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.Executors;
  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
  54     public enum TransactionType {
  55         READ_ONLY,
  56         WRITE_ONLY,
  57         READ_WRITE
  58     }
  59
  60     private static final AtomicLong counter = new AtomicLong();
  61
  62     private final TransactionType readOnly;
  63     private final ActorContext actorContext;
  64     private final Map<String, ActorSelection> remoteTransactionPaths = new HashMap<>();
  65     private final String identifier;
  66
  67     public TransactionProxy(
  68         ActorContext actorContext,
  69         TransactionType readOnly) {
  70
  71         this.identifier = "transaction-" + counter.getAndIncrement();
  72         this.readOnly = readOnly;
  73         this.actorContext = actorContext;
  74
  75         Object response = actorContext.executeShardOperation(Shard.DEFAULT_NAME, new CreateTransaction(), ActorContext.ASK_DURATION);
  76         if(response instanceof CreateTransactionReply){
  77             CreateTransactionReply reply = (CreateTransactionReply) response;
  78             remoteTransactionPaths.put(Shard.DEFAULT_NAME, actorContext.actorSelection(reply.getTransactionPath()));
  79         }
  80     }
  81
  82     @Override
  83     public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
  84         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
  85
  86         Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
  87
  88             @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
  89                 Object response = actorContext
  90                     .executeRemoteOperation(remoteTransaction, new ReadData(path),
  91                         ActorContext.ASK_DURATION);
  92                 if(response instanceof ReadDataReply){
  93                     ReadDataReply reply = (ReadDataReply) response;
  94                     //FIXME : A cast should not be required here ???
  95                     return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
  96                 }
  97
  98                 return Optional.absent();
  99             }
 100         };
 101
 102         ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
 103             future = ListenableFutureTask.create(call);
 104
 105         //FIXME : Use a thread pool here
 106         Executors.newSingleThreadExecutor().submit(future);
 107
 108         return future;
 109     }
 110
 111     @Override
 112     public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 113         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 114         remoteTransaction.tell(new WriteData(path, data), null);
 115     }
 116
 117     @Override
 118     public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 119         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 120         remoteTransaction.tell(new MergeData(path, data), null);
 121     }
 122
 123     @Override
 124     public void delete(InstanceIdentifier path) {
 125         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 126         remoteTransaction.tell(new DeleteData(path), null);
 127     }
 128
 129     @Override
 130     public DOMStoreThreePhaseCommitCohort ready() {
 131         List<ActorPath> cohortPaths = new ArrayList<>();
 132
 133         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 134             Object result = actorContext.executeRemoteOperation(remoteTransaction,
 135                 new ReadyTransaction(),
 136                 ActorContext.ASK_DURATION
 137             );
 138
 139             if(result instanceof ReadyTransactionReply){
 140                 ReadyTransactionReply reply = (ReadyTransactionReply) result;
 141                 cohortPaths.add(reply.getCohortPath());
 142             }
 143         }
 144
 145         return new ThreePhaseCommitCohortProxy(cohortPaths);
 146     }
 147
 148     @Override
 149     public Object getIdentifier() {
 150         return this.identifier;
 151     }
 152
 153     @Override
 154     public void close() {
 155         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 156             remoteTransaction.tell(new CloseTransaction(), null);
 157         }
 158     }
 159
 160     private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
 161         String shardName = shardNameFromIdentifier(path);
 162         return remoteTransactionPaths.get(shardName);
 163     }
 164
 165     private String shardNameFromIdentifier(InstanceIdentifier path){
 166         return Shard.DEFAULT_NAME;
 167     }
 168 }