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 static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.util.Optional;
  14 import javax.annotation.concurrent.NotThreadSafe;
  15 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
  16 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
  17 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  18 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionSuccess;
  19 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  20 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
  21 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
  22 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  23 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  24 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  25 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  26 import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
  27 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30
  31 /**
  32  * Read-only frontend transaction state as observed by the shard leader.
  33  *
  34  * @author Robert Varga
  35  */
  36 @NotThreadSafe
  37 final class FrontendReadOnlyTransaction extends FrontendTransaction {
  38     private static final Logger LOG = LoggerFactory.getLogger(FrontendReadOnlyTransaction.class);
  39
  40     private final ReadOnlyShardDataTreeTransaction openTransaction;
  41
  42     private FrontendReadOnlyTransaction(final AbstractFrontendHistory history,
  43             final ReadOnlyShardDataTreeTransaction transaction) {
  44         super(history, transaction.getIdentifier());
  45         this.openTransaction = requireNonNull(transaction);
  46     }
  47
  48     static FrontendReadOnlyTransaction create(final AbstractFrontendHistory history,
  49             final ReadOnlyShardDataTreeTransaction transaction) {
  50         return new FrontendReadOnlyTransaction(history, transaction);
  51     }
  52
  53     // Sequence has already been checked
  54     @Override
  55     TransactionSuccess<?> doHandleRequest(final TransactionRequest<?> request, final RequestEnvelope envelope,
  56             final long now) throws RequestException {
  57         if (request instanceof ExistsTransactionRequest) {
  58             return handleExistsTransaction((ExistsTransactionRequest) request);
  59         } else if (request instanceof ReadTransactionRequest) {
  60             return handleReadTransaction((ReadTransactionRequest) request);
  61         } else if (request instanceof ModifyTransactionRequest) {
  62             handleModifyTransaction((ModifyTransactionRequest) request, envelope, now);
  63             return null;
  64         } else {
  65             LOG.warn("Rejecting unsupported request {}", request);
  66             throw new UnsupportedRequestException(request);
  67         }
  68     }
  69
  70     @Override
  71     void retire() {
  72         // No-op
  73     }
  74
  75     private void handleModifyTransaction(final ModifyTransactionRequest request, final RequestEnvelope envelope,
  76             final long now) {
  77         // The only valid request here is with abort protocol
  78         final Optional<PersistenceProtocol> optProto = request.getPersistenceProtocol();
  79         checkArgument(optProto.isPresent(), "Commit protocol is missing in %s", request);
  80         checkArgument(optProto.get() == PersistenceProtocol.ABORT, "Unsupported commit protocol in %s", request);
  81         openTransaction.abort(() -> recordAndSendSuccess(envelope, now,
  82             new ModifyTransactionSuccess(request.getTarget(), request.getSequence())));
  83     }
  84
  85     private ExistsTransactionSuccess handleExistsTransaction(final ExistsTransactionRequest request) {
  86         final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
  87         return recordSuccess(request.getSequence(), new ExistsTransactionSuccess(openTransaction.getIdentifier(),
  88             request.getSequence(), data.isPresent()));
  89     }
  90
  91     private ReadTransactionSuccess handleReadTransaction(final ReadTransactionRequest request) {
  92         final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
  93         return recordSuccess(request.getSequence(), new ReadTransactionSuccess(openTransaction.getIdentifier(),
  94             request.getSequence(), data));
  95     }
  96 }