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.Set;
  17 import java.util.TreeMap;
  18 import javax.annotation.concurrent.GuardedBy;
  19 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  20 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  21 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeLoopException;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  26 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  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     private final Map<LogicalDatastoreType, ShardingTableEntry> shardingTables = new EnumMap<>(LogicalDatastoreType.class);
  37     @GuardedBy("this")
  38     private final Map<DOMDataTreeIdentifier, DOMDataTreeProducer> idToProducer = new TreeMap<>();
  39
  40     @GuardedBy("this")
  41     private ShardingTableEntry lookupShard(final DOMDataTreeIdentifier prefix) {
  42         final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  43         if (t == null) {
  44             return null;
  45         }
  46
  47         return t.lookup(prefix.getRootIdentifier());
  48     }
  49
  50     @GuardedBy("this")
  51     private void storeShard(final DOMDataTreeIdentifier prefix, final ShardRegistration<?> reg) {
  52         ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  53         if (t == null) {
  54             t = new ShardingTableEntry();
  55             shardingTables.put(prefix.getDatastoreType(), t);
  56         }
  57
  58         t.store(prefix.getRootIdentifier(), reg);
  59     }
  60
  61     void removeShard(final ShardRegistration<?> reg) {
  62         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  63         final ShardRegistration<?> parentReg;
  64
  65         synchronized (this) {
  66             final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  67             if (t == null) {
  68                 LOG.warn("Shard registration {} points to non-existent table", reg);
  69                 return;
  70             }
  71
  72             t.remove(prefix.getRootIdentifier());
  73             parentReg = lookupShard(prefix).getRegistration();
  74
  75             /*
  76              * FIXME: adjust all producers and listeners. This is tricky, as we need different
  77              * locking strategy, simply because we risk AB/BA deadlock with a producer being split
  78              * off from a producer.
  79              */
  80         }
  81
  82         if (parentReg != null) {
  83             parentReg.getInstance().onChildDetached(prefix, reg.getInstance());
  84         }
  85     }
  86
  87     @Override
  88     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(final DOMDataTreeIdentifier prefix, final T shard) throws DOMDataTreeShardingConflictException {
  89         final ShardRegistration<T> reg;
  90         final ShardRegistration<?> parentReg;
  91
  92         synchronized (this) {
  93             /*
  94              * Lookup the parent shard (e.g. the one which currently matches the prefix),
  95              * and if it exists, check if its registration prefix does not collide with
  96              * this registration.
  97              */
  98             final ShardingTableEntry parent = lookupShard(prefix);
  99             if (parent != null) {
 100                 parentReg = parent.getRegistration();
 101                 if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
 102                     throw new DOMDataTreeShardingConflictException(String.format(
 103                             "Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
 104                 }
 105             } else {
 106                 parentReg = null;
 107             }
 108
 109             // FIXME: wrap the shard in a proper adaptor based on implemented interface
 110
 111             reg = new ShardRegistration<T>(this, prefix, shard);
 112
 113             storeShard(prefix, reg);
 114
 115             // FIXME: update any producers/registrations
 116         }
 117
 118         // Notify the parent shard
 119         if (parentReg != null) {
 120             parentReg.getInstance().onChildAttached(prefix, shard);
 121         }
 122
 123         return reg;
 124     }
 125
 126     @GuardedBy("this")
 127     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 128         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : idToProducer.entrySet()) {
 129             if (e.getKey().contains(subtree)) {
 130                 return e.getValue();
 131             }
 132         }
 133
 134         return null;
 135     }
 136
 137     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 138         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 139             final DOMDataTreeProducer r = idToProducer.remove(s);
 140             if (!producer.equals(r)) {
 141                 LOG.error("Removed producer {} on subtree {} while removing {}", r, s, producer);
 142             }
 143         }
 144     }
 145
 146     @GuardedBy("this")
 147     private DOMDataTreeProducer createProducer(final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 148         // Record the producer's attachment points
 149         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, shardMap);
 150         for (final DOMDataTreeIdentifier s : shardMap.keySet()) {
 151             idToProducer.put(s, ret);
 152         }
 153
 154         return ret;
 155     }
 156
 157     @Override
 158     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 159         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 160
 161         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 162         for (final DOMDataTreeIdentifier s : subtrees) {
 163             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 164             final DOMDataTreeProducer producer = findProducer(s);
 165             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", s, producer);
 166
 167             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 168         }
 169
 170         return createProducer(shardMap);
 171     }
 172
 173     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent, final Collection<DOMDataTreeIdentifier> subtrees) {
 174         Preconditions.checkNotNull(parent);
 175
 176         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 177         for (final DOMDataTreeIdentifier s : subtrees) {
 178             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 179         }
 180
 181         return createProducer(shardMap);
 182     }
 183
 184     @Override
 185     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener,
 186             final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges,
 187             final Collection<DOMDataTreeProducer> producers) throws DOMDataTreeLoopException {
 188         Preconditions.checkNotNull(listener, "listener");
 189         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees must not be empty.");
 190         final ShardedDOMDataTreeListenerContext<T> listenerContext =
 191                 ShardedDOMDataTreeListenerContext.create(listener, subtrees, allowRxMerges);
 192         try {
 193             // FIXME: Add attachment of producers
 194             for (DOMDataTreeProducer producer : producers) {
 195                 Preconditions.checkArgument(producer instanceof ShardedDOMDataTreeProducer);
 196                 ShardedDOMDataTreeProducer castedProducer = ((ShardedDOMDataTreeProducer) producer);
 197                 simpleLoopCheck(subtrees, castedProducer.getSubtrees());
 198                 // FIXME: We should also unbound listeners
 199                 castedProducer.boundToListener(listenerContext);
 200             }
 201
 202             for (DOMDataTreeIdentifier subtree : subtrees) {
 203                 DOMDataTreeShard shard = lookupShard(subtree).getRegistration().getInstance();
 204                 // FIXME: What should we do if listener is wildcard? And shards are on per
 205                 // node basis?
 206                 Preconditions.checkArgument(shard instanceof DOMStoreTreeChangePublisher,
 207                         "Subtree %s does not point to listenable subtree.", subtree);
 208
 209                 listenerContext.register(subtree, (DOMStoreTreeChangePublisher) shard);
 210             }
 211         } catch (Exception e) {
 212             listenerContext.close();
 213             throw e;
 214         }
 215         return new AbstractListenerRegistration<T>(listener) {
 216             @Override
 217             protected void removeRegistration() {
 218                 ShardedDOMDataTree.this.removeListener(listenerContext);
 219             }
 220         };
 221     }
 222
 223     private static void simpleLoopCheck(Collection<DOMDataTreeIdentifier> listen, Set<DOMDataTreeIdentifier> writes)
 224             throws DOMDataTreeLoopException {
 225         for(DOMDataTreeIdentifier listenPath : listen) {
 226             for (DOMDataTreeIdentifier writePath : writes) {
 227                 if (listenPath.contains(writePath)) {
 228                     throw new DOMDataTreeLoopException(String.format(
 229                             "Listener must not listen on parent (%s), and also writes child (%s)", listenPath,
 230                             writePath));
 231                 } else if (writePath.contains(listenPath)) {
 232                     throw new DOMDataTreeLoopException(
 233                             String.format("Listener must not write parent (%s), and also listen on child (%s)",
 234                                     writePath, listenPath));
 235                 }
 236             }
 237         }
 238     }
 239
 240     void removeListener(ShardedDOMDataTreeListenerContext<?> listener) {
 241         // FIXME: detach producers
 242         listener.close();
 243     }
 244 }