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.Futures;
  12 import akka.dispatch.OnComplete;
  13 import com.google.common.base.MoreObjects.ToStringHelper;
  14 import com.google.common.base.Preconditions;
  15 import com.google.common.base.Verify;
  16 import com.google.common.primitives.UnsignedLong;
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import java.util.List;
  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.yang.data.api.schema.tree.DataTreeCandidate;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  25 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28 import scala.concurrent.Future;
  29
  30 abstract class SimpleShardDataTreeCohort extends ShardDataTreeCohort {
  31     static final class DeadOnArrival extends SimpleShardDataTreeCohort {
  32         private final Exception failure;
  33
  34         DeadOnArrival(final ShardDataTree dataTree, final DataTreeModification transaction,
  35             final TransactionIdentifier transactionId, final Exception failure) {
  36             super(dataTree, transaction, transactionId, null);
  37             this.failure = Preconditions.checkNotNull(failure);
  38         }
  39
  40         @Override
  41         void throwCanCommitFailure() throws Exception {
  42             throw failure;
  43         }
  44
  45         @Override
  46         ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
  47             return super.addToStringAttributes(toStringHelper).add("failure", failure);
  48         }
  49     }
  50
  51     static final class Normal extends SimpleShardDataTreeCohort {
  52         Normal(final ShardDataTree dataTree, final DataTreeModification transaction,
  53             final TransactionIdentifier transactionId, final CompositeDataTreeCohort userCohorts) {
  54             super(dataTree, transaction, transactionId, Preconditions.checkNotNull(userCohorts));
  55         }
  56
  57         @Override
  58         void throwCanCommitFailure() {
  59             // No-op
  60         }
  61     }
  62
  63     private static final Logger LOG = LoggerFactory.getLogger(SimpleShardDataTreeCohort.class);
  64
  65     private final DataTreeModification transaction;
  66     private final ShardDataTree dataTree;
  67     private final TransactionIdentifier transactionId;
  68     private final CompositeDataTreeCohort userCohorts;
  69
  70     private State state = State.READY;
  71     private DataTreeCandidateTip candidate;
  72     private FutureCallback<?> callback;
  73     private Exception nextFailure;
  74
  75     SimpleShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction,
  76             final TransactionIdentifier transactionId, final CompositeDataTreeCohort userCohorts) {
  77         this.dataTree = Preconditions.checkNotNull(dataTree);
  78         this.transaction = Preconditions.checkNotNull(transaction);
  79         this.transactionId = Preconditions.checkNotNull(transactionId);
  80         this.userCohorts = userCohorts;
  81     }
  82
  83     @Override
  84     public TransactionIdentifier getIdentifier() {
  85         return transactionId;
  86     }
  87
  88     @Override
  89     DataTreeCandidateTip getCandidate() {
  90         return candidate;
  91     }
  92
  93     @Override
  94     DataTreeModification getDataTreeModification() {
  95         return transaction;
  96     }
  97
  98     private void checkState(final State expected) {
  99         Preconditions.checkState(state == expected, "State %s does not match expected state %s", state, expected);
 100     }
 101
 102     @Override
 103     public void canCommit(final FutureCallback<Void> newCallback) {
 104         if (state == State.CAN_COMMIT_PENDING) {
 105             return;
 106         }
 107
 108         checkState(State.READY);
 109         this.callback = Preconditions.checkNotNull(newCallback);
 110         state = State.CAN_COMMIT_PENDING;
 111
 112         if (nextFailure == null) {
 113             dataTree.startCanCommit(this);
 114         } else {
 115             failedCanCommit(nextFailure);
 116         }
 117     }
 118
 119     @Override
 120     public void preCommit(final FutureCallback<DataTreeCandidate> newCallback) {
 121         checkState(State.CAN_COMMIT_COMPLETE);
 122         this.callback = Preconditions.checkNotNull(newCallback);
 123         state = State.PRE_COMMIT_PENDING;
 124
 125         if (nextFailure == null) {
 126             dataTree.startPreCommit(this);
 127         } else {
 128             failedPreCommit(nextFailure);
 129         }
 130     }
 131
 132     @Override
 133     public void abort(final FutureCallback<Void> abortCallback) {
 134         if (!dataTree.startAbort(this)) {
 135             abortCallback.onSuccess(null);
 136             return;
 137         }
 138
 139         candidate = null;
 140         state = State.ABORTED;
 141
 142         final Optional<List<Future<Object>>> maybeAborts = userCohorts.abort();
 143         if (!maybeAborts.isPresent()) {
 144             abortCallback.onSuccess(null);
 145             return;
 146         }
 147
 148         final Future<Iterable<Object>> aborts = Futures.sequence(maybeAborts.get(), ExecutionContexts.global());
 149         if (aborts.isCompleted()) {
 150             abortCallback.onSuccess(null);
 151             return;
 152         }
 153
 154         aborts.onComplete(new OnComplete<Iterable<Object>>() {
 155             @Override
 156             public void onComplete(final Throwable failure, final Iterable<Object> objs) {
 157                 if (failure != null) {
 158                     abortCallback.onFailure(failure);
 159                 } else {
 160                     abortCallback.onSuccess(null);
 161                 }
 162             }
 163         }, ExecutionContexts.global());
 164     }
 165
 166     @Override
 167     public void commit(final FutureCallback<UnsignedLong> newCallback) {
 168         checkState(State.PRE_COMMIT_COMPLETE);
 169         this.callback = Preconditions.checkNotNull(newCallback);
 170         state = State.COMMIT_PENDING;
 171
 172         if (nextFailure == null) {
 173             dataTree.startCommit(this, candidate);
 174         } else {
 175             failedCommit(nextFailure);
 176         }
 177     }
 178
 179     private <T> FutureCallback<T> switchState(final State newState) {
 180         @SuppressWarnings("unchecked")
 181         final FutureCallback<T> ret = (FutureCallback<T>) this.callback;
 182         this.callback = null;
 183         LOG.debug("Transaction {} changing state from {} to {}", transactionId, state, newState);
 184         this.state = newState;
 185         return ret;
 186     }
 187
 188     void setNewCandidate(final DataTreeCandidateTip dataTreeCandidate) {
 189         checkState(State.PRE_COMMIT_COMPLETE);
 190         this.candidate = Verify.verifyNotNull(dataTreeCandidate);
 191     }
 192
 193     void successfulCanCommit() {
 194         switchState(State.CAN_COMMIT_COMPLETE).onSuccess(null);
 195     }
 196
 197     void failedCanCommit(final Exception cause) {
 198         switchState(State.FAILED).onFailure(cause);
 199     }
 200
 201     /**
 202      * Run user-defined canCommit and preCommit hooks. We want to run these before we initiate persistence so that
 203      * any failure to validate is propagated before we record the transaction.
 204      *
 205      * @param dataTreeCandidate {@link DataTreeCandidate} under consideration
 206      * @throws ExecutionException if the operation fails
 207      * @throws TimeoutException if the operation times out
 208      */
 209     // FIXME: this should be asynchronous
 210     void userPreCommit(final DataTreeCandidate dataTreeCandidate) throws ExecutionException, TimeoutException {
 211         userCohorts.reset();
 212         userCohorts.canCommit(dataTreeCandidate);
 213         userCohorts.preCommit();
 214     }
 215
 216     void successfulPreCommit(final DataTreeCandidateTip dataTreeCandidate) {
 217         LOG.trace("Transaction {} prepared candidate {}", transaction, dataTreeCandidate);
 218         this.candidate = Verify.verifyNotNull(dataTreeCandidate);
 219         switchState(State.PRE_COMMIT_COMPLETE).onSuccess(dataTreeCandidate);
 220     }
 221
 222     void failedPreCommit(final Exception cause) {
 223         if (LOG.isTraceEnabled()) {
 224             LOG.trace("Transaction {} failed to prepare", transaction, cause);
 225         } else {
 226             LOG.error("Transaction {} failed to prepare", transactionId, cause);
 227         }
 228
 229         userCohorts.abort();
 230         switchState(State.FAILED).onFailure(cause);
 231     }
 232
 233     void successfulCommit(final UnsignedLong journalIndex) {
 234         try {
 235             userCohorts.commit();
 236         } catch (TimeoutException | ExecutionException e) {
 237             // We are probably dead, depending on what the cohorts end up doing
 238             LOG.error("User cohorts failed to commit", e);
 239         }
 240
 241         switchState(State.COMMITTED).onSuccess(journalIndex);
 242     }
 243
 244     void failedCommit(final Exception cause) {
 245         if (LOG.isTraceEnabled()) {
 246             LOG.trace("Transaction {} failed to commit", transaction, cause);
 247         } else {
 248             LOG.error("Transaction failed to commit", cause);
 249         }
 250
 251         userCohorts.abort();
 252         switchState(State.FAILED).onFailure(cause);
 253     }
 254
 255     @Override
 256     public State getState() {
 257         return state;
 258     }
 259
 260     void reportFailure(final Exception cause) {
 261         this.nextFailure = Preconditions.checkNotNull(cause);
 262     }
 263
 264     /**
 265      * If there is an initial failure, throw it so the caller can process it.
 266      *
 267      * @throws Exception reported failure.
 268      */
 269     abstract void throwCanCommitFailure() throws Exception;
 270
 271     @Override
 272     public boolean isFailed() {
 273         return state == State.FAILED || nextFailure != null;
 274     }
 275
 276     @Override
 277     ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 278         return super.addToStringAttributes(toStringHelper).add("nextFailure", nextFailure);
 279     }
 280 }