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