opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTreeCohort.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.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  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 ShardDataTreeCohort implements DOMStoreThreePhaseCommitCohort {
  20     private static final Logger LOG = LoggerFactory.getLogger(ShardDataTreeCohort.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     ShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction) {
  28         this.dataTree = Preconditions.checkNotNull(dataTree);
  29         this.transaction = Preconditions.checkNotNull(transaction);
  30     }
  31
  32     @Override
  33     public ListenableFuture<Boolean> canCommit() {
  34         try {
  35             dataTree.getDataTree().validate(transaction);
  36             LOG.debug("Transaction {} validated", transaction);
  37             return TRUE_FUTURE;
  38         } catch (Exception e) {
  39             return Futures.immediateFailedFuture(e);
  40         }
  41     }
  42
  43     @Override
  44     public ListenableFuture<Void> preCommit() {
  45         try {
  46             candidate = dataTree.getDataTree().prepare(transaction);
  47             /*
  48              * FIXME: this is the place where we should be interacting with persistence, specifically by invoking
  49              *        persist on the candidate (which gives us a Future).
  50              */
  51             LOG.debug("Transaction {} prepared candidate {}", transaction, candidate);
  52             return VOID_FUTURE;
  53         } catch (Exception e) {
  54             LOG.debug("Transaction {} failed to prepare", transaction, e);
  55             return Futures.immediateFailedFuture(e);
  56         }
  57     }
  58
  59     @Override
  60     public ListenableFuture<Void> abort() {
  61         // No-op, really
  62         return VOID_FUTURE;
  63     }
  64
  65     @Override
  66     public ListenableFuture<Void> commit() {
  67         try {
  68             dataTree.getDataTree().commit(candidate);
  69         } catch (Exception e) {
  70             LOG.error("Transaction {} failed to commit", transaction, e);
  71             return Futures.immediateFailedFuture(e);
  72         }
  73
  74         LOG.debug("Transaction {} committed, proceeding to notify", transaction);
  75         dataTree.notifyListeners(candidate);
  76         return VOID_FUTURE;
  77     }
  78 }