opendaylight/md-sal/sal-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 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.controller.md.sal.common.api.data.LogicalDatastoreType;
  19 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeIdentifier;
  20 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeListener;
  21 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeProducer;
  22 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeService;
  23 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeShard;
  24 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeShardingConflictException;
  25 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeShardingService;
  26 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 public final class ShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService {
  31     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTree.class);
  32     private final Map<LogicalDatastoreType, ShardingTableEntry> shardingTables = new EnumMap<>(LogicalDatastoreType.class);
  33     @GuardedBy("this")
  34     private final Map<DOMDataTreeIdentifier, DOMDataTreeProducer> idToProducer = new TreeMap<>();
  35
  36     @GuardedBy("this")
  37     private ShardingTableEntry lookupShard(final DOMDataTreeIdentifier prefix) {
  38         final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  39         if (t == null) {
  40             return null;
  41         }
  42
  43         return t.lookup(prefix.getRootIdentifier());
  44     }
  45
  46     @GuardedBy("this")
  47     private void storeShard(final DOMDataTreeIdentifier prefix, final ShardRegistration<?> reg) {
  48         ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  49         if (t == null) {
  50             t = new ShardingTableEntry();
  51             shardingTables.put(prefix.getDatastoreType(), t);
  52         }
  53
  54         t.store(prefix.getRootIdentifier(), reg);
  55     }
  56
  57     void removeShard(final ShardRegistration<?> reg) {
  58         final DOMDataTreeIdentifier prefix = reg.getPrefix();
  59         final ShardRegistration<?> parentReg;
  60
  61         synchronized (this) {
  62             final ShardingTableEntry t = shardingTables.get(prefix.getDatastoreType());
  63             if (t == null) {
  64                 LOG.warn("Shard registration {} points to non-existent table", reg);
  65                 return;
  66             }
  67
  68             t.remove(prefix.getRootIdentifier());
  69             parentReg = lookupShard(prefix).getRegistration();
  70
  71             /*
  72              * FIXME: adjust all producers. This is tricky, as we need different locking strategy,
  73              *        simply because we risk AB/BA deadlock with a producer being split off from
  74              *        a producer.
  75              *
  76              */
  77         }
  78
  79         if (parentReg != null) {
  80             parentReg.getInstance().onChildDetached(prefix, reg.getInstance());
  81         }
  82     }
  83
  84     @Override
  85     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(final DOMDataTreeIdentifier prefix, final T shard) throws DOMDataTreeShardingConflictException {
  86         final ShardRegistration<T> reg;
  87         final ShardRegistration<?> parentReg;
  88
  89         synchronized (this) {
  90             /*
  91              * Lookup the parent shard (e.g. the one which currently matches the prefix),
  92              * and if it exists, check if its registration prefix does not collide with
  93              * this registration.
  94              */
  95             final ShardingTableEntry parent = lookupShard(prefix);
  96             parentReg = parent.getRegistration();
  97             if (parentReg != null && prefix.equals(parentReg.getPrefix())) {
  98                 throw new DOMDataTreeShardingConflictException(String.format("Prefix %s is already occupied by shard %s", prefix, parentReg.getInstance()));
  99             }
 100
 101             // FIXME: wrap the shard in a proper adaptor based on implemented interface
 102
 103             reg = new ShardRegistration<T>(this, prefix, shard);
 104
 105             storeShard(prefix, reg);
 106
 107             // FIXME: update any producers/registrations
 108         }
 109
 110         // Notify the parent shard
 111         if (parentReg != null) {
 112             parentReg.getInstance().onChildAttached(prefix, shard);
 113         }
 114
 115         return reg;
 116     }
 117
 118     @GuardedBy("this")
 119     private DOMDataTreeProducer findProducer(final DOMDataTreeIdentifier subtree) {
 120         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : idToProducer.entrySet()) {
 121             if (e.getKey().contains(subtree)) {
 122                 return e.getValue();
 123             }
 124         }
 125
 126         return null;
 127     }
 128
 129     synchronized void destroyProducer(final ShardedDOMDataTreeProducer producer) {
 130         for (final DOMDataTreeIdentifier s : producer.getSubtrees()) {
 131             final DOMDataTreeProducer r = idToProducer.remove(s);
 132             if (!producer.equals(r)) {
 133                 LOG.error("Removed producer {} on subtree {} while removing {}", r, s, producer);
 134             }
 135         }
 136     }
 137
 138     @GuardedBy("this")
 139     private DOMDataTreeProducer createProducer(final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 140         // Record the producer's attachment points
 141         final DOMDataTreeProducer ret = ShardedDOMDataTreeProducer.create(this, shardMap);
 142         for (DOMDataTreeIdentifier s : shardMap.keySet()) {
 143             idToProducer.put(s, ret);
 144         }
 145
 146         return ret;
 147     }
 148
 149     @Override
 150     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 151         Preconditions.checkArgument(!subtrees.isEmpty(), "Subtrees may not be empty");
 152
 153         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 154         for (final DOMDataTreeIdentifier s : subtrees) {
 155             // Attempting to create a disconnected producer -- all subtrees have to be unclaimed
 156             final DOMDataTreeProducer producer = findProducer(s);
 157             Preconditions.checkArgument(producer == null, "Subtree %s is attached to producer %s", s, producer);
 158
 159             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 160         }
 161
 162         return createProducer(shardMap);
 163     }
 164
 165     synchronized DOMDataTreeProducer createProducer(final ShardedDOMDataTreeProducer parent, final Collection<DOMDataTreeIdentifier> subtrees) {
 166         Preconditions.checkNotNull(parent);
 167
 168         final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap = new HashMap<>();
 169         for (final DOMDataTreeIdentifier s : subtrees) {
 170             shardMap.put(s, lookupShard(s).getRegistration().getInstance());
 171         }
 172
 173         return createProducer(shardMap);
 174     }
 175
 176     @Override
 177     public synchronized <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(final T listener, final Collection<DOMDataTreeIdentifier> subtrees, final boolean allowRxMerges, final Collection<DOMDataTreeProducer> producers) {
 178         // FIXME Implement this.
 179         throw new UnsupportedOperationException("Not implemented yet.");
 180     }
 181 }