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
  32 public final class ShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService {
  33
  34     @GuardedBy("this")
  35     private final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<?>> shards = DOMDataTreePrefixTable.create();
  36     @GuardedBy("this")
  37     private final DOMDataTreePrefixTable<DOMDataTreeProducer> producers = DOMDataTreePrefixTable.create();
  38
  39     void removeShard(final DOMDataTreeShardRegistration<?> reg) {
  40         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  41         final DOMDataTreeShardRegistration<?> parentReg;
  42
  43         synchronized (this) {
  44             shards.remove(prefix);
  45             parentReg = shards.lookup(prefix).getValue();
  46
  47             /*
  48              * FIXME: adjust all producers and listeners. This is tricky, as we need different
  49              * locking strategy, simply because we risk AB/BA deadlock with a producer being split
  50              * off from a producer.
  51              */
  52         }
  53
  54         if (parentReg != null) {
  55             parentReg.getInstance().onChildDetached(prefix, reg.getInstance());
  56         }
  57     }
  58
  59     @Override
  60     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(
  61             final DOMDataTreeIdentifier prefix, final T shard, final DOMDataTreeProducer producer)
  62                     throws DOMDataTreeShardingConflictException {
  63
  64         final DOMDataTreeIdentifier firstSubtree = Iterables.getOnlyElement(((
  65                 ShardedDOMDataTreeProducer) producer).getSubtrees());
  66         Preconditions.checkArgument(firstSubtree != null, "Producer that is used to verify namespace claim can"
  67                 + " only claim a single namespace");
  68         Preconditions.checkArgument(prefix.equals(firstSubtree), "Trying to register shard to a different namespace"
  69                 + " than the producer has claimed");
  70
  71         final DOMDataTreeShardRegistration<T> reg;
  72         final DOMDataTreeShardRegistration<?> parentReg;
  73
  74         synchronized (this) {
  75             /*
  76              * Lookup the parent shard (e.g. the one which currently matches the prefix),
  77              * and if it exists, check if its registration prefix does not collide with
  78              * this registration.
  79              */
  80             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<?>> parent = shards.lookup(prefix);
  81             if (parent != null) {
  82                 parentReg = parent.getValue();
  83                 if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
  84                     throw new DOMDataTreeShardingConflictException(String.format(
  85                             "Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
  86                 }
  87             } else {
  88                 parentReg = null;
  89             }
  90
  91             // FIXME: wrap the shard in a proper adaptor based on implemented interface
  92
  93             reg = new DOMDataTreeShardRegistration<>(this, prefix, shard);
  94
  95             shards.store(prefix, reg);
  96
  97             ((ShardedDOMDataTreeProducer) producer).subshardAdded(Collections.singletonMap(prefix, shard));
  98         }
  99
 100         // Notify the parent shard
 101         if (parentReg != null) {
 102             parentReg.getInstance().onChildAttached(prefix, shard);
 103         }
 104
 105         return reg;
 106     }
 107
 108     @GuardedBy("this")
 109     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 110
 111         final DOMDataTreePrefixTableEntry<DOMDataTreeProducer> producerEntry = producers.lookup(subtree);
 112         if (producerEntry != null) {
 113             return producerEntry.getValue();
 114         }
 115         return null;
 116     }
 117
 118     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 119         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 120             producers.remove(s);
 121         }
 122     }
 123
 124     @GuardedBy("this")
 125     private DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees,
 126             final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 127         // Record the producer's attachment points
 128         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, subtrees, shardMap);
 129         for (final DOMDataTreeIdentifier subtree : subtrees) {
 130             producers.store(subtree, ret);
 131         }
 132
 133         return ret;
 134     }
 135
 136     @Override
 137     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 138         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 139
 140         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 141         for (final DOMDataTreeIdentifier subtree : subtrees) {
 142             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 143             final DOMDataTreeProducer producer = findProducer(subtree);
 144             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", subtree, producer);
 145
 146             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<?>> possibleShardReg =
 147                     shards.lookup(subtree);
 148             if (possibleShardReg != null && possibleShardReg.getValue() != null) {
 149                 shardMap.put(subtree, possibleShardReg.getValue().getInstance());
 150             }
 151         }
 152
 153         return createProducer(subtrees, shardMap);
 154     }
 155
 156     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent,
 157             final Collection<DOMDataTreeIdentifier> subtrees) {
 158         Preconditions.checkNotNull(parent);
 159
 160         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 161         for (final DOMDataTreeIdentifier s : subtrees) {
 162             shardMap.put(s, shards.lookup(s).getValue().getInstance());
 163         }
 164
 165         return createProducer(subtrees, shardMap);
 166     }
 167
 168     @SuppressWarnings("checkstyle:IllegalCatch")
 169     @Override
 170     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener,
 171             final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges,
 172             final Collection<DOMDataTreeProducer> producers) throws DOMDataTreeLoopException {
 173         Preconditions.checkNotNull(listener, "listener");
 174         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees must not be empty.");
 175         final ShardedDOMDataTreeListenerContext<T> listenerContext =
 176                 ShardedDOMDataTreeListenerContext.create(listener);
 177         try {
 178             // FIXME: Add attachment of producers
 179             for (final DOMDataTreeProducer producer : producers) {
 180                 Preconditions.checkArgument(producer instanceof ShardedDOMDataTreeProducer);
 181                 final ShardedDOMDataTreeProducer castedProducer = (ShardedDOMDataTreeProducer) producer;
 182                 simpleLoopCheck(subtrees, castedProducer.getSubtrees());
 183                 // FIXME: We should also unbound listeners
 184                 castedProducer.bindToListener(listenerContext);
 185             }
 186
 187             for (final DOMDataTreeIdentifier subtree : subtrees) {
 188                 final DOMDataTreeShard shard = shards.lookup(subtree).getValue().getInstance();
 189                 // FIXME: What should we do if listener is wildcard? And shards are on per
 190                 // node basis?
 191                 Preconditions.checkArgument(shard instanceof DOMStoreTreeChangePublisher,
 192                         "Subtree %s does not point to listenable subtree.", subtree);
 193
 194                 listenerContext.register(subtree, (DOMStoreTreeChangePublisher) shard);
 195             }
 196         } catch (final Exception e) {
 197             listenerContext.close();
 198             throw e;
 199         }
 200         return new AbstractListenerRegistration<T>(listener) {
 201             @Override
 202             protected void removeRegistration() {
 203                 ShardedDOMDataTree.this.removeListener(listenerContext);
 204             }
 205         };
 206     }
 207
 208     private static void simpleLoopCheck(final Collection<DOMDataTreeIdentifier> listen,
 209             final Set<DOMDataTreeIdentifier> writes) throws DOMDataTreeLoopException {
 210         for (final DOMDataTreeIdentifier listenPath : listen) {
 211             for (final DOMDataTreeIdentifier writePath : writes) {
 212                 if (listenPath.contains(writePath)) {
 213                     throw new DOMDataTreeLoopException(String.format(
 214                             "Listener must not listen on parent (%s), and also writes child (%s)", listenPath,
 215                             writePath));
 216                 } else if (writePath.contains(listenPath)) {
 217                     throw new DOMDataTreeLoopException(
 218                             String.format("Listener must not write parent (%s), and also listen on child (%s)",
 219                                     writePath, listenPath));
 220                 }
 221             }
 222         }
 223     }
 224
 225     void removeListener(final ShardedDOMDataTreeListenerContext<?> listener) {
 226         // FIXME: detach producers
 227         listener.close();
 228     }
 229 }