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
  28     private static final Logger LOG = LoggerFactory.getLogger(ShardDataTreeTransactionChain.class);
  29     private final LocalHistoryIdentifier chainId;
  30     private final ShardDataTree dataTree;
  31
  32     private ReadWriteShardDataTreeTransaction previousTx;
  33     private ReadWriteShardDataTreeTransaction openTransaction;
  34     private boolean closed;
  35
  36     ShardDataTreeTransactionChain(final LocalHistoryIdentifier localHistoryIdentifier, final ShardDataTree dataTree) {
  37         this.chainId = Preconditions.checkNotNull(localHistoryIdentifier);
  38         this.dataTree = Preconditions.checkNotNull(dataTree);
  39     }
  40
  41     private DataTreeSnapshot getSnapshot() {
  42         Preconditions.checkState(!closed, "TransactionChain %s has been closed", this);
  43         Preconditions.checkState(openTransaction == null, "Transaction %s is open", openTransaction);
  44
  45         if (previousTx == null) {
  46             LOG.debug("Opening an unchained snapshot in {}", chainId);
  47             return dataTree.takeSnapshot();
  48         }
  49
  50         LOG.debug("Reusing a chained snapshot in {}", chainId);
  51         return previousTx.getSnapshot();
  52     }
  53
  54     ReadOnlyShardDataTreeTransaction newReadOnlyTransaction(final TransactionIdentifier txId) {
  55         final DataTreeSnapshot snapshot = getSnapshot();
  56         LOG.debug("Allocated read-only transaction {} snapshot {}", txId, snapshot);
  57
  58         return new ReadOnlyShardDataTreeTransaction(this, txId, snapshot);
  59     }
  60
  61     ReadWriteShardDataTreeTransaction newReadWriteTransaction(final TransactionIdentifier txId) {
  62         final DataTreeSnapshot snapshot = getSnapshot();
  63         LOG.debug("Allocated read-write transaction {} snapshot {}", txId, snapshot);
  64
  65         openTransaction = new ReadWriteShardDataTreeTransaction(this, txId, snapshot.newModification());
  66         return openTransaction;
  67     }
  68
  69     void close() {
  70         closed = true;
  71         LOG.debug("Closing chain {}", chainId);
  72     }
  73
  74     @Override
  75     void abortTransaction(final AbstractShardDataTreeTransaction<?> transaction, final Runnable callback) {
  76         if (transaction instanceof ReadWriteShardDataTreeTransaction) {
  77             Preconditions.checkState(openTransaction != null,
  78                     "Attempted to abort transaction %s while none is outstanding", transaction);
  79             LOG.debug("Aborted open transaction {}", transaction);
  80             openTransaction = null;
  81         }
  82
  83         dataTree.abortTransaction(transaction, callback);
  84     }
  85
  86     @Override
  87     void purgeTransaction(final TransactionIdentifier id, final Runnable callback) {
  88         dataTree.purgeTransaction(id, callback);
  89     }
  90
  91     @Override
  92     ShardDataTreeCohort finishTransaction(final ReadWriteShardDataTreeTransaction transaction) {
  93         Preconditions.checkState(openTransaction != null,
  94                 "Attempted to finish transaction %s while none is outstanding", transaction);
  95
  96         // dataTree is finalizing ready the transaction, we just record it for the next
  97         // transaction in chain
  98         final ShardDataTreeCohort delegate = dataTree.finishTransaction(transaction);
  99         openTransaction = null;
 100         previousTx = transaction;
 101         LOG.debug("Committing transaction {}", transaction);
 102
 103         return new ChainedCommitCohort(this, transaction, delegate);
 104     }
 105
 106     @Override
 107     public String toString() {
 108         return MoreObjects.toStringHelper(this).add("id", chainId).toString();
 109     }
 110
 111     void clearTransaction(final ReadWriteShardDataTreeTransaction transaction) {
 112         if (transaction.equals(previousTx)) {
 113             previousTx = null;
 114         }
 115     }
 116
 117     @Override
 118     public LocalHistoryIdentifier getIdentifier() {
 119         return chainId;
 120     }
 121
 122     @Override
 123     ShardDataTreeCohort createReadyCohort(final TransactionIdentifier txId, final DataTreeModification modification) {
 124         return dataTree.createReadyCohort(txId, modification);
 125     }
 126 }