opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionProxy.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
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorSelection;
  12 import com.google.common.base.Optional;
  13 import com.google.common.util.concurrent.ListenableFuture;
  14 import com.google.common.util.concurrent.ListenableFutureTask;
  15 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  16 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  17 import org.opendaylight.controller.cluster.datastore.messages.ReadData;
  18 import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
  19 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  20 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  21 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  22 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  23 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  24
  25 import java.util.HashMap;
  26 import java.util.Map;
  27 import java.util.concurrent.Callable;
  28 import java.util.concurrent.Executors;
  29
  30 /**
  31  * TransactionProxy acts as a proxy for one or more transactions that were created on a remote shard
  32  *
  33  * Creating a transaction on the consumer side will create one instance of a transaction proxy. If during
  34  * the transaction reads and writes are done on data that belongs to different shards then a separate transaction will
  35  * be created on each of those shards by the TransactionProxy
  36  *
  37  * The TransactionProxy does not make any guarantees about atomicity or order in which the transactions on the various
  38  * shards will be executed.
  39  *
  40  */
  41 public class TransactionProxy implements DOMStoreReadWriteTransaction {
  42
  43     public enum TransactionType {
  44         READ_ONLY,
  45         WRITE_ONLY,
  46         READ_WRITE
  47     }
  48
  49     private final TransactionType readOnly;
  50     private final ActorContext actorContext;
  51     private final Map<String, ActorSelection> remoteTransactionPaths = new HashMap<>();
  52
  53     public TransactionProxy(
  54         ActorContext actorContext,
  55         TransactionType readOnly) {
  56
  57         this.readOnly = readOnly;
  58         this.actorContext = actorContext;
  59
  60         Object response = actorContext.executeShardOperation(Shard.DEFAULT_NAME, new CreateTransaction(), ActorContext.ASK_DURATION);
  61         if(response instanceof CreateTransactionReply){
  62             CreateTransactionReply reply = (CreateTransactionReply) response;
  63             remoteTransactionPaths.put(Shard.DEFAULT_NAME, actorContext.actorSelection(reply.getTransactionPath()));
  64         }
  65     }
  66
  67     @Override
  68     public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
  69         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
  70
  71         Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
  72
  73             @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
  74                 Object response = actorContext
  75                     .executeRemoteOperation(remoteTransaction, new ReadData(path),
  76                         ActorContext.ASK_DURATION);
  77                 if(response instanceof ReadDataReply){
  78                     ReadDataReply reply = (ReadDataReply) response;
  79                     //FIXME : A cast should not be required here ???
  80                     return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
  81                 }
  82
  83                 return Optional.absent();
  84             }
  85         };
  86
  87         ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
  88             future = ListenableFutureTask.create(call);
  89
  90         //FIXME : Use a thread pool here
  91         Executors.newSingleThreadExecutor().submit(future);
  92
  93         return future;
  94     }
  95
  96     @Override
  97     public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
  98         throw new UnsupportedOperationException("write");
  99     }
 100
 101     @Override
 102     public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 103         throw new UnsupportedOperationException("merge");
 104     }
 105
 106     @Override
 107     public void delete(InstanceIdentifier path) {
 108         throw new UnsupportedOperationException("delete");
 109     }
 110
 111     @Override
 112     public DOMStoreThreePhaseCommitCohort ready() {
 113         throw new UnsupportedOperationException("ready");
 114     }
 115
 116     @Override
 117     public Object getIdentifier() {
 118         throw new UnsupportedOperationException("getIdentifier");
 119     }
 120
 121     @Override
 122     public void close() {
 123         throw new UnsupportedOperationException("close");
 124     }
 125
 126     private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
 127         String shardName = shardNameFromIdentifier(path);
 128         return remoteTransactionPaths.get(shardName);
 129     }
 130
 131     private String shardNameFromIdentifier(InstanceIdentifier path){
 132         return Shard.DEFAULT_NAME;
 133     }
 134 }