dom/mdsal-dom-inmemory-datastore/src/main/java/org/opendaylight/mdsal/dom/store/inmemory/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.mdsal.dom.store.inmemory;
  10
  11 import static com.google.common.base.Preconditions.checkState;
  12
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.util.concurrent.Futures;
  15 import com.google.common.util.concurrent.ListenableFuture;
  16 import org.opendaylight.mdsal.common.api.OptimisticLockFailedException;
  17 import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
  18 import org.opendaylight.mdsal.dom.spi.store.AbstractDOMStoreTransaction;
  19 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  20 import org.opendaylight.mdsal.dom.spi.store.SnapshotBackedWriteTransaction;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 class InMemoryDOMStoreThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
  29     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMStoreThreePhaseCommitCohort.class);
  30     private static final ListenableFuture<Void> SUCCESSFUL_FUTURE = Futures.immediateFuture(null);
  31     private static final ListenableFuture<Boolean> CAN_COMMIT_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  32     private final SnapshotBackedWriteTransaction<String> transaction;
  33     private final DataTreeModification modification;
  34     private final InMemoryDOMDataStore store;
  35     private DataTreeCandidate candidate;
  36
  37     InMemoryDOMStoreThreePhaseCommitCohort(final InMemoryDOMDataStore store,
  38             final SnapshotBackedWriteTransaction<String> writeTransaction, final DataTreeModification modification) {
  39         this.transaction = Preconditions.checkNotNull(writeTransaction);
  40         this.modification = Preconditions.checkNotNull(modification);
  41         this.store = Preconditions.checkNotNull(store);
  42     }
  43
  44     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
  45         final Throwable ctx = transaction.getDebugContext();
  46         if (ctx != null) {
  47             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
  48         }
  49     }
  50
  51     @SuppressWarnings("checkstyle:IllegalCatch")
  52     @Override
  53     public final ListenableFuture<Boolean> canCommit() {
  54         try {
  55             store.validate(modification);
  56             LOG.debug("Store Transaction: {} can be committed", getTransaction().getIdentifier());
  57             return CAN_COMMIT_FUTURE;
  58         } catch (ConflictingModificationAppliedException e) {
  59             LOG.warn("Store Tx: {} Conflicting modification for {}.", getTransaction().getIdentifier(),
  60                     e.getPath());
  61             warnDebugContext(getTransaction());
  62             return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
  63         } catch (DataValidationFailedException e) {
  64             LOG.warn("Store Tx: {} Data Precondition failed for {}.", getTransaction().getIdentifier(),
  65                     e.getPath(), e);
  66             warnDebugContext(getTransaction());
  67
  68             // For debugging purposes, allow dumping of the modification. Coupled with the above
  69             // precondition log, it should allow us to understand what went on.
  70             LOG.trace("Store Tx: {} modifications: {} tree: {}", getTransaction().getIdentifier(),
  71                     modification, store);
  72
  73             return Futures.immediateFailedFuture(
  74                     new TransactionCommitFailedException("Data did not pass validation.", e));
  75         } catch (Exception e) {
  76             LOG.warn("Unexpected failure in validation phase", e);
  77             return Futures.immediateFailedFuture(e);
  78         }
  79     }
  80
  81     @SuppressWarnings("checkstyle:IllegalCatch")
  82     @Override
  83     public final ListenableFuture<Void> preCommit() {
  84         try {
  85             candidate = store.prepare(modification);
  86             return SUCCESSFUL_FUTURE;
  87         } catch (Exception e) {
  88             LOG.warn("Unexpected failure in pre-commit phase", e);
  89             return Futures.immediateFailedFuture(e);
  90         }
  91     }
  92
  93     @Override
  94     public final ListenableFuture<Void> abort() {
  95         candidate = null;
  96         return SUCCESSFUL_FUTURE;
  97     }
  98
  99     protected final SnapshotBackedWriteTransaction<String> getTransaction() {
 100         return transaction;
 101     }
 102
 103     @Override
 104     public ListenableFuture<Void> commit() {
 105         checkState(candidate != null, "Proposed subtree must be computed");
 106
 107         /*
 108          * The commit has to occur atomically with regard to listener
 109          * registrations.
 110          */
 111         store.commit(candidate);
 112         return SUCCESSFUL_FUTURE;
 113     }
 114 }
 115