312e11290c88e713827fe2b051d96b667eb633da
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / ShardDataTreeTransactionChain.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 com.google.common.base.MoreObjects;
11 import com.google.common.base.Preconditions;
12 import javax.annotation.concurrent.NotThreadSafe;
13 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
14 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
15 import org.opendaylight.yangtools.concepts.Identifiable;
16 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
17 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
18 import org.slf4j.Logger;
19 import org.slf4j.LoggerFactory;
20
21 /**
22  * A transaction chain attached to a Shard.
23  */
24 @NotThreadSafe
25 final class ShardDataTreeTransactionChain extends ShardDataTreeTransactionParent
26         implements Identifiable<LocalHistoryIdentifier> {
27     private static final Logger LOG = LoggerFactory.getLogger(ShardDataTreeTransactionChain.class);
28     private final LocalHistoryIdentifier chainId;
29     private final ShardDataTree dataTree;
30
31     private ReadWriteShardDataTreeTransaction previousTx;
32     private ReadWriteShardDataTreeTransaction openTransaction;
33     private boolean closed;
34
35     ShardDataTreeTransactionChain(final LocalHistoryIdentifier localHistoryIdentifier, final ShardDataTree dataTree) {
36         this.chainId = Preconditions.checkNotNull(localHistoryIdentifier);
37         this.dataTree = Preconditions.checkNotNull(dataTree);
38     }
39
40     private DataTreeSnapshot getSnapshot() {
41         Preconditions.checkState(!closed, "TransactionChain %s has been closed", this);
42         Preconditions.checkState(openTransaction == null, "Transaction %s is open", openTransaction);
43
44         if (previousTx == null) {
45             LOG.debug("Opening an unchained snapshot in {}", chainId);
46             return dataTree.takeSnapshot();
47         }
48
49         LOG.debug("Reusing a chained snapshot in {}", chainId);
50         return previousTx.getSnapshot();
51     }
52
53     ReadOnlyShardDataTreeTransaction newReadOnlyTransaction(final TransactionIdentifier txId) {
54         final DataTreeSnapshot snapshot = getSnapshot();
55         LOG.debug("Allocated read-only transaction {} snapshot {}", txId, snapshot);
56
57         return new ReadOnlyShardDataTreeTransaction(txId, snapshot);
58     }
59
60     ReadWriteShardDataTreeTransaction newReadWriteTransaction(final TransactionIdentifier txId) {
61         final DataTreeSnapshot snapshot = getSnapshot();
62         LOG.debug("Allocated read-write transaction {} snapshot {}", txId, snapshot);
63
64         openTransaction = new ReadWriteShardDataTreeTransaction(this, txId, snapshot.newModification());
65         return openTransaction;
66     }
67
68     void close() {
69         closed = true;
70     }
71
72     @Override
73     protected void abortTransaction(final AbstractShardDataTreeTransaction<?> transaction) {
74         if (transaction instanceof ReadWriteShardDataTreeTransaction) {
75             Preconditions.checkState(openTransaction != null,
76                     "Attempted to abort transaction %s while none is outstanding", transaction);
77             LOG.debug("Aborted transaction {}", transaction);
78             openTransaction = null;
79         }
80     }
81
82     @Override
83     protected ShardDataTreeCohort finishTransaction(final ReadWriteShardDataTreeTransaction transaction) {
84         Preconditions.checkState(openTransaction != null,
85                 "Attempted to finish transaction %s while none is outstanding", transaction);
86
87         // dataTree is finalizing ready the transaction, we just record it for the next
88         // transaction in chain
89         final ShardDataTreeCohort delegate = dataTree.finishTransaction(transaction);
90         openTransaction = null;
91         previousTx = transaction;
92         LOG.debug("Committing transaction {}", transaction);
93
94         return new ChainedCommitCohort(this, transaction, delegate);
95     }
96
97     @Override
98     public String toString() {
99         return MoreObjects.toStringHelper(this).add("id", chainId).toString();
100     }
101
102     void clearTransaction(final ReadWriteShardDataTreeTransaction transaction) {
103         if (transaction.equals(previousTx)) {
104             previousTx = null;
105         }
106     }
107
108     @Override
109     public LocalHistoryIdentifier getIdentifier() {
110         return chainId;
111     }
112
113     @Override
114     ShardDataTreeCohort createReadyCohort(final TransactionIdentifier txId, final DataTreeModification modification) {
115         return dataTree.createReadyCohort(txId, modification);
116     }
117 }