dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/ShardedDOMDataTreeProducer.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 org.opendaylight.mdsal.dom.spi.store.DOMStore;
  11 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTransactionChain;
  12 import org.opendaylight.mdsal.dom.spi.store.DOMStoreWriteTransaction;
  13
  14 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  15 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  16 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerBusyException;
  17 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerException;
  18 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  19 import org.opendaylight.mdsal.dom.api.DOMDataWriteTransaction;
  20 import com.google.common.base.Preconditions;
  21 import com.google.common.collect.BiMap;
  22 import com.google.common.collect.ImmutableBiMap;
  23 import com.google.common.collect.ImmutableBiMap.Builder;
  24 import com.google.common.collect.ImmutableMap;
  25 import com.google.common.collect.ImmutableSet;
  26 import java.util.Collection;
  27 import java.util.Collections;
  28 import java.util.HashMap;
  29 import java.util.LinkedList;
  30 import java.util.Map;
  31 import java.util.Map.Entry;
  32 import java.util.Queue;
  33 import java.util.Set;
  34 import javax.annotation.concurrent.GuardedBy;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 final class ShardedDOMDataTreeProducer implements DOMDataTreeProducer {
  39     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTreeProducer.class);
  40     private final BiMap<DOMDataTreeShard, DOMStoreTransactionChain> shardToChain;
  41     private final Map<DOMDataTreeIdentifier, DOMDataTreeShard> idToShard;
  42     private final ShardedDOMDataTree dataTree;
  43
  44     @GuardedBy("this")
  45     private Map<DOMDataTreeIdentifier, DOMDataTreeProducer> children = Collections.emptyMap();
  46     @GuardedBy("this")
  47     private DOMDataWriteTransaction openTx;
  48     @GuardedBy("this")
  49     private boolean closed;
  50
  51     ShardedDOMDataTreeProducer(final ShardedDOMDataTree dataTree, final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap, final Set<DOMDataTreeShard> shards) {
  52         this.dataTree = Preconditions.checkNotNull(dataTree);
  53
  54         // Create shard -> chain map
  55         final Builder<DOMDataTreeShard, DOMStoreTransactionChain> cb = ImmutableBiMap.builder();
  56         final Queue<Exception> es = new LinkedList<>();
  57
  58         for (final DOMDataTreeShard s : shards) {
  59             if (s instanceof DOMStore) {
  60                 try {
  61                     final DOMStoreTransactionChain c = ((DOMStore)s).createTransactionChain();
  62                     LOG.trace("Using DOMStore chain {} to access shard {}", c, s);
  63                     cb.put(s, c);
  64                 } catch (final Exception e) {
  65                     LOG.error("Failed to instantiate chain for shard {}", s, e);
  66                     es.add(e);
  67                 }
  68             } else {
  69                 LOG.error("Unhandled shard instance type {}", s.getClass());
  70             }
  71         }
  72         this.shardToChain = cb.build();
  73
  74         // An error was encountered, close chains and report the error
  75         if (shardToChain.size() != shards.size()) {
  76             for (final DOMStoreTransactionChain c : shardToChain.values()) {
  77                 try {
  78                     c.close();
  79                 } catch (final Exception e) {
  80                     LOG.warn("Exception raised while closing chain {}", c, e);
  81                 }
  82             }
  83
  84             final IllegalStateException e = new IllegalStateException("Failed to completely allocate contexts", es.poll());
  85             while (!es.isEmpty()) {
  86                 e.addSuppressed(es.poll());
  87             }
  88
  89             throw e;
  90         }
  91
  92         idToShard = ImmutableMap.copyOf(shardMap);
  93     }
  94
  95     @Override
  96     public synchronized DOMDataWriteTransaction createTransaction(final boolean isolated) {
  97         Preconditions.checkState(!closed, "Producer is already closed");
  98         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
  99
 100         // Allocate backing transactions
 101         final Map<DOMDataTreeShard, DOMStoreWriteTransaction> shardToTx = new HashMap<>();
 102         for (final Entry<DOMDataTreeShard, DOMStoreTransactionChain> e : shardToChain.entrySet()) {
 103             shardToTx.put(e.getKey(), e.getValue().newWriteOnlyTransaction());
 104         }
 105
 106         // Create the ID->transaction map
 107         final ImmutableMap.Builder<DOMDataTreeIdentifier, DOMStoreWriteTransaction> b = ImmutableMap.builder();
 108         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeShard> e : idToShard.entrySet()) {
 109             b.put(e.getKey(), shardToTx.get(e.getValue()));
 110         }
 111
 112         final ShardedDOMDataWriteTransaction ret = new ShardedDOMDataWriteTransaction(this, b.build());
 113         openTx = ret;
 114         return ret;
 115     }
 116
 117     @GuardedBy("this")
 118     private boolean haveSubtree(final DOMDataTreeIdentifier subtree) {
 119         for (final DOMDataTreeIdentifier i : idToShard.keySet()) {
 120             if (i.contains(subtree)) {
 121                 return true;
 122             }
 123         }
 124
 125         return false;
 126     }
 127
 128     @GuardedBy("this")
 129     private DOMDataTreeProducer lookupChild(final DOMDataTreeIdentifier s) {
 130         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : children.entrySet()) {
 131             if (e.getKey().contains(s)) {
 132                 return e.getValue();
 133             }
 134         }
 135
 136         return null;
 137     }
 138
 139     @Override
 140     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 141         Preconditions.checkState(!closed, "Producer is already closed");
 142         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
 143
 144         for (final DOMDataTreeIdentifier s : subtrees) {
 145             // Check if the subtree was visible at any time
 146             if (!haveSubtree(s)) {
 147                 throw new IllegalArgumentException(String.format("Subtree %s was never available in producer %s", s, this));
 148             }
 149
 150             // Check if the subtree has not been delegated to a child
 151             final DOMDataTreeProducer child = lookupChild(s);
 152             Preconditions.checkArgument(child == null, "Subtree %s is delegated to child producer %s", s, child);
 153
 154             // Check if part of the requested subtree is not delegated to a child.
 155             for (final DOMDataTreeIdentifier c : children.keySet()) {
 156                 if (s.contains(c)) {
 157                     throw new IllegalArgumentException(String.format("Subtree %s cannot be delegated as it is superset of already-delegated %s", s, c));
 158                 }
 159             }
 160         }
 161
 162         final DOMDataTreeProducer ret = dataTree.createProducer(this, subtrees);
 163         final ImmutableMap.Builder<DOMDataTreeIdentifier, DOMDataTreeProducer> cb = ImmutableMap.builder();
 164         cb.putAll(children);
 165         for (final DOMDataTreeIdentifier s : subtrees) {
 166             cb.put(s, ret);
 167         }
 168
 169         children = cb.build();
 170         return ret;
 171     }
 172
 173     @Override
 174     public synchronized void close() throws DOMDataTreeProducerException {
 175         if (!closed) {
 176             if (openTx != null) {
 177                 throw new DOMDataTreeProducerBusyException(String.format("Transaction %s is still open", openTx));
 178             }
 179
 180             closed = true;
 181             dataTree.destroyProducer(this);
 182         }
 183     }
 184
 185     static DOMDataTreeProducer create(final ShardedDOMDataTree dataTree, final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 186         /*
 187          * FIXME: we do not allow multiple multiple shards in a producer because we do not implement the
 188          *        synchronization primitives yet
 189          */
 190         final Set<DOMDataTreeShard> shards = ImmutableSet.copyOf(shardMap.values());
 191         if (shards.size() > 1) {
 192             throw new UnsupportedOperationException("Cross-shard producers are not supported yet");
 193         }
 194
 195         return new ShardedDOMDataTreeProducer(dataTree, shardMap, shards);
 196     }
 197
 198     Set<DOMDataTreeIdentifier> getSubtrees() {
 199         return idToShard.keySet();
 200     }
 201
 202     synchronized void cancelTransaction(final ShardedDOMDataWriteTransaction transaction) {
 203         if (!openTx.equals(transaction)) {
 204             LOG.warn("Transaction {} is not open in producer {}", transaction, this);
 205             return;
 206         }
 207
 208         LOG.debug("Transaction {} cancelled", transaction);
 209         openTx = null;
 210     }
 211 }