opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/LocalReadWriteProxyTransaction.java

   1 /*
   2  * Copyright (c) 2016 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.cluster.databroker.actors.dds;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.base.Verify;
  12 import java.util.Optional;
  13 import java.util.OptionalLong;
  14 import java.util.function.BiConsumer;
  15 import java.util.function.Consumer;
  16 import java.util.function.Supplier;
  17 import org.eclipse.jdt.annotation.NonNull;
  18 import org.eclipse.jdt.annotation.Nullable;
  19 import org.opendaylight.controller.cluster.access.commands.AbortLocalTransactionRequest;
  20 import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest;
  21 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  22 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  23 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequestBuilder;
  24 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  25 import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
  26 import org.opendaylight.controller.cluster.access.commands.TransactionDelete;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionMerge;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionModification;
  30 import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest;
  31 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  32 import org.opendaylight.controller.cluster.access.commands.TransactionWrite;
  33 import org.opendaylight.controller.cluster.access.concepts.Response;
  34 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  35 import org.opendaylight.controller.cluster.datastore.util.AbstractDataTreeModificationCursor;
  36 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  37 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  38 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  39 import org.opendaylight.yangtools.yang.data.tree.api.CursorAwareDataTreeModification;
  40 import org.opendaylight.yangtools.yang.data.tree.api.CursorAwareDataTreeSnapshot;
  41 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModification;
  42 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModificationCursor;
  43 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeSnapshot;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 /**
  48  * An {@link AbstractProxyTransaction} for dispatching a transaction towards a shard leader which is co-located with
  49  * the client instance. This class is NOT thread-safe.
  50  *
  51  * <p>
  52  * It requires a {@link DataTreeSnapshot}, which is used to instantiated a new {@link DataTreeModification}. Operations
  53  * are then performed on this modification and once the transaction is submitted, the modification is sent to the shard
  54  * leader.
  55  *
  56  * <p>
  57  * This class is not thread-safe as usual with transactions. Since it does not interact with the backend until the
  58  * transaction is submitted, at which point this class gets out of the picture, this is not a cause for concern.
  59  *
  60  * @author Robert Varga
  61  */
  62 final class LocalReadWriteProxyTransaction extends LocalProxyTransaction {
  63     private static final Logger LOG = LoggerFactory.getLogger(LocalReadWriteProxyTransaction.class);
  64
  65     /**
  66      * This field needs to be accessed via {@link #getModification()}, which performs state checking to ensure
  67      * the modification can actually be accessed.
  68      */
  69     private final CursorAwareDataTreeModification modification;
  70
  71     private Supplier<? extends RuntimeException> closedException;
  72
  73     private CursorAwareDataTreeModification sealedModification;
  74
  75     /**
  76      * Recorded failure from previous operations. Normally we would want to propagate the error directly to the
  77      * offending call site, but that exposes inconsistency in behavior during initial connection, when we go through
  78      * {@link RemoteProxyTransaction}, which detects this sort of issues at canCommit/directCommit time on the backend.
  79      *
  80      * <p>
  81      * We therefore do not report incurred exceptions directly, but report them once the user attempts to commit
  82      * this transaction.
  83      */
  84     private Exception recordedFailure;
  85
  86     LocalReadWriteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier,
  87         final DataTreeSnapshot snapshot) {
  88         super(parent, identifier, false);
  89         modification = (CursorAwareDataTreeModification) snapshot.newModification();
  90     }
  91
  92     LocalReadWriteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier) {
  93         super(parent, identifier, true);
  94         // This is DONE transaction, this should never be touched
  95         modification = null;
  96     }
  97
  98     @Override
  99     boolean isSnapshotOnly() {
 100         return false;
 101     }
 102
 103     @Override
 104     CursorAwareDataTreeSnapshot readOnlyView() {
 105         return getModification();
 106     }
 107
 108     @Override
 109     @SuppressWarnings("checkstyle:IllegalCatch")
 110     void doDelete(final YangInstanceIdentifier path) {
 111         final CursorAwareDataTreeModification mod = getModification();
 112         if (recordedFailure != null) {
 113             LOG.debug("Transaction {} recorded failure, ignoring delete of {}", getIdentifier(), path);
 114             return;
 115         }
 116
 117         try {
 118             mod.delete(path);
 119         } catch (Exception e) {
 120             LOG.debug("Transaction {} delete on {} incurred failure, delaying it until commit", getIdentifier(), path,
 121                 e);
 122             recordedFailure = e;
 123         }
 124     }
 125
 126     @Override
 127     @SuppressWarnings("checkstyle:IllegalCatch")
 128     void doMerge(final YangInstanceIdentifier path, final NormalizedNode data) {
 129         final CursorAwareDataTreeModification mod = getModification();
 130         if (recordedFailure != null) {
 131             LOG.debug("Transaction {} recorded failure, ignoring merge to {}", getIdentifier(), path);
 132             return;
 133         }
 134
 135         try {
 136             mod.merge(path, data);
 137         } catch (Exception e) {
 138             LOG.debug("Transaction {} merge to {} incurred failure, delaying it until commit", getIdentifier(), path,
 139                 e);
 140             recordedFailure = e;
 141         }
 142     }
 143
 144     @Override
 145     @SuppressWarnings("checkstyle:IllegalCatch")
 146     void doWrite(final YangInstanceIdentifier path, final NormalizedNode data) {
 147         final CursorAwareDataTreeModification mod = getModification();
 148         if (recordedFailure != null) {
 149             LOG.debug("Transaction {} recorded failure, ignoring write to {}", getIdentifier(), path);
 150             return;
 151         }
 152
 153         try {
 154             mod.write(path, data);
 155         } catch (Exception e) {
 156             LOG.debug("Transaction {} write to {} incurred failure, delaying it until commit", getIdentifier(), path,
 157                 e);
 158             recordedFailure = e;
 159         }
 160     }
 161
 162     private RuntimeException abortedException() {
 163         return new IllegalStateException("Tracker " + getIdentifier() + " has been aborted");
 164     }
 165
 166     private RuntimeException submittedException() {
 167         return new IllegalStateException("Tracker " + getIdentifier() + " has been submitted");
 168     }
 169
 170     @Override
 171     CommitLocalTransactionRequest commitRequest(final boolean coordinated) {
 172         final CursorAwareDataTreeModification mod = getModification();
 173         final CommitLocalTransactionRequest ret = new CommitLocalTransactionRequest(getIdentifier(), nextSequence(),
 174             localActor(), mod, recordedFailure, coordinated);
 175         closedException = this::submittedException;
 176         return ret;
 177     }
 178
 179     private void sealModification() {
 180         Preconditions.checkState(sealedModification == null, "Transaction %s is already sealed", this);
 181         final CursorAwareDataTreeModification mod = getModification();
 182         mod.ready();
 183         sealedModification = mod;
 184     }
 185
 186     @Override
 187     boolean sealOnly() {
 188         sealModification();
 189         return super.sealOnly();
 190     }
 191
 192     @Override
 193     boolean sealAndSend(final OptionalLong enqueuedTicks) {
 194         sealModification();
 195         return super.sealAndSend(enqueuedTicks);
 196     }
 197
 198     @Override
 199     Optional<ModifyTransactionRequest> flushState() {
 200         final ModifyTransactionRequestBuilder b = new ModifyTransactionRequestBuilder(getIdentifier(), localActor());
 201         b.setSequence(0);
 202
 203         sealedModification.applyToCursor(new AbstractDataTreeModificationCursor() {
 204             @Override
 205             public void write(final PathArgument child, final NormalizedNode data) {
 206                 b.addModification(new TransactionWrite(current().node(child), data));
 207             }
 208
 209             @Override
 210             public void merge(final PathArgument child, final NormalizedNode data) {
 211                 b.addModification(new TransactionMerge(current().node(child), data));
 212             }
 213
 214             @Override
 215             public void delete(final PathArgument child) {
 216                 b.addModification(new TransactionDelete(current().node(child)));
 217             }
 218         });
 219
 220         return Optional.of(b.build());
 221     }
 222
 223     DataTreeSnapshot getSnapshot() {
 224         Preconditions.checkState(sealedModification != null, "Proxy %s is not sealed yet", getIdentifier());
 225         return sealedModification;
 226     }
 227
 228     @Override
 229     void applyForwardedModifyTransactionRequest(final ModifyTransactionRequest request,
 230             final Consumer<Response<?, ?>> callback) {
 231         commonModifyTransactionRequest(request, callback, this::sendRequest);
 232     }
 233
 234     @Override
 235     void replayModifyTransactionRequest(final ModifyTransactionRequest request,
 236             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
 237         commonModifyTransactionRequest(request, callback, (req, cb) -> enqueueRequest(req, cb, enqueuedTicks));
 238     }
 239
 240     private void commonModifyTransactionRequest(final ModifyTransactionRequest request,
 241             final @Nullable Consumer<Response<?, ?>> callback,
 242             final BiConsumer<TransactionRequest<?>, Consumer<Response<?, ?>>> sendMethod) {
 243         for (final TransactionModification mod : request.getModifications()) {
 244             if (mod instanceof TransactionWrite) {
 245                 write(mod.getPath(), ((TransactionWrite)mod).getData());
 246             } else if (mod instanceof TransactionMerge) {
 247                 merge(mod.getPath(), ((TransactionMerge)mod).getData());
 248             } else if (mod instanceof TransactionDelete) {
 249                 delete(mod.getPath());
 250             } else {
 251                 throw new IllegalArgumentException("Unsupported modification " + mod);
 252             }
 253         }
 254
 255         final Optional<PersistenceProtocol> maybeProtocol = request.getPersistenceProtocol();
 256         if (maybeProtocol.isPresent()) {
 257             Verify.verify(callback != null, "Request %s has null callback", request);
 258             if (markSealed()) {
 259                 sealOnly();
 260             }
 261
 262             switch (maybeProtocol.get()) {
 263                 case ABORT:
 264                     sendMethod.accept(new AbortLocalTransactionRequest(getIdentifier(), localActor()), callback);
 265                     break;
 266                 case READY:
 267                     // No-op, as we have already issued a sealOnly() and we are not transmitting anything
 268                     break;
 269                 case SIMPLE:
 270                     sendMethod.accept(commitRequest(false), callback);
 271                     break;
 272                 case THREE_PHASE:
 273                     sendMethod.accept(commitRequest(true), callback);
 274                     break;
 275                 default:
 276                     throw new IllegalArgumentException("Unhandled protocol " + maybeProtocol.get());
 277             }
 278         }
 279     }
 280
 281     @Override
 282     void handleReplayedLocalRequest(final AbstractLocalTransactionRequest<?> request,
 283             final Consumer<Response<?, ?>> callback, final long now) {
 284         if (request instanceof CommitLocalTransactionRequest) {
 285             enqueueRequest(rebaseCommit((CommitLocalTransactionRequest)request), callback, now);
 286         } else {
 287             super.handleReplayedLocalRequest(request, callback, now);
 288         }
 289     }
 290
 291     @Override
 292     void handleReplayedRemoteRequest(final TransactionRequest<?> request,
 293             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
 294         LOG.debug("Applying replayed request {}", request);
 295
 296         if (request instanceof TransactionPreCommitRequest) {
 297             enqueueRequest(new TransactionPreCommitRequest(getIdentifier(), nextSequence(), localActor()), callback,
 298                 enqueuedTicks);
 299         } else if (request instanceof TransactionDoCommitRequest) {
 300             enqueueRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), callback,
 301                 enqueuedTicks);
 302         } else if (request instanceof TransactionAbortRequest) {
 303             enqueueDoAbort(callback, enqueuedTicks);
 304         } else {
 305             super.handleReplayedRemoteRequest(request, callback, enqueuedTicks);
 306         }
 307     }
 308
 309     @Override
 310     void handleForwardedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 311         LOG.debug("Applying forwarded request {}", request);
 312
 313         if (request instanceof TransactionPreCommitRequest) {
 314             sendRequest(new TransactionPreCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 315         } else if (request instanceof TransactionDoCommitRequest) {
 316             sendRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 317         } else if (request instanceof TransactionAbortRequest) {
 318             sendDoAbort(callback);
 319         } else {
 320             super.handleForwardedRemoteRequest(request, callback);
 321         }
 322     }
 323
 324     @Override
 325     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
 326             final Consumer<Response<?, ?>> callback) {
 327         if (request instanceof CommitLocalTransactionRequest) {
 328             verifyLocalReadWrite(successor).sendRebased((CommitLocalTransactionRequest)request, callback);
 329         } else if (request instanceof ModifyTransactionRequest) {
 330             verifyLocalReadWrite(successor).handleForwardedRemoteRequest(request, callback);
 331         } else {
 332             super.forwardToLocal(successor, request, callback);
 333             return;
 334         }
 335         LOG.debug("Forwarded request {} to successor {}", request, successor);
 336     }
 337
 338     private static LocalReadWriteProxyTransaction verifyLocalReadWrite(final LocalProxyTransaction successor) {
 339         Verify.verify(successor instanceof LocalReadWriteProxyTransaction, "Unexpected successor %s", successor);
 340         return (LocalReadWriteProxyTransaction) successor;
 341     }
 342
 343     @Override
 344     void sendAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 345         super.sendAbort(request, callback);
 346         closedException = this::abortedException;
 347     }
 348
 349     @Override
 350     void enqueueAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
 351             final long enqueuedTicks) {
 352         super.enqueueAbort(request, callback, enqueuedTicks);
 353         closedException = this::abortedException;
 354     }
 355
 356     private @NonNull CursorAwareDataTreeModification getModification() {
 357         if (closedException != null) {
 358             throw closedException.get();
 359         }
 360
 361         return Preconditions.checkNotNull(modification, "Transaction %s is DONE", getIdentifier());
 362     }
 363
 364     private void sendRebased(final CommitLocalTransactionRequest request, final Consumer<Response<?, ?>> callback) {
 365         sendRequest(rebaseCommit(request), callback);
 366     }
 367
 368     private CommitLocalTransactionRequest rebaseCommit(final CommitLocalTransactionRequest request) {
 369         // Rebase old modification on new data tree.
 370         final CursorAwareDataTreeModification mod = getModification();
 371
 372         try (DataTreeModificationCursor cursor = mod.openCursor()) {
 373             request.getModification().applyToCursor(cursor);
 374         }
 375
 376         if (markSealed()) {
 377             sealOnly();
 378         }
 379
 380         return commitRequest(request.isCoordinated());
 381     }
 382 }