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