opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/sharding/DistributedShardFrontend.java

   1 /*
   2  * Copyright (c) 2016 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
   9 package org.opendaylight.controller.cluster.sharding;
  10
  11 import com.google.common.base.Preconditions;
  12 import java.util.ArrayList;
  13 import java.util.Collection;
  14 import java.util.HashMap;
  15 import java.util.List;
  16 import java.util.Map;
  17 import javax.annotation.Nonnull;
  18 import javax.annotation.concurrent.GuardedBy;
  19 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  20 import org.opendaylight.controller.cluster.datastore.DistributedDataStore;
  21 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  24 import org.opendaylight.mdsal.dom.spi.shard.ChildShardContext;
  25 import org.opendaylight.mdsal.dom.spi.shard.DOMDataTreeShardProducer;
  26 import org.opendaylight.mdsal.dom.spi.shard.ForeignShardModificationContext;
  27 import org.opendaylight.mdsal.dom.spi.shard.ReadableWriteableDOMDataTreeShard;
  28 import org.opendaylight.mdsal.dom.spi.shard.SubshardProducerSpecification;
  29 import org.opendaylight.mdsal.dom.spi.shard.WriteableDOMDataTreeShard;
  30 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  31 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  33 import org.slf4j.Logger;
  34 import org.slf4j.LoggerFactory;
  35
  36 /**
  37  * Proxy implementation of a shard that creates forwarding producers to the backend shard.
  38  */
  39 class DistributedShardFrontend implements ReadableWriteableDOMDataTreeShard {
  40
  41     private static final Logger LOG = LoggerFactory.getLogger(DistributedShardFrontend.class);
  42
  43     private final DataStoreClient client;
  44     private final DOMDataTreeIdentifier shardRoot;
  45     @GuardedBy("this")
  46     private final Map<DOMDataTreeIdentifier, ChildShardContext> childShards = new HashMap<>();
  47     @GuardedBy("this")
  48     private final List<ShardProxyProducer> producers = new ArrayList<>();
  49     private final DistributedDataStore distributedDataStore;
  50
  51     DistributedShardFrontend(final DistributedDataStore distributedDataStore,
  52                              final DataStoreClient client,
  53                              final DOMDataTreeIdentifier shardRoot) {
  54         this.distributedDataStore = Preconditions.checkNotNull(distributedDataStore);
  55         this.client = Preconditions.checkNotNull(client);
  56         this.shardRoot = Preconditions.checkNotNull(shardRoot);
  57     }
  58
  59     @Override
  60     public synchronized DOMDataTreeShardProducer createProducer(final Collection<DOMDataTreeIdentifier> paths) {
  61         for (final DOMDataTreeIdentifier prodPrefix : paths) {
  62             Preconditions.checkArgument(paths.contains(prodPrefix), "Prefix %s is not contained under shard root",
  63                     prodPrefix, paths);
  64         }
  65
  66         final ShardProxyProducer ret =
  67                 new ShardProxyProducer(shardRoot, paths, client, createModificationFactory(paths));
  68         producers.add(ret);
  69         return ret;
  70     }
  71
  72     @Override
  73     public synchronized void onChildAttached(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  74         LOG.debug("{} : Child shard attached at {}", shardRoot, prefix);
  75         Preconditions.checkArgument(child != this, "Attempted to attach child %s onto self", this);
  76         addChildShard(prefix, child);
  77         updateProducers();
  78     }
  79
  80     @Override
  81     public synchronized void onChildDetached(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  82         LOG.debug("{} : Child shard detached at {}", shardRoot, prefix);
  83         childShards.remove(prefix);
  84         updateProducers();
  85         // TODO we should grab the dataTreeSnapshot that's in the shard and apply it to this shard
  86     }
  87
  88     private void addChildShard(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  89         Preconditions.checkArgument(child instanceof WriteableDOMDataTreeShard);
  90         childShards.put(prefix, new ChildShardContext(prefix, (WriteableDOMDataTreeShard) child));
  91     }
  92
  93     DistributedShardModificationFactory createModificationFactory(final Collection<DOMDataTreeIdentifier> prefixes) {
  94         // TODO this could be abstract
  95         final Map<DOMDataTreeIdentifier, SubshardProducerSpecification> affectedSubshards = new HashMap<>();
  96
  97         for (final DOMDataTreeIdentifier producerPrefix : prefixes) {
  98             for (final ChildShardContext maybeAffected : childShards.values()) {
  99                 final DOMDataTreeIdentifier bindPath;
 100                 if (producerPrefix.contains(maybeAffected.getPrefix())) {
 101                     bindPath = maybeAffected.getPrefix();
 102                 } else if (maybeAffected.getPrefix().contains(producerPrefix)) {
 103                     // Bound path is inside subshard
 104                     bindPath = producerPrefix;
 105                 } else {
 106                     continue;
 107                 }
 108
 109                 SubshardProducerSpecification spec = affectedSubshards.get(maybeAffected.getPrefix());
 110                 if (spec == null) {
 111                     spec = new SubshardProducerSpecification(maybeAffected);
 112                     affectedSubshards.put(maybeAffected.getPrefix(), spec);
 113                 }
 114                 spec.addPrefix(bindPath);
 115             }
 116         }
 117
 118         final DistributedShardModificationFactoryBuilder builder =
 119                 new DistributedShardModificationFactoryBuilder(shardRoot);
 120         for (final SubshardProducerSpecification spec : affectedSubshards.values()) {
 121             final ForeignShardModificationContext foreignContext =
 122                     new ForeignShardModificationContext(spec.getPrefix(), spec.createProducer());
 123             builder.addSubshard(foreignContext);
 124             builder.addSubshard(spec.getPrefix(), foreignContext);
 125         }
 126
 127         return builder.build();
 128     }
 129
 130     private void updateProducers() {
 131         for (final ShardProxyProducer producer : producers) {
 132             producer.setModificationFactory(createModificationFactory(producer.getPrefixes()));
 133         }
 134     }
 135
 136     @Nonnull
 137     @Override
 138     @SuppressWarnings("unchecked")
 139     public <L extends DOMDataTreeChangeListener> ListenerRegistration<L> registerTreeChangeListener(
 140             final YangInstanceIdentifier treeId, final L listener) {
 141
 142         final List<PathArgument> toStrip = new ArrayList<>(shardRoot.getRootIdentifier().getPathArguments());
 143         final List<PathArgument> stripFrom = new ArrayList<>(treeId.getPathArguments());
 144
 145         while (!toStrip.isEmpty()) {
 146             stripFrom.remove(0);
 147             toStrip.remove(0);
 148         }
 149
 150         return (ListenerRegistration<L>) new ProxyRegistration(distributedDataStore
 151                 .registerProxyListener(treeId, YangInstanceIdentifier.create(stripFrom), listener), listener);
 152     }
 153
 154     private static class ProxyRegistration implements ListenerRegistration<DOMDataTreeChangeListener> {
 155
 156         private ListenerRegistration<org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener> proxy;
 157         private DOMDataTreeChangeListener listener;
 158
 159         private ProxyRegistration(
 160                 final ListenerRegistration<
 161                         org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener> proxy,
 162                 final DOMDataTreeChangeListener listener) {
 163             this.proxy = proxy;
 164             this.listener = listener;
 165         }
 166
 167         @Override
 168         public DOMDataTreeChangeListener getInstance() {
 169             return listener;
 170         }
 171
 172         @Override
 173         public void close() {
 174             proxy.close();
 175         }
 176     }
 177
 178 }