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.controller.cluster.datastore.utils.PruningDataTreeModification;
  14 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  15 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  16 import org.slf4j.Logger;
  17 import org.slf4j.LoggerFactory;
  18
  19 final class SimpleShardDataTreeCohort extends ShardDataTreeCohort {
  20     private static final Logger LOG = LoggerFactory.getLogger(SimpleShardDataTreeCohort.class);
  21     private static final ListenableFuture<Boolean> TRUE_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  22     private static final ListenableFuture<Void> VOID_FUTURE = Futures.immediateFuture(null);
  23     private final DataTreeModification transaction;
  24     private final ShardDataTree dataTree;
  25     private DataTreeCandidateTip candidate;
  26
  27     SimpleShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction) {
  28         this.dataTree = Preconditions.checkNotNull(dataTree);
  29         this.transaction = Preconditions.checkNotNull(transaction);
  30     }
  31
  32     @Override
  33     DataTreeCandidateTip getCandidate() {
  34         return candidate;
  35     }
  36
  37     @Override
  38     public ListenableFuture<Boolean> canCommit() {
  39         try {
  40             dataTree.getDataTree().validate(dataTreeModification());
  41             LOG.trace("Transaction {} validated", transaction);
  42             return TRUE_FUTURE;
  43         } catch (Exception e) {
  44             return Futures.immediateFailedFuture(e);
  45         }
  46     }
  47
  48     @Override
  49     public ListenableFuture<Void> preCommit() {
  50         try {
  51             candidate = dataTree.getDataTree().prepare(dataTreeModification());
  52             /*
  53              * FIXME: this is the place where we should be interacting with persistence, specifically by invoking
  54              *        persist on the candidate (which gives us a Future).
  55              */
  56             LOG.trace("Transaction {} prepared candidate {}", transaction, candidate);
  57             return VOID_FUTURE;
  58         } catch (Exception e) {
  59             LOG.debug("Transaction {} failed to prepare", transaction, e);
  60             return Futures.immediateFailedFuture(e);
  61         }
  62     }
  63
  64     private DataTreeModification dataTreeModification() {
  65         DataTreeModification dataTreeModification = transaction;
  66         if(transaction instanceof PruningDataTreeModification){
  67             dataTreeModification = ((PruningDataTreeModification) transaction).getDelegate();
  68         }
  69         return dataTreeModification;
  70     }
  71
  72     @Override
  73     public ListenableFuture<Void> abort() {
  74         // No-op, really
  75         return VOID_FUTURE;
  76     }
  77
  78     @Override
  79     public ListenableFuture<Void> commit() {
  80         try {
  81             dataTree.getDataTree().commit(candidate);
  82         } catch (Exception e) {
  83             LOG.error("Transaction {} failed to commit", transaction, e);
  84             return Futures.immediateFailedFuture(e);
  85         }
  86
  87         LOG.trace("Transaction {} committed, proceeding to notify", transaction);
  88         dataTree.notifyListeners(candidate);
  89         return VOID_FUTURE;
  90     }
  91 }