opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/InMemoryDOMDataStore.java

   1 /*
   2  * Copyright (c) 2014 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.store.impl;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11
  12 import java.util.Collections;
  13 import java.util.concurrent.Callable;
  14 import java.util.concurrent.atomic.AtomicLong;
  15
  16 import javax.annotation.concurrent.GuardedBy;
  17
  18 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  19 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  20 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
  21 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  22 import org.opendaylight.controller.md.sal.dom.store.impl.SnapshotBackedWriteTransaction.TransactionReadyPrototype;
  23 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ConflictingModificationAppliedException;
  24 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTree;
  25 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeCandidate;
  26 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeModification;
  27 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeSnapshot;
  28 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataValidationFailedException;
  29 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  30 import org.opendaylight.controller.md.sal.dom.store.impl.tree.data.InMemoryDataTreeFactory;
  31 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  32 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  33 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  34 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  35 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  36 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  37 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  38 import org.opendaylight.yangtools.concepts.Identifiable;
  39 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  40 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  41 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  42 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  43 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 import com.google.common.base.Optional;
  48 import com.google.common.base.Preconditions;
  49 import com.google.common.util.concurrent.FutureCallback;
  50 import com.google.common.util.concurrent.Futures;
  51 import com.google.common.util.concurrent.ListenableFuture;
  52 import com.google.common.util.concurrent.ListeningExecutorService;
  53
  54 /**
  55  * In-memory DOM Data Store
  56  *
  57  * Implementation of {@link DOMStore} which uses {@link DataTree} and other
  58  * classes such as {@link SnapshotBackedWriteTransaction}.
  59  * {@link SnapshotBackedReadTransaction} and {@link ResolveDataChangeEventsTask}
  60  * to implement {@link DOMStore} contract.
  61  *
  62  */
  63 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener,
  64         TransactionReadyPrototype {
  65     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  66     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
  67     private final ListenerTree listenerTree = ListenerTree.create();
  68     private final AtomicLong txCounter = new AtomicLong(0);
  69     private final ListeningExecutorService executor;
  70     private final String name;
  71
  72     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  73         this.name = Preconditions.checkNotNull(name);
  74         this.executor = Preconditions.checkNotNull(executor);
  75     }
  76
  77     @Override
  78     public final String getIdentifier() {
  79         return name;
  80     }
  81
  82     @Override
  83     public DOMStoreReadTransaction newReadOnlyTransaction() {
  84         return new SnapshotBackedReadTransaction(nextIdentifier(), dataTree.takeSnapshot());
  85     }
  86
  87     @Override
  88     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  89         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  90     }
  91
  92     @Override
  93     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  94         return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  95     }
  96
  97     @Override
  98     public DOMStoreTransactionChain createTransactionChain() {
  99         return new DOMStoreTransactionChainImpl();
 100     }
 101
 102     @Override
 103     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
 104         dataTree.setSchemaContext(ctx);
 105     }
 106
 107     @Override
 108     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 109             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 110
 111         /*
 112          * Make sure commit is not occurring right now. Listener has to be
 113          * registered and its state capture enqueued at a consistent point.
 114          *
 115          * FIXME: improve this to read-write lock, such that multiple listener
 116          * registrations can occur simultaneously
 117          */
 118         final DataChangeListenerRegistration<L> reg;
 119         synchronized (this) {
 120             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 121
 122             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 123
 124             Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
 125             if (currentState.isPresent()) {
 126                 final NormalizedNode<?, ?> data = currentState.get();
 127
 128                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 129                         .setAfter(data) //
 130                         .addCreated(path, data) //
 131                         .build();
 132                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 133             }
 134         }
 135
 136         return new AbstractListenerRegistration<L>(listener) {
 137             @Override
 138             protected void removeRegistration() {
 139                 synchronized (InMemoryDOMDataStore.this) {
 140                     reg.close();
 141                 }
 142             }
 143         };
 144     }
 145
 146     @Override
 147     public synchronized DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction writeTx) {
 148         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
 149         return new ThreePhaseCommitImpl(writeTx);
 150     }
 151
 152     private Object nextIdentifier() {
 153         return name + "-" + txCounter.getAndIncrement();
 154     }
 155
 156     private class DOMStoreTransactionChainImpl implements DOMStoreTransactionChain, TransactionReadyPrototype {
 157
 158         @GuardedBy("this")
 159         private SnapshotBackedWriteTransaction latestOutstandingTx;
 160
 161         private boolean chainFailed = false;
 162
 163         private void checkFailed() {
 164             Preconditions.checkState(!chainFailed, "Transaction chain is failed.");
 165         }
 166
 167         @Override
 168         public synchronized DOMStoreReadTransaction newReadOnlyTransaction() {
 169             final DataTreeSnapshot snapshot;
 170             checkFailed();
 171             if (latestOutstandingTx != null) {
 172                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 173                 snapshot = latestOutstandingTx.getMutatedView();
 174             } else {
 175                 snapshot = dataTree.takeSnapshot();
 176             }
 177             return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot);
 178         }
 179
 180         @Override
 181         public synchronized DOMStoreReadWriteTransaction newReadWriteTransaction() {
 182             final DataTreeSnapshot snapshot;
 183             checkFailed();
 184             if (latestOutstandingTx != null) {
 185                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 186                 snapshot = latestOutstandingTx.getMutatedView();
 187             } else {
 188                 snapshot = dataTree.takeSnapshot();
 189             }
 190             final SnapshotBackedReadWriteTransaction ret = new SnapshotBackedReadWriteTransaction(nextIdentifier(),
 191                     snapshot, this);
 192             latestOutstandingTx = ret;
 193             return ret;
 194         }
 195
 196         @Override
 197         public synchronized DOMStoreWriteTransaction newWriteOnlyTransaction() {
 198             final DataTreeSnapshot snapshot;
 199             checkFailed();
 200             if (latestOutstandingTx != null) {
 201                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 202                 snapshot = latestOutstandingTx.getMutatedView();
 203             } else {
 204                 snapshot = dataTree.takeSnapshot();
 205             }
 206             final SnapshotBackedWriteTransaction ret = new SnapshotBackedWriteTransaction(nextIdentifier(), snapshot,
 207                     this);
 208             latestOutstandingTx = ret;
 209             return ret;
 210         }
 211
 212         @Override
 213         public DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction tx) {
 214             DOMStoreThreePhaseCommitCohort storeCohort = InMemoryDOMDataStore.this.ready(tx);
 215             return new ChainedTransactionCommitImpl(tx, storeCohort, this);
 216         }
 217
 218         @Override
 219         public void close() {
 220
 221         }
 222
 223         protected synchronized void onTransactionFailed(final SnapshotBackedWriteTransaction transaction,
 224                 final Throwable t) {
 225             chainFailed = true;
 226
 227         }
 228
 229         public synchronized void onTransactionCommited(final SnapshotBackedWriteTransaction transaction) {
 230             // If commited transaction is latestOutstandingTx we clear
 231             // latestOutstandingTx
 232             // field in order to base new transactions on Datastore Data Tree
 233             // directly.
 234             if (transaction.equals(latestOutstandingTx)) {
 235                 latestOutstandingTx = null;
 236             }
 237         }
 238
 239     }
 240
 241     private static class ChainedTransactionCommitImpl implements DOMStoreThreePhaseCommitCohort {
 242
 243         private final SnapshotBackedWriteTransaction transaction;
 244         private final DOMStoreThreePhaseCommitCohort delegate;
 245
 246         private final DOMStoreTransactionChainImpl txChain;
 247
 248         protected ChainedTransactionCommitImpl(final SnapshotBackedWriteTransaction transaction,
 249                 final DOMStoreThreePhaseCommitCohort delegate, final DOMStoreTransactionChainImpl txChain) {
 250             super();
 251             this.transaction = transaction;
 252             this.delegate = delegate;
 253             this.txChain = txChain;
 254         }
 255
 256         @Override
 257         public ListenableFuture<Boolean> canCommit() {
 258             return delegate.canCommit();
 259         }
 260
 261         @Override
 262         public ListenableFuture<Void> preCommit() {
 263             return delegate.preCommit();
 264         }
 265
 266         @Override
 267         public ListenableFuture<Void> abort() {
 268             return delegate.abort();
 269         }
 270
 271         @Override
 272         public ListenableFuture<Void> commit() {
 273             ListenableFuture<Void> commitFuture = delegate.commit();
 274             Futures.addCallback(commitFuture, new FutureCallback<Void>() {
 275                 @Override
 276                 public void onFailure(final Throwable t) {
 277                     txChain.onTransactionFailed(transaction, t);
 278                 }
 279
 280                 @Override
 281                 public void onSuccess(final Void result) {
 282                     txChain.onTransactionCommited(transaction);
 283                 }
 284
 285             });
 286             return commitFuture;
 287         }
 288
 289     }
 290
 291     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 292
 293         private final SnapshotBackedWriteTransaction transaction;
 294         private final DataTreeModification modification;
 295
 296         private ResolveDataChangeEventsTask listenerResolver;
 297         private DataTreeCandidate candidate;
 298
 299         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
 300             this.transaction = writeTransaction;
 301             this.modification = transaction.getMutatedView();
 302         }
 303
 304         @Override
 305         public ListenableFuture<Boolean> canCommit() {
 306             return executor.submit(new Callable<Boolean>() {
 307                 @Override
 308                 public Boolean call() throws TransactionCommitFailedException {
 309                     try {
 310                         dataTree.validate(modification);
 311                         LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
 312                         return true;
 313                     } catch (ConflictingModificationAppliedException e) {
 314                         LOG.warn("Store Tx: {} Conflicting modification for {}.", transaction.getIdentifier(),
 315                                 e.getPath());
 316                         throw new OptimisticLockFailedException("Optimistic lock failed.",e);
 317                     } catch (DataValidationFailedException e) {
 318                         LOG.warn("Store Tx: {} Data Precondition failed for {}.", transaction.getIdentifier(),
 319                                 e.getPath(), e);
 320                         throw new TransactionCommitFailedException("Data did not pass validation.",e);
 321                     }
 322                 }
 323             });
 324         }
 325
 326         @Override
 327         public ListenableFuture<Void> preCommit() {
 328             return executor.submit(new Callable<Void>() {
 329                 @Override
 330                 public Void call() {
 331                     candidate = dataTree.prepare(modification);
 332                     listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
 333                     return null;
 334                 }
 335             });
 336         }
 337
 338         @Override
 339         public ListenableFuture<Void> abort() {
 340             candidate = null;
 341             return Futures.immediateFuture(null);
 342         }
 343
 344         @Override
 345         public ListenableFuture<Void> commit() {
 346             checkState(candidate != null, "Proposed subtree must be computed");
 347
 348             /*
 349              * The commit has to occur atomically with regard to listener
 350              * registrations.
 351              */
 352             synchronized (this) {
 353                 dataTree.commit(candidate);
 354
 355                 for (ChangeListenerNotifyTask task : listenerResolver.call()) {
 356                     LOG.trace("Scheduling invocation of listeners: {}", task);
 357                     executor.submit(task);
 358                 }
 359             }
 360
 361             return Futures.immediateFuture(null);
 362         }
 363     }
 364 }