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