesBuilder; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.igp.node.attributes.igp.node.attributes.Prefix; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.igp.node.attributes.igp.node.attributes.PrefixBuilder; import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.nt.l3.unicast.igp.topology.rev131021.igp.node.attributes.igp.node.attributes.PrefixKey; import org.opendaylight.yangtools.yang.binding.DataObject; import org.opendaylight.yangtools.yang.binding.InstanceIdentifier; import org.opendaylight.yangtools.yang.binding.KeyedInstanceIdentifier; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * */ abstract class AbstractReachabilityTopologyBuilder<T extends Route> extends AbstractTopologyBuilder<T> { private static final Logger LOG = LoggerFactory.getLogger(AbstractReachabilityTopologyBuilder.class); private final Map<NodeId, NodeUsage> nodes = new HashMap<>(); private static final class NodeUsage { private final InstanceIdentifier<IgpNodeAttributes> attrId; private int useCount = 1; NodeUsage(final InstanceIdentifier<IgpNodeAttributes> attrId) { this.attrId = Preconditions.checkNotNull(attrId); } } protected AbstractReachabilityTopologyBuilder(final DataBroker dataProvider, final RibReference locRibReference, final TopologyId topologyId, final TopologyTypes topologyTypes, final Class<? extends AddressFamily> afi, final Class<? extends SubsequentAddressFamily> safi) { super(dataProvider, locRibReference, topologyId, topologyTypes, afi, safi); } private NodeId advertizingNode(final Attributes attrs) { final CNextHop nh = attrs.getCNextHop(); if (nh == null) { LOG.warn("Next hop value is null"); return null; } else if (nh instanceof Ipv4NextHopCase) { final Ipv4NextHop ipv4 = ((Ipv4NextHopCase) nh).getIpv4NextHop(); return new NodeId(ipv4.getGlobal().getValue()); } else if (nh instanceof Ipv6NextHopCase) { final Ipv6NextHop ipv6 = ((Ipv6NextHopCase) nh).getIpv6NextHop(); return new NodeId(ipv6.getGlobal().getValue()); } else { LOG.warn("Unhandled next hop class {}", nh.getImplementedInterface()); return null; } } private KeyedInstanceIdentifier<Node, NodeKey> nodeInstanceId(final NodeId ni) { return getInstanceIdentifier().child(Node.class, new NodeKey(ni)); } private static <T extends DataObject> T read(final ReadTransaction t, final InstanceIdentifier<T> id) { final Optional<T> o; try { o = t.read(LogicalDatastoreType.OPERATIONAL, id).get(); } catch (InterruptedException | ExecutionException e) { LOG.warn("Failed to read {}, assuming non-existent", id, e); return null; } return o.orNull(); } private InstanceIdentifier<IgpNodeAttributes> ensureNodePresent(final ReadWriteTransaction trans, final NodeId ni) { final NodeUsage present = this.nodes.get(ni); if (present != null) { return present.attrId; } final KeyedInstanceIdentifier<Node, NodeKey> nii = nodeInstanceId(ni); final InstanceIdentifier<IgpNodeAttributes> ret = nii.builder().augmentation(Node1.class) .child(IgpNodeAttributes.class).build(); trans.merge(LogicalDatastoreType.OPERATIONAL, nii, new NodeBuilder().setKey(nii.getKey()).setNodeId(ni) .addAugmentation(Node1.class, new Node1Builder().setIgpNodeAttributes( new IgpNodeAttributesBuilder().setPrefix(Collections.<Prefix>emptyList()).build()) .build()) .build()); this.nodes.put(ni, new NodeUsage(ret)); return ret; } protected abstract Attributes getAttributes(final T value); protected abstract IpPrefix getPrefix(final T value); @Override protected final void createObject(final ReadWriteTransaction trans, final InstanceIdentifier<T> id, final T value) { final NodeId ni = advertizingNode(getAttributes(value)); if (ni == null) { return; } final InstanceIdentifier<IgpNodeAttributes> nii = ensureNodePresent(trans, ni); final IpPrefix prefix = getPrefix(value); final PrefixKey pk = new PrefixKey(prefix); trans.put(LogicalDatastoreType.OPERATIONAL, nii.child(Prefix.class, pk), new PrefixBuilder().setKey(pk).setPrefix(prefix).build()); } @Override protected final void removeObject(final ReadWriteTransaction trans, final InstanceIdentifier<T> id, final T value) { if (value == null) { LOG.error("Empty before-data received in delete data change notification for instance id {}", id); return; } final NodeId ni = advertizingNode(getAttributes(value)); if (ni == null) { return; } final NodeUsage present = this.nodes.get(ni); Preconditions.checkState(present != null, "Removing prefix from non-existent node %s", present); final PrefixKey pk = new PrefixKey(getPrefix(value)); trans.delete(LogicalDatastoreType.OPERATIONAL, present.attrId.child(Prefix.class, pk)); /* * This is optimization magic: we are reading a list and we want to remove it once it * hits zero. We may be in a transaction, so the read is costly, especially since we * have just modified the list. * * Once we have performed the read, though, we can check the number of nodes, and reuse * it for that number of removals. Note that since we do not track data and thus have * no understanding about the difference between replace and add, we do not ever increase * the life of this in createObject(). */ present.useCount--; if (present.useCount == 0) { final IgpNodeAttributes attrs = read(trans, present.attrId); if (attrs != null) { present.useCount = attrs.getPrefix().size(); if (present.useCount == 0) { trans.delete(LogicalDatastoreType.OPERATIONAL, nodeInstanceId(ni)); this.nodes.remove(ni); } } } } @Override protected void clearTopology() { this.nodes.clear(); } }