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.DOMStoreTransaction;
  31 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  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
  58     private final ListeningExecutorService executor;
  59     private final String name;
  60     private final AtomicLong txCounter = new AtomicLong(0);
  61     private final ListenerRegistrationNode listenerTree;
  62     private final AtomicReference<DataAndMetadataSnapshot> snapshot;
  63
  64     private ModificationApplyOperation operationTree;
  65
  66     private SchemaContext schemaContext;
  67
  68     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  69         this.name = Preconditions.checkNotNull(name);
  70         this.executor = Preconditions.checkNotNull(executor);
  71         this.listenerTree = ListenerRegistrationNode.createRoot();
  72         this.snapshot = new AtomicReference<DataAndMetadataSnapshot>(DataAndMetadataSnapshot.createEmpty());
  73         this.operationTree = new AlwaysFailOperation();
  74     }
  75
  76     @Override
  77     public final String getIdentifier() {
  78         return name;
  79     }
  80
  81     @Override
  82     public DOMStoreReadTransaction newReadOnlyTransaction() {
  83         return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot.get());
  84     }
  85
  86     @Override
  87     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  88         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  89     }
  90
  91     @Override
  92     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  93         return new SnaphostBackedWriteTransaction(nextIdentifier(), snapshot.get(), this, operationTree);
  94     }
  95
  96     @Override
  97     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  98         operationTree = SchemaAwareApplyOperationRoot.from(ctx);
  99         schemaContext = ctx;
 100     }
 101
 102     @Override
 103     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 104             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 105         LOG.debug("{}: Registering data change listener {} for {}",name,listener,path);
 106         ListenerRegistrationNode listenerNode = listenerTree;
 107         for(PathArgument arg : path.getPath()) {
 108             listenerNode = listenerNode.ensureChild(arg);
 109         }
 110
 111         /*
 112          * Make sure commit is not occurring right now. Listener has to be registered and its
 113          * state capture enqueued at a consistent point.
 114          *
 115          * FIXME: improve this to read-write lock, such that multiple listener registrations
 116          *        can occur simultaneously
 117          */
 118         final DataChangeListenerRegistration<L> reg;
 119         synchronized (this) {
 120             reg = listenerNode.registerDataChangeListener(path, listener, scope);
 121
 122             Optional<StoreMetadataNode> currentState = snapshot.get().read(path);
 123             if (currentState.isPresent()) {
 124                 final NormalizedNode<?, ?> data = currentState.get().getData();
 125
 126                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder() //
 127                         .setAfter(data) //
 128                         .addCreated(path, data) //
 129                         .build();
 130                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 131             }
 132         }
 133
 134         return reg;
 135     }
 136
 137     private synchronized DOMStoreThreePhaseCommitCohort submit(
 138             final SnaphostBackedWriteTransaction writeTx) {
 139         LOG.debug("Tx: {} is submitted. Modifications: {}",writeTx.getIdentifier(),writeTx.getMutatedView());
 140         return new ThreePhaseCommitImpl(writeTx);
 141     }
 142
 143     private Object nextIdentifier() {
 144         return name + "-" + txCounter.getAndIncrement();
 145     }
 146
 147     private void commit(final DataAndMetadataSnapshot currentSnapshot,
 148             final StoreMetadataNode newDataTree, final Iterable<ChangeListenerNotifyTask> listenerTasks) {
 149         LOG.debug("Updating Store snaphot version: {} with version:{}",currentSnapshot.getMetadataTree().getSubtreeVersion(),newDataTree.getSubtreeVersion());
 150
 151         if(LOG.isTraceEnabled()) {
 152             LOG.trace("Data Tree is {}",StoreUtils.toStringTree(newDataTree));
 153         }
 154
 155         final DataAndMetadataSnapshot newSnapshot = DataAndMetadataSnapshot.builder() //
 156                 .setMetadataTree(newDataTree) //
 157                 .setSchemaContext(schemaContext) //
 158                 .build();
 159
 160         /*
 161          * The commit has to occur atomically with regard to listener registrations.
 162          */
 163         synchronized (this) {
 164             final boolean success = snapshot.compareAndSet(currentSnapshot, newSnapshot);
 165             checkState(success, "Store snapshot and transaction snapshot differ. This should never happen.");
 166
 167             for (ChangeListenerNotifyTask task : listenerTasks) {
 168                 executor.submit(task);
 169             }
 170         }
 171     }
 172
 173     private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
 174         private final Object identifier;
 175
 176         protected AbstractDOMStoreTransaction(final Object identifier) {
 177             this.identifier = identifier;
 178         }
 179
 180         @Override
 181         public final Object getIdentifier() {
 182             return identifier;
 183         }
 184
 185         @Override
 186         public final String toString() {
 187             return addToStringAttributes(Objects.toStringHelper(this)).toString();
 188         }
 189
 190         /**
 191          * Add class-specific toString attributes.
 192          *
 193          * @param toStringHelper ToStringHelper instance
 194          * @return ToStringHelper instance which was passed in
 195          */
 196         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 197             return toStringHelper.add("id", identifier);
 198         }
 199     }
 200
 201     private static class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements DOMStoreReadTransaction {
 202         private DataAndMetadataSnapshot stableSnapshot;
 203
 204         public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
 205             super(identifier);
 206             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 207             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot.getMetadataTree().getSubtreeVersion());
 208         }
 209
 210         @Override
 211         public void close() {
 212             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 213             stableSnapshot = null;
 214         }
 215
 216         @Override
 217         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 218             checkNotNull(path, "Path must not be null.");
 219             checkState(stableSnapshot != null, "Transaction is closed");
 220             return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
 221         }
 222     }
 223
 224     private static class SnaphostBackedWriteTransaction extends AbstractDOMStoreTransaction implements DOMStoreWriteTransaction {
 225         private MutableDataTree mutableTree;
 226         private InMemoryDOMDataStore store;
 227         private boolean ready = false;
 228
 229         public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 230                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 231             super(identifier);
 232             mutableTree = MutableDataTree.from(snapshot, applyOper);
 233             this.store = store;
 234             LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
 235         }
 236
 237         @Override
 238         public void close() {
 239             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 240             this.mutableTree = null;
 241             this.store = null;
 242         }
 243
 244         @Override
 245         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 246             checkNotReady();
 247             mutableTree.write(path, data);
 248         }
 249
 250         @Override
 251         public void delete(final InstanceIdentifier path) {
 252             checkNotReady();
 253             mutableTree.delete(path);
 254         }
 255
 256         protected final boolean isReady() {
 257             return ready;
 258         }
 259
 260         protected final void checkNotReady() {
 261             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 262         }
 263
 264         @Override
 265         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 266             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 267             ready = true;
 268
 269             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 270             mutableTree.seal();
 271             return store.submit(this);
 272         }
 273
 274         protected MutableDataTree getMutatedView() {
 275             return mutableTree;
 276         }
 277
 278         @Override
 279         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 280             return toStringHelper.add("ready", isReady());
 281         }
 282     }
 283
 284     private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
 285             DOMStoreReadWriteTransaction {
 286
 287         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
 288                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
 289             super(identifier, snapshot, store, applyOper);
 290         }
 291
 292         @Override
 293         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 294             return Futures.immediateFuture(getMutatedView().read(path));
 295         }
 296     }
 297
 298     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 299
 300         private final SnaphostBackedWriteTransaction transaction;
 301         private final NodeModification modification;
 302
 303         private DataAndMetadataSnapshot storeSnapshot;
 304         private Optional<StoreMetadataNode> proposedSubtree;
 305         private Iterable<ChangeListenerNotifyTask> listenerTasks;
 306
 307         public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
 308             this.transaction = writeTransaction;
 309             this.modification = transaction.getMutatedView().getRootModification();
 310         }
 311
 312         @Override
 313         public ListenableFuture<Boolean> canCommit() {
 314             final DataAndMetadataSnapshot snapshotCapture = snapshot.get();
 315             final ModificationApplyOperation snapshotOperation = operationTree;
 316
 317             return executor.submit(new Callable<Boolean>() {
 318
 319                 @Override
 320                 public Boolean call() throws Exception {
 321                     boolean applicable = snapshotOperation.isApplicable(modification,
 322                             Optional.of(snapshotCapture.getMetadataTree()));
 323                     LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
 324                     return applicable;
 325                 }
 326             });
 327         }
 328
 329         @Override
 330         public ListenableFuture<Void> preCommit() {
 331             storeSnapshot = snapshot.get();
 332             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 333                 return Futures.immediateFuture(null);
 334             }
 335             return executor.submit(new Callable<Void>() {
 336
 337
 338
 339                 @Override
 340                 public Void call() throws Exception {
 341                     StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
 342
 343                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
 344                             increase(metadataTree.getSubtreeVersion()));
 345
 346                     listenerTasks = DataChangeEventResolver.create() //
 347                             .setRootPath(PUBLIC_ROOT_PATH) //
 348                             .setBeforeRoot(Optional.of(metadataTree)) //
 349                             .setAfterRoot(proposedSubtree) //
 350                             .setModificationRoot(modification) //
 351                             .setListenerRoot(listenerTree) //
 352                             .resolve();
 353
 354                     return null;
 355                 }
 356             });
 357         }
 358
 359         @Override
 360         public ListenableFuture<Void> abort() {
 361             storeSnapshot = null;
 362             proposedSubtree = null;
 363             return Futures.<Void> immediateFuture(null);
 364         }
 365
 366         @Override
 367         public ListenableFuture<Void> commit() {
 368             if(modification.getModificationType() == ModificationType.UNMODIFIED) {
 369                 return Futures.immediateFuture(null);
 370             }
 371
 372             checkState(proposedSubtree != null,"Proposed subtree must be computed");
 373             checkState(storeSnapshot != null,"Proposed subtree must be computed");
 374             // return ImmediateFuture<>;
 375             InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerTasks);
 376             return Futures.<Void> immediateFuture(null);
 377         }
 378
 379     }
 380
 381     private static final class AlwaysFailOperation implements ModificationApplyOperation {
 382
 383         @Override
 384         public Optional<StoreMetadataNode> apply(final NodeModification modification,
 385                 final Optional<StoreMetadataNode> storeMeta, final UnsignedLong subtreeVersion) {
 386             throw new IllegalStateException("Schema Context is not available.");
 387         }
 388
 389         @Override
 390         public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
 391             throw new IllegalStateException("Schema Context is not available.");
 392         }
 393
 394         @Override
 395         public Optional<ModificationApplyOperation> getChild(final PathArgument child) {
 396             throw new IllegalStateException("Schema Context is not available.");
 397         }
 398
 399         @Override
 400         public void verifyStructure(final NodeModification modification) throws IllegalArgumentException {
 401             throw new IllegalStateException("Schema Context is not available.");
 402         }
 403
 404     }
 405 }