opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/LocalThreePhaseCommitCohort.java

   1 /*
   2  * Copyright (c) 2015 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.datastore;
   9
  10 import akka.actor.ActorSelection;
  11 import akka.dispatch.OnComplete;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.ListenableFuture;
  14 import javax.annotation.Nonnull;
  15 import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
  16 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  17 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  18 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  19 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  20 import org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24 import scala.concurrent.Future;
  25
  26 /**
  27  * Fake {@link DOMStoreThreePhaseCommitCohort} instantiated for local transactions to conform with the DOM
  28  * transaction APIs. It is only used to hold the data from a local DOM transaction ready operation and to
  29  * initiate direct or coordinated commits from the front-end by sending the ReadyLocalTransaction message.
  30  * It is not actually called by the front-end to perform 3PC thus the canCommit/preCommit/commit methods
  31  * are no-ops.
  32  */
  33 abstract class LocalThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
  34     private static final Logger LOG = LoggerFactory.getLogger(LocalThreePhaseCommitCohort.class);
  35
  36     private final SnapshotBackedWriteTransaction<TransactionIdentifier> transaction;
  37     private final DataTreeModification modification;
  38     private final ActorContext actorContext;
  39     private final ActorSelection leader;
  40
  41     protected LocalThreePhaseCommitCohort(final ActorContext actorContext, final ActorSelection leader,
  42             final SnapshotBackedWriteTransaction<TransactionIdentifier> transaction, final DataTreeModification modification) {
  43         this.actorContext = Preconditions.checkNotNull(actorContext);
  44         this.leader = Preconditions.checkNotNull(leader);
  45         this.transaction = Preconditions.checkNotNull(transaction);
  46         this.modification = Preconditions.checkNotNull(modification);
  47     }
  48
  49     private Future<Object> initiateCommit(final boolean immediate) {
  50         final ReadyLocalTransaction message = new ReadyLocalTransaction(transaction.getIdentifier().toString(),
  51                 modification, immediate);
  52         return actorContext.executeOperationAsync(leader, message, actorContext.getTransactionCommitOperationTimeout());
  53     }
  54
  55     /**
  56      * Return the {@link ActorContext} associated with this object.
  57      *
  58      * @return An actor context instance.
  59      */
  60     @Nonnull ActorContext getActorContext() {
  61         return actorContext;
  62     }
  63
  64     Future<ActorSelection> initiateCoordinatedCommit() {
  65         final Future<Object> messageFuture = initiateCommit(false);
  66         final Future<ActorSelection> ret = TransactionReadyReplyMapper.transform(messageFuture, actorContext,
  67                 transaction.getIdentifier());
  68         ret.onComplete(new OnComplete<ActorSelection>() {
  69             @Override
  70             public void onComplete(final Throwable failure, final ActorSelection success) throws Throwable {
  71                 if (failure != null) {
  72                     LOG.info("Failed to prepare transaction {} on backend", transaction.getIdentifier(), failure);
  73                     transactionAborted(transaction);
  74                     return;
  75                 }
  76
  77                 LOG.debug("Transaction {} resolved to actor {}", transaction.getIdentifier(), success);
  78             }
  79         }, actorContext.getClientDispatcher());
  80
  81         return ret;
  82     }
  83
  84     Future<Object> initiateDirectCommit() {
  85         final Future<Object> messageFuture = initiateCommit(true);
  86         messageFuture.onComplete(new OnComplete<Object>() {
  87             @Override
  88             public void onComplete(final Throwable failure, final Object message) throws Throwable {
  89                 if (failure != null) {
  90                     LOG.error("Failed to prepare transaction {} on backend", transaction.getIdentifier(), failure);
  91                     transactionAborted(transaction);
  92                 } else if (CommitTransactionReply.SERIALIZABLE_CLASS.isInstance(message)) {
  93                     LOG.debug("Transaction {} committed successfully", transaction.getIdentifier());
  94                     transactionCommitted(transaction);
  95                 } else {
  96                     LOG.error("Transaction {} resulted in unhandled message type {}, aborting", message.getClass());
  97                     transactionAborted(transaction);
  98                 }
  99             }
 100         }, actorContext.getClientDispatcher());
 101
 102         return messageFuture;
 103     }
 104
 105     @Override
 106     public final ListenableFuture<Boolean> canCommit() {
 107         // Intended no-op
 108         throw new UnsupportedOperationException();
 109     }
 110
 111     @Override
 112     public final ListenableFuture<Void> preCommit() {
 113         // Intended no-op
 114         throw new UnsupportedOperationException();
 115     }
 116
 117     @Override
 118     public final ListenableFuture<Void> abort() {
 119         // Intended no-op
 120         throw new UnsupportedOperationException();
 121     }
 122
 123     @Override
 124     public final ListenableFuture<Void> commit() {
 125         // Intended no-op
 126         throw new UnsupportedOperationException();
 127     }
 128
 129     protected abstract void transactionAborted(SnapshotBackedWriteTransaction<TransactionIdentifier> transaction);
 130     protected abstract void transactionCommitted(SnapshotBackedWriteTransaction<TransactionIdentifier> transaction);
 131 }