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 com.google.common.base.Preconditions;
  11 import com.google.common.base.Verify;
  12 import com.google.common.collect.ArrayListMultimap;
  13 import com.google.common.collect.BiMap;
  14 import com.google.common.collect.Collections2;
  15 import com.google.common.collect.ImmutableBiMap;
  16 import com.google.common.collect.ImmutableBiMap.Builder;
  17 import com.google.common.collect.ImmutableMap;
  18 import com.google.common.collect.ImmutableSet;
  19 import com.google.common.collect.Multimap;
  20 import java.util.Collection;
  21 import java.util.Map;
  22 import java.util.Map.Entry;
  23 import java.util.Set;
  24 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  25 import javax.annotation.concurrent.GuardedBy;
  26 import org.opendaylight.mdsal.dom.api.DOMDataTreeCursorAwareTransaction;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  28 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  29 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerBusyException;
  30 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerException;
  31 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  32 import org.opendaylight.mdsal.dom.store.inmemory.DOMDataTreeShardProducer;
  33 import org.opendaylight.mdsal.dom.store.inmemory.WriteableDOMDataTreeShard;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 class ShardedDOMDataTreeProducer implements DOMDataTreeProducer {
  39     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTreeProducer.class);
  40
  41     private final Set<DOMDataTreeIdentifier> subtrees;
  42     private final ShardedDOMDataTree dataTree;
  43
  44     private BiMap<DOMDataTreeIdentifier, DOMDataTreeShardProducer> idToProducer = ImmutableBiMap.of();
  45     private Map<DOMDataTreeIdentifier, DOMDataTreeShard> idToShard;
  46
  47     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  48         CURRENT_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  49             ShardedDOMDataTreeWriteTransaction.class, "currentTx");
  50     private volatile ShardedDOMDataTreeWriteTransaction currentTx;
  51
  52     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  53         OPEN_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  54             ShardedDOMDataTreeWriteTransaction.class, "openTx");
  55     private volatile ShardedDOMDataTreeWriteTransaction openTx;
  56
  57     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  58         LAST_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  59             ShardedDOMDataTreeWriteTransaction.class, "lastTx");
  60     private volatile ShardedDOMDataTreeWriteTransaction lastTx;
  61
  62     @GuardedBy("this")
  63     private Map<DOMDataTreeIdentifier, DOMDataTreeProducer> children = ImmutableMap.of();
  64     @GuardedBy("this")
  65     private Set<YangInstanceIdentifier> childRoots = ImmutableSet.of();
  66     @GuardedBy("this")
  67     private boolean closed;
  68
  69     @GuardedBy("this")
  70     private ShardedDOMDataTreeListenerContext<?> attachedListener;
  71
  72     ShardedDOMDataTreeProducer(final ShardedDOMDataTree dataTree,
  73                                final Collection<DOMDataTreeIdentifier> subtrees,
  74                                final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap,
  75                                final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToId) {
  76         this.dataTree = Preconditions.checkNotNull(dataTree);
  77         if (!shardToId.isEmpty()) {
  78             this.idToProducer = mapIdsToProducer(shardToId);
  79         }
  80         idToShard = ImmutableMap.copyOf(shardMap);
  81         this.subtrees = ImmutableSet.copyOf(subtrees);
  82     }
  83
  84     static DOMDataTreeProducer create(final ShardedDOMDataTree dataTree,
  85                                       final Collection<DOMDataTreeIdentifier> subtrees,
  86                                       final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
  87         final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToIdentifiers = ArrayListMultimap.create();
  88         // map which identifier belongs to which shard
  89         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeShard> entry : shardMap.entrySet()) {
  90             shardToIdentifiers.put(entry.getValue(), entry.getKey());
  91         }
  92
  93         return new ShardedDOMDataTreeProducer(dataTree, subtrees, shardMap, shardToIdentifiers);
  94     }
  95
  96     void subshardAdded(final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
  97         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
  98         final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToIdentifiers = ArrayListMultimap.create();
  99         // map which identifier belongs to which shard
 100         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeShard> entry : shardMap.entrySet()) {
 101             shardToIdentifiers.put(entry.getValue(), entry.getKey());
 102         }
 103         this.idToProducer = mapIdsToProducer(shardToIdentifiers);
 104         idToShard = ImmutableMap.copyOf(shardMap);
 105     }
 106
 107     private static BiMap<DOMDataTreeIdentifier, DOMDataTreeShardProducer> mapIdsToProducer(
 108             final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToId) {
 109         final Builder<DOMDataTreeIdentifier, DOMDataTreeShardProducer> idToProducerBuilder = ImmutableBiMap.builder();
 110         for (final Entry<DOMDataTreeShard, Collection<DOMDataTreeIdentifier>> entry : shardToId.asMap().entrySet()) {
 111             if (entry.getKey() instanceof WriteableDOMDataTreeShard) {
 112                 //create a single producer for all prefixes in a single shard
 113                 final DOMDataTreeShardProducer producer = ((WriteableDOMDataTreeShard) entry.getKey())
 114                         .createProducer(entry.getValue());
 115                 // id mapped to producers
 116                 for (final DOMDataTreeIdentifier id : entry.getValue()) {
 117                     idToProducerBuilder.put(id, producer);
 118                 }
 119             } else {
 120                 LOG.error("Unable to create a producer for shard that's not a WriteableDOMDataTreeShard");
 121             }
 122         }
 123
 124         return idToProducerBuilder.build();
 125     }
 126
 127     @Override
 128     public synchronized DOMDataTreeCursorAwareTransaction createTransaction(final boolean isolated) {
 129         Preconditions.checkState(!closed, "Producer is already closed");
 130         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
 131
 132         LOG.debug("Creating transaction from producer");
 133         final ShardedDOMDataTreeWriteTransaction current = CURRENT_UPDATER.getAndSet(this, null);
 134         final ShardedDOMDataTreeWriteTransaction ret;
 135         if (isolated) {
 136             // Isolated case. If we have a previous transaction, submit it before returning this one.
 137             if (current != null) {
 138                 submitTransaction(current);
 139             }
 140             ret = new ShardedDOMDataTreeWriteTransaction(this, idToProducer, childRoots);
 141         } else {
 142             // Non-isolated case, see if we can reuse the transaction
 143             if (current != null) {
 144                 LOG.debug("Reusing previous transaction {} since there is still a transaction inflight",
 145                         current.getIdentifier());
 146                 ret = current;
 147             } else {
 148                 ret = new ShardedDOMDataTreeWriteTransaction(this, idToProducer, childRoots);
 149             }
 150         }
 151
 152         final boolean success = OPEN_UPDATER.compareAndSet(this, null, ret);
 153         Verify.verify(success);
 154         return ret;
 155     }
 156
 157     @GuardedBy("this")
 158     private void submitTransaction(final ShardedDOMDataTreeWriteTransaction current) {
 159         lastTx = current;
 160         current.doSubmit(this::transactionSuccessful, this::transactionFailed);
 161     }
 162
 163     @GuardedBy("this")
 164     private boolean haveSubtree(final DOMDataTreeIdentifier subtree) {
 165         for (final DOMDataTreeIdentifier i : idToShard.keySet()) {
 166             if (i.contains(subtree)) {
 167                 return true;
 168             }
 169         }
 170
 171         return false;
 172     }
 173
 174     @GuardedBy("this")
 175     private DOMDataTreeProducer lookupChild(final DOMDataTreeIdentifier domDataTreeIdentifier) {
 176         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : children.entrySet()) {
 177             if (e.getKey().contains(domDataTreeIdentifier)) {
 178                 return e.getValue();
 179             }
 180         }
 181
 182         return null;
 183     }
 184
 185     @Override
 186     public synchronized DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 187         Preconditions.checkState(!closed, "Producer is already closed");
 188         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
 189
 190         for (final DOMDataTreeIdentifier s : subtrees) {
 191             // Check if the subtree was visible at any time
 192             Preconditions.checkArgument(haveSubtree(s), "Subtree %s was never available in producer %s", s, this);
 193             // Check if the subtree has not been delegated to a child
 194             final DOMDataTreeProducer child = lookupChild(s);
 195             Preconditions.checkArgument(child == null, "Subtree %s is delegated to child producer %s", s, child);
 196
 197             // Check if part of the requested subtree is not delegated to a child.
 198             for (final DOMDataTreeIdentifier c : children.keySet()) {
 199                 if (s.contains(c)) {
 200                     throw new IllegalArgumentException(String.format("Subtree %s cannot be delegated as it is"
 201                             + " superset of already-delegated %s", s, c));
 202                 }
 203             }
 204         }
 205
 206         final DOMDataTreeProducer ret = dataTree.createProducer(this, subtrees);
 207         final ImmutableMap.Builder<DOMDataTreeIdentifier, DOMDataTreeProducer> cb = ImmutableMap.builder();
 208         cb.putAll(children);
 209         for (final DOMDataTreeIdentifier s : subtrees) {
 210             cb.put(s, ret);
 211         }
 212
 213         children = cb.build();
 214         childRoots = ImmutableSet.copyOf(Collections2.transform(children.keySet(),
 215             DOMDataTreeIdentifier::getRootIdentifier));
 216         return ret;
 217     }
 218
 219     boolean isDelegatedToChild(final DOMDataTreeIdentifier path) {
 220         for (final DOMDataTreeIdentifier c : children.keySet()) {
 221             if (c.contains(path)) {
 222                 return true;
 223             }
 224         }
 225         return false;
 226     }
 227
 228
 229     @Override
 230     public synchronized void close() throws DOMDataTreeProducerException {
 231         if (!closed) {
 232             if (openTx != null) {
 233                 throw new DOMDataTreeProducerBusyException(String.format("Transaction %s is still open", openTx));
 234             }
 235
 236             closed = true;
 237             dataTree.destroyProducer(this);
 238         }
 239     }
 240
 241     protected Set<DOMDataTreeIdentifier> getSubtrees() {
 242         return subtrees;
 243     }
 244
 245     void cancelTransaction(final ShardedDOMDataTreeWriteTransaction transaction) {
 246         final boolean success = OPEN_UPDATER.compareAndSet(this, transaction, null);
 247         if (success) {
 248             LOG.debug("Transaction {} cancelled", transaction);
 249         } else {
 250             LOG.warn("Transaction {} is not open in producer {}", transaction, this);
 251         }
 252     }
 253
 254     // Called when the user submits a transaction
 255     void transactionSubmitted(final ShardedDOMDataTreeWriteTransaction transaction) {
 256         final boolean wasOpen = OPEN_UPDATER.compareAndSet(this, transaction, null);
 257         Preconditions.checkState(wasOpen, "Attempted to submit non-open transaction %s", transaction);
 258
 259         if (lastTx == null) {
 260             // No transaction outstanding, we need to submit it now
 261             synchronized (this) {
 262                 submitTransaction(transaction);
 263             }
 264
 265             return;
 266         }
 267
 268         // There is a potentially-racing submitted transaction. Publish the new one, which may end up being
 269         // picked up by processNextTransaction.
 270         final boolean success = CURRENT_UPDATER.compareAndSet(this, null, transaction);
 271         Verify.verify(success);
 272
 273         // Now a quick check: if the racing transaction completed in between, it may have missed the current
 274         // transaction, hence we need to re-check
 275         if (lastTx == null) {
 276             submitCurrentTransaction();
 277         }
 278     }
 279
 280     private void submitCurrentTransaction() {
 281         final ShardedDOMDataTreeWriteTransaction current = currentTx;
 282         if (current != null) {
 283             synchronized (this) {
 284                 if (CURRENT_UPDATER.compareAndSet(this, current, null)) {
 285                     submitTransaction(current);
 286                 }
 287             }
 288         }
 289     }
 290
 291     private void transactionSuccessful(final ShardedDOMDataTreeWriteTransaction tx) {
 292         LOG.debug("Transaction {} completed successfully", tx.getIdentifier());
 293
 294         tx.onTransactionSuccess(null);
 295         transactionCompleted(tx);
 296     }
 297
 298     private void transactionFailed(final ShardedDOMDataTreeWriteTransaction tx, final Throwable throwable) {
 299         LOG.debug("Transaction {} failed", tx.getIdentifier(), throwable);
 300
 301         tx.onTransactionFailure(throwable);
 302         transactionCompleted(tx);
 303     }
 304
 305     private void transactionCompleted(final ShardedDOMDataTreeWriteTransaction tx) {
 306         final boolean wasLast = LAST_UPDATER.compareAndSet(this, tx, null);
 307         if (wasLast) {
 308             submitCurrentTransaction();
 309         }
 310     }
 311
 312     synchronized void boundToListener(final ShardedDOMDataTreeListenerContext<?> listener) {
 313         // FIXME: Add option to detach
 314         Preconditions.checkState(this.attachedListener == null, "Producer %s is already attached to other listener.",
 315                 listener.getListener());
 316         this.attachedListener = listener;
 317     }
 318 }