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.shardstrategy.ShardStrategyFactory;
  27 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  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.YangInstanceIdentifier;
  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, TransactionContext> 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 = actorContext.getCurrentMemberName() + "-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 YangInstanceIdentifier 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(YangInstanceIdentifier 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(YangInstanceIdentifier 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(YangInstanceIdentifier 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(TransactionContext transactionContext : remoteTransactionPaths.values()) {
 152             Object result = actorContext.executeRemoteOperation(transactionContext.getActor(),
 153                 new ReadyTransaction().toSerializable(),
 154                 ActorContext.ASK_DURATION
 155             );
 156
 157             if(result.getClass().equals(ReadyTransactionReply.SERIALIZABLE_CLASS)){
 158                 ReadyTransactionReply reply = ReadyTransactionReply.fromSerializable(actorContext.getActorSystem(),result);
 159                 String resolvedCohortPath = transactionContext
 160                     .getResolvedCohortPath(reply.getCohortPath().toString());
 161                 cohortPaths.add(actorContext.actorFor(resolvedCohortPath));
 162             }
 163         }
 164
 165         return new ThreePhaseCommitCohortProxy(actorContext, cohortPaths, identifier, executor);
 166     }
 167
 168     @Override
 169     public Object getIdentifier() {
 170         return this.identifier;
 171     }
 172
 173     @Override
 174     public void close() {
 175         for(TransactionContext transactionContext : remoteTransactionPaths.values()) {
 176             transactionContext.getActor().tell(
 177                 new CloseTransaction().toSerializable(), null);
 178         }
 179     }
 180
 181     private ActorSelection remoteTransactionFromIdentifier(YangInstanceIdentifier path){
 182         String shardName = shardNameFromIdentifier(path);
 183         return remoteTransactionPaths.get(shardName).getActor();
 184     }
 185
 186     private String shardNameFromIdentifier(YangInstanceIdentifier path){
 187         return ShardStrategyFactory.getStrategy(path).findShard(path);
 188     }
 189
 190     private void createTransactionIfMissing(ActorContext actorContext, YangInstanceIdentifier path) {
 191         String shardName = ShardStrategyFactory.getStrategy(path).findShard(path);
 192
 193         TransactionContext transactionContext =
 194             remoteTransactionPaths.get(shardName);
 195
 196         if(transactionContext != null){
 197             // A transaction already exists with that shard
 198             return;
 199         }
 200
 201         Object response = actorContext.executeShardOperation(shardName, new CreateTransaction(identifier).toSerializable(), ActorContext.ASK_DURATION);
 202         if(response.getClass().equals(CreateTransactionReply.SERIALIZABLE_CLASS)){
 203             CreateTransactionReply reply = CreateTransactionReply.fromSerializable(response);
 204             String transactionPath = actorContext.getRemoteActorPath(shardName, reply.getTransactionPath());
 205
 206             ActorSelection transactionActor = actorContext.actorSelection(transactionPath);
 207             transactionContext = new TransactionContext(shardName, transactionPath, transactionActor);
 208
 209             remoteTransactionPaths.put(shardName, transactionContext);
 210         }
 211     }
 212
 213
 214     private class TransactionContext {
 215         private final String shardName;
 216         private final String actorPath;
 217         private final ActorSelection  actor;
 218
 219
 220         private TransactionContext(String shardName, String actorPath,
 221             ActorSelection actor) {
 222             this.shardName = shardName;
 223             this.actorPath = actorPath;
 224             this.actor = actor;
 225         }
 226
 227
 228         public String getShardName() {
 229             return shardName;
 230         }
 231
 232         public String getActorPath() {
 233             return actorPath;
 234         }
 235
 236         public ActorSelection getActor() {
 237             return actor;
 238         }
 239
 240         public String getResolvedCohortPath(String cohortPath){
 241             return actorContext.resolvePath(actorPath, cohortPath);
 242         }
 243     }
 244
 245 }