opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/FrontendReadOnlyTransaction.java

   1 /*
   2  * Copyright (c) 2016 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.Optional;
  11 import com.google.common.base.Preconditions;
  12 import javax.annotation.Nullable;
  13 import javax.annotation.concurrent.NotThreadSafe;
  14 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
  15 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
  16 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  17 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionSuccess;
  18 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  19 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
  20 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
  21 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  22 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  23 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  24 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  25 import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
  26 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 /**
  31  * Read-only frontend transaction state as observed by the shard leader.
  32  *
  33  * @author Robert Varga
  34  */
  35 @NotThreadSafe
  36 final class FrontendReadOnlyTransaction extends FrontendTransaction {
  37     private static final Logger LOG = LoggerFactory.getLogger(FrontendReadOnlyTransaction.class);
  38
  39     private final ReadOnlyShardDataTreeTransaction openTransaction;
  40
  41     private FrontendReadOnlyTransaction(final AbstractFrontendHistory history,
  42             final ReadOnlyShardDataTreeTransaction transaction) {
  43         super(history, transaction.getIdentifier());
  44         this.openTransaction = Preconditions.checkNotNull(transaction);
  45     }
  46
  47     static FrontendReadOnlyTransaction create(final AbstractFrontendHistory history,
  48             final ReadOnlyShardDataTreeTransaction transaction) {
  49         return new FrontendReadOnlyTransaction(history, transaction);
  50     }
  51
  52     // Sequence has already been checked
  53     @Override
  54     @Nullable TransactionSuccess<?> handleRequest(final TransactionRequest<?> request, final RequestEnvelope envelope,
  55             final long now) throws RequestException {
  56         if (request instanceof ExistsTransactionRequest) {
  57             return handleExistsTransaction((ExistsTransactionRequest) request);
  58         } else if (request instanceof ReadTransactionRequest) {
  59             return handleReadTransaction((ReadTransactionRequest) request);
  60         } else if (request instanceof ModifyTransactionRequest) {
  61             handleModifyTransaction((ModifyTransactionRequest) request, envelope, now);
  62             return null;
  63         } else {
  64             LOG.warn("Rejecting unsupported request {}", request);
  65             throw new UnsupportedRequestException(request);
  66         }
  67     }
  68
  69     private void handleModifyTransaction(final ModifyTransactionRequest request, final RequestEnvelope envelope,
  70             final long now) {
  71         // The only valid request here is with abort protocol
  72         final java.util.Optional<PersistenceProtocol> optProto = request.getPersistenceProtocol();
  73         Preconditions.checkArgument(optProto.isPresent(), "Commit protocol is missing in %s", request);
  74         Preconditions.checkArgument(optProto.get() == PersistenceProtocol.ABORT, "Unsupported commit protocol in %s",
  75                 request);
  76         openTransaction.abort(() -> recordAndSendSuccess(envelope, now,
  77             new ModifyTransactionSuccess(request.getTarget(), request.getSequence())));
  78     }
  79
  80     private ExistsTransactionSuccess handleExistsTransaction(final ExistsTransactionRequest request)
  81             throws RequestException {
  82         final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
  83         return recordSuccess(request.getSequence(), new ExistsTransactionSuccess(openTransaction.getIdentifier(),
  84             request.getSequence(), data.isPresent()));
  85     }
  86
  87     private ReadTransactionSuccess handleReadTransaction(final ReadTransactionRequest request)
  88             throws RequestException {
  89         final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
  90         return recordSuccess(request.getSequence(), new ReadTransactionSuccess(openTransaction.getIdentifier(),
  91             request.getSequence(), data));
  92     }
  93 }