opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/NoOpDOMStoreThreePhaseCommitCohort.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 com.google.common.util.concurrent.Futures;
  11 import com.google.common.util.concurrent.ListenableFuture;
  12 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  13
  14 /**
  15  * A {@link DOMStoreThreePhaseCommitCohort} instance given out for empty transactions.
  16  */
  17 final class NoOpDOMStoreThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
  18     static final NoOpDOMStoreThreePhaseCommitCohort INSTANCE = new NoOpDOMStoreThreePhaseCommitCohort();
  19
  20     private static final ListenableFuture<Void> IMMEDIATE_VOID_SUCCESS = Futures.immediateFuture(null);
  21     private static final ListenableFuture<Boolean> IMMEDIATE_BOOLEAN_SUCCESS = Futures.immediateFuture(Boolean.TRUE);
  22
  23     private NoOpDOMStoreThreePhaseCommitCohort() {
  24         // Hidden to prevent instantiation
  25     }
  26
  27     @Override
  28     public ListenableFuture<Boolean> canCommit() {
  29         return IMMEDIATE_BOOLEAN_SUCCESS;
  30     }
  31
  32     @Override
  33     public ListenableFuture<Void> preCommit() {
  34         return IMMEDIATE_VOID_SUCCESS;
  35     }
  36
  37     @Override
  38     public ListenableFuture<Void> abort() {
  39         return IMMEDIATE_VOID_SUCCESS;
  40     }
  41
  42     @Override
  43     public ListenableFuture<Void> commit() {
  44         return IMMEDIATE_VOID_SUCCESS;
  45     }
  46 }