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     private final Exception operationError;
  36
  37     public InMemoryDOMStoreThreePhaseCommitCohort(final InMemoryDOMDataStore store,
  38                                                   final SnapshotBackedWriteTransaction<String> writeTransaction,
  39                                                   final DataTreeModification modification,
  40                                                   final Exception operationError) {
  41         this.transaction = Preconditions.checkNotNull(writeTransaction);
  42         this.modification = Preconditions.checkNotNull(modification);
  43         this.store = Preconditions.checkNotNull(store);
  44         this.operationError = operationError;
  45     }
  46
  47     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
  48         final Throwable ctx = transaction.getDebugContext();
  49         if (ctx != null) {
  50             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
  51         }
  52     }
  53
  54     @Override
  55     public final ListenableFuture<Boolean> canCommit() {
  56         if (operationError != null) {
  57             return Futures.immediateFailedFuture(operationError);
  58         }
  59
  60         try {
  61             store.validate(modification);
  62             LOG.debug("Store Transaction: {} can be committed", getTransaction().getIdentifier());
  63             return CAN_COMMIT_FUTURE;
  64         } catch (ConflictingModificationAppliedException e) {
  65             LOG.warn("Store Tx: {} Conflicting modification for {}.", getTransaction().getIdentifier(),
  66                     e.getPath());
  67             warnDebugContext(getTransaction());
  68             return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
  69         } catch (DataValidationFailedException e) {
  70             LOG.warn("Store Tx: {} Data Precondition failed for {}.", getTransaction().getIdentifier(),
  71                     e.getPath(), e);
  72             warnDebugContext(getTransaction());
  73
  74             // For debugging purposes, allow dumping of the modification. Coupled with the above
  75             // precondition log, it should allow us to understand what went on.
  76             LOG.trace("Store Tx: {} modifications: {} tree: {}", modification, store);
  77
  78             return Futures.immediateFailedFuture(new TransactionCommitFailedException("Data did not pass validation.", e));
  79         } catch (Exception e) {
  80             LOG.warn("Unexpected failure in validation phase", e);
  81             return Futures.immediateFailedFuture(e);
  82         }
  83     }
  84
  85     @Override
  86     public final ListenableFuture<Void> preCommit() {
  87         try {
  88             candidate = store.prepare(modification);
  89             return SUCCESSFUL_FUTURE;
  90         } catch (Exception e) {
  91             LOG.warn("Unexpected failure in pre-commit phase", e);
  92             return Futures.immediateFailedFuture(e);
  93         }
  94     }
  95
  96     @Override
  97     public final ListenableFuture<Void> abort() {
  98         candidate = null;
  99         return SUCCESSFUL_FUTURE;
 100     }
 101
 102     protected final SnapshotBackedWriteTransaction<String> getTransaction() {
 103         return transaction;
 104     }
 105
 106     @Override
 107     public ListenableFuture<Void> commit() {
 108         checkState(candidate != null, "Proposed subtree must be computed");
 109
 110         /*
 111          * The commit has to occur atomically with regard to listener
 112          * registrations.
 113          */
 114         store.commit(candidate);
 115         return SUCCESSFUL_FUTURE;
 116     }
 117 }
 118