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.Futures;
  12 import akka.dispatch.OnComplete;
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.util.concurrent.ListenableFuture;
  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 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     private Exception operationError;
  41
  42     protected LocalThreePhaseCommitCohort(final ActorContext actorContext, final ActorSelection leader,
  43             final SnapshotBackedWriteTransaction<TransactionIdentifier> transaction, final DataTreeModification modification) {
  44         this.actorContext = Preconditions.checkNotNull(actorContext);
  45         this.leader = Preconditions.checkNotNull(leader);
  46         this.transaction = Preconditions.checkNotNull(transaction);
  47         this.modification = Preconditions.checkNotNull(modification);
  48     }
  49
  50     protected LocalThreePhaseCommitCohort(final ActorContext actorContext, final ActorSelection leader,
  51             final SnapshotBackedWriteTransaction<TransactionIdentifier> transaction, final Exception operationError) {
  52         this.actorContext = Preconditions.checkNotNull(actorContext);
  53         this.leader = Preconditions.checkNotNull(leader);
  54         this.transaction = Preconditions.checkNotNull(transaction);
  55         this.operationError = Preconditions.checkNotNull(operationError);
  56         this.modification = null;
  57     }
  58
  59     private Future<Object> initiateCommit(final boolean immediate) {
  60         if(operationError != null) {
  61             return Futures.failed(operationError);
  62         }
  63
  64         final ReadyLocalTransaction message = new ReadyLocalTransaction(transaction.getIdentifier().toString(),
  65                 modification, immediate);
  66         return actorContext.executeOperationAsync(leader, message, actorContext.getTransactionCommitOperationTimeout());
  67     }
  68
  69     void setOperationError(Exception operationError) {
  70         this.operationError = operationError;
  71     }
  72
  73     Future<ActorSelection> initiateCoordinatedCommit() {
  74         final Future<Object> messageFuture = initiateCommit(false);
  75         final Future<ActorSelection> ret = TransactionReadyReplyMapper.transform(messageFuture, actorContext,
  76                 transaction.getIdentifier());
  77         ret.onComplete(new OnComplete<ActorSelection>() {
  78             @Override
  79             public void onComplete(final Throwable failure, final ActorSelection success) throws Throwable {
  80                 if (failure != null) {
  81                     LOG.info("Failed to prepare transaction {} on backend", transaction.getIdentifier(), failure);
  82                     transactionAborted(transaction);
  83                     return;
  84                 }
  85
  86                 LOG.debug("Transaction {} resolved to actor {}", transaction.getIdentifier(), success);
  87             }
  88         }, actorContext.getClientDispatcher());
  89
  90         return ret;
  91     }
  92
  93     Future<Object> initiateDirectCommit() {
  94         final Future<Object> messageFuture = initiateCommit(true);
  95         messageFuture.onComplete(new OnComplete<Object>() {
  96             @Override
  97             public void onComplete(final Throwable failure, final Object message) throws Throwable {
  98                 if (failure != null) {
  99                     LOG.error("Failed to prepare transaction {} on backend", transaction.getIdentifier(), failure);
 100                     transactionAborted(transaction);
 101                 } else if (CommitTransactionReply.SERIALIZABLE_CLASS.isInstance(message)) {
 102                     LOG.debug("Transaction {} committed successfully", transaction.getIdentifier());
 103                     transactionCommitted(transaction);
 104                 } else {
 105                     LOG.error("Transaction {} resulted in unhandled message type {}, aborting", message.getClass());
 106                     transactionAborted(transaction);
 107                 }
 108             }
 109         }, actorContext.getClientDispatcher());
 110
 111         return messageFuture;
 112     }
 113
 114     @Override
 115     public final ListenableFuture<Boolean> canCommit() {
 116         // Intended no-op
 117         throw new UnsupportedOperationException();
 118     }
 119
 120     @Override
 121     public final ListenableFuture<Void> preCommit() {
 122         // Intended no-op
 123         throw new UnsupportedOperationException();
 124     }
 125
 126     @Override
 127     public final ListenableFuture<Void> abort() {
 128         // Intended no-op
 129         throw new UnsupportedOperationException();
 130     }
 131
 132     @Override
 133     public final ListenableFuture<Void> commit() {
 134         // Intended no-op
 135         throw new UnsupportedOperationException();
 136     }
 137
 138     protected void transactionAborted(SnapshotBackedWriteTransaction<TransactionIdentifier> transaction) {
 139     }
 140
 141     protected void transactionCommitted(SnapshotBackedWriteTransaction<TransactionIdentifier> transaction) {
 142     }
 143 }