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 package org.opendaylight.controller.cluster.sharding;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.util.ArrayList;
  14 import java.util.Collection;
  15 import java.util.HashMap;
  16 import java.util.List;
  17 import java.util.Map;
  18 import javax.annotation.concurrent.GuardedBy;
  19 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  20 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  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.slf4j.Logger;
  33 import org.slf4j.LoggerFactory;
  34
  35 /**
  36  * Proxy implementation of a shard that creates forwarding producers to the backend shard.
  37  */
  38 class DistributedShardFrontend implements ReadableWriteableDOMDataTreeShard {
  39
  40     private static final Logger LOG = LoggerFactory.getLogger(DistributedShardFrontend.class);
  41
  42     private final DataStoreClient client;
  43     private final DOMDataTreeIdentifier shardRoot;
  44     @GuardedBy("this")
  45     private final Map<DOMDataTreeIdentifier, ChildShardContext> childShards = new HashMap<>();
  46     @GuardedBy("this")
  47     private final List<ShardProxyProducer> producers = new ArrayList<>();
  48
  49     private final DistributedShardChangePublisher publisher;
  50
  51     DistributedShardFrontend(final AbstractDataStore distributedDataStore,
  52                              final DataStoreClient client,
  53                              final DOMDataTreeIdentifier shardRoot) {
  54         this.client = requireNonNull(client);
  55         this.shardRoot = requireNonNull(shardRoot);
  56
  57         publisher = new DistributedShardChangePublisher(client, requireNonNull(distributedDataStore), shardRoot,
  58             childShards);
  59     }
  60
  61     @Override
  62     public synchronized DOMDataTreeShardProducer createProducer(final Collection<DOMDataTreeIdentifier> paths) {
  63         for (final DOMDataTreeIdentifier prodPrefix : paths) {
  64             checkArgument(shardRoot.contains(prodPrefix), "Prefix %s is not contained under shard root", prodPrefix,
  65                 paths);
  66         }
  67
  68         final ShardProxyProducer ret =
  69                 new ShardProxyProducer(shardRoot, paths, client, createModificationFactory(paths));
  70         producers.add(ret);
  71         return ret;
  72     }
  73
  74     @Override
  75     public synchronized void onChildAttached(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  76         LOG.debug("{} : Child shard attached at {}", shardRoot, prefix);
  77         checkArgument(child != this, "Attempted to attach child %s onto self", this);
  78         addChildShard(prefix, child);
  79         updateProducers();
  80     }
  81
  82     @Override
  83     public synchronized void onChildDetached(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  84         LOG.debug("{} : Child shard detached at {}", shardRoot, prefix);
  85         childShards.remove(prefix);
  86         updateProducers();
  87         // TODO we should grab the dataTreeSnapshot that's in the shard and apply it to this shard
  88     }
  89
  90     private void addChildShard(final DOMDataTreeIdentifier prefix, final DOMDataTreeShard child) {
  91         checkArgument(child instanceof WriteableDOMDataTreeShard);
  92         childShards.put(prefix, new ChildShardContext(prefix, (WriteableDOMDataTreeShard) child));
  93     }
  94
  95     DistributedShardModificationFactory createModificationFactory(final Collection<DOMDataTreeIdentifier> prefixes) {
  96         // TODO this could be abstract
  97         final Map<DOMDataTreeIdentifier, SubshardProducerSpecification> affectedSubshards = new HashMap<>();
  98
  99         for (final DOMDataTreeIdentifier producerPrefix : prefixes) {
 100             for (final ChildShardContext maybeAffected : childShards.values()) {
 101                 final DOMDataTreeIdentifier bindPath;
 102                 if (producerPrefix.contains(maybeAffected.getPrefix())) {
 103                     bindPath = maybeAffected.getPrefix();
 104                 } else if (maybeAffected.getPrefix().contains(producerPrefix)) {
 105                     // Bound path is inside subshard
 106                     bindPath = producerPrefix;
 107                 } else {
 108                     continue;
 109                 }
 110
 111                 SubshardProducerSpecification spec = affectedSubshards.computeIfAbsent(maybeAffected.getPrefix(),
 112                     k -> new SubshardProducerSpecification(maybeAffected));
 113                 spec.addPrefix(bindPath);
 114             }
 115         }
 116
 117         final DistributedShardModificationFactoryBuilder builder =
 118                 new DistributedShardModificationFactoryBuilder(shardRoot);
 119         for (final SubshardProducerSpecification spec : affectedSubshards.values()) {
 120             final ForeignShardModificationContext foreignContext =
 121                     new ForeignShardModificationContext(spec.getPrefix(), spec.createProducer());
 122             builder.addSubshard(foreignContext);
 123             builder.addSubshard(spec.getPrefix(), foreignContext);
 124         }
 125
 126         return builder.build();
 127     }
 128
 129     private void updateProducers() {
 130         for (final ShardProxyProducer producer : producers) {
 131             producer.setModificationFactory(createModificationFactory(producer.getPrefixes()));
 132         }
 133     }
 134
 135     @Override
 136     public <L extends DOMDataTreeChangeListener> ListenerRegistration<L> registerTreeChangeListener(
 137             final YangInstanceIdentifier treeId, final L listener) {
 138         return publisher.registerTreeChangeListener(treeId, listener);
 139     }
 140 }