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

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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.dispatch.OnComplete;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.util.concurrent.ListenableFuture;
  13 import com.google.common.util.concurrent.SettableFuture;
  14 import java.util.Arrays;
  15 import java.util.List;
  16 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  17 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  18 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21 import scala.concurrent.Future;
  22
  23 /**
  24  * A cohort proxy implementation for a single-shard transaction commit. If the transaction was a direct commit
  25  * to the shard, this implementation elides the CanCommitTransaction and CommitTransaction messages to the
  26  * shard as an optimization.
  27  *
  28  * @author Thomas Pantelis
  29  */
  30 class SingleCommitCohortProxy extends AbstractThreePhaseCommitCohort<Object> {
  31     private static final Logger LOG = LoggerFactory.getLogger(SingleCommitCohortProxy.class);
  32
  33     private final ActorContext actorContext;
  34     private final Future<Object> cohortFuture;
  35     private final TransactionIdentifier transactionId;
  36     private volatile DOMStoreThreePhaseCommitCohort delegateCohort = NoOpDOMStoreThreePhaseCommitCohort.INSTANCE;
  37     private final OperationCallback.Reference operationCallbackRef;
  38
  39     SingleCommitCohortProxy(ActorContext actorContext, Future<Object> cohortFuture, TransactionIdentifier transactionId,
  40             OperationCallback.Reference operationCallbackRef) {
  41         this.actorContext = actorContext;
  42         this.cohortFuture = cohortFuture;
  43         this.transactionId = Preconditions.checkNotNull(transactionId);
  44         this.operationCallbackRef = operationCallbackRef;
  45     }
  46
  47     @Override
  48     public ListenableFuture<Boolean> canCommit() {
  49         LOG.debug("Tx {} canCommit", transactionId);
  50
  51         final SettableFuture<Boolean> returnFuture = SettableFuture.create();
  52
  53         cohortFuture.onComplete(new OnComplete<Object>() {
  54             @Override
  55             public void onComplete(Throwable failure, Object cohortResponse) {
  56                 if (failure != null) {
  57                     operationCallbackRef.get().failure();
  58                     returnFuture.setException(failure);
  59                     return;
  60                 }
  61
  62                 operationCallbackRef.get().success();
  63
  64                 LOG.debug("Tx {} successfully completed direct commit", transactionId);
  65
  66                 // The Future was the result of a direct commit to the shard, essentially eliding the
  67                 // front-end 3PC coordination. We don't really care about the specific Future
  68                 // response object, only that it completed successfully. At this point the Tx is complete
  69                 // so return true. The subsequent preCommit and commit phases will be no-ops, ie return
  70                 // immediate success, to complete the 3PC for the front-end.
  71                 returnFuture.set(Boolean.TRUE);
  72             }
  73         }, actorContext.getClientDispatcher());
  74
  75         return returnFuture;
  76     }
  77
  78     @Override
  79     public ListenableFuture<Void> preCommit() {
  80         return delegateCohort.preCommit();
  81     }
  82
  83     @Override
  84     public ListenableFuture<Void> abort() {
  85         return delegateCohort.abort();
  86     }
  87
  88     @Override
  89     public ListenableFuture<Void> commit() {
  90         return delegateCohort.commit();
  91     }
  92
  93     @Override
  94     List<Future<Object>> getCohortFutures() {
  95         return Arrays.asList(cohortFuture);
  96     }
  97 }