1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
* Copyright 2015 Open Networking Laboratory
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.onosproject.store.consistent.impl;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Arrays;
import java.util.Collection;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
import org.onlab.util.KryoNamespace;
import org.onosproject.store.serializers.KryoNamespaces;
import org.onosproject.store.service.AsyncConsistentMap;
import org.onosproject.store.service.ConsistentMapBuilder;
import org.onosproject.store.service.DatabaseUpdate;
import org.onosproject.store.service.Serializer;
import org.onosproject.store.service.Transaction;
import org.onosproject.store.service.Versioned;
import org.onosproject.store.service.Transaction.State;
import com.google.common.collect.ImmutableList;
/**
* Agent that runs the two phase commit protocol.
*/
public class TransactionManager {
private static final KryoNamespace KRYO_NAMESPACE = KryoNamespace.newBuilder()
.register(KryoNamespaces.BASIC)
.nextId(KryoNamespace.FLOATING_ID)
.register(Versioned.class)
.register(DatabaseUpdate.class)
.register(DatabaseUpdate.Type.class)
.register(DefaultTransaction.class)
.register(Transaction.State.class)
.build();
private final Serializer serializer = Serializer.using(Arrays.asList(KRYO_NAMESPACE));
private final Database database;
private final AsyncConsistentMap<Long, Transaction> transactions;
/**
* Constructs a new TransactionManager for the specified database instance.
*
* @param database database
* @param mapBuilder builder for ConsistentMap instances
*/
public TransactionManager(Database database, ConsistentMapBuilder<Long, Transaction> mapBuilder) {
this.database = checkNotNull(database, "database cannot be null");
this.transactions = mapBuilder.withName("onos-transactions")
.withSerializer(serializer)
.buildAsyncMap();
}
/**
* Executes the specified transaction by employing a two phase commit protocol.
*
* @param transaction transaction to commit
* @return transaction result. Result value true indicates a successful commit, false
* indicates abort
*/
public CompletableFuture<CommitResponse> execute(Transaction transaction) {
// clean up if this transaction in already in a terminal state.
if (transaction.state() == Transaction.State.COMMITTED ||
transaction.state() == Transaction.State.ROLLEDBACK) {
return transactions.remove(transaction.id()).thenApply(v -> CommitResponse.success(ImmutableList.of()));
} else if (transaction.state() == Transaction.State.COMMITTING) {
return commit(transaction);
} else if (transaction.state() == Transaction.State.ROLLINGBACK) {
return rollback(transaction).thenApply(v -> CommitResponse.success(ImmutableList.of()));
} else {
return prepare(transaction).thenCompose(v -> v ? commit(transaction) : rollback(transaction));
}
}
/**
* Returns all transactions in the system.
*
* @return future for a collection of transactions
*/
public CompletableFuture<Collection<Transaction>> getTransactions() {
return transactions.values().thenApply(c -> {
Collection<Transaction> txns = c.stream().map(v -> v.value()).collect(Collectors.toList());
return txns;
});
}
private CompletableFuture<Boolean> prepare(Transaction transaction) {
return transactions.put(transaction.id(), transaction)
.thenCompose(v -> database.prepare(transaction))
.thenCompose(status -> transactions.put(
transaction.id(),
transaction.transition(status ? State.COMMITTING : State.ROLLINGBACK))
.thenApply(v -> status));
}
private CompletableFuture<CommitResponse> commit(Transaction transaction) {
return database.commit(transaction)
.whenComplete((r, e) -> transactions.put(
transaction.id(),
transaction.transition(Transaction.State.COMMITTED)));
}
private CompletableFuture<CommitResponse> rollback(Transaction transaction) {
return database.rollback(transaction)
.thenCompose(v -> transactions.put(
transaction.id(),
transaction.transition(Transaction.State.ROLLEDBACK)))
.thenApply(v -> CommitResponse.failure());
}
}
|
