+public class Shard extends RaftActor {
+
+ public static final String DEFAULT_NAME = "default";
+
+ private final ListeningExecutorService storeExecutor =
+ MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(2));
+
+ private final InMemoryDOMDataStore store;
+
+ private final Map<Object, DOMStoreThreePhaseCommitCohort>
+ modificationToCohort = new HashMap<>();
+
+ private final LoggingAdapter LOG =
+ Logging.getLogger(getContext().system(), this);
+
+ // By default persistent will be true and can be turned off using the system
+ // property persistent
+ private final boolean persistent;
+
+ private final String name;
+
+ private SchemaContext schemaContext;
+
+ private final ShardStats shardMBean;
+
+ private Shard(String name, Map<String, String> peerAddresses) {
+ super(name, peerAddresses);
+
+ this.name = name;
+
+ String setting = System.getProperty("shard.persistent");
+
+ this.persistent = !"false".equals(setting);
+
+ LOG.info("Creating shard : {} persistent : {}", name, persistent);
+
+ store = new InMemoryDOMDataStore(name, storeExecutor);
+
+ shardMBean = ShardMBeanFactory.getShardStatsMBean(name);
+
+ }
+
+ public static Props props(final String name, final Map<String, String> peerAddresses) {
+ return Props.create(new Creator<Shard>() {
+
+ @Override
+ public Shard create() throws Exception {
+ return new Shard(name, peerAddresses);
+ }
+
+ });
+ }
+
+
+ @Override public void onReceiveCommand(Object message){
+ LOG.debug("Received message {} from {}", message.getClass().toString(), getSender());
+
+ if (message.getClass().equals(CreateTransactionChain.SERIALIZABLE_CLASS)) {
+ if(isLeader()) {
+ createTransactionChain();
+ } else if(getLeader() != null){
+ getLeader().forward(message, getContext());
+ }
+ } else if (message.getClass().equals(RegisterChangeListener.SERIALIZABLE_CLASS)) {
+ registerChangeListener(RegisterChangeListener.fromSerializable(getContext().system(), message));
+ } else if (message instanceof UpdateSchemaContext) {
+ updateSchemaContext((UpdateSchemaContext) message);
+ } else if (message instanceof ForwardedCommitTransaction) {
+ handleForwardedCommit((ForwardedCommitTransaction) message);
+ } else if (message.getClass().equals(CreateTransaction.SERIALIZABLE_CLASS)) {
+ if(isLeader()) {
+ createTransaction(CreateTransaction.fromSerializable(message));
+ } else if(getLeader() != null){
+ getLeader().forward(message, getContext());
+ }
+ } else if (message instanceof PeerAddressResolved){
+ PeerAddressResolved resolved = (PeerAddressResolved) message;
+ setPeerAddress(resolved.getPeerId(), resolved.getPeerAddress());
+ } else {
+ super.onReceiveCommand(message);
+ }
+ }
+
+ private void createTransaction(CreateTransaction createTransaction) {
+ DOMStoreReadWriteTransaction transaction =
+ store.newReadWriteTransaction();
+ String transactionId = "shard-" + createTransaction.getTransactionId();
+ LOG.info("Creating transaction : {} " , transactionId);
+ ActorRef transactionActor = getContext().actorOf(
+ ShardTransaction.props(transaction, getSelf(), schemaContext), transactionId);
+
+ getSender()
+ .tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor), createTransaction.getTransactionId()).toSerializable(),
+ getSelf());
+ }
+
+ private void commit(final ActorRef sender, Object serialized) {
+ Modification modification = MutableCompositeModification.fromSerializable(serialized, schemaContext);
+ DOMStoreThreePhaseCommitCohort cohort =
+ modificationToCohort.remove(serialized);
+ if (cohort == null) {
+ LOG.error(
+ "Could not find cohort for modification : " + modification);
+ LOG.info("Writing modification using a new transaction");
+ modification.apply(store.newReadWriteTransaction());
+ return;
+ }
+
+ final ListenableFuture<Void> future = cohort.commit();
+ shardMBean.incrementCommittedTransactionCount();
+ final ActorRef self = getSelf();
+ future.addListener(new Runnable() {
+ @Override
+ public void run() {
+ try {
+ future.get();
+
+ if(sender != null) {
+ sender
+ .tell(new CommitTransactionReply().toSerializable(),
+ self);
+ } else {
+ LOG.error("sender is null ???");
+ }
+ } catch (InterruptedException | ExecutionException e) {
+ // FIXME : Handle this properly
+ LOG.error(e, "An exception happened when committing");
+ }
+ }
+ }, getContext().dispatcher());
+ }
+
+ private void handleForwardedCommit(ForwardedCommitTransaction message) {
+ Object serializedModification = message.getModification().toSerializable();
+
+ modificationToCohort
+ .put(serializedModification , message.getCohort());
+
+ if(persistent) {
+ this.persistData(getSender(), "identifier", new CompositeModificationPayload(serializedModification));
+ } else {
+ this.commit(getSender(), serializedModification);
+ }
+ }
+
+ private void updateSchemaContext(UpdateSchemaContext message) {
+ this.schemaContext = message.getSchemaContext();
+ store.onGlobalContextUpdated(message.getSchemaContext());
+ }
+
+ private void registerChangeListener(
+ RegisterChangeListener registerChangeListener) {
+
+ LOG.debug("registerDataChangeListener for " + registerChangeListener.getPath());