opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.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 akka.actor.ActorRef;
  11 import com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.base.Verify;
  14 import com.google.common.util.concurrent.CheckedFuture;
  15 import com.google.common.util.concurrent.ListenableFuture;
  16 import com.google.common.util.concurrent.SettableFuture;
  17 import java.util.ArrayDeque;
  18 import java.util.Deque;
  19 import java.util.function.Consumer;
  20 import javax.annotation.Nonnull;
  21 import javax.annotation.Nullable;
  22 import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
  23 import org.opendaylight.controller.cluster.access.commands.TransactionAbortSuccess;
  24 import org.opendaylight.controller.cluster.access.commands.TransactionCanCommitSuccess;
  25 import org.opendaylight.controller.cluster.access.commands.TransactionCommitSuccess;
  26 import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitSuccess;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  30 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  31 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
  32 import org.opendaylight.controller.cluster.access.concepts.Response;
  33 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  34 import org.opendaylight.mdsal.common.api.ReadFailedException;
  35 import org.opendaylight.yangtools.concepts.Identifiable;
  36 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  37 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 /**
  42  * Class translating transaction operations towards a particular backend shard.
  43  *
  44  * <p>
  45  * This class is not safe to access from multiple application threads, as is usual for transactions. Internal state
  46  * transitions coming from interactions with backend are expected to be thread-safe.
  47  *
  48  * <p>
  49  * This class interacts with the queueing mechanism in ClientActorBehavior, hence once we arrive at a decision
  50  * to use either a local or remote implementation, we are stuck with it. We can re-evaluate on the next transaction.
  51  *
  52  * @author Robert Varga
  53  */
  54 abstract class AbstractProxyTransaction implements Identifiable<TransactionIdentifier> {
  55     private static final class IncrementSequence {
  56         private long delta = 1;
  57
  58         long getDelta() {
  59             return delta;
  60         }
  61
  62         void incrementDelta() {
  63             delta++;
  64         }
  65     }
  66
  67     private static final Logger LOG = LoggerFactory.getLogger(AbstractProxyTransaction.class);
  68
  69     private final Deque<Object> successfulRequests = new ArrayDeque<>();
  70     private final ProxyHistory parent;
  71
  72     private AbstractProxyTransaction successor;
  73     private long sequence;
  74     private boolean sealed;
  75
  76     AbstractProxyTransaction(final ProxyHistory parent) {
  77         this.parent = Preconditions.checkNotNull(parent);
  78     }
  79
  80     final ActorRef localActor() {
  81         return parent.localActor();
  82     }
  83
  84     private void incrementSequence(final long delta) {
  85         sequence += delta;
  86         LOG.debug("Transaction {} incremented sequence to {}", this, sequence);
  87     }
  88
  89     final long nextSequence() {
  90         final long ret = sequence++;
  91         LOG.debug("Transaction {} allocated sequence {}", this, ret);
  92         return ret;
  93     }
  94
  95     final void delete(final YangInstanceIdentifier path) {
  96         checkNotSealed();
  97         doDelete(path);
  98     }
  99
 100     final void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
 101         checkNotSealed();
 102         doMerge(path, data);
 103     }
 104
 105     final void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
 106         checkNotSealed();
 107         doWrite(path, data);
 108     }
 109
 110     final CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
 111         checkNotSealed();
 112         return doExists(path);
 113     }
 114
 115     final CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
 116         checkNotSealed();
 117         return doRead(path);
 118     }
 119
 120     final void sendRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 121         LOG.debug("Transaction proxy {} sending request {} callback {}", this, request, callback);
 122         parent.sendRequest(request, callback);
 123     }
 124
 125     /**
 126      * Seal this transaction before it is either committed or aborted.
 127      */
 128     final void seal() {
 129         checkNotSealed();
 130         doSeal();
 131         sealed = true;
 132         parent.onTransactionSealed(this);
 133     }
 134
 135     private void checkNotSealed() {
 136         Preconditions.checkState(!sealed, "Transaction %s has already been sealed", getIdentifier());
 137     }
 138
 139     private void checkSealed() {
 140         Preconditions.checkState(sealed, "Transaction %s has not been sealed yet", getIdentifier());
 141     }
 142
 143     final void recordSuccessfulRequest(final @Nonnull TransactionRequest<?> req) {
 144         successfulRequests.add(Verify.verifyNotNull(req));
 145     }
 146
 147     final void recordFinishedRequest() {
 148         final Object last = successfulRequests.peekLast();
 149         if (last instanceof IncrementSequence) {
 150             ((IncrementSequence) last).incrementDelta();
 151         } else {
 152             successfulRequests.addLast(new IncrementSequence());
 153         }
 154     }
 155
 156     /**
 157      * Abort this transaction. This is invoked only for read-only transactions and will result in an explicit message
 158      * being sent to the backend.
 159      */
 160     final void abort() {
 161         checkNotSealed();
 162         doAbort();
 163         parent.abortTransaction(this);
 164     }
 165
 166     final void abort(final VotingFuture<Void> ret) {
 167         checkSealed();
 168
 169         sendAbort(t -> {
 170             if (t instanceof TransactionAbortSuccess) {
 171                 ret.voteYes();
 172             } else if (t instanceof RequestFailure) {
 173                 ret.voteNo(((RequestFailure<?, ?>) t).getCause());
 174             } else {
 175                 ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass()));
 176             }
 177
 178             // This is a terminal request, hence we do not need to record it
 179             LOG.debug("Transaction {} abort completed", this);
 180             parent.completeTransaction(this);
 181         });
 182     }
 183
 184     final void sendAbort(final Consumer<Response<?, ?>> callback) {
 185         sendRequest(new TransactionAbortRequest(getIdentifier(), nextSequence(), localActor()), callback);
 186     }
 187
 188     /**
 189      * Commit this transaction, possibly in a coordinated fashion.
 190      *
 191      * @param coordinated True if this transaction should be coordinated across multiple participants.
 192      * @return Future completion
 193      */
 194     final ListenableFuture<Boolean> directCommit() {
 195         checkSealed();
 196
 197         final SettableFuture<Boolean> ret = SettableFuture.create();
 198         sendRequest(Verify.verifyNotNull(commitRequest(false)), t -> {
 199             if (t instanceof TransactionCommitSuccess) {
 200                 ret.set(Boolean.TRUE);
 201             } else if (t instanceof RequestFailure) {
 202                 ret.setException(((RequestFailure<?, ?>) t).getCause());
 203             } else {
 204                 ret.setException(new IllegalStateException("Unhandled response " + t.getClass()));
 205             }
 206
 207             // This is a terminal request, hence we do not need to record it
 208             LOG.debug("Transaction {} directCommit completed", this);
 209             parent.completeTransaction(this);
 210         });
 211         return ret;
 212     }
 213
 214
 215     void canCommit(final VotingFuture<?> ret) {
 216         checkSealed();
 217
 218         final TransactionRequest<?> req = Verify.verifyNotNull(commitRequest(true));
 219         sendRequest(req, t -> {
 220             if (t instanceof TransactionCanCommitSuccess) {
 221                 ret.voteYes();
 222             } else if (t instanceof RequestFailure) {
 223                 ret.voteNo(((RequestFailure<?, ?>) t).getCause());
 224             } else {
 225                 ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass()));
 226             }
 227
 228             recordSuccessfulRequest(req);
 229             LOG.debug("Transaction {} canCommit completed", this);
 230         });
 231     }
 232
 233     void preCommit(final VotingFuture<?> ret) {
 234         checkSealed();
 235
 236         final TransactionRequest<?> req = new TransactionPreCommitRequest(getIdentifier(), nextSequence(),
 237             localActor());
 238         sendRequest(req, t -> {
 239             if (t instanceof TransactionPreCommitSuccess) {
 240                 ret.voteYes();
 241             } else if (t instanceof RequestFailure) {
 242                 ret.voteNo(((RequestFailure<?, ?>) t).getCause());
 243             } else {
 244                 ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass()));
 245             }
 246
 247             recordSuccessfulRequest(req);
 248             LOG.debug("Transaction {} preCommit completed", this);
 249         });
 250     }
 251
 252     void doCommit(final VotingFuture<?> ret) {
 253         checkSealed();
 254
 255         sendRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), t -> {
 256             if (t instanceof TransactionCommitSuccess) {
 257                 ret.voteYes();
 258             } else if (t instanceof RequestFailure) {
 259                 ret.voteNo(((RequestFailure<?, ?>) t).getCause());
 260             } else {
 261                 ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass()));
 262             }
 263
 264             LOG.debug("Transaction {} doCommit completed", this);
 265             parent.completeTransaction(this);
 266         });
 267     }
 268
 269     final void replaySuccessfulRequests(final AbstractProxyTransaction successor) {
 270         this.successor = Preconditions.checkNotNull(successor);
 271
 272         for (Object obj : successfulRequests) {
 273             if (obj instanceof TransactionRequest) {
 274                 LOG.debug("Forwarding request {} to successor {}", obj, successor);
 275                 successor.handleForwardedRemoteRequest((TransactionRequest<?>) obj, null);
 276             } else {
 277                 Verify.verify(obj instanceof IncrementSequence);
 278                 successor.incrementSequence(((IncrementSequence) obj).getDelta());
 279             }
 280         }
 281         LOG.debug("{} replayed {} successful requests", getIdentifier(), successfulRequests.size());
 282         successfulRequests.clear();
 283     }
 284
 285     /**
 286      * Invoked from a retired connection for requests which have been in-flight and need to be re-adjusted
 287      * and forwarded to the successor connection.
 288      *
 289      * @param request Request to be forwarded
 290      * @param callback Original callback
 291      * @throws RequestException when the request is unhandled by the successor
 292      */
 293     final void replayRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback)
 294             throws RequestException {
 295         Preconditions.checkState(successor != null, "%s does not have a successor set", this);
 296
 297         if (successor instanceof LocalProxyTransaction) {
 298             forwardToLocal((LocalProxyTransaction)successor, request, callback);
 299         } else if (successor instanceof RemoteProxyTransaction) {
 300             forwardToRemote((RemoteProxyTransaction)successor, request, callback);
 301         } else {
 302             throw new IllegalStateException("Unhandled successor " + successor);
 303         }
 304     }
 305
 306     abstract void doDelete(final YangInstanceIdentifier path);
 307
 308     abstract void doMerge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data);
 309
 310     abstract void doWrite(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data);
 311
 312     abstract CheckedFuture<Boolean, ReadFailedException> doExists(final YangInstanceIdentifier path);
 313
 314     abstract CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> doRead(
 315             final YangInstanceIdentifier path);
 316
 317     abstract void doSeal();
 318
 319     abstract void doAbort();
 320
 321     abstract TransactionRequest<?> commitRequest(boolean coordinated);
 322
 323     /**
 324      * Invoked from {@link RemoteProxyTransaction} when it replays its successful requests to its successor. There is
 325      * no equivalent of this call from {@link LocalProxyTransaction} because it does not send a request until all
 326      * operations are packaged in the message.
 327      *
 328      * <p>
 329      * Note: this method is invoked by the predecessor on the successor.
 330      *
 331      * @param request Request which needs to be forwarded
 332      * @param callback Callback to be invoked once the request completes
 333      */
 334     abstract void handleForwardedRemoteRequest(TransactionRequest<?> request,
 335             @Nullable Consumer<Response<?, ?>> callback);
 336
 337     /**
 338      * Replay a request originating in this proxy to a successor remote proxy.
 339      */
 340     abstract void forwardToRemote(RemoteProxyTransaction successor, TransactionRequest<?> request,
 341             Consumer<Response<?, ?>> callback) throws RequestException;
 342
 343     /**
 344      * Replay a request originating in this proxy to a successor local proxy.
 345      */
 346     abstract void forwardToLocal(LocalProxyTransaction successor, TransactionRequest<?> request,
 347             Consumer<Response<?, ?>> callback) throws RequestException;
 348 }