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 }