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