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.data.InMemoryDataTreeFactory;
  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.AbstractListenerRegistration;
  33 import org.opendaylight.yangtools.concepts.Identifiable;
  34 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  35 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  36 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  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.Objects;
  43 import com.google.common.base.Objects.ToStringHelper;
  44 import com.google.common.base.Optional;
  45 import com.google.common.base.Preconditions;
  46 import com.google.common.util.concurrent.Futures;
  47 import com.google.common.util.concurrent.ListenableFuture;
  48 import com.google.common.util.concurrent.ListeningExecutorService;
  49
  50 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener {
  51     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  52     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
  53     private final ListenerTree listenerTree = ListenerTree.create();
  54     private final AtomicLong txCounter = new AtomicLong(0);
  55     private final ListeningExecutorService executor;
  56     private final String name;
  57
  58     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  59         this.name = Preconditions.checkNotNull(name);
  60         this.executor = Preconditions.checkNotNull(executor);
  61     }
  62
  63     @Override
  64     public final String getIdentifier() {
  65         return name;
  66     }
  67
  68     @Override
  69     public DOMStoreReadTransaction newReadOnlyTransaction() {
  70         return new SnapshotBackedReadTransaction(nextIdentifier(), dataTree.takeSnapshot());
  71     }
  72
  73     @Override
  74     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  75         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  76     }
  77
  78     @Override
  79     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  80         return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  81     }
  82
  83     @Override
  84     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  85         dataTree.setSchemaContext(ctx);
  86     }
  87
  88     @Override
  89     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
  90             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
  91
  92         /*
  93          * Make sure commit is not occurring right now. Listener has to be
  94          * registered and its state capture enqueued at a consistent point.
  95          *
  96          * FIXME: improve this to read-write lock, such that multiple listener
  97          * registrations can occur simultaneously
  98          */
  99         final DataChangeListenerRegistration<L> reg;
 100         synchronized (this) {
 101             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 102
 103             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 104
 105             Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
 106             if (currentState.isPresent()) {
 107                 final NormalizedNode<?, ?> data = currentState.get();
 108
 109                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 110                         .setAfter(data) //
 111                         .addCreated(path, data) //
 112                         .build();
 113                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 114             }
 115         }
 116
 117         return new AbstractListenerRegistration<L>(listener) {
 118             @Override
 119             protected void removeRegistration() {
 120                 synchronized (InMemoryDOMDataStore.this) {
 121                     reg.close();
 122                 }
 123             }
 124         };
 125     }
 126
 127     private synchronized DOMStoreThreePhaseCommitCohort submit(final SnapshotBackedWriteTransaction writeTx) {
 128         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
 129         return new ThreePhaseCommitImpl(writeTx);
 130     }
 131
 132     private Object nextIdentifier() {
 133         return name + "-" + txCounter.getAndIncrement();
 134     }
 135
 136     private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
 137         private final Object identifier;
 138
 139         protected AbstractDOMStoreTransaction(final Object identifier) {
 140             this.identifier = identifier;
 141         }
 142
 143         @Override
 144         public final Object getIdentifier() {
 145             return identifier;
 146         }
 147
 148         @Override
 149         public final String toString() {
 150             return addToStringAttributes(Objects.toStringHelper(this)).toString();
 151         }
 152
 153         /**
 154          * Add class-specific toString attributes.
 155          *
 156          * @param toStringHelper
 157          *            ToStringHelper instance
 158          * @return ToStringHelper instance which was passed in
 159          */
 160         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 161             return toStringHelper.add("id", identifier);
 162         }
 163     }
 164
 165     private static final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
 166     DOMStoreReadTransaction {
 167         private DataTreeSnapshot stableSnapshot;
 168
 169         public SnapshotBackedReadTransaction(final Object identifier, final DataTreeSnapshot snapshot) {
 170             super(identifier);
 171             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 172             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot);
 173         }
 174
 175         @Override
 176         public void close() {
 177             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 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(stableSnapshot.readNode(path));
 186         }
 187     }
 188
 189     private static class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements
 190     DOMStoreWriteTransaction {
 191         private DataTreeModification mutableTree;
 192         private InMemoryDOMDataStore store;
 193         private boolean ready = false;
 194
 195         public SnapshotBackedWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
 196                 final InMemoryDOMDataStore store) {
 197             super(identifier);
 198             mutableTree = snapshot.newModification();
 199             this.store = store;
 200             LOG.debug("Write Tx: {} allocated with snapshot {}", identifier, snapshot);
 201         }
 202
 203         @Override
 204         public void close() {
 205             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 206             this.mutableTree = null;
 207             this.store = null;
 208         }
 209
 210         @Override
 211         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 212             checkNotReady();
 213             try {
 214                 LOG.trace("Tx: {} Write: {}:{}", getIdentifier(), path, data);
 215                 mutableTree.write(path, data);
 216                 // FIXME: Add checked exception
 217             } catch (Exception e) {
 218                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 219             }
 220         }
 221
 222         @Override
 223         public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 224             checkNotReady();
 225             try {
 226                 LOG.trace("Tx: {} Merge: {}:{}", getIdentifier(), path, data);
 227                 mutableTree.merge(path, data);
 228                 // FIXME: Add checked exception
 229             } catch (Exception e) {
 230                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 231             }
 232         }
 233
 234         @Override
 235         public void delete(final InstanceIdentifier path) {
 236             checkNotReady();
 237             try {
 238                 LOG.trace("Tx: {} Delete: {}", getIdentifier(), path);
 239                 mutableTree.delete(path);
 240                 // FIXME: Add checked exception
 241             } catch (Exception e) {
 242                 LOG.error("Tx: {}, failed to delete {} in {}", getIdentifier(), path, mutableTree, e);
 243             }
 244         }
 245
 246         protected final boolean isReady() {
 247             return ready;
 248         }
 249
 250         protected final void checkNotReady() {
 251             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 252         }
 253
 254         @Override
 255         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 256             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 257             ready = true;
 258
 259             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 260             mutableTree.seal();
 261             return store.submit(this);
 262         }
 263
 264         protected DataTreeModification getMutatedView() {
 265             return mutableTree;
 266         }
 267
 268         @Override
 269         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 270             return toStringHelper.add("ready", isReady());
 271         }
 272     }
 273
 274     private static class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
 275     DOMStoreReadWriteTransaction {
 276
 277         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
 278                 final InMemoryDOMDataStore store) {
 279             super(identifier, snapshot, store);
 280         }
 281
 282         @Override
 283         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 284             LOG.trace("Tx: {} Read: {}", getIdentifier(), path);
 285             try {
 286                 return Futures.immediateFuture(getMutatedView().readNode(path));
 287             } catch (Exception e) {
 288                 LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
 289                 throw e;
 290             }
 291         }
 292     }
 293
 294     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 295
 296         private final SnapshotBackedWriteTransaction transaction;
 297         private final DataTreeModification modification;
 298
 299         private ResolveDataChangeEventsTask listenerResolver;
 300         private DataTreeCandidate candidate;
 301
 302         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
 303             this.transaction = writeTransaction;
 304             this.modification = transaction.getMutatedView();
 305         }
 306
 307         @Override
 308         public ListenableFuture<Boolean> canCommit() {
 309             return executor.submit(new Callable<Boolean>() {
 310                 @Override
 311                 public Boolean call() {
 312                     try {
 313                         dataTree.validate(modification);
 314                         LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
 315                         return true;
 316                     } catch (DataPreconditionFailedException e) {
 317                         LOG.warn("Store Tx: {} Data Precondition failed for {}.",transaction.getIdentifier(),e.getPath(),e);
 318                         return false;
 319                     }
 320                 }
 321             });
 322         }
 323
 324         @Override
 325         public ListenableFuture<Void> preCommit() {
 326             return executor.submit(new Callable<Void>() {
 327                 @Override
 328                 public Void call() {
 329                     candidate = dataTree.prepare(modification);
 330                     listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
 331                     return null;
 332                 }
 333             });
 334         }
 335
 336         @Override
 337         public ListenableFuture<Void> abort() {
 338             candidate = null;
 339             return Futures.immediateFuture(null);
 340         }
 341
 342         @Override
 343         public ListenableFuture<Void> commit() {
 344             checkState(candidate != null, "Proposed subtree must be computed");
 345
 346             /*
 347              * The commit has to occur atomically with regard to listener
 348              * registrations.
 349              */
 350             synchronized (this) {
 351                 dataTree.commit(candidate);
 352
 353                 for (ChangeListenerNotifyTask task : listenerResolver.call()) {
 354                     LOG.trace("Scheduling invocation of listeners: {}", task);
 355                     executor.submit(task);
 356                 }
 357             }
 358
 359             return Futures.immediateFuture(null);
 360         }
 361     }
 362 }