opendaylight/md-sal/sal-inmemory-datastore/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/InMemoryDOMStoreThreePhaseCommitCohort.java

   1 package org.opendaylight.controller.md.sal.dom.store.impl;
   2
   3 import static com.google.common.base.Preconditions.checkState;
   4 import com.google.common.base.Preconditions;
   5 import com.google.common.util.concurrent.Futures;
   6 import com.google.common.util.concurrent.ListenableFuture;
   7 import org.opendaylight.controller.md.sal.common.api.data.OptimisticLockFailedException;
   8 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
   9 import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
  10 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  11 import org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction;
  12 import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException;
  13 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  14 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  15 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  16 import org.slf4j.Logger;
  17 import org.slf4j.LoggerFactory;
  18
  19 class InMemoryDOMStoreThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
  20     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMStoreThreePhaseCommitCohort.class);
  21     private static final ListenableFuture<Void> SUCCESSFUL_FUTURE = Futures.immediateFuture(null);
  22     private static final ListenableFuture<Boolean> CAN_COMMIT_FUTURE = Futures.immediateFuture(Boolean.TRUE);
  23     private final SnapshotBackedWriteTransaction<String> transaction;
  24     private final DataTreeModification modification;
  25     private final InMemoryDOMDataStore store;
  26     private DataTreeCandidate candidate;
  27
  28     public InMemoryDOMStoreThreePhaseCommitCohort(final InMemoryDOMDataStore store, final SnapshotBackedWriteTransaction<String> writeTransaction, final DataTreeModification modification) {
  29         this.transaction = Preconditions.checkNotNull(writeTransaction);
  30         this.modification = Preconditions.checkNotNull(modification);
  31         this.store = Preconditions.checkNotNull(store);
  32     }
  33
  34     private static void warnDebugContext(final AbstractDOMStoreTransaction<?> transaction) {
  35         final Throwable ctx = transaction.getDebugContext();
  36         if (ctx != null) {
  37             LOG.warn("Transaction {} has been allocated in the following context", transaction.getIdentifier(), ctx);
  38         }
  39     }
  40
  41     @Override
  42     public final ListenableFuture<Boolean> canCommit() {
  43         try {
  44             store.validate(modification);
  45             LOG.debug("Store Transaction: {} can be committed", getTransaction().getIdentifier());
  46             return CAN_COMMIT_FUTURE;
  47         } catch (ConflictingModificationAppliedException e) {
  48             LOG.warn("Store Tx: {} Conflicting modification for {}.", getTransaction().getIdentifier(),
  49                     e.getPath());
  50             warnDebugContext(getTransaction());
  51             return Futures.immediateFailedFuture(new OptimisticLockFailedException("Optimistic lock failed.", e));
  52         } catch (DataValidationFailedException e) {
  53             LOG.warn("Store Tx: {} Data Precondition failed for {}.", getTransaction().getIdentifier(),
  54                     e.getPath(), e);
  55             warnDebugContext(getTransaction());
  56
  57             // For debugging purposes, allow dumping of the modification. Coupled with the above
  58             // precondition log, it should allow us to understand what went on.
  59             LOG.trace("Store Tx: {} modifications: {} tree: {}", modification, store);
  60
  61             return Futures.immediateFailedFuture(new TransactionCommitFailedException("Data did not pass validation.", e));
  62         } catch (Exception e) {
  63             LOG.warn("Unexpected failure in validation phase", e);
  64             return Futures.immediateFailedFuture(e);
  65         }
  66     }
  67
  68     @Override
  69     public final ListenableFuture<Void> preCommit() {
  70         try {
  71             candidate = store.prepare(modification);
  72             return SUCCESSFUL_FUTURE;
  73         } catch (Exception e) {
  74             LOG.warn("Unexpected failure in pre-commit phase", e);
  75             return Futures.immediateFailedFuture(e);
  76         }
  77     }
  78
  79     @Override
  80     public final ListenableFuture<Void> abort() {
  81         candidate = null;
  82         return SUCCESSFUL_FUTURE;
  83     }
  84
  85     protected final SnapshotBackedWriteTransaction<String> getTransaction() {
  86         return transaction;
  87     }
  88
  89     @Override
  90     public ListenableFuture<Void> commit() {
  91         checkState(candidate != null, "Proposed subtree must be computed");
  92
  93         /*
  94          * The commit has to occur atomically with regard to listener
  95          * registrations.
  96          */
  97         store.commit(candidate);
  98         return SUCCESSFUL_FUTURE;
  99     }
 100 }