opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/SimpleShardDataTreeCohort.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 com.google.common.base.Preconditions;
  11 import com.google.common.util.concurrent.Futures;
  12 import com.google.common.util.concurrent.ListenableFuture;
  13 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  14 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  15 import org.slf4j.Logger;
  16 import org.slf4j.LoggerFactory;
  17
  18 final class SimpleShardDataTreeCohort extends ShardDataTreeCohort {
  19     private static final Logger LOG = LoggerFactory.getLogger(SimpleShardDataTreeCohort.class);
  20     private static final ListenableFuture<Boolean> TRUE_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  21     private static final ListenableFuture<Void> VOID_FUTURE = Futures.immediateFuture(null);
  22     private final DataTreeModification transaction;
  23     private final ShardDataTree dataTree;
  24     private DataTreeCandidateTip candidate;
  25
  26     SimpleShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction) {
  27         this.dataTree = Preconditions.checkNotNull(dataTree);
  28         this.transaction = Preconditions.checkNotNull(transaction);
  29     }
  30
  31     @Override
  32     DataTreeCandidateTip getCandidate() {
  33         return candidate;
  34     }
  35
  36     @Override
  37     public ListenableFuture<Boolean> canCommit() {
  38         try {
  39             dataTree.getDataTree().validate(transaction);
  40             LOG.debug("Transaction {} validated", transaction);
  41             return TRUE_FUTURE;
  42         } catch (Exception e) {
  43             return Futures.immediateFailedFuture(e);
  44         }
  45     }
  46
  47     @Override
  48     public ListenableFuture<Void> preCommit() {
  49         try {
  50             candidate = dataTree.getDataTree().prepare(transaction);
  51             /*
  52              * FIXME: this is the place where we should be interacting with persistence, specifically by invoking
  53              *        persist on the candidate (which gives us a Future).
  54              */
  55             LOG.debug("Transaction {} prepared candidate {}", transaction, candidate);
  56             return VOID_FUTURE;
  57         } catch (Exception e) {
  58             LOG.debug("Transaction {} failed to prepare", transaction, e);
  59             return Futures.immediateFailedFuture(e);
  60         }
  61     }
  62
  63     @Override
  64     public ListenableFuture<Void> abort() {
  65         // No-op, really
  66         return VOID_FUTURE;
  67     }
  68
  69     @Override
  70     public ListenableFuture<Void> commit() {
  71         try {
  72             dataTree.getDataTree().commit(candidate);
  73         } catch (Exception e) {
  74             LOG.error("Transaction {} failed to commit", transaction, e);
  75             return Futures.immediateFailedFuture(e);
  76         }
  77
  78         LOG.debug("Transaction {} committed, proceeding to notify", transaction);
  79         dataTree.notifyListeners(candidate);
  80         return VOID_FUTURE;
  81     }
  82 }