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.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.ListenerRegistrationNode;
  20 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ModificationType;
  21 import org.opendaylight.controller.md.sal.dom.store.impl.tree.NodeModification;
  22 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreMetadataNode;
  23 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  24 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  25 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  26 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  28 import org.opendaylight.yangtools.concepts.Identifiable;
  29 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  30 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  31 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
  32 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  33 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
  34 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  35 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 import com.google.common.base.Optional;
  40 import com.google.common.base.Preconditions;
  41 import com.google.common.primitives.UnsignedLong;
  42 import com.google.common.util.concurrent.Futures;
  43 import com.google.common.util.concurrent.ListenableFuture;
  44 import com.google.common.util.concurrent.ListeningExecutorService;
  45
  46 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener {
  47
  48     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  49     private static final InstanceIdentifier PUBLIC_ROOT_PATH = InstanceIdentifier.builder().build();
  50
  51
  52     private final ListeningExecutorService executor;
  53     private final String name;
  54     private final AtomicLong txCounter = new AtomicLong(0);
  55
  56     private DataAndMetadataSnapshot snapshot;
  57     private ModificationApplyOperation operationTree;
  58     private final ListenerRegistrationNode listenerTree;
  59
  60
  61
  62     private SchemaContext schemaContext;
  63
  64     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  65         this.name = Preconditions.checkNotNull(name);
  66         this.executor = Preconditions.checkNotNull(executor);
  67         this.operationTree = new AlwaysFailOperation();
  68         this.snapshot = DataAndMetadataSnapshot.createEmpty();
  69         this.listenerTree = ListenerRegistrationNode.createRoot();
  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(), snapshot);
  80     }
  81
  82     @Override
  83     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  84         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot, this, operationTree);
  85     }
  86
  87     @Override
  88     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  89         return new SnaphostBackedWriteTransaction(nextIdentifier(), snapshot, this, operationTree);
  90     }
  91
  92     @Override
  93     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  94         operationTree = SchemaAwareApplyOperationRoot.from(ctx);
  95         schemaContext = ctx;
  96     }
  97
  98     @Override
  99     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 100             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 101         LOG.debug("{}: Registering data change listener {} for {}",name,listener,path);
 102         ListenerRegistrationNode listenerNode = listenerTree;
 103         for(PathArgument arg :path.getPath()) {
 104             listenerNode = listenerNode.ensureChild(arg);
 105         }
 106         synchronized (listener) {
 107             notifyInitialState(path, listener);
 108         }
 109         return listenerNode.registerDataChangeListener(path,listener, scope);
 110     }
 111
 112     private void notifyInitialState(final InstanceIdentifier path,
 113             final AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>> listener) {
 114         Optional<StoreMetadataNode> currentState = snapshot.read(path);
 115         try {
 116             if (currentState.isPresent()) {
 117                 NormalizedNode<?, ?> data = currentState.get().getData();
 118                 listener.onDataChanged(DOMImmutableDataChangeEvent.builder() //
 119                         .setAfter(data) //
 120                         .addCreated(path, data) //
 121                         .build() //
 122                 );
 123             }
 124         } catch (Exception e) {
 125             LOG.error("Unhandled exception encountered when invoking listener {}", listener, e);
 126         }
 127
 128     }
 129
 130     private synchronized DOMStoreThreePhaseCommitCohort submit(
 131             final SnaphostBackedWriteTransaction writeTx) {
 132         LOG.debug("Tx: {} is submitted. Modifications: {}",writeTx.getIdentifier(),writeTx.getMutatedView());
 133         return new ThreePhaseCommitImpl(writeTx);
 134     }
 135
 136     private Object nextIdentifier() {
 137         return name + "-" + txCounter.getAndIncrement();
 138     }
 139
 140     private synchronized void commit(final DataAndMetadataSnapshot currentSnapshot,
 141             final StoreMetadataNode newDataTree, final Iterable<ChangeListenerNotifyTask> listenerTasks) {
 142         LOG.debug("Updating Store snaphot version: {} with version:{}",currentSnapshot.getMetadataTree().getSubtreeVersion(),newDataTree.getSubtreeVersion());
 143
 144         if(LOG.isTraceEnabled()) {
 145             LOG.trace("Data Tree is {}",StoreUtils.toStringTree(newDataTree));
 146         }
 147         checkState(snapshot == currentSnapshot, "Store snapshot and transaction snapshot differs");
 148         snapshot = DataAndMetadataSnapshot.builder() //
 149                 .setMetadataTree(newDataTree) //
 150                 .setSchemaContext(schemaContext) //
 151                 .build();
 152
 153         for(ChangeListenerNotifyTask task : listenerTasks) {
 154             executor.submit(task);
 155         }
 156
 157     }
 158
 159     private static class SnapshotBackedReadTransaction implements DOMStoreReadTransaction {
 160
 161         private DataAndMetadataSnapshot stableSnapshot;
 162         private final Object identifier;
 163
 164         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 165             this.identifier = identifier;
 166             this.stableSnapshot = snapshot;
 167             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 168
 169         }
 170
 171         @Override
 172         public Object getIdentifier() {
 173             return identifier;
 174         }
 175
 176         @Override
 177         public void close() {
 178             stableSnapshot = null;
 179         }
 180
 181         @Override
 182         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 183             checkNotNull(path, "Path must not be null.");
 184             checkState(stableSnapshot != null, "Transaction is closed");
 185             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 186         }
 187
 188         @Override
 189         public String toString() {
 190             return "SnapshotBackedReadTransaction [id =" + identifier + "]";
 191         }
 192
 193     }
 194
 195     private static class SnaphostBackedWriteTransaction implements DOMStoreWriteTransaction {
 196
 197         private MutableDataTree mutableTree;
 198         private final Object identifier;
 199         private InMemoryDOMDataStore store;
 200
 201         private boolean ready = false;
 202
 203         public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 204                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 205             this.identifier = identifier;
 206             mutableTree = MutableDataTree.from(snapshot, applyOper);
 207             this.store = store;
 208             LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 209         }
 210
 211         @Override
 212         public Object getIdentifier() {
 213             return identifier;
 214         }
 215
 216         @Override
 217         public void close() {
 218             this.mutableTree = null;
 219             this.store = null;
 220         }
 221
 222         @Override
 223         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 224             checkNotReady();
 225             mutableTree.write(path, data);
 226         }
 227
 228         @Override
 229         public void delete(final InstanceIdentifier path) {
 230             checkNotReady();
 231             mutableTree.delete(path);
 232         }
 233
 234         protected boolean isReady() {
 235             return ready;
 236         }
 237
 238         protected void checkNotReady() {
 239             checkState(!ready, "Transaction is ready. No further modifications allowed.");
 240         }
 241
 242         @Override
 243         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 244             ready = true;
 245             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 246             mutableTree.seal();
 247             return store.submit(this);
 248         }
 249
 250         protected MutableDataTree getMutatedView() {
 251             return mutableTree;
 252         }
 253
 254         @Override
 255         public String toString() {
 256             return "SnaphostBackedWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
 257         }
 258
 259     }
 260
 261     private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
 262             DOMStoreReadWriteTransaction {
 263
 264         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 265                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 266             super(identifier, snapshot, store, applyOper);
 267         }
 268
 269         @Override
 270         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 271             return Futures.immediateFuture(getMutatedView().read(path));
 272         }
 273
 274         @Override
 275         public String toString() {
 276             return "SnapshotBackedReadWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
 277         }
 278
 279     }
 280
 281     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 282
 283         private final SnaphostBackedWriteTransaction transaction;
 284         private final NodeModification modification;
 285
 286         private DataAndMetadataSnapshot storeSnapshot;
 287         private Optional<StoreMetadataNode> proposedSubtree;
 288         private Iterable<ChangeListenerNotifyTask> listenerTasks;
 289
 290         public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
 291             this.transaction = writeTransaction;
 292             this.modification = transaction.getMutatedView().getRootModification();
 293         }
 294
 295         @Override
 296         public ListenableFuture<Boolean> canCommit() {
 297             final DataAndMetadataSnapshot snapshotCapture = snapshot;
 298             final ModificationApplyOperation snapshotOperation = operationTree;
 299
 300             return executor.submit(new Callable<Boolean>() {
 301
 302                 @Override
 303                 public Boolean call() throws Exception {
 304                     boolean applicable = snapshotOperation.isApplicable(modification,
 305                             Optional.of(snapshotCapture.getMetadataTree()));
 306                     LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 307                     return applicable;
 308                 }
 309             });
 310         }
 311
 312         @Override
 313         public ListenableFuture<Void> preCommit() {
 314             storeSnapshot = snapshot;
 315             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 316                 return Futures.immediateFuture(null);
 317             }
 318             return executor.submit(new Callable<Void>() {
 319
 320
 321
 322                 @Override
 323                 public Void call() throws Exception {
 324                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 325
 326                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 327                             increase(metadataTree.getSubtreeVersion()));
 328
 329                     listenerTasks = DataChangeEventResolver.create() //
 330                             .setRootPath(PUBLIC_ROOT_PATH) //
 331                             .setBeforeRoot(Optional.of(metadataTree)) //
 332                             .setAfterRoot(proposedSubtree) //
 333                             .setModificationRoot(modification) //
 334                             .setListenerRoot(listenerTree) //
 335                             .resolve();
 336
 337                     return null;
 338                 }
 339             });
 340         }
 341
 342         @Override
 343         public ListenableFuture<Void> abort() {
 344             storeSnapshot = null;
 345             proposedSubtree = null;
 346             return Futures.<Void> immediateFuture(null);
 347         }
 348
 349         @Override
 350         public ListenableFuture<Void> commit() {
 351             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 352                 return Futures.immediateFuture(null);
 353             }
 354
 355             checkState(proposedSubtree != null,"Proposed subtree must be computed");
 356             checkState(storeSnapshot != null,"Proposed subtree must be computed");
 357             // return ImmediateFuture<>;
 358             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerTasks);
 359             return Futures.<Void> immediateFuture(null);
 360         }
 361
 362     }
 363
 364     private static final class AlwaysFailOperation implements ModificationApplyOperation {
 365
 366         @Override
 367         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 368                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 369             throw new IllegalStateException("Schema Context is not available.");
 370         }
 371
 372         @Override
 373         public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 374             throw new IllegalStateException("Schema Context is not available.");
 375         }
 376
 377         @Override
 378         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 379             throw new IllegalStateException("Schema Context is not available.");
 380         }
 381
 382         @Override
 383         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 384             throw new IllegalStateException("Schema Context is not available.");
 385         }
 386
 387     }
 388 }