dom/mdsal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/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.controller.md.sal.dom.broker.impl;
   9
  10 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  11 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  12 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  13 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  14 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  15 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  16 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  17
  18 import com.google.common.base.Preconditions;
  19 import java.util.Collection;
  20 import java.util.EnumMap;
  21 import java.util.HashMap;
  22 import java.util.Map;
  23 import java.util.Map.Entry;
  24 import java.util.TreeMap;
  25 import javax.annotation.concurrent.GuardedBy;
  26 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  27 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30
  31 public final class ShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService {
  32     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTree.class);
  33     private final Map<LogicalDatastoreType, ShardingTableEntry> shardingTables = new EnumMap<>(LogicalDatastoreType.class);
  34     @GuardedBy("this")
  35     private final Map<DOMDataTreeIdentifier, DOMDataTreeProducer> idToProducer = new TreeMap<>();
  36
  37     @GuardedBy("this")
  38     private ShardingTableEntry lookupShard(final DOMDataTreeIdentifier prefix) {
  39         final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  40         if (t == null) {
  41             return null;
  42         }
  43
  44         return t.lookup(prefix.getRootIdentifier());
  45     }
  46
  47     @GuardedBy("this")
  48     private void storeShard(final DOMDataTreeIdentifier prefix, final ShardRegistration<?> reg) {
  49         ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  50         if (t == null) {
  51             t = new ShardingTableEntry();
  52             shardingTables.put(prefix.getDatastoreType(), t);
  53         }
  54
  55         t.store(prefix.getRootIdentifier(), reg);
  56     }
  57
  58     void removeShard(final ShardRegistration<?> reg) {
  59         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  60         final ShardRegistration<?> parentReg;
  61
  62         synchronized (this) {
  63             final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  64             if (t == null) {
  65                 LOG.warn("Shard registration {} points to non-existent table", reg);
  66                 return;
  67             }
  68
  69             t.remove(prefix.getRootIdentifier());
  70             parentReg = lookupShard(prefix).getRegistration();
  71
  72             /*
  73              * FIXME: adjust all producers. This is tricky, as we need different locking strategy,
  74              *        simply because we risk AB/BA deadlock with a producer being split off from
  75              *        a producer.
  76              *
  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             parentReg = parent.getRegistration();
  98             if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
  99                 throw new DOMDataTreeShardingConflictException(String.format("Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
 100             }
 101
 102             // FIXME: wrap the shard in a proper adaptor based on implemented interface
 103
 104             reg = new ShardRegistration<T>(this, prefix, shard);
 105
 106             storeShard(prefix, reg);
 107
 108             // FIXME: update any producers/registrations
 109         }
 110
 111         // Notify the parent shard
 112         if (parentReg != null) {
 113             parentReg.getInstance().onChildAttached(prefix, shard);
 114         }
 115
 116         return reg;
 117     }
 118
 119     @GuardedBy("this")
 120     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 121         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : idToProducer.entrySet()) {
 122             if (e.getKey().contains(subtree)) {
 123                 return e.getValue();
 124             }
 125         }
 126
 127         return null;
 128     }
 129
 130     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 131         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 132             final DOMDataTreeProducer r = idToProducer.remove(s);
 133             if (!producer.equals(r)) {
 134                 LOG.error("Removed producer {} on subtree {} while removing {}", r, s, producer);
 135             }
 136         }
 137     }
 138
 139     @GuardedBy("this")
 140     private DOMDataTreeProducer createProducer(final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 141         // Record the producer's attachment points
 142         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, shardMap);
 143         for (DOMDataTreeIdentifier s : shardMap.keySet()) {
 144             idToProducer.put(s, ret);
 145         }
 146
 147         return ret;
 148     }
 149
 150     @Override
 151     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 152         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 153
 154         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 155         for (final DOMDataTreeIdentifier s : subtrees) {
 156             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 157             final DOMDataTreeProducer producer = findProducer(s);
 158             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", s, producer);
 159
 160             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 161         }
 162
 163         return createProducer(shardMap);
 164     }
 165
 166     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent, final Collection<DOMDataTreeIdentifier> subtrees) {
 167         Preconditions.checkNotNull(parent);
 168
 169         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 170         for (final DOMDataTreeIdentifier s : subtrees) {
 171             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 172         }
 173
 174         return createProducer(shardMap);
 175     }
 176
 177     @Override
 178     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener, final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges, final Collection<DOMDataTreeProducer> producers) {
 179         // FIXME Implement this.
 180         throw new UnsupportedOperationException("Not implemented yet.");
 181     }
 182 }