opendaylight/md-sal/sal-inmemory-datastore/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/InMemoryDOMStoreThreePhaseCommitCohort.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
   9 package org.opendaylight.controller.md.sal.dom.store.impl;
  10
  11 import static com.google.common.base.Preconditions.checkState;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
  16 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  17 import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
  18 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  19 import org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 class InMemoryDOMStoreThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
  28     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMStoreThreePhaseCommitCohort.class);
  29     private static final ListenableFuture<Void> SUCCESSFUL_FUTURE = Futures.immediateFuture(null);
  30     private static final ListenableFuture<Boolean> CAN_COMMIT_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  31     private final SnapshotBackedWriteTransaction<String> transaction;
  32     private final DataTreeModification modification;
  33     private final InMemoryDOMDataStore store;
  34     private DataTreeCandidate candidate;
  35
  36     public InMemoryDOMStoreThreePhaseCommitCohort(final InMemoryDOMDataStore store, final SnapshotBackedWriteTransaction<String> writeTransaction, final DataTreeModification modification) {
  37         this.transaction = Preconditions.checkNotNull(writeTransaction);
  38         this.modification = Preconditions.checkNotNull(modification);
  39         this.store = Preconditions.checkNotNull(store);
  40     }
  41
  42     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
  43         final Throwable ctx = transaction.getDebugContext();
  44         if (ctx != null) {
  45             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
  46         }
  47     }
  48
  49     @Override
  50     public final ListenableFuture<Boolean> canCommit() {
  51         try {
  52             store.validate(modification);
  53             LOG.debug("Store Transaction: {} can be committed", getTransaction().getIdentifier());
  54             return CAN_COMMIT_FUTURE;
  55         } catch (ConflictingModificationAppliedException e) {
  56             LOG.warn("Store Tx: {} Conflicting modification for {}.", getTransaction().getIdentifier(),
  57                     e.getPath());
  58             warnDebugContext(getTransaction());
  59             return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
  60         } catch (DataValidationFailedException e) {
  61             LOG.warn("Store Tx: {} Data Precondition failed for {}.", getTransaction().getIdentifier(),
  62                     e.getPath(), e);
  63             warnDebugContext(getTransaction());
  64
  65             // For debugging purposes, allow dumping of the modification. Coupled with the above
  66             // precondition log, it should allow us to understand what went on.
  67             LOG.trace("Store Tx: {} modifications: {} tree: {}", modification, store);
  68
  69             return Futures.immediateFailedFuture(new TransactionCommitFailedException("Data did not pass validation.", e));
  70         } catch (Exception e) {
  71             LOG.warn("Unexpected failure in validation phase", e);
  72             return Futures.immediateFailedFuture(e);
  73         }
  74     }
  75
  76     @Override
  77     public final ListenableFuture<Void> preCommit() {
  78         try {
  79             candidate = store.prepare(modification);
  80             return SUCCESSFUL_FUTURE;
  81         } catch (Exception e) {
  82             LOG.warn("Unexpected failure in pre-commit phase", e);
  83             return Futures.immediateFailedFuture(e);
  84         }
  85     }
  86
  87     @Override
  88     public final ListenableFuture<Void> abort() {
  89         candidate = null;
  90         return SUCCESSFUL_FUTURE;
  91     }
  92
  93     protected final SnapshotBackedWriteTransaction<String> getTransaction() {
  94         return transaction;
  95     }
  96
  97     @Override
  98     public ListenableFuture<Void> commit() {
  99         checkState(candidate != null, "Proposed subtree must be computed");
 100
 101         /*
 102          * The commit has to occur atomically with regard to listener
 103          * registrations.
 104          */
 105         store.commit(candidate);
 106         return SUCCESSFUL_FUTURE;
 107     }
 108 }
 109