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