opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/SimpleShardDataTreeCohort.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 package org.opendaylight.controller.cluster.datastore;
   9
  10 import akka.dispatch.ExecutionContexts;
  11 import akka.dispatch.OnComplete;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.base.Verify;
  14 import com.google.common.primitives.UnsignedLong;
  15 import com.google.common.util.concurrent.FutureCallback;
  16 import com.google.common.util.concurrent.Futures;
  17 import com.google.common.util.concurrent.ListenableFuture;
  18 import com.google.common.util.concurrent.SettableFuture;
  19 import java.util.Optional;
  20 import java.util.concurrent.ExecutionException;
  21 import java.util.concurrent.TimeoutException;
  22 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  23 import org.opendaylight.yangtools.concepts.Identifiable;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  25 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  26 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29 import scala.concurrent.Future;
  30
  31 final class SimpleShardDataTreeCohort extends ShardDataTreeCohort implements Identifiable<TransactionIdentifier> {
  32     private static final Logger LOG = LoggerFactory.getLogger(SimpleShardDataTreeCohort.class);
  33     private static final ListenableFuture<Void> VOID_FUTURE = Futures.immediateFuture(null);
  34     private final DataTreeModification transaction;
  35     private final ShardDataTree dataTree;
  36     private final TransactionIdentifier transactionId;
  37     private final CompositeDataTreeCohort userCohorts;
  38
  39     private State state = State.READY;
  40     private DataTreeCandidateTip candidate;
  41     private FutureCallback<?> callback;
  42     private Exception nextFailure;
  43
  44     SimpleShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction,
  45             final TransactionIdentifier transactionId, final CompositeDataTreeCohort userCohorts) {
  46         this.dataTree = Preconditions.checkNotNull(dataTree);
  47         this.transaction = Preconditions.checkNotNull(transaction);
  48         this.transactionId = Preconditions.checkNotNull(transactionId);
  49         this.userCohorts = Preconditions.checkNotNull(userCohorts);
  50     }
  51
  52     @Override
  53     public TransactionIdentifier getIdentifier() {
  54         return transactionId;
  55     }
  56
  57     @Override
  58     DataTreeCandidateTip getCandidate() {
  59         return candidate;
  60     }
  61
  62     @Override
  63
  64     DataTreeModification getDataTreeModification() {
  65         return transaction;
  66     }
  67
  68     private void checkState(final State expected) {
  69         Preconditions.checkState(state == expected, "State %s does not match expected state %s", state, expected);
  70     }
  71
  72     @Override
  73     public void canCommit(final FutureCallback<Void> newCallback) {
  74         if (state == State.CAN_COMMIT_PENDING) {
  75             return;
  76         }
  77
  78         checkState(State.READY);
  79         this.callback = Preconditions.checkNotNull(newCallback);
  80         state = State.CAN_COMMIT_PENDING;
  81         dataTree.startCanCommit(this);
  82     }
  83
  84     @Override
  85     public void preCommit(final FutureCallback<DataTreeCandidate> newCallback) {
  86         checkState(State.CAN_COMMIT_COMPLETE);
  87         this.callback = Preconditions.checkNotNull(newCallback);
  88         state = State.PRE_COMMIT_PENDING;
  89
  90         if (nextFailure == null) {
  91             dataTree.startPreCommit(this);
  92         } else {
  93             failedPreCommit(nextFailure);
  94         }
  95     }
  96
  97     @Override
  98     public ListenableFuture<Void> abort() {
  99         dataTree.startAbort(this);
 100         state = State.ABORTED;
 101
 102         final Optional<Future<Iterable<Object>>> maybeAborts = userCohorts.abort();
 103         if (!maybeAborts.isPresent()) {
 104             return VOID_FUTURE;
 105         }
 106
 107         final Future<Iterable<Object>> aborts = maybeAborts.get();
 108         if (aborts.isCompleted()) {
 109             return VOID_FUTURE;
 110         }
 111
 112         final SettableFuture<Void> ret = SettableFuture.create();
 113         aborts.onComplete(new OnComplete<Iterable<Object>>() {
 114             @Override
 115             public void onComplete(final Throwable failure, final Iterable<Object> objs) {
 116                 if (failure != null) {
 117                     ret.setException(failure);
 118                 } else {
 119                     ret.set(null);
 120                 }
 121             }
 122         }, ExecutionContexts.global());
 123
 124         return ret;
 125     }
 126
 127     @Override
 128     public void commit(final FutureCallback<UnsignedLong> newCallback) {
 129         checkState(State.PRE_COMMIT_COMPLETE);
 130         this.callback = Preconditions.checkNotNull(newCallback);
 131         state = State.COMMIT_PENDING;
 132         dataTree.startCommit(this, candidate);
 133     }
 134
 135     private <T> FutureCallback<T> switchState(final State newState) {
 136         @SuppressWarnings("unchecked")
 137         final FutureCallback<T> ret = (FutureCallback<T>) this.callback;
 138         this.callback = null;
 139         LOG.debug("Transaction {} changing state from {} to {}", transactionId, state, newState);
 140         this.state = newState;
 141         return ret;
 142     }
 143
 144     void successfulCanCommit() {
 145         switchState(State.CAN_COMMIT_COMPLETE).onSuccess(null);
 146     }
 147
 148     void failedCanCommit(final Exception cause) {
 149         switchState(State.FAILED).onFailure(cause);
 150     }
 151
 152     /**
 153      * Run user-defined canCommit and preCommit hooks. We want to run these before we initiate persistence so that
 154      * any failure to validate is propagated before we record the transaction.
 155      *
 156      * @param dataTreeCandidate {@link DataTreeCandidate} under consideration
 157      * @throws ExecutionException if the operation fails
 158      * @throws TimeoutException if the operation times out
 159      */
 160     // FIXME: this should be asynchronous
 161     void userPreCommit(final DataTreeCandidate dataTreeCandidate) throws ExecutionException, TimeoutException {
 162         userCohorts.canCommit(dataTreeCandidate);
 163         userCohorts.preCommit();
 164     }
 165
 166     void successfulPreCommit(final DataTreeCandidateTip dataTreeCandidate) {
 167         LOG.trace("Transaction {} prepared candidate {}", transaction, dataTreeCandidate);
 168         this.candidate = Verify.verifyNotNull(dataTreeCandidate);
 169         switchState(State.PRE_COMMIT_COMPLETE).onSuccess(dataTreeCandidate);
 170     }
 171
 172     void failedPreCommit(final Exception cause) {
 173         if (LOG.isTraceEnabled()) {
 174             LOG.trace("Transaction {} failed to prepare", transaction, cause);
 175         } else {
 176             LOG.error("Transaction {} failed to prepare", transactionId, cause);
 177         }
 178
 179         userCohorts.abort();
 180         switchState(State.FAILED).onFailure(cause);
 181     }
 182
 183     void successfulCommit(final UnsignedLong journalIndex) {
 184         try {
 185             userCohorts.commit();
 186         } catch (TimeoutException | ExecutionException e) {
 187             // We are probably dead, depending on what the cohorts end up doing
 188             LOG.error("User cohorts failed to commit", e);
 189         }
 190
 191         switchState(State.COMMITTED).onSuccess(journalIndex);
 192     }
 193
 194     void failedCommit(final Exception cause) {
 195         if (LOG.isTraceEnabled()) {
 196             LOG.trace("Transaction {} failed to commit", transaction, cause);
 197         } else {
 198             LOG.error("Transaction failed to commit", cause);
 199         }
 200
 201         userCohorts.abort();
 202         switchState(State.FAILED).onFailure(cause);
 203     }
 204
 205     @Override
 206     public State getState() {
 207         return state;
 208     }
 209
 210     void reportFailure(final Exception cause) {
 211         this.nextFailure = Preconditions.checkNotNull(cause);
 212     }
 213
 214     @Override
 215     public boolean isFailed() {
 216         return state == State.FAILED || nextFailure != null;
 217     }
 218 }