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