opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/SnapshotBackedWriteTransaction.java

   1 /*
   2  * Copyright (c) 2014 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.sal.core.spi.data;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import com.google.common.annotations.Beta;
  12 import com.google.common.base.MoreObjects.ToStringHelper;
  13 import com.google.common.base.Optional;
  14 import com.google.common.base.Preconditions;
  15 import com.google.common.base.Throwables;
  16 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  17 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  18 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  19 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  21 import org.slf4j.Logger;
  22 import org.slf4j.LoggerFactory;
  23
  24 /**
  25  * Implementation of Write transaction which is backed by
  26  * {@link DataTreeSnapshot} and executed according to
  27  * {@link org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction.TransactionReadyPrototype}.
  28  *
  29  * @param <T> Identifier type
  30  */
  31 @Beta
  32 public class SnapshotBackedWriteTransaction<T> extends AbstractDOMStoreTransaction<T> implements DOMStoreWriteTransaction {
  33     private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedWriteTransaction.class);
  34     @SuppressWarnings("rawtypes")
  35     private static final AtomicReferenceFieldUpdater<SnapshotBackedWriteTransaction, TransactionReadyPrototype> READY_UPDATER =
  36             AtomicReferenceFieldUpdater.newUpdater(SnapshotBackedWriteTransaction.class, TransactionReadyPrototype.class, "readyImpl");
  37     @SuppressWarnings("rawtypes")
  38     private static final AtomicReferenceFieldUpdater<SnapshotBackedWriteTransaction, DataTreeModification> TREE_UPDATER =
  39             AtomicReferenceFieldUpdater.newUpdater(SnapshotBackedWriteTransaction.class, DataTreeModification.class, "mutableTree");
  40
  41     // non-null when not ready
  42     private volatile TransactionReadyPrototype<T> readyImpl;
  43     // non-null when not committed/closed
  44     private volatile DataTreeModification mutableTree;
  45
  46     SnapshotBackedWriteTransaction(final T identifier, final boolean debug,
  47             final DataTreeSnapshot snapshot, final TransactionReadyPrototype<T> readyImpl) {
  48         super(identifier, debug);
  49         this.readyImpl = Preconditions.checkNotNull(readyImpl, "readyImpl must not be null.");
  50         mutableTree = snapshot.newModification();
  51         LOG.debug("Write Tx: {} allocated with snapshot {}", identifier, snapshot);
  52     }
  53
  54     @Override
  55     public void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  56         checkNotReady();
  57
  58         final DataTreeModification tree = mutableTree;
  59         LOG.debug("Tx: {} Write: {}:{}", getIdentifier(), path, data);
  60
  61         try {
  62             tree.write(path, data);
  63             // FIXME: Add checked exception
  64         } catch (Exception e) {
  65             LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, tree, e);
  66             // Rethrow original ones if they are subclasses of RuntimeException
  67             // or Error
  68             Throwables.propagateIfPossible(e);
  69             // FIXME: Introduce proper checked exception
  70             throw new IllegalArgumentException("Illegal input data.", e);
  71         }
  72     }
  73
  74     @Override
  75     public void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  76         checkNotReady();
  77
  78         final DataTreeModification tree = mutableTree;
  79         LOG.debug("Tx: {} Merge: {}:{}", getIdentifier(), path, data);
  80
  81         try {
  82             tree.merge(path, data);
  83             // FIXME: Add checked exception
  84         } catch (Exception e) {
  85             LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, tree, e);
  86             // Rethrow original ones if they are subclasses of RuntimeException
  87             // or Error
  88             Throwables.propagateIfPossible(e);
  89             // FIXME: Introduce proper checked exception
  90             throw new IllegalArgumentException("Illegal input data.", e);
  91         }
  92     }
  93
  94     @Override
  95     public void delete(final YangInstanceIdentifier path) {
  96         checkNotReady();
  97
  98         final DataTreeModification tree = mutableTree;
  99         LOG.debug("Tx: {} Delete: {}", getIdentifier(), path);
 100
 101         try {
 102             tree.delete(path);
 103             // FIXME: Add checked exception
 104         } catch (Exception e) {
 105             LOG.error("Tx: {}, failed to delete {} in {}", getIdentifier(), path, tree, e);
 106             // Rethrow original ones if they are subclasses of RuntimeException
 107             // or Error
 108             Throwables.propagateIfPossible(e);
 109             // FIXME: Introduce proper checked exception
 110             throw new IllegalArgumentException("Illegal path to delete.", e);
 111         }
 112     }
 113
 114     /**
 115      * Exposed for {@link SnapshotBackedReadWriteTransaction}'s sake only. The contract does
 116      * not allow data access after the transaction has been closed or readied.
 117      *
 118      * @param path Path to read
 119      * @return null if the the transaction has been closed;
 120      */
 121     final Optional<NormalizedNode<?, ?>> readSnapshotNode(final YangInstanceIdentifier path) {
 122         return readyImpl == null ? null : mutableTree.readNode(path);
 123     }
 124
 125     private final void checkNotReady() {
 126         checkState(readyImpl != null, "Transaction %s is no longer open. No further modifications allowed.", getIdentifier());
 127     }
 128
 129     @Override
 130     public DOMStoreThreePhaseCommitCohort ready() {
 131         @SuppressWarnings("unchecked")
 132         final TransactionReadyPrototype<T> wasReady = READY_UPDATER.getAndSet(this, null);
 133         checkState(wasReady != null, "Transaction %s is no longer open", getIdentifier());
 134
 135         LOG.debug("Store transaction: {} : Ready", getIdentifier());
 136
 137         final DataTreeModification tree = mutableTree;
 138         TREE_UPDATER.lazySet(this, null);
 139         tree.ready();
 140         return wasReady.transactionReady(this, tree);
 141     }
 142
 143     @Override
 144     public void close() {
 145         @SuppressWarnings("unchecked")
 146         final TransactionReadyPrototype<T> wasReady = READY_UPDATER.getAndSet(this, null);
 147         if (wasReady != null) {
 148             LOG.debug("Store transaction: {} : Closed", getIdentifier());
 149             TREE_UPDATER.lazySet(this, null);
 150             wasReady.transactionAborted(this);
 151         } else {
 152             LOG.debug("Store transaction: {} : Closed after submit", getIdentifier());
 153         }
 154     }
 155
 156     @Override
 157     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 158         return toStringHelper.add("ready", readyImpl == null);
 159     }
 160
 161     /**
 162      * Prototype implementation of
 163      * {@link #ready(org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction)}
 164      *
 165      * This class is intended to be implemented by Transaction factories
 166      * responsible for allocation of {@link org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction} and
 167      * providing underlying logic for applying implementation.
 168      *
 169      * @param <T> identifier type
 170      */
 171     public abstract static class TransactionReadyPrototype<T> {
 172         /**
 173          * Called when a transaction is closed without being readied. This is not invoked for
 174          * transactions which are ready.
 175          *
 176          * @param tx Transaction which got aborted.
 177          */
 178         protected abstract void transactionAborted(final SnapshotBackedWriteTransaction<T> tx);
 179
 180         /**
 181          * Returns a commit coordinator associated with supplied transactions.
 182          *
 183          * This call must not fail.
 184          *
 185          * @param tx
 186          *            Transaction on which ready was invoked.
 187          * @param tree
 188          *            Modified data tree which has been constructed.
 189          * @return DOMStoreThreePhaseCommitCohort associated with transaction
 190          */
 191         protected abstract DOMStoreThreePhaseCommitCohort transactionReady(SnapshotBackedWriteTransaction<T> tx, DataTreeModification tree);
 192     }
 193 }