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 edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  16 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
  17 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  18 import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
  19 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  20 import org.opendaylight.controller.sal.core.spi.data.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 @SuppressFBWarnings(value = "NP_NONNULL_PARAM_VIOLATION", justification = "Void is the only allowed value")
  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     private final Exception operationError;
  38
  39     public InMemoryDOMStoreThreePhaseCommitCohort(final InMemoryDOMDataStore store,
  40                                                   final SnapshotBackedWriteTransaction<String> writeTransaction,
  41                                                   final DataTreeModification modification,
  42                                                   final Exception operationError) {
  43         this.transaction = Preconditions.checkNotNull(writeTransaction);
  44         this.modification = Preconditions.checkNotNull(modification);
  45         this.store = Preconditions.checkNotNull(store);
  46         this.operationError = operationError;
  47     }
  48
  49     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
  50         final Throwable ctx = transaction.getDebugContext();
  51         if (ctx != null) {
  52             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
  53         }
  54     }
  55
  56     @Override
  57     public final ListenableFuture<Boolean> canCommit() {
  58         if (operationError != null) {
  59             return Futures.immediateFailedFuture(operationError);
  60         }
  61
  62         try {
  63             store.validate(modification);
  64             LOG.debug("Store Transaction: {} can be committed", getTransaction().getIdentifier());
  65             return CAN_COMMIT_FUTURE;
  66         } catch (ConflictingModificationAppliedException e) {
  67             LOG.warn("Store Tx: {} Conflicting modification for {}.", getTransaction().getIdentifier(),
  68                     e.getPath());
  69             warnDebugContext(getTransaction());
  70             return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
  71         } catch (DataValidationFailedException e) {
  72             LOG.warn("Store Tx: {} Data Precondition failed for {}.", getTransaction().getIdentifier(),
  73                     e.getPath(), e);
  74             warnDebugContext(getTransaction());
  75
  76             // For debugging purposes, allow dumping of the modification. Coupled with the above
  77             // precondition log, it should allow us to understand what went on.
  78             LOG.trace("Store Tx: {} modifications: {} tree: {}", modification, store);
  79
  80             return Futures.immediateFailedFuture(new TransactionCommitFailedException("Data did not pass validation.", e));
  81         } catch (Exception e) {
  82             LOG.warn("Unexpected failure in validation phase", e);
  83             return Futures.immediateFailedFuture(e);
  84         }
  85     }
  86
  87     @Override
  88     public final ListenableFuture<Void> preCommit() {
  89         try {
  90             candidate = store.prepare(modification);
  91             return SUCCESSFUL_FUTURE;
  92         } catch (Exception e) {
  93             LOG.warn("Unexpected failure in pre-commit phase", e);
  94             return Futures.immediateFailedFuture(e);
  95         }
  96     }
  97
  98     @Override
  99     public final ListenableFuture<Void> abort() {
 100         candidate = null;
 101         return SUCCESSFUL_FUTURE;
 102     }
 103
 104     protected final SnapshotBackedWriteTransaction<String> getTransaction() {
 105         return transaction;
 106     }
 107
 108     @Override
 109     public ListenableFuture<Void> commit() {
 110         checkState(candidate != null, "Proposed subtree must be computed");
 111
 112         /*
 113          * The commit has to occur atomically with regard to listener
 114          * registrations.
 115          */
 116         store.commit(candidate);
 117         return SUCCESSFUL_FUTURE;
 118     }
 119 }
 120