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