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.AtomicIntegerFieldUpdater;
  25 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  26 import javax.annotation.concurrent.GuardedBy;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeCursorAwareTransaction;
  28 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  29 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  30 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerBusyException;
  31 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerException;
  32 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  33 import org.opendaylight.mdsal.dom.store.inmemory.DOMDataTreeShardProducer;
  34 import org.opendaylight.mdsal.dom.store.inmemory.WriteableDOMDataTreeShard;
  35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 class ShardedDOMDataTreeProducer implements DOMDataTreeProducer {
  40     private static final Logger LOG = LoggerFactory.getLogger(ShardedDOMDataTreeProducer.class);
  41
  42     private final Set<DOMDataTreeIdentifier> subtrees;
  43     private final ShardedDOMDataTree dataTree;
  44
  45     private BiMap<DOMDataTreeIdentifier, DOMDataTreeShardProducer> idToProducer = ImmutableBiMap.of();
  46     private Map<DOMDataTreeIdentifier, DOMDataTreeShard> idToShard;
  47
  48     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  49         CURRENT_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  50             ShardedDOMDataTreeWriteTransaction.class, "currentTx");
  51     private volatile ShardedDOMDataTreeWriteTransaction currentTx;
  52
  53     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  54         OPEN_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  55             ShardedDOMDataTreeWriteTransaction.class, "openTx");
  56     private volatile ShardedDOMDataTreeWriteTransaction openTx;
  57
  58     private static final AtomicReferenceFieldUpdater<ShardedDOMDataTreeProducer, ShardedDOMDataTreeWriteTransaction>
  59         LAST_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class,
  60             ShardedDOMDataTreeWriteTransaction.class, "lastTx");
  61     private volatile ShardedDOMDataTreeWriteTransaction lastTx;
  62
  63     private static final AtomicIntegerFieldUpdater<ShardedDOMDataTreeProducer> CLOSED_UPDATER =
  64             AtomicIntegerFieldUpdater.newUpdater(ShardedDOMDataTreeProducer.class, "closed");
  65     private volatile int closed;
  66
  67     @GuardedBy("this")
  68     private Map<DOMDataTreeIdentifier, DOMDataTreeProducer> children = ImmutableMap.of();
  69     @GuardedBy("this")
  70     private Set<YangInstanceIdentifier> childRoots = ImmutableSet.of();
  71
  72     @GuardedBy("this")
  73     private ShardedDOMDataTreeListenerContext<?> attachedListener;
  74
  75     ShardedDOMDataTreeProducer(final ShardedDOMDataTree dataTree,
  76                                final Collection<DOMDataTreeIdentifier> subtrees,
  77                                final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap,
  78                                final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToId) {
  79         this.dataTree = Preconditions.checkNotNull(dataTree);
  80         if (!shardToId.isEmpty()) {
  81             this.idToProducer = mapIdsToProducer(shardToId);
  82         }
  83         idToShard = ImmutableMap.copyOf(shardMap);
  84         this.subtrees = ImmutableSet.copyOf(subtrees);
  85     }
  86
  87     static DOMDataTreeProducer create(final ShardedDOMDataTree dataTree,
  88                                       final Collection<DOMDataTreeIdentifier> subtrees,
  89                                       final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
  90         final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToIdentifiers = ArrayListMultimap.create();
  91         // map which identifier belongs to which shard
  92         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeShard> entry : shardMap.entrySet()) {
  93             shardToIdentifiers.put(entry.getValue(), entry.getKey());
  94         }
  95
  96         return new ShardedDOMDataTreeProducer(dataTree, subtrees, shardMap, shardToIdentifiers);
  97     }
  98
  99     private static BiMap<DOMDataTreeIdentifier, DOMDataTreeShardProducer> mapIdsToProducer(
 100             final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToId) {
 101         final Builder<DOMDataTreeIdentifier, DOMDataTreeShardProducer> idToProducerBuilder = ImmutableBiMap.builder();
 102         for (final Entry<DOMDataTreeShard, Collection<DOMDataTreeIdentifier>> entry : shardToId.asMap().entrySet()) {
 103             if (entry.getKey() instanceof WriteableDOMDataTreeShard) {
 104                 //create a single producer for all prefixes in a single shard
 105                 final DOMDataTreeShardProducer producer = ((WriteableDOMDataTreeShard) entry.getKey())
 106                         .createProducer(entry.getValue());
 107                 // id mapped to producers
 108                 for (final DOMDataTreeIdentifier id : entry.getValue()) {
 109                     idToProducerBuilder.put(id, producer);
 110                 }
 111             } else {
 112                 LOG.error("Unable to create a producer for shard that's not a WriteableDOMDataTreeShard");
 113             }
 114         }
 115
 116         return idToProducerBuilder.build();
 117     }
 118
 119     private void checkNotClosed() {
 120         Preconditions.checkState(closed == 0, "Producer is already closed");
 121     }
 122
 123     private void checkIdle() {
 124         Preconditions.checkState(openTx == null, "Transaction %s is still open", openTx);
 125     }
 126
 127     void subshardAdded(final Map<DOMDataTreeIdentifier, DOMDataTreeShard> shardMap) {
 128         checkIdle();
 129
 130         final Multimap<DOMDataTreeShard, DOMDataTreeIdentifier> shardToIdentifiers = ArrayListMultimap.create();
 131         // map which identifier belongs to which shard
 132         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeShard> entry : shardMap.entrySet()) {
 133             shardToIdentifiers.put(entry.getValue(), entry.getKey());
 134         }
 135         this.idToProducer = mapIdsToProducer(shardToIdentifiers);
 136         idToShard = ImmutableMap.copyOf(shardMap);
 137     }
 138
 139     @Override
 140     public DOMDataTreeCursorAwareTransaction createTransaction(final boolean isolated) {
 141         checkNotClosed();
 142         checkIdle();
 143
 144         final ShardedDOMDataTreeWriteTransaction ret;
 145         LOG.debug("Creating transaction from producer {}", this);
 146
 147         final ShardedDOMDataTreeWriteTransaction current = CURRENT_UPDATER.getAndSet(this, null);
 148         if (isolated) {
 149             // Isolated case. If we have a previous transaction, submit it before returning this one.
 150             synchronized (this) {
 151                 if (current != null) {
 152                     submitTransaction(current);
 153                 }
 154                 ret = new ShardedDOMDataTreeWriteTransaction(this, idToProducer, childRoots);
 155             }
 156         } else {
 157             // Non-isolated case, see if we can reuse the transaction
 158             if (current != null) {
 159                 LOG.debug("Reusing previous transaction {} since there is still a transaction inflight",
 160                     current.getIdentifier());
 161                 ret = current;
 162             } else {
 163                 synchronized (this) {
 164                     ret = new ShardedDOMDataTreeWriteTransaction(this, idToProducer, childRoots);
 165                 }
 166             }
 167         }
 168
 169         final boolean success = OPEN_UPDATER.compareAndSet(this, null, ret);
 170         Preconditions.checkState(success, "Illegal concurrent access to producer %s detected", this);
 171         return ret;
 172     }
 173
 174     @GuardedBy("this")
 175     private void submitTransaction(final ShardedDOMDataTreeWriteTransaction current) {
 176         lastTx = current;
 177         current.doSubmit(this::transactionSuccessful, this::transactionFailed);
 178     }
 179
 180     @GuardedBy("this")
 181     private boolean haveSubtree(final DOMDataTreeIdentifier subtree) {
 182         for (final DOMDataTreeIdentifier i : idToShard.keySet()) {
 183             if (i.contains(subtree)) {
 184                 return true;
 185             }
 186         }
 187
 188         return false;
 189     }
 190
 191     @GuardedBy("this")
 192     private DOMDataTreeProducer lookupChild(final DOMDataTreeIdentifier domDataTreeIdentifier) {
 193         for (final Entry<DOMDataTreeIdentifier, DOMDataTreeProducer> e : children.entrySet()) {
 194             if (e.getKey().contains(domDataTreeIdentifier)) {
 195                 return e.getValue();
 196             }
 197         }
 198
 199         return null;
 200     }
 201
 202     @Override
 203     public DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 204         checkNotClosed();
 205         checkIdle();
 206
 207         for (final DOMDataTreeIdentifier s : subtrees) {
 208             // Check if the subtree was visible at any time
 209             Preconditions.checkArgument(haveSubtree(s), "Subtree %s was never available in producer %s", s, this);
 210             // Check if the subtree has not been delegated to a child
 211             final DOMDataTreeProducer child = lookupChild(s);
 212             Preconditions.checkArgument(child == null, "Subtree %s is delegated to child producer %s", s, child);
 213
 214             // Check if part of the requested subtree is not delegated to a child.
 215             for (final DOMDataTreeIdentifier c : children.keySet()) {
 216                 Preconditions.checkArgument(!s.contains(c),
 217                     "Subtree %s cannot be delegated as it is a superset of already-delegated %s", s, c);
 218             }
 219         }
 220
 221         synchronized (this) {
 222             final DOMDataTreeProducer ret = dataTree.createProducer(this, subtrees);
 223             final ImmutableMap.Builder<DOMDataTreeIdentifier, DOMDataTreeProducer> cb = ImmutableMap.builder();
 224             cb.putAll(children);
 225             for (final DOMDataTreeIdentifier s : subtrees) {
 226                 cb.put(s, ret);
 227             }
 228
 229             children = cb.build();
 230             childRoots = ImmutableSet.copyOf(Collections2.transform(children.keySet(),
 231                 DOMDataTreeIdentifier::getRootIdentifier));
 232             return ret;
 233         }
 234     }
 235
 236     boolean isDelegatedToChild(final DOMDataTreeIdentifier path) {
 237         for (final DOMDataTreeIdentifier c : children.keySet()) {
 238             if (c.contains(path)) {
 239                 return true;
 240             }
 241         }
 242         return false;
 243     }
 244
 245
 246     @Override
 247     public void close() throws DOMDataTreeProducerException {
 248         if (openTx != null) {
 249             throw new DOMDataTreeProducerBusyException(String.format("Transaction %s is still open", openTx));
 250         }
 251
 252         if (CLOSED_UPDATER.compareAndSet(this, 0, 1)) {
 253             synchronized (this) {
 254                 dataTree.destroyProducer(this);
 255             }
 256         }
 257     }
 258
 259     protected Set<DOMDataTreeIdentifier> getSubtrees() {
 260         return subtrees;
 261     }
 262
 263     void cancelTransaction(final ShardedDOMDataTreeWriteTransaction transaction) {
 264         final boolean success = OPEN_UPDATER.compareAndSet(this, transaction, null);
 265         if (success) {
 266             LOG.debug("Transaction {} cancelled", transaction);
 267         } else {
 268             LOG.warn("Transaction {} is not open in producer {}", transaction, this);
 269         }
 270     }
 271
 272     // Called when the user submits a transaction
 273     void transactionSubmitted(final ShardedDOMDataTreeWriteTransaction transaction) {
 274         final boolean wasOpen = OPEN_UPDATER.compareAndSet(this, transaction, null);
 275         Preconditions.checkState(wasOpen, "Attempted to submit non-open transaction %s", transaction);
 276
 277         if (lastTx == null) {
 278             // No transaction outstanding, we need to submit it now
 279             synchronized (this) {
 280                 submitTransaction(transaction);
 281             }
 282
 283             return;
 284         }
 285
 286         // There is a potentially-racing submitted transaction. Publish the new one, which may end up being
 287         // picked up by processNextTransaction.
 288         final boolean success = CURRENT_UPDATER.compareAndSet(this, null, transaction);
 289         Verify.verify(success);
 290
 291         // Now a quick check: if the racing transaction completed in between, it may have missed the current
 292         // transaction, hence we need to re-check
 293         if (lastTx == null) {
 294             submitCurrentTransaction();
 295         }
 296     }
 297
 298     private void submitCurrentTransaction() {
 299         final ShardedDOMDataTreeWriteTransaction current = currentTx;
 300         if (current != null) {
 301             synchronized (this) {
 302                 if (CURRENT_UPDATER.compareAndSet(this, current, null)) {
 303                     submitTransaction(current);
 304                 }
 305             }
 306         }
 307     }
 308
 309     private void transactionSuccessful(final ShardedDOMDataTreeWriteTransaction tx) {
 310         LOG.debug("Transaction {} completed successfully", tx.getIdentifier());
 311
 312         tx.onTransactionSuccess(null);
 313         transactionCompleted(tx);
 314     }
 315
 316     private void transactionFailed(final ShardedDOMDataTreeWriteTransaction tx, final Throwable throwable) {
 317         LOG.debug("Transaction {} failed", tx.getIdentifier(), throwable);
 318
 319         tx.onTransactionFailure(throwable);
 320         transactionCompleted(tx);
 321     }
 322
 323     private void transactionCompleted(final ShardedDOMDataTreeWriteTransaction tx) {
 324         final boolean wasLast = LAST_UPDATER.compareAndSet(this, tx, null);
 325         if (wasLast) {
 326             submitCurrentTransaction();
 327         }
 328     }
 329
 330     synchronized void boundToListener(final ShardedDOMDataTreeListenerContext<?> listener) {
 331         // FIXME: Add option to detach
 332         Preconditions.checkState(this.attachedListener == null, "Producer %s is already attached to other listener.",
 333                 listener.getListener());
 334         this.attachedListener = listener;
 335     }
 336 }