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