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