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.DOMStoreTransactionChain;
  32 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  33 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  34 import org.opendaylight.yangtools.concepts.Identifiable;
  35 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  36 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  37 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  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.util.concurrent.Futures;
  48 import com.google.common.util.concurrent.ListenableFuture;
  49 import com.google.common.util.concurrent.ListeningExecutorService;
  50
  51 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener {
  52     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  53     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
  54     private final ListenerTree listenerTree = ListenerTree.create();
  55     private final AtomicLong txCounter = new AtomicLong(0);
  56     private final ListeningExecutorService executor;
  57     private final String name;
  58
  59     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  60         this.name = Preconditions.checkNotNull(name);
  61         this.executor = Preconditions.checkNotNull(executor);
  62     }
  63
  64     @Override
  65     public final String getIdentifier() {
  66         return name;
  67     }
  68
  69     @Override
  70     public DOMStoreReadTransaction newReadOnlyTransaction() {
  71         return new SnapshotBackedReadTransaction(nextIdentifier(), dataTree.takeSnapshot());
  72     }
  73
  74     @Override
  75     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  76         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  77     }
  78
  79     @Override
  80     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  81         return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  82     }
  83
  84     @Override
  85     public DOMStoreTransactionChain createTransactionChain() {
  86         throw new UnsupportedOperationException("Not implemented yet.");
  87     }
  88
  89     @Override
  90     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
  91         dataTree.setSchemaContext(ctx);
  92     }
  93
  94     @Override
  95     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
  96             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
  97
  98         /*
  99          * Make sure commit is not occurring right now. Listener has to be
 100          * registered and its state capture enqueued at a consistent point.
 101          *
 102          * FIXME: improve this to read-write lock, such that multiple listener
 103          * registrations can occur simultaneously
 104          */
 105         final DataChangeListenerRegistration<L> reg;
 106         synchronized (this) {
 107             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 108
 109             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 110
 111             Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
 112             if (currentState.isPresent()) {
 113                 final NormalizedNode<?, ?> data = currentState.get();
 114
 115                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 116                         .setAfter(data) //
 117                         .addCreated(path, data) //
 118                         .build();
 119                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 120             }
 121         }
 122
 123         return new AbstractListenerRegistration<L>(listener) {
 124             @Override
 125             protected void removeRegistration() {
 126                 synchronized (InMemoryDOMDataStore.this) {
 127                     reg.close();
 128                 }
 129             }
 130         };
 131     }
 132
 133     private synchronized DOMStoreThreePhaseCommitCohort submit(final SnapshotBackedWriteTransaction writeTx) {
 134         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
 135         return new ThreePhaseCommitImpl(writeTx);
 136     }
 137
 138     private Object nextIdentifier() {
 139         return name + "-" + txCounter.getAndIncrement();
 140     }
 141
 142     private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
 143         private final Object identifier;
 144
 145         protected AbstractDOMStoreTransaction(final Object identifier) {
 146             this.identifier = identifier;
 147         }
 148
 149         @Override
 150         public final Object getIdentifier() {
 151             return identifier;
 152         }
 153
 154         @Override
 155         public final String toString() {
 156             return addToStringAttributes(Objects.toStringHelper(this)).toString();
 157         }
 158
 159         /**
 160          * Add class-specific toString attributes.
 161          *
 162          * @param toStringHelper
 163          *            ToStringHelper instance
 164          * @return ToStringHelper instance which was passed in
 165          */
 166         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 167             return toStringHelper.add("id", identifier);
 168         }
 169     }
 170
 171     private static final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
 172     DOMStoreReadTransaction {
 173         private DataTreeSnapshot stableSnapshot;
 174
 175         public SnapshotBackedReadTransaction(final Object identifier, final DataTreeSnapshot snapshot) {
 176             super(identifier);
 177             this.stableSnapshot = Preconditions.checkNotNull(snapshot);
 178             LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot);
 179         }
 180
 181         @Override
 182         public void close() {
 183             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 184             stableSnapshot = null;
 185         }
 186
 187         @Override
 188         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 189             checkNotNull(path, "Path must not be null.");
 190             checkState(stableSnapshot != null, "Transaction is closed");
 191             return Futures.immediateFuture(stableSnapshot.readNode(path));
 192         }
 193     }
 194
 195     private static class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements
 196     DOMStoreWriteTransaction {
 197         private DataTreeModification mutableTree;
 198         private InMemoryDOMDataStore store;
 199         private boolean ready = false;
 200
 201         public SnapshotBackedWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
 202                 final InMemoryDOMDataStore store) {
 203             super(identifier);
 204             mutableTree = snapshot.newModification();
 205             this.store = store;
 206             LOG.debug("Write Tx: {} allocated with snapshot {}", identifier, snapshot);
 207         }
 208
 209         @Override
 210         public void close() {
 211             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 212             this.mutableTree = null;
 213             this.store = null;
 214         }
 215
 216         @Override
 217         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 218             checkNotReady();
 219             try {
 220                 LOG.trace("Tx: {} Write: {}:{}", getIdentifier(), path, data);
 221                 mutableTree.write(path, data);
 222                 // FIXME: Add checked exception
 223             } catch (Exception e) {
 224                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 225             }
 226         }
 227
 228         @Override
 229         public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
 230             checkNotReady();
 231             try {
 232                 LOG.trace("Tx: {} Merge: {}:{}", getIdentifier(), path, data);
 233                 mutableTree.merge(path, data);
 234                 // FIXME: Add checked exception
 235             } catch (Exception e) {
 236                 LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
 237             }
 238         }
 239
 240         @Override
 241         public void delete(final InstanceIdentifier path) {
 242             checkNotReady();
 243             try {
 244                 LOG.trace("Tx: {} Delete: {}", getIdentifier(), path);
 245                 mutableTree.delete(path);
 246                 // FIXME: Add checked exception
 247             } catch (Exception e) {
 248                 LOG.error("Tx: {}, failed to delete {} in {}", getIdentifier(), path, mutableTree, e);
 249             }
 250         }
 251
 252         protected final boolean isReady() {
 253             return ready;
 254         }
 255
 256         protected final void checkNotReady() {
 257             checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
 258         }
 259
 260         @Override
 261         public synchronized DOMStoreThreePhaseCommitCohort ready() {
 262             checkState(!ready, "Transaction %s is already ready.", getIdentifier());
 263             ready = true;
 264
 265             LOG.debug("Store transaction: {} : Ready", getIdentifier());
 266             mutableTree.seal();
 267             return store.submit(this);
 268         }
 269
 270         protected DataTreeModification getMutatedView() {
 271             return mutableTree;
 272         }
 273
 274         @Override
 275         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 276             return toStringHelper.add("ready", isReady());
 277         }
 278     }
 279
 280     private static class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
 281     DOMStoreReadWriteTransaction {
 282
 283         protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
 284                 final InMemoryDOMDataStore store) {
 285             super(identifier, snapshot, store);
 286         }
 287
 288         @Override
 289         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
 290             LOG.trace("Tx: {} Read: {}", getIdentifier(), path);
 291             try {
 292                 return Futures.immediateFuture(getMutatedView().readNode(path));
 293             } catch (Exception e) {
 294                 LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
 295                 throw e;
 296             }
 297         }
 298     }
 299
 300     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 301
 302         private final SnapshotBackedWriteTransaction transaction;
 303         private final DataTreeModification modification;
 304
 305         private ResolveDataChangeEventsTask listenerResolver;
 306         private DataTreeCandidate candidate;
 307
 308         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
 309             this.transaction = writeTransaction;
 310             this.modification = transaction.getMutatedView();
 311         }
 312
 313         @Override
 314         public ListenableFuture<Boolean> canCommit() {
 315             return executor.submit(new Callable<Boolean>() {
 316                 @Override
 317                 public Boolean call() {
 318                     try {
 319                         dataTree.validate(modification);
 320                         LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
 321                         return true;
 322                     } catch (DataPreconditionFailedException e) {
 323                         LOG.warn("Store Tx: {} Data Precondition failed for {}.",transaction.getIdentifier(),e.getPath(),e);
 324                         return false;
 325                     }
 326                 }
 327             });
 328         }
 329
 330         @Override
 331         public ListenableFuture<Void> preCommit() {
 332             return executor.submit(new Callable<Void>() {
 333                 @Override
 334                 public Void call() {
 335                     candidate = dataTree.prepare(modification);
 336                     listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
 337                     return null;
 338                 }
 339             });
 340         }
 341
 342         @Override
 343         public ListenableFuture<Void> abort() {
 344             candidate = null;
 345             return Futures.immediateFuture(null);
 346         }
 347
 348         @Override
 349         public ListenableFuture<Void> commit() {
 350             checkState(candidate != null, "Proposed subtree must be computed");
 351
 352             /*
 353              * The commit has to occur atomically with regard to listener
 354              * registrations.
 355              */
 356             synchronized (this) {
 357                 dataTree.commit(candidate);
 358
 359                 for (ChangeListenerNotifyTask task : listenerResolver.call()) {
 360                     LOG.trace("Scheduling invocation of listeners: {}", task);
 361                     executor.submit(task);
 362                 }
 363             }
 364
 365             return Futures.immediateFuture(null);
 366         }
 367     }
 368 }