opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/LocalProxyTransaction.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.databroker.actors.dds;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.util.concurrent.FluentFuture;
  13 import java.util.Optional;
  14 import java.util.function.Consumer;
  15 import org.eclipse.jdt.annotation.NonNull;
  16 import org.eclipse.jdt.annotation.Nullable;
  17 import org.opendaylight.controller.cluster.access.commands.AbortLocalTransactionRequest;
  18 import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest;
  19 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  20 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
  21 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
  22 import org.opendaylight.controller.cluster.access.commands.IncrementTransactionSequenceRequest;
  23 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  24 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
  25 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
  26 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  28 import org.opendaylight.controller.cluster.access.concepts.Response;
  29 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  30 import org.opendaylight.controller.cluster.datastore.util.AbstractDataTreeModificationCursor;
  31 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
  32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  34 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  35 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModification;
  36 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeSnapshot;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * An {@link AbstractProxyTransaction} for dispatching a transaction towards a shard leader which is co-located with
  42  * the client instance. This class is NOT thread-safe.
  43  *
  44  * <p>
  45  * It requires a {@link DataTreeSnapshot}, which is used to instantiated a new {@link DataTreeModification}. Operations
  46  * are then performed on this modification and once the transaction is submitted, the modification is sent to the shard
  47  * leader.
  48  *
  49  * <p>
  50  * This class is not thread-safe as usual with transactions. Since it does not interact with the backend until the
  51  * transaction is submitted, at which point this class gets out of the picture, this is not a cause for concern.
  52  *
  53  * @author Robert Varga
  54  */
  55 abstract class LocalProxyTransaction extends AbstractProxyTransaction {
  56     private static final Logger LOG = LoggerFactory.getLogger(LocalProxyTransaction.class);
  57
  58     private final @NonNull TransactionIdentifier identifier;
  59
  60     LocalProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier, final boolean isDone) {
  61         super(parent, isDone);
  62         this.identifier = requireNonNull(identifier);
  63     }
  64
  65     @Override
  66     public final TransactionIdentifier getIdentifier() {
  67         return identifier;
  68     }
  69
  70     abstract @NonNull DataTreeSnapshot readOnlyView();
  71
  72     abstract void applyForwardedModifyTransactionRequest(ModifyTransactionRequest request,
  73             @Nullable Consumer<Response<?, ?>> callback);
  74
  75     abstract void replayModifyTransactionRequest(ModifyTransactionRequest request,
  76             @Nullable Consumer<Response<?, ?>> callback, long enqueuedTicks);
  77
  78     @Override
  79     FluentFuture<Boolean> doExists(final YangInstanceIdentifier path) {
  80         return FluentFutures.immediateBooleanFluentFuture(readOnlyView().readNode(path).isPresent());
  81     }
  82
  83     @Override
  84     FluentFuture<Optional<NormalizedNode>> doRead(final YangInstanceIdentifier path) {
  85         return FluentFutures.immediateFluentFuture(readOnlyView().readNode(path));
  86     }
  87
  88     @Override
  89     final AbortLocalTransactionRequest abortRequest() {
  90         return new AbortLocalTransactionRequest(identifier, localActor());
  91     }
  92
  93     @Override
  94     void handleReplayedLocalRequest(final AbstractLocalTransactionRequest<?> request,
  95             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
  96         if (request instanceof AbortLocalTransactionRequest) {
  97             enqueueAbort(request, callback, enqueuedTicks);
  98         } else {
  99             throw unhandledRequest(request);
 100         }
 101     }
 102
 103     @Override
 104     void handleReplayedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
 105             final long enqueuedTicks) {
 106         if (request instanceof ModifyTransactionRequest) {
 107             replayModifyTransactionRequest((ModifyTransactionRequest) request, callback, enqueuedTicks);
 108         } else if (handleReadRequest(request, callback)) {
 109             // No-op
 110         } else if (request instanceof TransactionPurgeRequest) {
 111             enqueuePurge(callback, enqueuedTicks);
 112         } else if (request instanceof IncrementTransactionSequenceRequest) {
 113             // Local transactions do not have non-replayable requests which would be visible to the backend,
 114             // hence we can skip sequence increments.
 115             LOG.debug("Not replaying {}", request);
 116         } else {
 117             throw unhandledRequest(request);
 118         }
 119     }
 120
 121     /**
 122      * Remote-to-local equivalent of {@link #handleReplayedRemoteRequest(TransactionRequest, Consumer, long)},
 123      * except it is invoked in the forwarding path from
 124      * {@link RemoteProxyTransaction#forwardToLocal(LocalProxyTransaction, TransactionRequest, Consumer)}.
 125      *
 126      * @param request Forwarded request
 127      * @param callback Callback to be invoked once the request completes
 128      */
 129     void handleForwardedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 130         if (request instanceof ModifyTransactionRequest) {
 131             applyForwardedModifyTransactionRequest((ModifyTransactionRequest) request, callback);
 132         } else if (handleReadRequest(request, callback)) {
 133             // No-op
 134         } else if (request instanceof TransactionPurgeRequest) {
 135             enqueuePurge(callback);
 136         } else {
 137             throw unhandledRequest(request);
 138         }
 139     }
 140
 141     @NonNull Response<?, ?> handleExistsRequest(final @NonNull DataTreeSnapshot snapshot,
 142             final @NonNull ExistsTransactionRequest request) {
 143         return new ExistsTransactionSuccess(request.getTarget(), request.getSequence(),
 144             snapshot.readNode(request.getPath()).isPresent());
 145     }
 146
 147     @NonNull Response<?, ?> handleReadRequest(final @NonNull DataTreeSnapshot snapshot,
 148             final @NonNull ReadTransactionRequest request) {
 149         return new ReadTransactionSuccess(request.getTarget(), request.getSequence(),
 150             snapshot.readNode(request.getPath()));
 151     }
 152
 153     private boolean handleReadRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 154         // Note we delay completion of read requests to limit the scope at which the client can run, as they have
 155         // listeners, which we do not want to execute while we are reconnecting.
 156         if (request instanceof ReadTransactionRequest) {
 157             if (callback != null) {
 158                 final var response = handleReadRequest(readOnlyView(), (ReadTransactionRequest) request);
 159                 executeInActor(() -> callback.accept(response));
 160             }
 161             return true;
 162         } else if (request instanceof ExistsTransactionRequest) {
 163             if (callback != null) {
 164                 final var response = handleExistsRequest(readOnlyView(), (ExistsTransactionRequest) request);
 165                 executeInActor(() -> callback.accept(response));
 166             }
 167             return true;
 168         } else {
 169             return false;
 170         }
 171     }
 172
 173     @Override
 174     final void forwardToRemote(final RemoteProxyTransaction successor, final TransactionRequest<?> request,
 175                          final Consumer<Response<?, ?>> callback) {
 176         if (request instanceof CommitLocalTransactionRequest) {
 177             final CommitLocalTransactionRequest req = (CommitLocalTransactionRequest) request;
 178             final DataTreeModification mod = req.getModification();
 179
 180             LOG.debug("Applying modification {} to successor {}", mod, successor);
 181             mod.applyToCursor(new AbstractDataTreeModificationCursor() {
 182                 @Override
 183                 public void write(final PathArgument child, final NormalizedNode data) {
 184                     successor.write(current().node(child), data);
 185                 }
 186
 187                 @Override
 188                 public void merge(final PathArgument child, final NormalizedNode data) {
 189                     successor.merge(current().node(child), data);
 190                 }
 191
 192                 @Override
 193                 public void delete(final PathArgument child) {
 194                     successor.delete(current().node(child));
 195                 }
 196             });
 197
 198             successor.sealOnly();
 199             final ModifyTransactionRequest successorReq = successor.commitRequest(req.isCoordinated());
 200             successor.sendRequest(successorReq, callback);
 201         } else if (request instanceof AbortLocalTransactionRequest) {
 202             LOG.debug("Forwarding abort {} to successor {}", request, successor);
 203             successor.abort();
 204         } else if (request instanceof TransactionPurgeRequest) {
 205             LOG.debug("Forwarding purge {} to successor {}", request, successor);
 206             successor.enqueuePurge(callback);
 207         } else if (request instanceof ModifyTransactionRequest) {
 208             successor.handleForwardedRequest(request, callback);
 209         } else {
 210             throw unhandledRequest(request);
 211         }
 212     }
 213
 214     @Override
 215     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
 216             final Consumer<Response<?, ?>> callback) {
 217         if (request instanceof AbortLocalTransactionRequest) {
 218             successor.sendAbort(request, callback);
 219         } else if (request instanceof TransactionPurgeRequest) {
 220             successor.enqueuePurge(callback);
 221         } else {
 222             throw unhandledRequest(request);
 223         }
 224
 225         LOG.debug("Forwarded request {} to successor {}", request, successor);
 226     }
 227
 228     void sendAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 229         sendRequest(request, callback);
 230     }
 231
 232     void enqueueAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
 233             final long enqueuedTicks) {
 234         enqueueRequest(request, callback, enqueuedTicks);
 235     }
 236 }