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.md.sal.dom.store.impl.tree.TreeNodeUtils;
  24 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  25 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  26 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  29 import org.opendaylight.yangtools.concepts.Identifiable;
  30 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  31 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  32 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
  33 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  34 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
  35 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  36 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 import com.google.common.base.Optional;
  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.executor = executor;
  66         this.name = name;
  67         this.operationTree = new AllwaysFailOperation();
  68         this.snapshot = DataAndMetadataSnapshot.createEmpty();
  69         this.listenerTree = ListenerRegistrationNode.createRoot();
  70     }
  71
  72     @Override
  73     public 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
 102         Optional<ListenerRegistrationNode> listenerNode = TreeNodeUtils.findNode(listenerTree, path);
 103         checkState(listenerNode.isPresent());
 104         synchronized (listener) {
 105             notifyInitialState(path, listener);
 106         }
 107         return listenerNode.get().registerDataChangeListener(listener, scope);
 108     }
 109
 110     private void notifyInitialState(final InstanceIdentifier path,
 111             final AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>> listener) {
 112         Optional<StoreMetadataNode> currentState = snapshot.read(path);
 113         try {
 114             if (currentState.isPresent()) {
 115                 NormalizedNode<?, ?> data = currentState.get().getData();
 116                 listener.onDataChanged(DOMImmutableDataChangeEvent.builder() //
 117                         .setAfter(data) //
 118                         .addCreated(path, data) //
 119                         .build() //
 120                 );
 121             }
 122         } catch (Exception e) {
 123             LOG.error("Unhandled exception encountered when invoking listener {}", listener, e);
 124         }
 125
 126     }
 127
 128     private synchronized DOMStoreThreePhaseCommitCohort submit(
 129             final SnaphostBackedWriteTransaction writeTx) {
 130         LOG.debug("Tx: {} is submitted. Modifications: {}",writeTx.getIdentifier(),writeTx.getMutatedView());
 131         return new ThreePhaseCommitImpl(writeTx);
 132     }
 133
 134     private Object nextIdentifier() {
 135         return name + "-" + txCounter.getAndIncrement();
 136     }
 137
 138     private synchronized void commit(final DataAndMetadataSnapshot currentSnapshot,
 139             final StoreMetadataNode newDataTree, final Iterable<ChangeListenerNotifyTask> listenerTasks) {
 140         LOG.debug("Updating Store snaphot version: {} with version:{}",currentSnapshot.getMetadataTree().getSubtreeVersion(),newDataTree.getSubtreeVersion());
 141         if(LOG.isTraceEnabled()) {
 142             LOG.trace("Data Tree is {}",StoreUtils.toStringTree(newDataTree));
 143         }
 144         checkState(snapshot == currentSnapshot, "Store snapshot and transaction snapshot differs");
 145         snapshot = DataAndMetadataSnapshot.builder() //
 146                 .setMetadataTree(newDataTree) //
 147                 .setSchemaContext(schemaContext) //
 148                 .build();
 149
 150         for(ChangeListenerNotifyTask task : listenerTasks) {
 151             executor.submit(task);
 152         }
 153
 154     }
 155
 156     private static class SnapshotBackedReadTransaction implements DOMStoreReadTransaction {
 157
 158         private DataAndMetadataSnapshot stableSnapshot;
 159         private final Object identifier;
 160
 161         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 162             this.identifier = identifier;
 163             this.stableSnapshot = snapshot;
 164             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 165
 166         }
 167
 168         @Override
 169         public Object getIdentifier() {
 170             return identifier;
 171         }
 172
 173         @Override
 174         public void close() {
 175             stableSnapshot = null;
 176         }
 177
 178         @Override
 179         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 180             checkNotNull(path, "Path must not be null.");
 181             checkState(stableSnapshot != null, "Transaction is closed");
 182             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 183         }
 184
 185         @Override
 186         public String toString() {
 187             return "SnapshotBackedReadTransaction [id =" + identifier + "]";
 188         }
 189
 190     }
 191
 192     private static class SnaphostBackedWriteTransaction implements DOMStoreWriteTransaction {
 193
 194         private MutableDataTree mutableTree;
 195         private final Object identifier;
 196         private InMemoryDOMDataStore store;
 197
 198         private boolean ready = false;
 199
 200         public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 201                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 202             this.identifier = identifier;
 203             mutableTree = MutableDataTree.from(snapshot, applyOper);
 204             this.store = store;
 205             LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 206         }
 207
 208         @Override
 209         public Object getIdentifier() {
 210             return identifier;
 211         }
 212
 213         @Override
 214         public void close() {
 215             this.mutableTree = null;
 216             this.store = null;
 217         }
 218
 219         @Override
 220         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 221             checkNotReady();
 222             mutableTree.write(path, data);
 223         }
 224
 225         @Override
 226         public void delete(final InstanceIdentifier path) {
 227             checkNotReady();
 228             mutableTree.delete(path);
 229         }
 230
 231         protected boolean isReady() {
 232             return ready;
 233         }
 234
 235         protected void checkNotReady() {
 236             checkState(!ready, "Transaction is ready. No further modifications allowed.");
 237         }
 238
 239         @Override
 240         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 241             ready = true;
 242             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 243             mutableTree.seal();
 244             return store.submit(this);
 245         }
 246
 247         protected MutableDataTree getMutatedView() {
 248             return mutableTree;
 249         }
 250
 251         @Override
 252         public String toString() {
 253             return "SnaphostBackedWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
 254         }
 255
 256     }
 257
 258     private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
 259             DOMStoreReadWriteTransaction {
 260
 261         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 262                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 263             super(identifier, snapshot, store, applyOper);
 264         }
 265
 266         @Override
 267         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 268             return Futures.immediateFuture(getMutatedView().read(path));
 269         }
 270
 271         @Override
 272         public String toString() {
 273             return "SnapshotBackedReadWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
 274         }
 275
 276     }
 277
 278     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 279
 280         private final SnaphostBackedWriteTransaction transaction;
 281         private final NodeModification modification;
 282
 283         private DataAndMetadataSnapshot storeSnapshot;
 284         private Optional<StoreMetadataNode> proposedSubtree;
 285         private Iterable<ChangeListenerNotifyTask> listenerTasks;
 286
 287         public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
 288             this.transaction = writeTransaction;
 289             this.modification = transaction.getMutatedView().getRootModification();
 290         }
 291
 292         @Override
 293         public ListenableFuture<Boolean> canCommit() {
 294             final DataAndMetadataSnapshot snapshotCapture = snapshot;
 295             final ModificationApplyOperation snapshotOperation = operationTree;
 296
 297             return executor.submit(new Callable<Boolean>() {
 298
 299                 @Override
 300                 public Boolean call() throws Exception {
 301                     boolean applicable = snapshotOperation.isApplicable(modification,
 302                             Optional.of(snapshotCapture.getMetadataTree()));
 303                     LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 304                     return applicable;
 305                 }
 306             });
 307         }
 308
 309         @Override
 310         public ListenableFuture<Void> preCommit() {
 311             storeSnapshot = snapshot;
 312             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 313                 return Futures.immediateFuture(null);
 314             }
 315             return executor.submit(new Callable<Void>() {
 316
 317
 318
 319                 @Override
 320                 public Void call() throws Exception {
 321                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 322
 323                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 324                             increase(metadataTree.getSubtreeVersion()));
 325
 326
 327                     listenerTasks = DataChangeEventResolver.create() //
 328                             .setRootPath(PUBLIC_ROOT_PATH) //
 329                             .setBeforeRoot(Optional.of(metadataTree)) //
 330                             .setAfterRoot(proposedSubtree) //
 331                             .setModificationRoot(modification) //
 332                             .setListenerRoot(listenerTree) //
 333                             .resolve();
 334
 335                     return null;
 336                 }
 337             });
 338         }
 339
 340         @Override
 341         public ListenableFuture<Void> abort() {
 342             storeSnapshot = null;
 343             proposedSubtree = null;
 344             return Futures.<Void> immediateFuture(null);
 345         }
 346
 347         @Override
 348         public ListenableFuture<Void> commit() {
 349             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 350                 return Futures.immediateFuture(null);
 351             }
 352
 353             checkState(proposedSubtree != null,"Proposed subtree must be computed");
 354             checkState(storeSnapshot != null,"Proposed subtree must be computed");
 355             // return ImmediateFuture<>;
 356             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerTasks);
 357             return Futures.<Void> immediateFuture(null);
 358         }
 359
 360     }
 361
 362     private class AllwaysFailOperation implements ModificationApplyOperation {
 363
 364         @Override
 365         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 366                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 367             throw new IllegalStateException("Schema Context is not available.");
 368         }
 369
 370         @Override
 371         public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 372             throw new IllegalStateException("Schema Context is not available.");
 373         }
 374
 375         @Override
 376         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 377             throw new IllegalStateException("Schema Context is not available.");
 378         }
 379
 380         @Override
 381         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 382             throw new IllegalStateException("Schema Context is not available.");
 383         }
 384
 385     }
 386 }