dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/ShardedDOMDataTree.java

   1 /*
   2  * Copyright (c) 2015 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.mdsal.dom.broker;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.collect.Iterables;
  12 import java.util.Collection;
  13 import java.util.Collections;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16 import java.util.Set;
  17 import javax.annotation.concurrent.GuardedBy;
  18 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  19 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  20 import org.opendaylight.mdsal.dom.api.DOMDataTreeLoopException;
  21 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  26 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTable;
  27 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTableEntry;
  28 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTreeChangePublisher;
  29 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  30 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 public final class ShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService {
  35     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTree.class);
  36
  37     @GuardedBy("this")
  38     private final DOMDataTreePrefixTable<ShardRegistration<?>> shards = DOMDataTreePrefixTable.create();
  39     @GuardedBy("this")
  40     private final DOMDataTreePrefixTable<DOMDataTreeProducer> producers = DOMDataTreePrefixTable.create();
  41
  42
  43     void removeShard(final ShardRegistration<?> reg) {
  44         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  45         final ShardRegistration<?> parentReg;
  46
  47         synchronized (this) {
  48             shards.remove(prefix);
  49             parentReg = shards.lookup(prefix).getValue();
  50
  51             /*
  52              * FIXME: adjust all producers and listeners. This is tricky, as we need different
  53              * locking strategy, simply because we risk AB/BA deadlock with a producer being split
  54              * off from a producer.
  55              */
  56         }
  57
  58         if (parentReg != null) {
  59             parentReg.getInstance().onChildDetached(prefix, reg.getInstance());
  60         }
  61     }
  62
  63     @Override
  64     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(final DOMDataTreeIdentifier prefix, final T shard, final DOMDataTreeProducer producer) throws DOMDataTreeShardingConflictException {
  65
  66         final DOMDataTreeIdentifier firstSubtree = Iterables.getOnlyElement(((ShardedDOMDataTreeProducer) producer).getSubtrees());
  67         Preconditions.checkArgument(firstSubtree != null, "Producer that is used to verify namespace claim can only claim a single namespace");
  68         Preconditions.checkArgument(prefix.equals(firstSubtree), "Trying to register shard to a different namespace than the producer has claimed");
  69
  70         final ShardRegistration<T> reg;
  71         final ShardRegistration<?> parentReg;
  72
  73         synchronized (this) {
  74             /*
  75              * Lookup the parent shard (e.g. the one which currently matches the prefix),
  76              * and if it exists, check if its registration prefix does not collide with
  77              * this registration.
  78              */
  79             final DOMDataTreePrefixTableEntry<ShardRegistration<?>> parent = shards.lookup(prefix);
  80             if (parent != null) {
  81                 parentReg = parent.getValue();
  82                 if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
  83                     throw new DOMDataTreeShardingConflictException(String.format(
  84                             "Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
  85                 }
  86             } else {
  87                 parentReg = null;
  88             }
  89
  90             // FIXME: wrap the shard in a proper adaptor based on implemented interface
  91
  92             reg = new ShardRegistration<T>(this, prefix, shard);
  93
  94             shards.store(prefix, reg);
  95
  96             ((ShardedDOMDataTreeProducer) producer).subshardAdded(Collections.singletonMap(prefix, shard));
  97         }
  98
  99         // Notify the parent shard
 100         if (parentReg != null) {
 101             parentReg.getInstance().onChildAttached(prefix, shard);
 102         }
 103
 104         return reg;
 105     }
 106
 107     @GuardedBy("this")
 108     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 109
 110         final DOMDataTreePrefixTableEntry<DOMDataTreeProducer> producerEntry = producers.lookup(subtree);
 111         if (producerEntry != null) {
 112             return producerEntry.getValue();
 113         }
 114         return null;
 115     }
 116
 117     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 118         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 119             producers.remove(s);
 120         }
 121     }
 122
 123     @GuardedBy("this")
 124     private DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees, final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 125         // Record the producer's attachment points
 126         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, subtrees, shardMap);
 127         for (final DOMDataTreeIdentifier subtree : subtrees) {
 128             producers.store(subtree, ret);
 129         }
 130
 131         return ret;
 132     }
 133
 134     @Override
 135     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 136         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 137
 138         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 139         for (final DOMDataTreeIdentifier subtree : subtrees) {
 140             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 141             final DOMDataTreeProducer producer = findProducer(subtree);
 142             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", subtree, producer);
 143
 144             final DOMDataTreePrefixTableEntry<ShardRegistration<?>> possibleShardReg = shards.lookup(subtree);
 145             if (possibleShardReg != null && possibleShardReg.getValue() != null) {
 146                 shardMap.put(subtree, possibleShardReg.getValue().getInstance());
 147             }
 148         }
 149
 150         return createProducer(subtrees, shardMap);
 151     }
 152
 153     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent, final Collection<DOMDataTreeIdentifier> subtrees) {
 154         Preconditions.checkNotNull(parent);
 155
 156         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 157         for (final DOMDataTreeIdentifier s : subtrees) {
 158             shardMap.put(s, shards.lookup(s).getValue().getInstance());
 159         }
 160
 161         return createProducer(subtrees, shardMap);
 162     }
 163
 164     @Override
 165     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener,
 166             final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges,
 167             final Collection<DOMDataTreeProducer> producers) throws DOMDataTreeLoopException {
 168         Preconditions.checkNotNull(listener, "listener");
 169         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees must not be empty.");
 170         final ShardedDOMDataTreeListenerContext<T> listenerContext =
 171                 ShardedDOMDataTreeListenerContext.create(listener, subtrees, allowRxMerges);
 172         try {
 173             // FIXME: Add attachment of producers
 174             for (final DOMDataTreeProducer producer : producers) {
 175                 Preconditions.checkArgument(producer instanceof ShardedDOMDataTreeProducer);
 176                 final ShardedDOMDataTreeProducer castedProducer = ((ShardedDOMDataTreeProducer) producer);
 177                 simpleLoopCheck(subtrees, castedProducer.getSubtrees());
 178                 // FIXME: We should also unbound listeners
 179                 castedProducer.boundToListener(listenerContext);
 180             }
 181
 182             for (final DOMDataTreeIdentifier subtree : subtrees) {
 183                 final DOMDataTreeShard shard = shards.lookup(subtree).getValue().getInstance();
 184                 // FIXME: What should we do if listener is wildcard? And shards are on per
 185                 // node basis?
 186                 Preconditions.checkArgument(shard instanceof DOMStoreTreeChangePublisher,
 187                         "Subtree %s does not point to listenable subtree.", subtree);
 188
 189                 listenerContext.register(subtree, (DOMStoreTreeChangePublisher) shard);
 190             }
 191         } catch (final Exception e) {
 192             listenerContext.close();
 193             throw e;
 194         }
 195         return new AbstractListenerRegistration<T>(listener) {
 196             @Override
 197             protected void removeRegistration() {
 198                 ShardedDOMDataTree.this.removeListener(listenerContext);
 199             }
 200         };
 201     }
 202
 203     private static void simpleLoopCheck(final Collection<DOMDataTreeIdentifier> listen, final Set<DOMDataTreeIdentifier> writes)
 204             throws DOMDataTreeLoopException {
 205         for(final DOMDataTreeIdentifier listenPath : listen) {
 206             for (final DOMDataTreeIdentifier writePath : writes) {
 207                 if (listenPath.contains(writePath)) {
 208                     throw new DOMDataTreeLoopException(String.format(
 209                             "Listener must not listen on parent (%s), and also writes child (%s)", listenPath,
 210                             writePath));
 211                 } else if (writePath.contains(listenPath)) {
 212                     throw new DOMDataTreeLoopException(
 213                             String.format("Listener must not write parent (%s), and also listen on child (%s)",
 214                                     writePath, listenPath));
 215                 }
 216             }
 217         }
 218     }
 219
 220     void removeListener(final ShardedDOMDataTreeListenerContext<?> listener) {
 221         // FIXME: detach producers
 222         listener.close();
 223     }
 224 }