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