opendaylight/md-sal/sal-inmemory-datastore/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 com.google.common.base.Optional;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.util.concurrent.FutureCallback;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import com.google.common.util.concurrent.ListeningExecutorService;
  16 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  17 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  18 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
  19 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  20 import org.opendaylight.controller.md.sal.dom.store.impl.SnapshotBackedWriteTransaction.TransactionReadyPrototype;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  25 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  26 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  27 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  28 import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  30 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
  31 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  32 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  33 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  34 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  35 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  36 import org.opendaylight.yangtools.concepts.Identifiable;
  37 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  38 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  39 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  40 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  41 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 import javax.annotation.concurrent.GuardedBy;
  46 import java.util.Collections;
  47 import java.util.concurrent.Callable;
  48 import java.util.concurrent.atomic.AtomicLong;
  49
  50 import static com.google.common.base.Preconditions.checkState;
  51
  52 /**
  53  * In-memory DOM Data Store
  54  *
  55  * Implementation of {@link DOMStore} which uses {@link DataTree} and other
  56  * classes such as {@link SnapshotBackedWriteTransaction}.
  57  * {@link SnapshotBackedReadTransaction} and {@link ResolveDataChangeEventsTask}
  58  * to implement {@link DOMStore} contract.
  59  *
  60  */
  61 public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener,
  62         TransactionReadyPrototype,AutoCloseable {
  63     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
  64     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
  65     private final ListenerTree listenerTree = ListenerTree.create();
  66     private final AtomicLong txCounter = new AtomicLong(0);
  67     private final ListeningExecutorService executor;
  68
  69     private final String name;
  70
  71     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
  72         this.name = Preconditions.checkNotNull(name);
  73         this.executor = Preconditions.checkNotNull(executor);
  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(), dataTree.takeSnapshot());
  84     }
  85
  86     @Override
  87     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
  88         return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  89     }
  90
  91     @Override
  92     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
  93         return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
  94     }
  95
  96     @Override
  97     public DOMStoreTransactionChain createTransactionChain() {
  98         return new DOMStoreTransactionChainImpl();
  99     }
 100
 101     @Override
 102     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
 103         dataTree.setSchemaContext(ctx);
 104     }
 105
 106     @Override
 107     public void close(){
 108         executor.shutdownNow();
 109     }
 110     @Override
 111     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
 112             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 113
 114         /*
 115          * Make sure commit is not occurring right now. Listener has to be
 116          * registered and its state capture enqueued at a consistent point.
 117          *
 118          * FIXME: improve this to read-write lock, such that multiple listener
 119          * registrations can occur simultaneously
 120          */
 121         final DataChangeListenerRegistration<L> reg;
 122         synchronized (this) {
 123             LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 124
 125             reg = listenerTree.registerDataChangeListener(path, listener, scope);
 126
 127             Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
 128             if (currentState.isPresent()) {
 129                 final NormalizedNode<?, ?> data = currentState.get();
 130
 131                 final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
 132                         .setAfter(data) //
 133                         .addCreated(path, data) //
 134                         .build();
 135                 executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
 136             }
 137         }
 138
 139         return new AbstractListenerRegistration<L>(listener) {
 140             @Override
 141             protected void removeRegistration() {
 142                 synchronized (InMemoryDOMDataStore.this) {
 143                     reg.close();
 144                 }
 145             }
 146         };
 147     }
 148
 149     @Override
 150     public synchronized DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction writeTx) {
 151         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
 152         return new ThreePhaseCommitImpl(writeTx);
 153     }
 154
 155     private Object nextIdentifier() {
 156         return name + "-" + txCounter.getAndIncrement();
 157     }
 158
 159     private class DOMStoreTransactionChainImpl implements DOMStoreTransactionChain, TransactionReadyPrototype {
 160
 161         @GuardedBy("this")
 162         private SnapshotBackedWriteTransaction latestOutstandingTx;
 163
 164         private boolean chainFailed = false;
 165
 166         private void checkFailed() {
 167             Preconditions.checkState(!chainFailed, "Transaction chain is failed.");
 168         }
 169
 170         @Override
 171         public synchronized DOMStoreReadTransaction newReadOnlyTransaction() {
 172             final DataTreeSnapshot snapshot;
 173             checkFailed();
 174             if (latestOutstandingTx != null) {
 175                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 176                 snapshot = latestOutstandingTx.getMutatedView();
 177             } else {
 178                 snapshot = dataTree.takeSnapshot();
 179             }
 180             return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot);
 181         }
 182
 183         @Override
 184         public synchronized DOMStoreReadWriteTransaction newReadWriteTransaction() {
 185             final DataTreeSnapshot snapshot;
 186             checkFailed();
 187             if (latestOutstandingTx != null) {
 188                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 189                 snapshot = latestOutstandingTx.getMutatedView();
 190             } else {
 191                 snapshot = dataTree.takeSnapshot();
 192             }
 193             final SnapshotBackedReadWriteTransaction ret = new SnapshotBackedReadWriteTransaction(nextIdentifier(),
 194                     snapshot, this);
 195             latestOutstandingTx = ret;
 196             return ret;
 197         }
 198
 199         @Override
 200         public synchronized DOMStoreWriteTransaction newWriteOnlyTransaction() {
 201             final DataTreeSnapshot snapshot;
 202             checkFailed();
 203             if (latestOutstandingTx != null) {
 204                 checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
 205                 snapshot = latestOutstandingTx.getMutatedView();
 206             } else {
 207                 snapshot = dataTree.takeSnapshot();
 208             }
 209             final SnapshotBackedWriteTransaction ret = new SnapshotBackedWriteTransaction(nextIdentifier(), snapshot,
 210                     this);
 211             latestOutstandingTx = ret;
 212             return ret;
 213         }
 214
 215         @Override
 216         public DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction tx) {
 217             DOMStoreThreePhaseCommitCohort storeCohort = InMemoryDOMDataStore.this.ready(tx);
 218             return new ChainedTransactionCommitImpl(tx, storeCohort, this);
 219         }
 220
 221         @Override
 222         public void close() {
 223
 224              executor.shutdownNow();
 225
 226         }
 227
 228         protected synchronized void onTransactionFailed(final SnapshotBackedWriteTransaction transaction,
 229                 final Throwable t) {
 230             chainFailed = true;
 231
 232         }
 233
 234         public synchronized void onTransactionCommited(final SnapshotBackedWriteTransaction transaction) {
 235             // If commited transaction is latestOutstandingTx we clear
 236             // latestOutstandingTx
 237             // field in order to base new transactions on Datastore Data Tree
 238             // directly.
 239             if (transaction.equals(latestOutstandingTx)) {
 240                 latestOutstandingTx = null;
 241             }
 242         }
 243
 244     }
 245
 246     private static class ChainedTransactionCommitImpl implements DOMStoreThreePhaseCommitCohort {
 247
 248         private final SnapshotBackedWriteTransaction transaction;
 249         private final DOMStoreThreePhaseCommitCohort delegate;
 250
 251         private final DOMStoreTransactionChainImpl txChain;
 252
 253         protected ChainedTransactionCommitImpl(final SnapshotBackedWriteTransaction transaction,
 254                 final DOMStoreThreePhaseCommitCohort delegate, final DOMStoreTransactionChainImpl txChain) {
 255             super();
 256             this.transaction = transaction;
 257             this.delegate = delegate;
 258             this.txChain = txChain;
 259         }
 260
 261         @Override
 262         public ListenableFuture<Boolean> canCommit() {
 263             return delegate.canCommit();
 264         }
 265
 266         @Override
 267         public ListenableFuture<Void> preCommit() {
 268             return delegate.preCommit();
 269         }
 270
 271         @Override
 272         public ListenableFuture<Void> abort() {
 273             return delegate.abort();
 274         }
 275
 276         @Override
 277         public ListenableFuture<Void> commit() {
 278             ListenableFuture<Void> commitFuture = delegate.commit();
 279             Futures.addCallback(commitFuture, new FutureCallback<Void>() {
 280                 @Override
 281                 public void onFailure(final Throwable t) {
 282                     txChain.onTransactionFailed(transaction, t);
 283                 }
 284
 285                 @Override
 286                 public void onSuccess(final Void result) {
 287                     txChain.onTransactionCommited(transaction);
 288                 }
 289
 290             });
 291             return commitFuture;
 292         }
 293
 294     }
 295
 296     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 297
 298         private final SnapshotBackedWriteTransaction transaction;
 299         private final DataTreeModification modification;
 300
 301         private ResolveDataChangeEventsTask listenerResolver;
 302         private DataTreeCandidate candidate;
 303
 304         public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
 305             this.transaction = writeTransaction;
 306             this.modification = transaction.getMutatedView();
 307         }
 308
 309         @Override
 310         public ListenableFuture<Boolean> canCommit() {
 311             return executor.submit(new Callable<Boolean>() {
 312                 @Override
 313                 public Boolean call() throws TransactionCommitFailedException {
 314                     try {
 315                         dataTree.validate(modification);
 316                         LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
 317                         return true;
 318                     } catch (ConflictingModificationAppliedException e) {
 319                         LOG.warn("Store Tx: {} Conflicting modification for {}.", transaction.getIdentifier(),
 320                                 e.getPath());
 321                         throw new OptimisticLockFailedException("Optimistic lock failed.",e);
 322                     } catch (DataValidationFailedException e) {
 323                         LOG.warn("Store Tx: {} Data Precondition failed for {}.", transaction.getIdentifier(),
 324                                 e.getPath(), e);
 325                         throw new TransactionCommitFailedException("Data did not pass validation.",e);
 326                     }
 327                 }
 328             });
 329         }
 330
 331         @Override
 332         public ListenableFuture<Void> preCommit() {
 333             return executor.submit(new Callable<Void>() {
 334                 @Override
 335                 public Void call() {
 336                     candidate = dataTree.prepare(modification);
 337                     listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
 338                     return null;
 339                 }
 340             });
 341         }
 342
 343         @Override
 344         public ListenableFuture<Void> abort() {
 345             candidate = null;
 346             return Futures.immediateFuture(null);
 347         }
 348
 349         @Override
 350         public ListenableFuture<Void> commit() {
 351             checkState(candidate != null, "Proposed subtree must be computed");
 352
 353             /*
 354              * The commit has to occur atomically with regard to listener
 355              * registrations.
 356              */
 357             synchronized (this) {
 358                 dataTree.commit(candidate);
 359
 360                 for (ChangeListenerNotifyTask task : listenerResolver.call()) {
 361                     LOG.trace("Scheduling invocation of listeners: {}", task);
 362                     executor.submit(task);
 363                 }
 364             }
 365
 366             return Futures.immediateFuture(null);
 367         }
 368     }
 369 }