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