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.checkNotNull;
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static org.opendaylight.controller.md.sal.dom.store.impl.StoreUtils.increase;
  13
  14 import java.util.Collections;
  15 import java.util.concurrent.Callable;
  16 import java.util.concurrent.atomic.AtomicLong;
  17 import java.util.concurrent.atomic.AtomicReference;
  18
  19 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  20 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  21 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  22 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ModificationType;
  23 import org.opendaylight.controller.md.sal.dom.store.impl.tree.NodeModification;
  24 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreMetadataNode;
  25 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  26 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
  30 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  31 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  32 import org.opendaylight.yangtools.concepts.Identifiable;
  33 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  34 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  35 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
  36 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  37 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
  38 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  39 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 import com.google.common.base.Objects;
  44 import com.google.common.base.Objects.ToStringHelper;
  45 import com.google.common.base.Optional;
  46 import com.google.common.base.Preconditions;
  47 import com.google.common.primitives.UnsignedLong;
  48 import com.google.common.util.concurrent.Futures;
  49 import com.google.common.util.concurrent.ListenableFuture;
  50 import com.google.common.util.concurrent.ListeningExecutorService;
  51
  52 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener {
  53
  54     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  55     private static final InstanceIdentifier PUBLIC_ROOT_PATH = InstanceIdentifier.builder().build();
  56
  57
  58     private final ListeningExecutorService executor;
  59     private final String name;
  60     private final AtomicLong txCounter = new AtomicLong(0);
  61     private final ListenerTree listenerTree;
  62     private final AtomicReference<DataAndMetadataSnapshot> snapshot;
  63
  64     private ModificationApplyOperation operationTree;
  65
  66     private SchemaContext schemaContext;
  67
  68     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  69         this.name = Preconditions.checkNotNull(name);
  70         this.executor = Preconditions.checkNotNull(executor);
  71         this.listenerTree = ListenerTree.create();
  72         this.snapshot = new AtomicReference<DataAndMetadataSnapshot>(DataAndMetadataSnapshot.createEmpty());
  73         this.operationTree = new AlwaysFailOperation();
  74     }
  75
  76     @Override
  77     public final String getIdentifier() {
  78         return name;
  79     }
  80
  81     @Override
  82     public DOMStoreReadTransaction newReadOnlyTransaction() {
  83         return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot.get());
  84     }
  85
  86     @Override
  87     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  88         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  89     }
  90
  91     @Override
  92     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  93         return new SnaphostBackedWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  94     }
  95
  96     @Override
  97     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  98         operationTree = SchemaAwareApplyOperationRoot.from(ctx);
  99         schemaContext = ctx;
 100     }
 101
 102     @Override
 103     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 104             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 105
 106         /*
 107          * Make sure commit is not occurring right now. Listener has to be registered and its
 108          * state capture enqueued at a consistent point.
 109          *
 110          * FIXME: improve this to read-write lock, such that multiple listener registrations
 111          *        can occur simultaneously
 112          */
 113         final DataChangeListenerRegistration<L> reg;
 114         synchronized (this) {
 115             LOG.debug("{}: Registering data change listener {} for {}",name,listener,path);
 116
 117             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 118
 119             Optional<StoreMetadataNode> currentState = snapshot.get().read(path);
 120             if (currentState.isPresent()) {
 121                 final NormalizedNode<?, ?> data = currentState.get().getData();
 122
 123                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 124                         .setAfter(data) //
 125                         .addCreated(path, data) //
 126                         .build();
 127                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 128             }
 129         }
 130
 131         return new AbstractListenerRegistration<L>(listener) {
 132             @Override
 133             protected void removeRegistration() {
 134                 synchronized (InMemoryDOMDataStore.this) {
 135                     reg.close();
 136                 }
 137             }
 138         };
 139     }
 140
 141     private synchronized DOMStoreThreePhaseCommitCohort submit(
 142             final SnaphostBackedWriteTransaction writeTx) {
 143         LOG.debug("Tx: {} is submitted. Modifications: {}",writeTx.getIdentifier(),writeTx.getMutatedView());
 144         return new ThreePhaseCommitImpl(writeTx);
 145     }
 146
 147     private Object nextIdentifier() {
 148         return name + "-" + txCounter.getAndIncrement();
 149     }
 150
 151     private void commit(final DataAndMetadataSnapshot currentSnapshot,
 152             final StoreMetadataNode newDataTree, final ResolveDataChangeEventsTask listenerResolver) {
 153         LOG.debug("Updating Store snaphot version: {} with version:{}",currentSnapshot.getMetadataTree().getSubtreeVersion(),newDataTree.getSubtreeVersion());
 154
 155         if(LOG.isTraceEnabled()) {
 156             LOG.trace("Data Tree is {}",StoreUtils.toStringTree(newDataTree));
 157         }
 158
 159         final DataAndMetadataSnapshot newSnapshot = DataAndMetadataSnapshot.builder() //
 160                 .setMetadataTree(newDataTree) //
 161                 .setSchemaContext(schemaContext) //
 162                 .build();
 163
 164         /*
 165          * The commit has to occur atomically with regard to listener registrations.
 166          */
 167         synchronized (this) {
 168             final boolean success = snapshot.compareAndSet(currentSnapshot, newSnapshot);
 169             checkState(success, "Store snapshot and transaction snapshot differ. This should never happen.");
 170
 171             for (ChangeListenerNotifyTask task : listenerResolver.call()) {
 172                 LOG.trace("Scheduling invocation of listeners: {}",task);
 173                 executor.submit(task);
 174             }
 175         }
 176     }
 177
 178     private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
 179         private final Object identifier;
 180
 181         protected AbstractDOMStoreTransaction(final Object identifier) {
 182             this.identifier = identifier;
 183         }
 184
 185         @Override
 186         public final Object getIdentifier() {
 187             return identifier;
 188         }
 189
 190         @Override
 191         public final String toString() {
 192             return addToStringAttributes(Objects.toStringHelper(this)).toString();
 193         }
 194
 195         /**
 196          * Add class-specific toString attributes.
 197          *
 198          * @param toStringHelper ToStringHelper instance
 199          * @return ToStringHelper instance which was passed in
 200          */
 201         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 202             return toStringHelper.add("id", identifier);
 203         }
 204     }
 205
 206     private static class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements DOMStoreReadTransaction {
 207         private DataAndMetadataSnapshot stableSnapshot;
 208
 209         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 210             super(identifier);
 211             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 212             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot.getMetadataTree().getSubtreeVersion());
 213         }
 214
 215         @Override
 216         public void close() {
 217             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 218             stableSnapshot = null;
 219         }
 220
 221         @Override
 222         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 223             checkNotNull(path, "Path must not be null.");
 224             checkState(stableSnapshot != null, "Transaction is closed");
 225             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 226         }
 227     }
 228
 229     private static class SnaphostBackedWriteTransaction extends AbstractDOMStoreTransaction implements DOMStoreWriteTransaction {
 230         private MutableDataTree mutableTree;
 231         private InMemoryDOMDataStore store;
 232         private boolean ready = false;
 233
 234         public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 235                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 236             super(identifier);
 237             mutableTree = MutableDataTree.from(snapshot, applyOper);
 238             this.store = store;
 239             LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 240         }
 241
 242         @Override
 243         public void close() {
 244             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 245             this.mutableTree = null;
 246             this.store = null;
 247         }
 248
 249         @Override
 250         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 251             checkNotReady();
 252             try {
 253                 LOG.trace("Tx: {} Write: {}:{}",getIdentifier(),path,data);
 254                 mutableTree.write(path, data);
 255               // FIXME: Add checked exception
 256             } catch (Exception e) {
 257                 LOG.error("Tx: {}, failed to write {}:{} in {}",getIdentifier(),path,data,mutableTree,e);
 258             }
 259         }
 260
 261         @Override
 262         public void delete(final InstanceIdentifier path) {
 263             checkNotReady();
 264             try {
 265                 LOG.trace("Tx: {} Delete: {}",getIdentifier(),path);
 266                 mutableTree.delete(path);
 267              // FIXME: Add checked exception
 268             } catch (Exception e) {
 269                 LOG.error("Tx: {}, failed to delete {} in {}",getIdentifier(),path,mutableTree,e);
 270             }
 271         }
 272
 273         protected final boolean isReady() {
 274             return ready;
 275         }
 276
 277         protected final void checkNotReady() {
 278             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 279         }
 280
 281         @Override
 282         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 283             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 284             ready = true;
 285
 286             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 287             mutableTree.seal();
 288             return store.submit(this);
 289         }
 290
 291         protected MutableDataTree getMutatedView() {
 292             return mutableTree;
 293         }
 294
 295         @Override
 296         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 297             return toStringHelper.add("ready", isReady());
 298         }
 299     }
 300
 301     private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
 302             DOMStoreReadWriteTransaction {
 303
 304         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 305                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 306             super(identifier, snapshot, store, applyOper);
 307         }
 308
 309         @Override
 310         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 311             LOG.trace("Tx: {} Read: {}",getIdentifier(),path);
 312             try {
 313                 return Futures.immediateFuture(getMutatedView().read(path));
 314             } catch (Exception e) {
 315                 LOG.error("Tx: {} Failed Read of {}",getIdentifier(),path,e);
 316                 throw e;
 317             }
 318         }
 319     }
 320
 321     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 322
 323         private final SnaphostBackedWriteTransaction transaction;
 324         private final NodeModification modification;
 325
 326         private DataAndMetadataSnapshot storeSnapshot;
 327         private Optional<StoreMetadataNode> proposedSubtree;
 328         private ResolveDataChangeEventsTask listenerResolver;
 329
 330         public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
 331             this.transaction = writeTransaction;
 332             this.modification = transaction.getMutatedView().getRootModification();
 333         }
 334
 335         @Override
 336         public ListenableFuture<Boolean> canCommit() {
 337             final DataAndMetadataSnapshot snapshotCapture = snapshot.get();
 338             final ModificationApplyOperation snapshotOperation = operationTree;
 339
 340             return executor.submit(new Callable<Boolean>() {
 341
 342                 @Override
 343                 public Boolean call() throws Exception {
 344                     boolean applicable = snapshotOperation.isApplicable(modification,
 345                             Optional.of(snapshotCapture.getMetadataTree()));
 346                     LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 347                     return applicable;
 348                 }
 349             });
 350         }
 351
 352         @Override
 353         public ListenableFuture<Void> preCommit() {
 354             storeSnapshot = snapshot.get();
 355             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 356                 return Futures.immediateFuture(null);
 357             }
 358             return executor.submit(new Callable<Void>() {
 359
 360
 361
 362                 @Override
 363                 public Void call() throws Exception {
 364                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 365
 366                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 367                             increase(metadataTree.getSubtreeVersion()));
 368
 369                     listenerResolver = ResolveDataChangeEventsTask.create() //
 370                             .setRootPath(PUBLIC_ROOT_PATH) //
 371                             .setBeforeRoot(Optional.of(metadataTree)) //
 372                             .setAfterRoot(proposedSubtree) //
 373                             .setModificationRoot(modification) //
 374                             .setListenerRoot(listenerTree);
 375
 376                     return null;
 377                 }
 378             });
 379         }
 380
 381         @Override
 382         public ListenableFuture<Void> abort() {
 383             storeSnapshot = null;
 384             proposedSubtree = null;
 385             return Futures.<Void> immediateFuture(null);
 386         }
 387
 388         @Override
 389         public ListenableFuture<Void> commit() {
 390             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 391                 return Futures.immediateFuture(null);
 392             }
 393
 394             checkState(proposedSubtree != null,"Proposed subtree must be computed");
 395             checkState(storeSnapshot != null,"Proposed subtree must be computed");
 396             // return ImmediateFuture<>;
 397             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerResolver);
 398             return Futures.<Void> immediateFuture(null);
 399         }
 400
 401     }
 402
 403     private static final class AlwaysFailOperation implements ModificationApplyOperation {
 404
 405         @Override
 406         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 407                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 408             throw new IllegalStateException("Schema Context is not available.");
 409         }
 410
 411         @Override
 412         public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 413             throw new IllegalStateException("Schema Context is not available.");
 414         }
 415
 416         @Override
 417         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 418             throw new IllegalStateException("Schema Context is not available.");
 419         }
 420
 421         @Override
 422         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 423             throw new IllegalStateException("Schema Context is not available.");
 424         }
 425
 426     }
 427 }