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