b9e39975e5c869529a31fa2a56dad6e0c0db9378
[controller.git] / 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.Preconditions;
14 import com.google.common.base.Verify;
15 import com.google.common.primitives.UnsignedLong;
16 import com.google.common.util.concurrent.FutureCallback;
17 import java.util.List;
18 import java.util.Optional;
19 import java.util.concurrent.ExecutionException;
20 import java.util.concurrent.TimeoutException;
21 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
25 import org.slf4j.Logger;
26 import org.slf4j.LoggerFactory;
27 import scala.concurrent.Future;
28
29 abstract class SimpleShardDataTreeCohort extends ShardDataTreeCohort {
30     static final class DeadOnArrival extends SimpleShardDataTreeCohort {
31         private final Exception failure;
32
33         DeadOnArrival(final ShardDataTree dataTree, final DataTreeModification transaction,
34             final TransactionIdentifier transactionId, final Exception failure) {
35             super(dataTree, transaction, transactionId, null);
36             this.failure = Preconditions.checkNotNull(failure);
37         }
38
39         @Override
40         void throwCanCommitFailure() throws Exception {
41             throw failure;
42         }
43     }
44
45     static final class Normal extends SimpleShardDataTreeCohort {
46         Normal(final ShardDataTree dataTree, final DataTreeModification transaction,
47             final TransactionIdentifier transactionId, final CompositeDataTreeCohort userCohorts) {
48             super(dataTree, transaction, transactionId, Preconditions.checkNotNull(userCohorts));
49         }
50
51         @Override
52         void throwCanCommitFailure() {
53             // No-op
54         }
55     }
56
57     private static final Logger LOG = LoggerFactory.getLogger(SimpleShardDataTreeCohort.class);
58
59     private final DataTreeModification transaction;
60     private final ShardDataTree dataTree;
61     private final TransactionIdentifier transactionId;
62     private final CompositeDataTreeCohort userCohorts;
63
64     private State state = State.READY;
65     private DataTreeCandidateTip candidate;
66     private FutureCallback<?> callback;
67     private Exception nextFailure;
68
69     SimpleShardDataTreeCohort(final ShardDataTree dataTree, final DataTreeModification transaction,
70             final TransactionIdentifier transactionId, final CompositeDataTreeCohort userCohorts) {
71         this.dataTree = Preconditions.checkNotNull(dataTree);
72         this.transaction = Preconditions.checkNotNull(transaction);
73         this.transactionId = Preconditions.checkNotNull(transactionId);
74         this.userCohorts = userCohorts;
75     }
76
77     @Override
78     public TransactionIdentifier getIdentifier() {
79         return transactionId;
80     }
81
82     @Override
83     DataTreeCandidateTip getCandidate() {
84         return candidate;
85     }
86
87     @Override
88     DataTreeModification getDataTreeModification() {
89         return transaction;
90     }
91
92     private void checkState(final State expected) {
93         Preconditions.checkState(state == expected, "State %s does not match expected state %s", state, expected);
94     }
95
96     @Override
97     public void canCommit(final FutureCallback<Void> newCallback) {
98         if (state == State.CAN_COMMIT_PENDING) {
99             return;
100         }
101
102         checkState(State.READY);
103         this.callback = Preconditions.checkNotNull(newCallback);
104         state = State.CAN_COMMIT_PENDING;
105         dataTree.startCanCommit(this);
106     }
107
108     @Override
109     public void preCommit(final FutureCallback<DataTreeCandidate> newCallback) {
110         checkState(State.CAN_COMMIT_COMPLETE);
111         this.callback = Preconditions.checkNotNull(newCallback);
112         state = State.PRE_COMMIT_PENDING;
113
114         if (nextFailure == null) {
115             dataTree.startPreCommit(this);
116         } else {
117             failedPreCommit(nextFailure);
118         }
119     }
120
121     @Override
122     public void abort(final FutureCallback<Void> abortCallback) {
123         if (!dataTree.startAbort(this)) {
124             abortCallback.onSuccess(null);
125             return;
126         }
127
128         candidate = null;
129         state = State.ABORTED;
130
131         final Optional<List<Future<Object>>> maybeAborts = userCohorts.abort();
132         if (!maybeAborts.isPresent()) {
133             abortCallback.onSuccess(null);
134             return;
135         }
136
137         final Future<Iterable<Object>> aborts = Futures.sequence(maybeAborts.get(), ExecutionContexts.global());
138         if (aborts.isCompleted()) {
139             abortCallback.onSuccess(null);
140             return;
141         }
142
143         aborts.onComplete(new OnComplete<Iterable<Object>>() {
144             @Override
145             public void onComplete(final Throwable failure, final Iterable<Object> objs) {
146                 if (failure != null) {
147                     abortCallback.onFailure(failure);
148                 } else {
149                     abortCallback.onSuccess(null);
150                 }
151             }
152         }, ExecutionContexts.global());
153     }
154
155     @Override
156     public void commit(final FutureCallback<UnsignedLong> newCallback) {
157         checkState(State.PRE_COMMIT_COMPLETE);
158         this.callback = Preconditions.checkNotNull(newCallback);
159         state = State.COMMIT_PENDING;
160
161         if (nextFailure == null) {
162             dataTree.startCommit(this, candidate);
163         } else {
164             failedCommit(nextFailure);
165         }
166     }
167
168     private <T> FutureCallback<T> switchState(final State newState) {
169         @SuppressWarnings("unchecked")
170         final FutureCallback<T> ret = (FutureCallback<T>) this.callback;
171         this.callback = null;
172         LOG.debug("Transaction {} changing state from {} to {}", transactionId, state, newState);
173         this.state = newState;
174         return ret;
175     }
176
177     void setNewCandidate(final DataTreeCandidateTip dataTreeCandidate) {
178         checkState(State.PRE_COMMIT_COMPLETE);
179         this.candidate = Verify.verifyNotNull(dataTreeCandidate);
180     }
181
182     void successfulCanCommit() {
183         switchState(State.CAN_COMMIT_COMPLETE).onSuccess(null);
184     }
185
186     void failedCanCommit(final Exception cause) {
187         switchState(State.FAILED).onFailure(cause);
188     }
189
190     /**
191      * Run user-defined canCommit and preCommit hooks. We want to run these before we initiate persistence so that
192      * any failure to validate is propagated before we record the transaction.
193      *
194      * @param dataTreeCandidate {@link DataTreeCandidate} under consideration
195      * @throws ExecutionException if the operation fails
196      * @throws TimeoutException if the operation times out
197      */
198     // FIXME: this should be asynchronous
199     void userPreCommit(final DataTreeCandidate dataTreeCandidate) throws ExecutionException, TimeoutException {
200         userCohorts.reset();
201         userCohorts.canCommit(dataTreeCandidate);
202         userCohorts.preCommit();
203     }
204
205     void successfulPreCommit(final DataTreeCandidateTip dataTreeCandidate) {
206         LOG.trace("Transaction {} prepared candidate {}", transaction, dataTreeCandidate);
207         this.candidate = Verify.verifyNotNull(dataTreeCandidate);
208         switchState(State.PRE_COMMIT_COMPLETE).onSuccess(dataTreeCandidate);
209     }
210
211     void failedPreCommit(final Exception cause) {
212         if (LOG.isTraceEnabled()) {
213             LOG.trace("Transaction {} failed to prepare", transaction, cause);
214         } else {
215             LOG.error("Transaction {} failed to prepare", transactionId, cause);
216         }
217
218         userCohorts.abort();
219         switchState(State.FAILED).onFailure(cause);
220     }
221
222     void successfulCommit(final UnsignedLong journalIndex) {
223         try {
224             userCohorts.commit();
225         } catch (TimeoutException | ExecutionException e) {
226             // We are probably dead, depending on what the cohorts end up doing
227             LOG.error("User cohorts failed to commit", e);
228         }
229
230         switchState(State.COMMITTED).onSuccess(journalIndex);
231     }
232
233     void failedCommit(final Exception cause) {
234         if (LOG.isTraceEnabled()) {
235             LOG.trace("Transaction {} failed to commit", transaction, cause);
236         } else {
237             LOG.error("Transaction failed to commit", cause);
238         }
239
240         userCohorts.abort();
241         switchState(State.FAILED).onFailure(cause);
242     }
243
244     @Override
245     public State getState() {
246         return state;
247     }
248
249     void reportFailure(final Exception cause) {
250         this.nextFailure = Preconditions.checkNotNull(cause);
251     }
252
253     /**
254      * If there is an initial failure, throw it so the caller can process it.
255      *
256      * @throws Exception reported failure.
257      */
258     abstract void throwCanCommitFailure() throws Exception;
259
260     @Override
261     public boolean isFailed() {
262         return state == State.FAILED || nextFailure != null;
263     }
264 }

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