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