opendaylight/md-sal/sal-inmemory-datastore/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 import com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import java.util.concurrent.ExecutorService;
  16 import java.util.concurrent.TimeUnit;
  17 import java.util.concurrent.atomic.AtomicLong;
  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.api.DOMDataTreeChangeListener;
  23 import org.opendaylight.controller.md.sal.dom.store.impl.SnapshotBackedWriteTransaction.TransactionReadyPrototype;
  24 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  25 import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
  26 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  30 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  31 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTreeChangePublisher;
  32 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  33 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  34 import org.opendaylight.yangtools.concepts.Identifiable;
  35 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  36 import org.opendaylight.yangtools.util.ExecutorServiceUtil;
  37 import org.opendaylight.yangtools.util.concurrent.QueuedNotificationManager;
  38 import org.opendaylight.yangtools.util.concurrent.QueuedNotificationManager.Invoker;
  39 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  40 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  41 import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException;
  42 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  43 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  44 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  45 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  46 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  47 import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
  48 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  49 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  50 import org.slf4j.Logger;
  51 import org.slf4j.LoggerFactory;
  52
  53 /**
  54  * In-memory DOM Data Store
  55  *
  56  * Implementation of {@link DOMStore} which uses {@link DataTree} and other
  57  * classes such as {@link SnapshotBackedWriteTransaction}.
  58  * {@link SnapshotBackedReadTransaction} and {@link ResolveDataChangeEventsTask}
  59  * to implement {@link DOMStore} contract.
  60  *
  61  */
  62 public class InMemoryDOMDataStore extends TransactionReadyPrototype implements DOMStore, Identifiable<String>, SchemaContextListener, AutoCloseable, DOMStoreTreeChangePublisher {
  63     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  64     private static final ListenableFuture<Void> SUCCESSFUL_FUTURE = Futures.immediateFuture(null);
  65     private static final ListenableFuture<Boolean> CAN_COMMIT_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  66
  67     private static final Invoker<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> DCL_NOTIFICATION_MGR_INVOKER =
  68             new Invoker<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent>() {
  69                 @Override
  70                 public void invokeListener(final DataChangeListenerRegistration<?> listener,
  71                                            final DOMImmutableDataChangeEvent notification ) {
  72                     final AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> inst = listener.getInstance();
  73                     if (inst != null) {
  74                         inst.onDataChanged(notification);
  75                     }
  76                 }
  77             };
  78
  79     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
  80     private final ListenerTree listenerTree = ListenerTree.create();
  81     private final AtomicLong txCounter = new AtomicLong(0);
  82
  83     private final QueuedNotificationManager<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> dataChangeListenerNotificationManager;
  84     private final InMemoryDOMStoreTreeChangePublisher changePublisher;
  85     private final ExecutorService dataChangeListenerExecutor;
  86     private final boolean debugTransactions;
  87     private final String name;
  88
  89     private volatile AutoCloseable closeable;
  90
  91     public InMemoryDOMDataStore(final String name, final ExecutorService dataChangeListenerExecutor) {
  92         this(name, dataChangeListenerExecutor, InMemoryDOMDataStoreConfigProperties.DEFAULT_MAX_DATA_CHANGE_LISTENER_QUEUE_SIZE, false);
  93     }
  94
  95     public InMemoryDOMDataStore(final String name, final ExecutorService dataChangeListenerExecutor,
  96             final int maxDataChangeListenerQueueSize, final boolean debugTransactions) {
  97         this.name = Preconditions.checkNotNull(name);
  98         this.dataChangeListenerExecutor = Preconditions.checkNotNull(dataChangeListenerExecutor);
  99         this.debugTransactions = debugTransactions;
 100
 101         dataChangeListenerNotificationManager =
 102                 new QueuedNotificationManager<>(this.dataChangeListenerExecutor,
 103                         DCL_NOTIFICATION_MGR_INVOKER, maxDataChangeListenerQueueSize,
 104                         "DataChangeListenerQueueMgr");
 105         changePublisher = new InMemoryDOMStoreTreeChangePublisher(this.dataChangeListenerExecutor, maxDataChangeListenerQueueSize);
 106     }
 107
 108     public void setCloseable(final AutoCloseable closeable) {
 109         this.closeable = closeable;
 110     }
 111
 112     public QueuedNotificationManager<?, ?> getDataChangeListenerNotificationManager() {
 113         return dataChangeListenerNotificationManager;
 114     }
 115
 116     @Override
 117     public final String getIdentifier() {
 118         return name;
 119     }
 120
 121     @Override
 122     public DOMStoreReadTransaction newReadOnlyTransaction() {
 123         return new SnapshotBackedReadTransaction(nextIdentifier(), debugTransactions, dataTree.takeSnapshot());
 124     }
 125
 126     @Override
 127     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
 128         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), debugTransactions, dataTree.takeSnapshot(), this);
 129     }
 130
 131     @Override
 132     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
 133         return new SnapshotBackedWriteTransaction(nextIdentifier(), debugTransactions, dataTree.takeSnapshot(), this);
 134     }
 135
 136     @Override
 137     public DOMStoreTransactionChain createTransactionChain() {
 138         return new DOMStoreTransactionChainImpl(this);
 139     }
 140
 141     @Override
 142     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
 143         dataTree.setSchemaContext(ctx);
 144     }
 145
 146     @Override
 147     public void close() {
 148         ExecutorServiceUtil.tryGracefulShutdown(dataChangeListenerExecutor, 30, TimeUnit.SECONDS);
 149
 150         if(closeable != null) {
 151             try {
 152                 closeable.close();
 153             } catch(Exception e) {
 154                 LOG.debug("Error closing instance", e);
 155             }
 156         }
 157     }
 158
 159     public final boolean getDebugTransactions() {
 160         return debugTransactions;
 161     }
 162
 163     final DataTreeSnapshot takeSnapshot() {
 164         return dataTree.takeSnapshot();
 165     }
 166
 167     @Override
 168     public <L extends AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 169             final YangInstanceIdentifier path, final L listener, final DataChangeScope scope) {
 170
 171         /*
 172          * Make sure commit is not occurring right now. Listener has to be
 173          * registered and its state capture enqueued at a consistent point.
 174          *
 175          * FIXME: improve this to read-write lock, such that multiple listener
 176          * registrations can occur simultaneously
 177          */
 178         final DataChangeListenerRegistration<L> reg;
 179         synchronized (this) {
 180             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 181
 182             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 183
 184             Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
 185             if (currentState.isPresent()) {
 186                 final NormalizedNode<?, ?> data = currentState.get();
 187
 188                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 189                         .setAfter(data) //
 190                         .addCreated(path, data) //
 191                         .build();
 192
 193                 dataChangeListenerNotificationManager.submitNotification(reg, event);
 194             }
 195         }
 196
 197         return new AbstractListenerRegistration<L>(listener) {
 198             @Override
 199             protected void removeRegistration() {
 200                 synchronized (InMemoryDOMDataStore.this) {
 201                     reg.close();
 202                 }
 203             }
 204         };
 205     }
 206
 207     @Override
 208     public synchronized <L extends DOMDataTreeChangeListener> ListenerRegistration<L> registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
 209         /*
 210          * Make sure commit is not occurring right now. Listener has to be
 211          * registered and its state capture enqueued at a consistent point.
 212          */
 213         return changePublisher.registerTreeChangeListener(treeId, listener, dataTree.takeSnapshot());
 214     }
 215
 216     @Override
 217     protected void transactionAborted(final SnapshotBackedWriteTransaction tx) {
 218         LOG.debug("Tx: {} is closed.", tx.getIdentifier());
 219     }
 220
 221     @Override
 222     protected DOMStoreThreePhaseCommitCohort transactionReady(final SnapshotBackedWriteTransaction tx, final DataTreeModification tree) {
 223         LOG.debug("Tx: {} is submitted. Modifications: {}", tx.getIdentifier(), tree);
 224         return new ThreePhaseCommitImpl(tx, tree);
 225     }
 226
 227     Object nextIdentifier() {
 228         return name + "-" + txCounter.getAndIncrement();
 229     }
 230
 231     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
 232         final Throwable ctx = transaction.getDebugContext();
 233         if (ctx != null) {
 234             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
 235         }
 236     }
 237
 238     private final class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 239         private final SnapshotBackedWriteTransaction transaction;
 240         private final DataTreeModification modification;
 241
 242         private ResolveDataChangeEventsTask listenerResolver;
 243         private DataTreeCandidate candidate;
 244
 245         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction, final DataTreeModification modification) {
 246             this.transaction = writeTransaction;
 247             this.modification = modification;
 248         }
 249
 250         @Override
 251         public ListenableFuture<Boolean> canCommit() {
 252             try {
 253                 dataTree.validate(modification);
 254                 LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
 255                 return CAN_COMMIT_FUTURE;
 256             } catch (ConflictingModificationAppliedException e) {
 257                 LOG.warn("Store Tx: {} Conflicting modification for {}.", transaction.getIdentifier(),
 258                         e.getPath());
 259                 warnDebugContext(transaction);
 260                 return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
 261             } catch (DataValidationFailedException e) {
 262                 LOG.warn("Store Tx: {} Data Precondition failed for {}.", transaction.getIdentifier(),
 263                         e.getPath(), e);
 264                 warnDebugContext(transaction);
 265
 266                 // For debugging purposes, allow dumping of the modification. Coupled with the above
 267                 // precondition log, it should allow us to understand what went on.
 268                 LOG.trace("Store Tx: {} modifications: {} tree: {}", modification, dataTree);
 269
 270                 return Futures.immediateFailedFuture(new TransactionCommitFailedException("Data did not pass validation.", e));
 271             } catch (Exception e) {
 272                 LOG.warn("Unexpected failure in validation phase", e);
 273                 return Futures.immediateFailedFuture(e);
 274             }
 275         }
 276
 277         @Override
 278         public ListenableFuture<Void> preCommit() {
 279             try {
 280                 candidate = dataTree.prepare(modification);
 281                 listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
 282                 return SUCCESSFUL_FUTURE;
 283             } catch (Exception e) {
 284                 LOG.warn("Unexpected failure in pre-commit phase", e);
 285                 return Futures.immediateFailedFuture(e);
 286             }
 287         }
 288
 289         @Override
 290         public ListenableFuture<Void> abort() {
 291             candidate = null;
 292             return SUCCESSFUL_FUTURE;
 293         }
 294
 295         @Override
 296         public ListenableFuture<Void> commit() {
 297             checkState(candidate != null, "Proposed subtree must be computed");
 298
 299             /*
 300              * The commit has to occur atomically with regard to listener
 301              * registrations.
 302              */
 303             synchronized (InMemoryDOMDataStore.this) {
 304                 dataTree.commit(candidate);
 305                 changePublisher.publishChange(candidate);
 306                 listenerResolver.resolve(dataChangeListenerNotificationManager);
 307             }
 308
 309             return SUCCESSFUL_FUTURE;
 310         }
 311     }
 312 }