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() //
 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 DataChangeEventResolver 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.resolve()) {
 172                 executor.submit(task);
 173             }
 174         }
 175     }
 176
 177     private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
 178         private final Object identifier;
 179
 180         protected AbstractDOMStoreTransaction(final Object identifier) {
 181             this.identifier = identifier;
 182         }
 183
 184         @Override
 185         public final Object getIdentifier() {
 186             return identifier;
 187         }
 188
 189         @Override
 190         public final String toString() {
 191             return addToStringAttributes(Objects.toStringHelper(this)).toString();
 192         }
 193
 194         /**
 195          * Add class-specific toString attributes.
 196          *
 197          * @param toStringHelper ToStringHelper instance
 198          * @return ToStringHelper instance which was passed in
 199          */
 200         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 201             return toStringHelper.add("id", identifier);
 202         }
 203     }
 204
 205     private static class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements DOMStoreReadTransaction {
 206         private DataAndMetadataSnapshot stableSnapshot;
 207
 208         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 209             super(identifier);
 210             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 211             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot.getMetadataTree().getSubtreeVersion());
 212         }
 213
 214         @Override
 215         public void close() {
 216             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 217             stableSnapshot = null;
 218         }
 219
 220         @Override
 221         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 222             checkNotNull(path, "Path must not be null.");
 223             checkState(stableSnapshot != null, "Transaction is closed");
 224             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 225         }
 226     }
 227
 228     private static class SnaphostBackedWriteTransaction extends AbstractDOMStoreTransaction implements DOMStoreWriteTransaction {
 229         private MutableDataTree mutableTree;
 230         private InMemoryDOMDataStore store;
 231         private boolean ready = false;
 232
 233         public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 234                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 235             super(identifier);
 236             mutableTree = MutableDataTree.from(snapshot, applyOper);
 237             this.store = store;
 238             LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 239         }
 240
 241         @Override
 242         public void close() {
 243             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 244             this.mutableTree = null;
 245             this.store = null;
 246         }
 247
 248         @Override
 249         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 250             checkNotReady();
 251             mutableTree.write(path, data);
 252         }
 253
 254         @Override
 255         public void delete(final InstanceIdentifier path) {
 256             checkNotReady();
 257             mutableTree.delete(path);
 258         }
 259
 260         protected final boolean isReady() {
 261             return ready;
 262         }
 263
 264         protected final void checkNotReady() {
 265             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 266         }
 267
 268         @Override
 269         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 270             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 271             ready = true;
 272
 273             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 274             mutableTree.seal();
 275             return store.submit(this);
 276         }
 277
 278         protected MutableDataTree getMutatedView() {
 279             return mutableTree;
 280         }
 281
 282         @Override
 283         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 284             return toStringHelper.add("ready", isReady());
 285         }
 286     }
 287
 288     private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
 289             DOMStoreReadWriteTransaction {
 290
 291         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 292                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 293             super(identifier, snapshot, store, applyOper);
 294         }
 295
 296         @Override
 297         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 298             return Futures.immediateFuture(getMutatedView().read(path));
 299         }
 300     }
 301
 302     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 303
 304         private final SnaphostBackedWriteTransaction transaction;
 305         private final NodeModification modification;
 306
 307         private DataAndMetadataSnapshot storeSnapshot;
 308         private Optional<StoreMetadataNode> proposedSubtree;
 309         private DataChangeEventResolver listenerResolver;
 310
 311         public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
 312             this.transaction = writeTransaction;
 313             this.modification = transaction.getMutatedView().getRootModification();
 314         }
 315
 316         @Override
 317         public ListenableFuture<Boolean> canCommit() {
 318             final DataAndMetadataSnapshot snapshotCapture = snapshot.get();
 319             final ModificationApplyOperation snapshotOperation = operationTree;
 320
 321             return executor.submit(new Callable<Boolean>() {
 322
 323                 @Override
 324                 public Boolean call() throws Exception {
 325                     boolean applicable = snapshotOperation.isApplicable(modification,
 326                             Optional.of(snapshotCapture.getMetadataTree()));
 327                     LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 328                     return applicable;
 329                 }
 330             });
 331         }
 332
 333         @Override
 334         public ListenableFuture<Void> preCommit() {
 335             storeSnapshot = snapshot.get();
 336             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 337                 return Futures.immediateFuture(null);
 338             }
 339             return executor.submit(new Callable<Void>() {
 340
 341
 342
 343                 @Override
 344                 public Void call() throws Exception {
 345                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 346
 347                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 348                             increase(metadataTree.getSubtreeVersion()));
 349
 350                     listenerResolver = DataChangeEventResolver.create() //
 351                             .setRootPath(PUBLIC_ROOT_PATH) //
 352                             .setBeforeRoot(Optional.of(metadataTree)) //
 353                             .setAfterRoot(proposedSubtree) //
 354                             .setModificationRoot(modification) //
 355                             .setListenerRoot(listenerTree);
 356
 357                     return null;
 358                 }
 359             });
 360         }
 361
 362         @Override
 363         public ListenableFuture<Void> abort() {
 364             storeSnapshot = null;
 365             proposedSubtree = null;
 366             return Futures.<Void> immediateFuture(null);
 367         }
 368
 369         @Override
 370         public ListenableFuture<Void> commit() {
 371             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 372                 return Futures.immediateFuture(null);
 373             }
 374
 375             checkState(proposedSubtree != null,"Proposed subtree must be computed");
 376             checkState(storeSnapshot != null,"Proposed subtree must be computed");
 377             // return ImmediateFuture<>;
 378             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerResolver);
 379             return Futures.<Void> immediateFuture(null);
 380         }
 381
 382     }
 383
 384     private static final class AlwaysFailOperation implements ModificationApplyOperation {
 385
 386         @Override
 387         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 388                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 389             throw new IllegalStateException("Schema Context is not available.");
 390         }
 391
 392         @Override
 393         public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 394             throw new IllegalStateException("Schema Context is not available.");
 395         }
 396
 397         @Override
 398         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 399             throw new IllegalStateException("Schema Context is not available.");
 400         }
 401
 402         @Override
 403         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 404             throw new IllegalStateException("Schema Context is not available.");
 405         }
 406
 407     }
 408 }