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.DeleteData;
  19 import org.opendaylight.controller.cluster.datastore.messages.MergeData;
  20 import org.opendaylight.controller.cluster.datastore.messages.ReadData;
  21 import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
  22 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
  23 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  24 import org.opendaylight.controller.cluster.datastore.messages.WriteData;
  25 import org.opendaylight.controller.cluster.datastore.shardstrategy.ShardStrategyFactory;
  26 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  27 import org.opendaylight.controller.protobuff.messages.transaction.ShardTransactionMessages.CreateTransactionReply;
  28 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  30 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  31 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  32 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  33
  34 import java.util.ArrayList;
  35 import java.util.HashMap;
  36 import java.util.List;
  37 import java.util.Map;
  38 import java.util.concurrent.Callable;
  39 import java.util.concurrent.ExecutorService;
  40 import java.util.concurrent.atomic.AtomicLong;
  41
  42 /**
  43  * TransactionProxy acts as a proxy for one or more transactions that were created on a remote shard
  44  * <p>
  45  * Creating a transaction on the consumer side will create one instance of a transaction proxy. If during
  46  * the transaction reads and writes are done on data that belongs to different shards then a separate transaction will
  47  * be created on each of those shards by the TransactionProxy
  48  *</p>
  49  * <p>
  50  * The TransactionProxy does not make any guarantees about atomicity or order in which the transactions on the various
  51  * shards will be executed.
  52  * </p>
  53  */
  54 public class TransactionProxy implements DOMStoreReadWriteTransaction {
  55     public enum TransactionType {
  56         READ_ONLY,
  57         WRITE_ONLY,
  58         READ_WRITE
  59     }
  60
  61     private static final AtomicLong counter = new AtomicLong();
  62
  63     private final TransactionType transactionType;
  64     private final ActorContext actorContext;
  65     private final Map<String, ActorSelection> remoteTransactionPaths = new HashMap<>();
  66     private final String identifier;
  67     private final ExecutorService executor;
  68     private final SchemaContext schemaContext;
  69
  70     public TransactionProxy(
  71         ActorContext actorContext,
  72         TransactionType transactionType,
  73         ExecutorService executor,
  74         SchemaContext schemaContext
  75         ) {
  76
  77         this.identifier = "txn-" + counter.getAndIncrement();
  78         this.transactionType = transactionType;
  79         this.actorContext = actorContext;
  80         this.executor = executor;
  81         this.schemaContext = schemaContext;
  82
  83
  84     }
  85
  86     @Override
  87     public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
  88
  89         createTransactionIfMissing(actorContext, path);
  90
  91         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
  92
  93         Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
  94
  95             @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
  96                 Object response = actorContext
  97                     .executeRemoteOperation(remoteTransaction, new ReadData(path).toSerializable(),
  98                         ActorContext.ASK_DURATION);
  99                 if(response.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)){
 100                     ReadDataReply reply = ReadDataReply.fromSerializable(schemaContext,path, response);
 101                     if(reply.getNormalizedNode() == null){
 102                         return Optional.absent();
 103                     }
 104                     //FIXME : A cast should not be required here ???
 105                     return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
 106                 }
 107
 108                 return Optional.absent();
 109             }
 110         };
 111
 112         ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
 113             future = ListenableFutureTask.create(call);
 114
 115         executor.submit(future);
 116
 117         return future;
 118     }
 119
 120     @Override
 121     public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 122
 123         createTransactionIfMissing(actorContext, path);
 124
 125         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 126         remoteTransaction.tell(new WriteData(path, data, schemaContext).toSerializable(), null);
 127     }
 128
 129     @Override
 130     public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
 131
 132         createTransactionIfMissing(actorContext, path);
 133
 134         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 135         remoteTransaction.tell(new MergeData(path, data, schemaContext).toSerializable(), null);
 136     }
 137
 138     @Override
 139     public void delete(InstanceIdentifier path) {
 140
 141         createTransactionIfMissing(actorContext, path);
 142
 143         final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
 144         remoteTransaction.tell(new DeleteData(path).toSerializable(), null);
 145     }
 146
 147     @Override
 148     public DOMStoreThreePhaseCommitCohort ready() {
 149         List<ActorPath> cohortPaths = new ArrayList<>();
 150
 151         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 152             Object result = actorContext.executeRemoteOperation(remoteTransaction,
 153                 new ReadyTransaction(),
 154                 ActorContext.ASK_DURATION
 155             );
 156
 157             if(result instanceof ReadyTransactionReply){
 158                 ReadyTransactionReply reply = (ReadyTransactionReply) result;
 159                 cohortPaths.add(reply.getCohortPath());
 160             }
 161         }
 162
 163         return new ThreePhaseCommitCohortProxy(actorContext, cohortPaths, identifier, executor);
 164     }
 165
 166     @Override
 167     public Object getIdentifier() {
 168         return this.identifier;
 169     }
 170
 171     @Override
 172     public void close() {
 173         for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
 174             remoteTransaction.tell(new CloseTransaction(), null);
 175         }
 176     }
 177
 178     private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
 179         String shardName = shardNameFromIdentifier(path);
 180         return remoteTransactionPaths.get(shardName);
 181     }
 182
 183     private String shardNameFromIdentifier(InstanceIdentifier path){
 184         return ShardStrategyFactory.getStrategy(path).findShard(path);
 185     }
 186
 187     private void createTransactionIfMissing(ActorContext actorContext, InstanceIdentifier path) {
 188         String shardName = ShardStrategyFactory.getStrategy(path).findShard(path);
 189
 190         ActorSelection actorSelection =
 191             remoteTransactionPaths.get(shardName);
 192
 193         if(actorSelection != null){
 194             // A transaction already exists with that shard
 195             return;
 196         }
 197
 198         Object response = actorContext.executeShardOperation(shardName, new CreateTransaction(identifier), ActorContext.ASK_DURATION);
 199         if(response instanceof CreateTransactionReply){
 200             CreateTransactionReply reply = (CreateTransactionReply) response;
 201             remoteTransactionPaths.put(shardName, actorContext.actorSelection(reply.getTransactionActorPath()));
 202         }
 203     }
 204
 205
 206 }