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