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.yang.data.api.schema.tree.DataTreeSnapshot;
  16 import org.slf4j.Logger;
  17 import org.slf4j.LoggerFactory;
  18
  19 /**
  20  * A transaction chain attached to a Shard.
  21  */
  22 @NotThreadSafe
  23 final class ShardDataTreeTransactionChain extends ShardDataTreeTransactionParent {
  24     private static final Logger LOG = LoggerFactory.getLogger(ShardDataTreeTransactionChain.class);
  25     private final ShardDataTree dataTree;
  26     private final LocalHistoryIdentifier chainId;
  27
  28     private ReadWriteShardDataTreeTransaction previousTx;
  29     private ReadWriteShardDataTreeTransaction openTransaction;
  30     private boolean closed;
  31
  32     ShardDataTreeTransactionChain(final LocalHistoryIdentifier localHistoryIdentifier, final ShardDataTree dataTree) {
  33         this.dataTree = Preconditions.checkNotNull(dataTree);
  34         this.chainId = Preconditions.checkNotNull(localHistoryIdentifier);
  35     }
  36
  37     private DataTreeSnapshot getSnapshot() {
  38         Preconditions.checkState(!closed, "TransactionChain %s has been closed", this);
  39         Preconditions.checkState(openTransaction == null, "Transaction %s is open", openTransaction);
  40
  41         if (previousTx == null) {
  42             return dataTree.takeSnapshot();
  43         } else {
  44             return previousTx.getSnapshot();
  45         }
  46     }
  47
  48     ReadOnlyShardDataTreeTransaction newReadOnlyTransaction(final TransactionIdentifier txId) {
  49         final DataTreeSnapshot snapshot = getSnapshot();
  50         LOG.debug("Allocated read-only transaction {} snapshot {}", txId, snapshot);
  51
  52         return new ReadOnlyShardDataTreeTransaction(txId, snapshot);
  53     }
  54
  55     ReadWriteShardDataTreeTransaction newReadWriteTransaction(final TransactionIdentifier txId) {
  56         final DataTreeSnapshot snapshot = getSnapshot();
  57         LOG.debug("Allocated read-write transaction {} snapshot {}", txId, snapshot);
  58
  59         openTransaction = new ReadWriteShardDataTreeTransaction(this, txId, snapshot.newModification());
  60         return openTransaction;
  61     }
  62
  63     void close() {
  64         closed = true;
  65     }
  66
  67     @Override
  68     protected void abortTransaction(final AbstractShardDataTreeTransaction<?> transaction) {
  69         if (transaction instanceof ReadWriteShardDataTreeTransaction) {
  70             Preconditions.checkState(openTransaction != null, "Attempted to abort transaction %s while none is outstanding", transaction);
  71             LOG.debug("Aborted transaction {}", transaction);
  72             openTransaction = null;
  73         }
  74     }
  75
  76     @Override
  77     protected ShardDataTreeCohort finishTransaction(final ReadWriteShardDataTreeTransaction transaction) {
  78         Preconditions.checkState(openTransaction != null, "Attempted to finish transaction %s while none is outstanding", transaction);
  79
  80         // dataTree is finalizing ready the transaction, we just record it for the next
  81         // transaction in chain
  82         final ShardDataTreeCohort delegate = dataTree.finishTransaction(transaction);
  83         openTransaction = null;
  84         previousTx = transaction;
  85         LOG.debug("Committing transaction {}", transaction);
  86
  87         return new ChainedCommitCohort(this, transaction, delegate);
  88     }
  89
  90     @Override
  91     public String toString() {
  92         return MoreObjects.toStringHelper(this).add("id", chainId).toString();
  93     }
  94
  95     void clearTransaction(ReadWriteShardDataTreeTransaction transaction) {
  96         if (transaction.equals(previousTx)) {
  97             previousTx = null;
  98         }
  99     }
 100 }