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     private final ListeningExecutorService executor;
  58     private final String name;
  59     private final AtomicLong txCounter = new AtomicLong(0);
  60     private final ListenerTree listenerTree;
  61     private final AtomicReference<DataAndMetadataSnapshot> snapshot;
  62
  63     private ModificationApplyOperation operationTree;
  64
  65     private SchemaContext schemaContext;
  66
  67     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  68         this.name = Preconditions.checkNotNull(name);
  69         this.executor = Preconditions.checkNotNull(executor);
  70         this.listenerTree = ListenerTree.create();
  71         this.snapshot = new AtomicReference<DataAndMetadataSnapshot>(DataAndMetadataSnapshot.createEmpty());
  72         this.operationTree = new AlwaysFailOperation();
  73     }
  74
  75     @Override
  76     public final String getIdentifier() {
  77         return name;
  78     }
  79
  80     @Override
  81     public DOMStoreReadTransaction newReadOnlyTransaction() {
  82         return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot.get());
  83     }
  84
  85     @Override
  86     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  87         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  88     }
  89
  90     @Override
  91     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  92         return new SnapshotBackedWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  93     }
  94
  95     @Override
  96     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  97         operationTree = SchemaAwareApplyOperationRoot.from(ctx);
  98         schemaContext = ctx;
  99     }
 100
 101     @Override
 102     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 103             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 104
 105         /*
 106          * Make sure commit is not occurring right now. Listener has to be
 107          * registered and its state capture enqueued at a consistent point.
 108          *
 109          * FIXME: improve this to read-write lock, such that multiple listener
 110          * registrations can occur simultaneously
 111          */
 112         final DataChangeListenerRegistration<L> reg;
 113         synchronized (this) {
 114             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 115
 116             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 117
 118             Optional<StoreMetadataNode> currentState = snapshot.get().read(path);
 119             if (currentState.isPresent()) {
 120                 final NormalizedNode<?, ?> data = currentState.get().getData();
 121
 122                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 123                         .setAfter(data) //
 124                         .addCreated(path, data) //
 125                         .build();
 126                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 127             }
 128         }
 129
 130         return new AbstractListenerRegistration<L>(listener) {
 131             @Override
 132             protected void removeRegistration() {
 133                 synchronized (InMemoryDOMDataStore.this) {
 134                     reg.close();
 135                 }
 136             }
 137         };
 138     }
 139
 140     private synchronized DOMStoreThreePhaseCommitCohort submit(final SnapshotBackedWriteTransaction writeTx) {
 141         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
 142         return new ThreePhaseCommitImpl(writeTx);
 143     }
 144
 145     private Object nextIdentifier() {
 146         return name + "-" + txCounter.getAndIncrement();
 147     }
 148
 149     private void commit(final DataAndMetadataSnapshot currentSnapshot, final StoreMetadataNode newDataTree,
 150             final ResolveDataChangeEventsTask listenerResolver) {
 151         LOG.debug("Updating Store snaphot version: {} with version:{}", currentSnapshot.getMetadataTree()
 152                 .getSubtreeVersion(), newDataTree.getSubtreeVersion());
 153
 154         if (LOG.isTraceEnabled()) {
 155             LOG.trace("Data Tree is {}", StoreUtils.toStringTree(newDataTree));
 156         }
 157
 158         final DataAndMetadataSnapshot newSnapshot = DataAndMetadataSnapshot.builder() //
 159                 .setMetadataTree(newDataTree) //
 160                 .setSchemaContext(schemaContext) //
 161                 .build();
 162
 163         /*
 164          * The commit has to occur atomically with regard to listener
 165          * 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
 199          *            ToStringHelper instance
 200          * @return ToStringHelper instance which was passed in
 201          */
 202         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 203             return toStringHelper.add("id", identifier);
 204         }
 205     }
 206
 207     private static class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
 208             DOMStoreReadTransaction {
 209         private DataAndMetadataSnapshot stableSnapshot;
 210
 211         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 212             super(identifier);
 213             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 214             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot.getMetadataTree()
 215                     .getSubtreeVersion());
 216         }
 217
 218         @Override
 219         public void close() {
 220             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 221             stableSnapshot = null;
 222         }
 223
 224         @Override
 225         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 226             checkNotNull(path, "Path must not be null.");
 227             checkState(stableSnapshot != null, "Transaction is closed");
 228             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 229         }
 230     }
 231
 232     private static class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements
 233             DOMStoreWriteTransaction {
 234         private MutableDataTree mutableTree;
 235         private InMemoryDOMDataStore store;
 236         private boolean ready = false;
 237
 238         public SnapshotBackedWriteTransaction(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()
 244                     .getSubtreeVersion());
 245         }
 246
 247         @Override
 248         public void close() {
 249             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 250             this.mutableTree = null;
 251             this.store = null;
 252         }
 253
 254         @Override
 255         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 256             checkNotReady();
 257             try {
 258                 LOG.trace("Tx: {} Write: {}:{}", getIdentifier(), path, data);
 259                 mutableTree.write(path, data);
 260                 // FIXME: Add checked exception
 261             } catch (Exception e) {
 262                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 263             }
 264         }
 265
 266         @Override
 267         public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 268             checkNotReady();
 269             try {
 270                 LOG.trace("Tx: {} Merge: {}:{}", getIdentifier(), path, data);
 271                 mutableTree.merge(path, data);
 272                 // FIXME: Add checked exception
 273             } catch (Exception e) {
 274                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 275             }
 276         }
 277
 278         @Override
 279         public void delete(final InstanceIdentifier path) {
 280             checkNotReady();
 281             try {
 282                 LOG.trace("Tx: {} Delete: {}", getIdentifier(), path);
 283                 mutableTree.delete(path);
 284                 // FIXME: Add checked exception
 285             } catch (Exception e) {
 286                 LOG.error("Tx: {}, failed to delete {} in {}", getIdentifier(), path, mutableTree, e);
 287             }
 288         }
 289
 290         protected final boolean isReady() {
 291             return ready;
 292         }
 293
 294         protected final void checkNotReady() {
 295             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 296         }
 297
 298         @Override
 299         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 300             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 301             ready = true;
 302
 303             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 304             mutableTree.seal();
 305             return store.submit(this);
 306         }
 307
 308         protected MutableDataTree getMutatedView() {
 309             return mutableTree;
 310         }
 311
 312         @Override
 313         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 314             return toStringHelper.add("ready", isReady());
 315         }
 316     }
 317
 318     private static class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
 319             DOMStoreReadWriteTransaction {
 320
 321         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 322                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 323             super(identifier, snapshot, store, applyOper);
 324         }
 325
 326         @Override
 327         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 328             LOG.trace("Tx: {} Read: {}", getIdentifier(), path);
 329             try {
 330                 return Futures.immediateFuture(getMutatedView().read(path));
 331             } catch (Exception e) {
 332                 LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
 333                 throw e;
 334             }
 335         }
 336     }
 337
 338     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 339
 340         private final SnapshotBackedWriteTransaction transaction;
 341         private final NodeModification modification;
 342
 343         private DataAndMetadataSnapshot storeSnapshot;
 344         private Optional<StoreMetadataNode> proposedSubtree;
 345         private ResolveDataChangeEventsTask listenerResolver;
 346
 347         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
 348             this.transaction = writeTransaction;
 349             this.modification = transaction.getMutatedView().getRootModification();
 350         }
 351
 352         @Override
 353         public ListenableFuture<Boolean> canCommit() {
 354             final DataAndMetadataSnapshot snapshotCapture = snapshot.get();
 355             final ModificationApplyOperation snapshotOperation = operationTree;
 356
 357             return executor.submit(new Callable<Boolean>() {
 358
 359                 @Override
 360                 public Boolean call() throws Exception {
 361                     Boolean applicable = false;
 362                     try {
 363                         snapshotOperation.checkApplicable(PUBLIC_ROOT_PATH, modification,
 364                             Optional.of(snapshotCapture.getMetadataTree()));
 365                         applicable = true;
 366                     } catch (DataPreconditionFailedException e) {
 367                         LOG.warn("Store Tx: {} Data Precondition failed for {}.",transaction.getIdentifier(),e.getPath(),e);
 368                         applicable = false;
 369                     }
 370                     LOG.debug("Store Transaction: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 371                     return applicable;
 372                 }
 373             });
 374         }
 375
 376         @Override
 377         public ListenableFuture<Void> preCommit() {
 378             storeSnapshot = snapshot.get();
 379             if (modification.getModificationType() == ModificationType.UNMODIFIED) {
 380                 return Futures.immediateFuture(null);
 381             }
 382             return executor.submit(new Callable<Void>() {
 383
 384                 @Override
 385                 public Void call() throws Exception {
 386                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 387
 388                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 389                             increase(metadataTree.getSubtreeVersion()));
 390
 391                     listenerResolver = ResolveDataChangeEventsTask.create() //
 392                             .setRootPath(PUBLIC_ROOT_PATH) //
 393                             .setBeforeRoot(Optional.of(metadataTree)) //
 394                             .setAfterRoot(proposedSubtree) //
 395                             .setModificationRoot(modification) //
 396                             .setListenerRoot(listenerTree);
 397
 398                     return null;
 399                 }
 400             });
 401         }
 402
 403         @Override
 404         public ListenableFuture<Void> abort() {
 405             storeSnapshot = null;
 406             proposedSubtree = null;
 407             return Futures.<Void> immediateFuture(null);
 408         }
 409
 410         @Override
 411         public ListenableFuture<Void> commit() {
 412             if (modification.getModificationType() == ModificationType.UNMODIFIED) {
 413                 return Futures.immediateFuture(null);
 414             }
 415
 416             checkState(proposedSubtree != null, "Proposed subtree must be computed");
 417             checkState(storeSnapshot != null, "Proposed subtree must be computed");
 418             // return ImmediateFuture<>;
 419             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(), listenerResolver);
 420             return Futures.<Void> immediateFuture(null);
 421         }
 422
 423     }
 424
 425     private static final class AlwaysFailOperation implements ModificationApplyOperation {
 426
 427         @Override
 428         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 429                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 430             throw new IllegalStateException("Schema Context is not available.");
 431         }
 432
 433         @Override
 434         public void checkApplicable(final InstanceIdentifier path,final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 435             throw new IllegalStateException("Schema Context is not available.");
 436         }
 437
 438         @Override
 439         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 440             throw new IllegalStateException("Schema Context is not available.");
 441         }
 442
 443         @Override
 444         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 445             throw new IllegalStateException("Schema Context is not available.");
 446         }
 447
 448     }
 449 }