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 static com.google.common.base.Preconditions.checkState;
  11 import static com.google.common.base.Verify.verify;
  12 import static com.google.common.base.Verify.verifyNotNull;
  13
  14 import java.util.Optional;
  15 import java.util.OptionalLong;
  16 import java.util.function.BiConsumer;
  17 import java.util.function.Consumer;
  18 import java.util.function.Supplier;
  19 import org.eclipse.jdt.annotation.NonNull;
  20 import org.eclipse.jdt.annotation.Nullable;
  21 import org.opendaylight.controller.cluster.access.commands.AbortLocalTransactionRequest;
  22 import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest;
  23 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  24 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  25 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequestBuilder;
  26 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionDelete;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest;
  30 import org.opendaylight.controller.cluster.access.commands.TransactionMerge;
  31 import org.opendaylight.controller.cluster.access.commands.TransactionModification;
  32 import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest;
  33 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  34 import org.opendaylight.controller.cluster.access.commands.TransactionWrite;
  35 import org.opendaylight.controller.cluster.access.concepts.Response;
  36 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  37 import org.opendaylight.controller.cluster.datastore.util.AbstractDataTreeModificationCursor;
  38 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  39 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  40 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  41 import org.opendaylight.yangtools.yang.data.tree.api.CursorAwareDataTreeModification;
  42 import org.opendaylight.yangtools.yang.data.tree.api.CursorAwareDataTreeSnapshot;
  43 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModification;
  44 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModificationCursor;
  45 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeSnapshot;
  46 import org.slf4j.Logger;
  47 import org.slf4j.LoggerFactory;
  48
  49 /**
  50  * An {@link AbstractProxyTransaction} for dispatching a transaction towards a shard leader which is co-located with
  51  * the client instance. This class is NOT thread-safe.
  52  *
  53  * <p>
  54  * It requires a {@link DataTreeSnapshot}, which is used to instantiated a new {@link DataTreeModification}. Operations
  55  * are then performed on this modification and once the transaction is submitted, the modification is sent to the shard
  56  * leader.
  57  *
  58  * <p>
  59  * This class is not thread-safe as usual with transactions. Since it does not interact with the backend until the
  60  * transaction is submitted, at which point this class gets out of the picture, this is not a cause for concern.
  61  *
  62  * @author Robert Varga
  63  */
  64 final class LocalReadWriteProxyTransaction extends LocalProxyTransaction {
  65     private static final Logger LOG = LoggerFactory.getLogger(LocalReadWriteProxyTransaction.class);
  66
  67     /**
  68      * This field needs to be accessed via {@link #getModification()}, which performs state checking to ensure
  69      * the modification can actually be accessed.
  70      */
  71     private final CursorAwareDataTreeModification modification;
  72
  73     private Supplier<? extends RuntimeException> closedException;
  74
  75     private CursorAwareDataTreeModification sealedModification;
  76
  77     /**
  78      * Recorded failure from previous operations. Normally we would want to propagate the error directly to the
  79      * offending call site, but that exposes inconsistency in behavior during initial connection, when we go through
  80      * {@link RemoteProxyTransaction}, which detects this sort of issues at canCommit/directCommit time on the backend.
  81      *
  82      * <p>
  83      * We therefore do not report incurred exceptions directly, but report them once the user attempts to commit
  84      * this transaction.
  85      */
  86     private Exception recordedFailure;
  87
  88     LocalReadWriteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier,
  89         final DataTreeSnapshot snapshot) {
  90         super(parent, identifier, false);
  91         modification = (CursorAwareDataTreeModification) snapshot.newModification();
  92     }
  93
  94     LocalReadWriteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier) {
  95         super(parent, identifier, true);
  96         // This is DONE transaction, this should never be touched
  97         modification = null;
  98     }
  99
 100     @Override
 101     boolean isSnapshotOnly() {
 102         return false;
 103     }
 104
 105     @Override
 106     CursorAwareDataTreeSnapshot readOnlyView() {
 107         return getModification();
 108     }
 109
 110     @Override
 111     @SuppressWarnings("checkstyle:IllegalCatch")
 112     void doDelete(final YangInstanceIdentifier path) {
 113         final CursorAwareDataTreeModification mod = getModification();
 114         if (recordedFailure != null) {
 115             LOG.debug("Transaction {} recorded failure, ignoring delete of {}", getIdentifier(), path);
 116             return;
 117         }
 118
 119         try {
 120             mod.delete(path);
 121         } catch (Exception e) {
 122             LOG.debug("Transaction {} delete on {} incurred failure, delaying it until commit", getIdentifier(), path,
 123                 e);
 124             recordedFailure = e;
 125         }
 126     }
 127
 128     @Override
 129     @SuppressWarnings("checkstyle:IllegalCatch")
 130     void doMerge(final YangInstanceIdentifier path, final NormalizedNode data) {
 131         final CursorAwareDataTreeModification mod = getModification();
 132         if (recordedFailure != null) {
 133             LOG.debug("Transaction {} recorded failure, ignoring merge to {}", getIdentifier(), path);
 134             return;
 135         }
 136
 137         try {
 138             mod.merge(path, data);
 139         } catch (Exception e) {
 140             LOG.debug("Transaction {} merge to {} incurred failure, delaying it until commit", getIdentifier(), path,
 141                 e);
 142             recordedFailure = e;
 143         }
 144     }
 145
 146     @Override
 147     @SuppressWarnings("checkstyle:IllegalCatch")
 148     void doWrite(final YangInstanceIdentifier path, final NormalizedNode data) {
 149         final CursorAwareDataTreeModification mod = getModification();
 150         if (recordedFailure != null) {
 151             LOG.debug("Transaction {} recorded failure, ignoring write to {}", getIdentifier(), path);
 152             return;
 153         }
 154
 155         try {
 156             mod.write(path, data);
 157         } catch (Exception e) {
 158             LOG.debug("Transaction {} write to {} incurred failure, delaying it until commit", getIdentifier(), path,
 159                 e);
 160             recordedFailure = e;
 161         }
 162     }
 163
 164     private RuntimeException abortedException() {
 165         return new IllegalStateException("Tracker " + getIdentifier() + " has been aborted");
 166     }
 167
 168     private RuntimeException submittedException() {
 169         return new IllegalStateException("Tracker " + getIdentifier() + " has been submitted");
 170     }
 171
 172     @Override
 173     CommitLocalTransactionRequest commitRequest(final boolean coordinated) {
 174         final CursorAwareDataTreeModification mod = getModification();
 175         final CommitLocalTransactionRequest ret = new CommitLocalTransactionRequest(getIdentifier(), nextSequence(),
 176             localActor(), mod, recordedFailure, coordinated);
 177         closedException = this::submittedException;
 178         return ret;
 179     }
 180
 181     private void sealModification() {
 182         checkState(sealedModification == null, "Transaction %s is already sealed", this);
 183         final CursorAwareDataTreeModification mod = getModification();
 184         mod.ready();
 185         sealedModification = mod;
 186     }
 187
 188     @Override
 189     boolean sealOnly() {
 190         sealModification();
 191         return super.sealOnly();
 192     }
 193
 194     @Override
 195     boolean sealAndSend(final OptionalLong enqueuedTicks) {
 196         sealModification();
 197         return super.sealAndSend(enqueuedTicks);
 198     }
 199
 200     @Override
 201     Optional<ModifyTransactionRequest> flushState() {
 202         final ModifyTransactionRequestBuilder b = new ModifyTransactionRequestBuilder(getIdentifier(), localActor());
 203         b.setSequence(0);
 204
 205         sealedModification.applyToCursor(new AbstractDataTreeModificationCursor() {
 206             @Override
 207             public void write(final PathArgument child, final NormalizedNode data) {
 208                 b.addModification(new TransactionWrite(current().node(child), data));
 209             }
 210
 211             @Override
 212             public void merge(final PathArgument child, final NormalizedNode data) {
 213                 b.addModification(new TransactionMerge(current().node(child), data));
 214             }
 215
 216             @Override
 217             public void delete(final PathArgument child) {
 218                 b.addModification(new TransactionDelete(current().node(child)));
 219             }
 220         });
 221
 222         return Optional.of(b.build());
 223     }
 224
 225     CursorAwareDataTreeSnapshot getSnapshot() {
 226         checkState(sealedModification != null, "Proxy %s is not sealed yet", getIdentifier());
 227         return sealedModification;
 228     }
 229
 230     @Override
 231     void applyForwardedModifyTransactionRequest(final ModifyTransactionRequest request,
 232             final Consumer<Response<?, ?>> callback) {
 233         commonModifyTransactionRequest(request, callback, this::sendRequest);
 234     }
 235
 236     @Override
 237     void replayModifyTransactionRequest(final ModifyTransactionRequest request,
 238             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
 239         commonModifyTransactionRequest(request, callback, (req, cb) -> enqueueRequest(req, cb, enqueuedTicks));
 240     }
 241
 242     private void commonModifyTransactionRequest(final ModifyTransactionRequest request,
 243             final @Nullable Consumer<Response<?, ?>> callback,
 244             final BiConsumer<TransactionRequest<?>, Consumer<Response<?, ?>>> sendMethod) {
 245         for (final TransactionModification mod : request.getModifications()) {
 246             if (mod instanceof TransactionWrite) {
 247                 write(mod.getPath(), ((TransactionWrite)mod).getData());
 248             } else if (mod instanceof TransactionMerge) {
 249                 merge(mod.getPath(), ((TransactionMerge)mod).getData());
 250             } else if (mod instanceof TransactionDelete) {
 251                 delete(mod.getPath());
 252             } else {
 253                 throw new IllegalArgumentException("Unsupported modification " + mod);
 254             }
 255         }
 256
 257         final Optional<PersistenceProtocol> maybeProtocol = request.getPersistenceProtocol();
 258         if (maybeProtocol.isPresent()) {
 259             final var cb = verifyNotNull(callback, "Request %s has null callback", request);
 260             if (markSealed()) {
 261                 sealOnly();
 262             }
 263
 264             switch (maybeProtocol.get()) {
 265                 case ABORT:
 266                     sendMethod.accept(new AbortLocalTransactionRequest(getIdentifier(), localActor()), cb);
 267                     break;
 268                 case READY:
 269                     // No-op, as we have already issued a sealOnly() and we are not transmitting anything
 270                     break;
 271                 case SIMPLE:
 272                     sendMethod.accept(commitRequest(false), cb);
 273                     break;
 274                 case THREE_PHASE:
 275                     sendMethod.accept(commitRequest(true), cb);
 276                     break;
 277                 default:
 278                     throw new IllegalArgumentException("Unhandled protocol " + maybeProtocol.get());
 279             }
 280         }
 281     }
 282
 283     @Override
 284     void handleReplayedLocalRequest(final AbstractLocalTransactionRequest<?> request,
 285             final Consumer<Response<?, ?>> callback, final long now) {
 286         if (request instanceof CommitLocalTransactionRequest) {
 287             enqueueRequest(rebaseCommit((CommitLocalTransactionRequest)request), callback, now);
 288         } else {
 289             super.handleReplayedLocalRequest(request, callback, now);
 290         }
 291     }
 292
 293     @Override
 294     void handleReplayedRemoteRequest(final TransactionRequest<?> request,
 295             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
 296         LOG.debug("Applying replayed request {}", request);
 297
 298         if (request instanceof TransactionPreCommitRequest) {
 299             enqueueRequest(new TransactionPreCommitRequest(getIdentifier(), nextSequence(), localActor()), callback,
 300                 enqueuedTicks);
 301         } else if (request instanceof TransactionDoCommitRequest) {
 302             enqueueRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), callback,
 303                 enqueuedTicks);
 304         } else if (request instanceof TransactionAbortRequest) {
 305             enqueueDoAbort(callback, enqueuedTicks);
 306         } else {
 307             super.handleReplayedRemoteRequest(request, callback, enqueuedTicks);
 308         }
 309     }
 310
 311     @Override
 312     void handleForwardedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 313         LOG.debug("Applying forwarded request {}", request);
 314
 315         if (request instanceof TransactionPreCommitRequest) {
 316             sendRequest(new TransactionPreCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 317         } else if (request instanceof TransactionDoCommitRequest) {
 318             sendRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 319         } else if (request instanceof TransactionAbortRequest) {
 320             sendDoAbort(callback);
 321         } else {
 322             super.handleForwardedRemoteRequest(request, callback);
 323         }
 324     }
 325
 326     @Override
 327     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
 328             final Consumer<Response<?, ?>> callback) {
 329         if (request instanceof CommitLocalTransactionRequest) {
 330             verifyLocalReadWrite(successor).sendRebased((CommitLocalTransactionRequest)request, callback);
 331         } else if (request instanceof ModifyTransactionRequest) {
 332             verifyLocalReadWrite(successor).handleForwardedRemoteRequest(request, callback);
 333         } else {
 334             super.forwardToLocal(successor, request, callback);
 335             return;
 336         }
 337         LOG.debug("Forwarded request {} to successor {}", request, successor);
 338     }
 339
 340     private static LocalReadWriteProxyTransaction verifyLocalReadWrite(final LocalProxyTransaction successor) {
 341         verify(successor instanceof LocalReadWriteProxyTransaction, "Unexpected successor %s", successor);
 342         return (LocalReadWriteProxyTransaction) successor;
 343     }
 344
 345     @Override
 346     void sendAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 347         super.sendAbort(request, callback);
 348         closedException = this::abortedException;
 349     }
 350
 351     @Override
 352     void enqueueAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
 353             final long enqueuedTicks) {
 354         super.enqueueAbort(request, callback, enqueuedTicks);
 355         closedException = this::abortedException;
 356     }
 357
 358     private @NonNull CursorAwareDataTreeModification getModification() {
 359         if (closedException != null) {
 360             throw closedException.get();
 361         }
 362         return verifyNotNull(modification, "Transaction %s is DONE", getIdentifier());
 363     }
 364
 365     private void sendRebased(final CommitLocalTransactionRequest request, final Consumer<Response<?, ?>> callback) {
 366         sendRequest(rebaseCommit(request), callback);
 367     }
 368
 369     private CommitLocalTransactionRequest rebaseCommit(final CommitLocalTransactionRequest request) {
 370         // Rebase old modification on new data tree.
 371         final CursorAwareDataTreeModification mod = getModification();
 372
 373         try (DataTreeModificationCursor cursor = mod.openCursor()) {
 374             request.getModification().applyToCursor(cursor);
 375         }
 376
 377         if (markSealed()) {
 378             sealOnly();
 379         }
 380
 381         return commitRequest(request.isCoordinated());
 382     }
 383 }