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.ActorPath;
  12 import akka.actor.ActorSelection;
  13 import com.google.common.base.Optional;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import com.google.common.util.concurrent.ListenableFutureTask;
  16 import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
  17 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  18 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  19 import org.opendaylight.controller.cluster.datastore.messages.DeleteData;
  20 import org.opendaylight.controller.cluster.datastore.messages.MergeData;
  21 import org.opendaylight.controller.cluster.datastore.messages.ReadData;
  22 import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
  23 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
  24 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  25 import org.opendaylight.controller.cluster.datastore.messages.WriteData;
  26 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  27 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  29 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  30 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  31
  32 import java.util.ArrayList;
  33 import java.util.HashMap;
  34 import java.util.List;
  35 import java.util.Map;
  36 import java.util.concurrent.Callable;
  37 import java.util.concurrent.ExecutorService;
  38 import java.util.concurrent.atomic.AtomicLong;
  39
  40 /**
  41  * TransactionProxy acts as a proxy for one or more transactions that were created on a remote shard
  42  * <p>
  43  * Creating a transaction on the consumer side will create one instance of a transaction proxy. If during
  44  * the transaction reads and writes are done on data that belongs to different shards then a separate transaction will
  45  * be created on each of those shards by the TransactionProxy
  46  *</p>
  47  * <p>
  48  * The TransactionProxy does not make any guarantees about atomicity or order in which the transactions on the various
  49  * shards will be executed.
  50  * </p>
  51  */
  52 public class TransactionProxy implements DOMStoreReadWriteTransaction {
  53     public enum TransactionType {
  54         READ_ONLY,
  55         WRITE_ONLY,
  56         READ_WRITE
  57     }
  58
  59     private static final AtomicLong counter = new AtomicLong();
  60
  61     private final TransactionType transactionType;
  62     private final ActorContext actorContext;
  63     private final Map<String, ActorSelection> remoteTransactionPaths = new HashMap<>();
  64     private final String identifier;
  65     private final ExecutorService executor;
  66
  67     public TransactionProxy(
  68         ActorContext actorContext,
  69         TransactionType transactionType,
  70         ExecutorService executor
  71         ) {
  72
  73         this.identifier = "txn-" + counter.getAndIncrement();
  74         this.transactionType = transactionType;
  75         this.actorContext = actorContext;
  76         this.executor = executor;
  77
  78         Object response = actorContext.executeShardOperation(Shard.DEFAULT_NAME, new CreateTransaction(identifier), ActorContext.ASK_DURATION);
  79         if(response instanceof CreateTransactionReply){
  80             CreateTransactionReply reply = (CreateTransactionReply) response;
  81             remoteTransactionPaths.put(Shard.DEFAULT_NAME, actorContext.actorSelection(reply.getTransactionPath()));
  82         }
  83     }
  84
  85     @Override
  86     public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
  87         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
  88
  89         Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
  90
  91             @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
  92                 Object response = actorContext
  93                     .executeRemoteOperation(remoteTransaction, new ReadData(path),
  94                         ActorContext.ASK_DURATION);
  95                 if(response instanceof ReadDataReply){
  96                     ReadDataReply reply = (ReadDataReply) response;
  97                     if(reply.getNormalizedNode() == null){
  98                         return Optional.absent();
  99                     }
 100                     //FIXME : A cast should not be required here ???
 101                     return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
 102                 }
 103
 104                 return Optional.absent();
 105             }
 106         };
 107
 108         ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
 109             future = ListenableFutureTask.create(call);
 110
 111         executor.submit(future);
 112
 113         return future;
 114     }
 115
 116     @Override
 117     public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 118         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 119         remoteTransaction.tell(new WriteData(path, data), null);
 120     }
 121
 122     @Override
 123     public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 124         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 125         remoteTransaction.tell(new MergeData(path, data), null);
 126     }
 127
 128     @Override
 129     public void delete(InstanceIdentifier path) {
 130         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 131         remoteTransaction.tell(new DeleteData(path), null);
 132     }
 133
 134     @Override
 135     public DOMStoreThreePhaseCommitCohort ready() {
 136         List<ActorPath> cohortPaths = new ArrayList<>();
 137
 138         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 139             Object result = actorContext.executeRemoteOperation(remoteTransaction,
 140                 new ReadyTransaction(),
 141                 ActorContext.ASK_DURATION
 142             );
 143
 144             if(result instanceof ReadyTransactionReply){
 145                 ReadyTransactionReply reply = (ReadyTransactionReply) result;
 146                 cohortPaths.add(reply.getCohortPath());
 147             }
 148         }
 149
 150         return new ThreePhaseCommitCohortProxy(actorContext, cohortPaths, identifier, executor);
 151     }
 152
 153     @Override
 154     public Object getIdentifier() {
 155         return this.identifier;
 156     }
 157
 158     @Override
 159     public void close() {
 160         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 161             remoteTransaction.tell(new CloseTransaction(), null);
 162         }
 163     }
 164
 165     private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
 166         String shardName = shardNameFromIdentifier(path);
 167         return remoteTransactionPaths.get(shardName);
 168     }
 169
 170     private String shardNameFromIdentifier(InstanceIdentifier path){
 171         return Shard.DEFAULT_NAME;
 172     }
 173 }