+ /**
+ * Implements a Future OnComplete callback for a CreateTransaction message. This class handles
+ * retries, up to a limit, if the shard doesn't have a leader yet. This is done by scheduling a
+ * retry task after a short delay.
+ * <p>
+ * The end result from a completed CreateTransaction message is a TransactionContext that is
+ * used to perform transaction operations. Transaction operations that occur before the
+ * CreateTransaction completes are cache and executed once the CreateTransaction completes,
+ * successfully or not.
+ */
+ private class TransactionFutureCallback extends OnComplete<Object> {
+
+ /**
+ * The list of transaction operations to execute once the CreateTransaction completes.
+ */
+ @GuardedBy("txOperationsOnComplete")
+ private final List<TransactionOperation> txOperationsOnComplete = Lists.newArrayList();
+
+ /**
+ * The TransactionContext resulting from the CreateTransaction reply.
+ */
+ private volatile TransactionContext transactionContext;
+
+ /**
+ * The target primary shard.
+ */
+ private volatile ActorSelection primaryShard;
+
+ private volatile int createTxTries = (int) (actorContext.getDatastoreContext().
+ getShardLeaderElectionTimeout().duration().toMillis() /
+ CREATE_TX_TRY_INTERVAL.toMillis());
+
+ private final String shardName;
+
+ TransactionFutureCallback(String shardName) {
+ this.shardName = shardName;
+ }
+
+ String getShardName() {
+ return shardName;
+ }
+
+ TransactionContext getTransactionContext() {
+ return transactionContext;
+ }
+
+
+ /**
+ * Sets the target primary shard and initiates a CreateTransaction try.
+ */
+ void setPrimaryShard(ActorSelection primaryShard) {
+ LOG.debug("Tx {} Primary shard found - trying create transaction", identifier);
+
+ this.primaryShard = primaryShard;
+ tryCreateTransaction();
+ }
+
+ /**
+ * Adds a TransactionOperation to be executed after the CreateTransaction completes.
+ */
+ void addTxOperationOnComplete(TransactionOperation operation) {
+ synchronized(txOperationsOnComplete) {
+ if(transactionContext == null) {
+ LOG.debug("Tx {} Adding operation on complete {}", identifier);
+
+ txOperationsOnComplete.add(operation);
+ } else {
+ operation.invoke(transactionContext);
+ }
+ }
+ }
+
+ /**
+ * Performs a CreateTransaction try async.
+ */
+ private void tryCreateTransaction() {
+ Future<Object> createTxFuture = sendCreateTransaction(primaryShard,
+ new CreateTransaction(identifier.toString(),
+ TransactionProxy.this.transactionType.ordinal(),
+ getTransactionChainId()).toSerializable());
+
+ createTxFuture.onComplete(this, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public void onComplete(Throwable failure, Object response) {
+ if(failure instanceof NoShardLeaderException) {
+ // There's no leader for the shard yet - schedule and try again, unless we're out
+ // of retries. Note: createTxTries is volatile as it may be written by different
+ // threads however not concurrently, therefore decrementing it non-atomically here
+ // is ok.
+ if(--createTxTries > 0) {
+ LOG.debug("Tx {} Shard {} has no leader yet - scheduling create Tx retry",
+ identifier, shardName);
+
+ actorContext.getActorSystem().scheduler().scheduleOnce(CREATE_TX_TRY_INTERVAL,
+ new Runnable() {
+ @Override
+ public void run() {
+ tryCreateTransaction();
+ }
+ }, actorContext.getActorSystem().dispatcher());
+ return;
+ }
+ }
+
+ // Create the TransactionContext from the response or failure and execute delayed
+ // TransactionOperations. This entire section is done atomically (ie synchronized) with
+ // respect to #addTxOperationOnComplete to handle timing issues and ensure no
+ // TransactionOperation is missed and that they are processed in the order they occurred.
+ synchronized(txOperationsOnComplete) {
+ // Store the new TransactionContext locally until we've completed invoking the
+ // TransactionOperations. This avoids thread timing issues which could cause
+ // out-of-order TransactionOperations. Eg, on a modification operation, if the
+ // TransactionContext is non-null, then we directly call the TransactionContext.
+ // However, at the same time, the code may be executing the cached
+ // TransactionOperations. So to avoid thus timing, we don't publish the
+ // TransactionContext until after we've executed all cached TransactionOperations.
+ TransactionContext localTransactionContext;
+ if(failure != null) {
+ LOG.debug("Tx {} Creating NoOpTransaction because of error: {}", identifier,
+ failure.getMessage());
+
+ localTransactionContext = new NoOpTransactionContext(failure, identifier);
+ } else if (response.getClass().equals(CreateTransactionReply.SERIALIZABLE_CLASS)) {
+ localTransactionContext = createValidTransactionContext(
+ CreateTransactionReply.fromSerializable(response));
+ } else {
+ IllegalArgumentException exception = new IllegalArgumentException(String.format(
+ "Invalid reply type %s for CreateTransaction", response.getClass()));
+
+ localTransactionContext = new NoOpTransactionContext(exception, identifier);
+ }
+
+ for(TransactionOperation oper: txOperationsOnComplete) {
+ oper.invoke(localTransactionContext);
+ }
+
+ txOperationsOnComplete.clear();
+
+ // We're done invoking the TransactionOperations so we can now publish the
+ // TransactionContext.
+ transactionContext = localTransactionContext;
+ }
+ }
+
+ private TransactionContext createValidTransactionContext(CreateTransactionReply reply) {
+ String transactionPath = reply.getTransactionPath();
+
+ LOG.debug("Tx {} Received transaction actor path {}", identifier, transactionPath);
+
+ ActorSelection transactionActor = actorContext.actorSelection(transactionPath);
+
+ if (transactionType == TransactionType.READ_ONLY) {
+ // Add the actor to the remoteTransactionActors list for access by the
+ // cleanup PhantonReference.
+ remoteTransactionActors.add(transactionActor);
+
+ // Write to the memory barrier volatile to publish the above update to the
+ // remoteTransactionActors list for thread visibility.
+ remoteTransactionActorsMB.set(true);
+ }
+
+ // TxActor is always created where the leader of the shard is.
+ // Check if TxActor is created in the same node
+ boolean isTxActorLocal = actorContext.isLocalPath(transactionPath);
+
+ return new TransactionContextImpl(transactionPath, transactionActor, identifier,
+ actorContext, schemaContext, isTxActorLocal, reply.getVersion());
+ }
+ }
+
+ private interface TransactionContext {
+ void closeTransaction();
+
+ Future<ActorSelection> readyTransaction();
+
+ void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data);
+
+ void deleteData(YangInstanceIdentifier path);
+
+ void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data);
+
+ CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ final YangInstanceIdentifier path);
+
+ CheckedFuture<Boolean, ReadFailedException> dataExists(YangInstanceIdentifier path);
+
+ List<Future<Object>> getRecordedOperationFutures();
+ }
+
+ private static abstract class AbstractTransactionContext implements TransactionContext {
+
+ protected final TransactionIdentifier identifier;
+ protected final List<Future<Object>> recordedOperationFutures = Lists.newArrayList();
+
+ AbstractTransactionContext(TransactionIdentifier identifier) {
+ this.identifier = identifier;
+ }
+
+ @Override
+ public List<Future<Object>> getRecordedOperationFutures() {
+ return recordedOperationFutures;
+ }
+ }
+
+ private static class TransactionContextImpl extends AbstractTransactionContext {
+ private final Logger LOG = LoggerFactory.getLogger(TransactionContextImpl.class);
+
+ private final ActorContext actorContext;
+ private final SchemaContext schemaContext;
+ private final String transactionPath;
+ private final ActorSelection actor;
+ private final boolean isTxActorLocal;
+ private final int remoteTransactionVersion;
+
+ private TransactionContextImpl(String transactionPath, ActorSelection actor, TransactionIdentifier identifier,
+ ActorContext actorContext, SchemaContext schemaContext,
+ boolean isTxActorLocal, int remoteTransactionVersion) {
+ super(identifier);
+ this.transactionPath = transactionPath;
+ this.actor = actor;
+ this.actorContext = actorContext;
+ this.schemaContext = schemaContext;
+ this.isTxActorLocal = isTxActorLocal;
+ this.remoteTransactionVersion = remoteTransactionVersion;
+ }
+
+ private ActorSelection getActor() {
+ return actor;
+ }
+
+ @Override
+ public void closeTransaction() {
+ LOG.debug("Tx {} closeTransaction called", identifier);
+
+ actorContext.sendOperationAsync(getActor(), new CloseTransaction().toSerializable());
+ }
+
+ @Override
+ public Future<ActorSelection> readyTransaction() {
+ LOG.debug("Tx {} readyTransaction called with {} previous recorded operations pending",
+ identifier, recordedOperationFutures.size());
+
+ // Send the ReadyTransaction message to the Tx actor.
+
+ ReadyTransaction readyTransaction = new ReadyTransaction();
+ final Future<Object> replyFuture = actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? readyTransaction : readyTransaction.toSerializable());
+
+ // Combine all the previously recorded put/merge/delete operation reply Futures and the
+ // ReadyTransactionReply Future into one Future. If any one fails then the combined
+ // Future will fail. We need all prior operations and the ready operation to succeed
+ // in order to attempt commit.
+
+ List<Future<Object>> futureList =
+ Lists.newArrayListWithCapacity(recordedOperationFutures.size() + 1);
+ futureList.addAll(recordedOperationFutures);
+ futureList.add(replyFuture);
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(futureList,
+ actorContext.getActorSystem().dispatcher());
+
+ // Transform the combined Future into a Future that returns the cohort actor path from
+ // the ReadyTransactionReply. That's the end result of the ready operation.
+
+ return combinedFutures.transform(new Mapper<Iterable<Object>, ActorSelection>() {
+ @Override
+ public ActorSelection checkedApply(Iterable<Object> notUsed) {
+ LOG.debug("Tx {} readyTransaction: pending recorded operations succeeded",
+ identifier);
+
+ // At this point all the Futures succeeded and we need to extract the cohort
+ // actor path from the ReadyTransactionReply. For the recorded operations, they
+ // don't return any data so we're only interested that they completed
+ // successfully. We could be paranoid and verify the correct reply types but
+ // that really should never happen so it's not worth the overhead of
+ // de-serializing each reply.
+
+ // Note the Future get call here won't block as it's complete.
+ Object serializedReadyReply = replyFuture.value().get().get();
+ if (serializedReadyReply instanceof ReadyTransactionReply) {
+ return actorContext.actorSelection(((ReadyTransactionReply)serializedReadyReply).getCohortPath());
+
+ } else if(serializedReadyReply.getClass().equals(ReadyTransactionReply.SERIALIZABLE_CLASS)) {
+ ReadyTransactionReply reply = ReadyTransactionReply.fromSerializable(serializedReadyReply);
+ String cohortPath = reply.getCohortPath();
+
+ // In Helium we used to return the local path of the actor which represented
+ // a remote ThreePhaseCommitCohort. The local path would then be converted to
+ // a remote path using this resolvePath method. To maintain compatibility with
+ // a Helium node we need to continue to do this conversion.
+ // At some point in the future when upgrades from Helium are not supported
+ // we could remove this code to resolvePath and just use the cohortPath as the
+ // resolved cohortPath
+ if(TransactionContextImpl.this.remoteTransactionVersion < CreateTransaction.HELIUM_1_VERSION) {
+ cohortPath = actorContext.resolvePath(transactionPath, cohortPath);
+ }
+
+ return actorContext.actorSelection(cohortPath);
+
+ } else {
+ // Throwing an exception here will fail the Future.
+ throw new IllegalArgumentException(String.format("Invalid reply type {}",
+ serializedReadyReply.getClass()));
+ }
+ }
+ }, SAME_FAILURE_TRANSFORMER, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public void deleteData(YangInstanceIdentifier path) {
+ LOG.debug("Tx {} deleteData called path = {}", identifier, path);
+
+ DeleteData deleteData = new DeleteData(path);
+ recordedOperationFutures.add(actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? deleteData : deleteData.toSerializable()));
+ }
+
+ @Override
+ public void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} mergeData called path = {}", identifier, path);
+
+ MergeData mergeData = new MergeData(path, data, schemaContext);
+ recordedOperationFutures.add(actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? mergeData : mergeData.toSerializable()));
+ }
+
+ @Override
+ public void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} writeData called path = {}", identifier, path);
+
+ WriteData writeData = new WriteData(path, data, schemaContext);
+ recordedOperationFutures.add(actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? writeData : writeData.toSerializable()));
+ }
+
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ final YangInstanceIdentifier path) {
+
+ LOG.debug("Tx {} readData called path = {}", identifier, path);
+
+ final SettableFuture<Optional<NormalizedNode<?, ?>>> returnFuture = SettableFuture.create();
+
+ // If there were any previous recorded put/merge/delete operation reply Futures then we
+ // must wait for them to successfully complete. This is necessary to honor the read
+ // uncommitted semantics of the public API contract. If any one fails then fail the read.
+
+ if(recordedOperationFutures.isEmpty()) {
+ finishReadData(path, returnFuture);
+ } else {
+ LOG.debug("Tx {} readData: verifying {} previous recorded operations",
+ identifier, recordedOperationFutures.size());
+
+ // Note: we make a copy of recordedOperationFutures to be on the safe side in case
+ // Futures#sequence accesses the passed List on a different thread, as
+ // recordedOperationFutures is not synchronized.
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(
+ Lists.newArrayList(recordedOperationFutures),
+ actorContext.getActorSystem().dispatcher());
+
+ OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
+ @Override
+ public void onComplete(Throwable failure, Iterable<Object> notUsed)
+ throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} readData: a recorded operation failed: {}",
+ identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "The read could not be performed because a previous put, merge,"
+ + "or delete operation failed", failure));
+ } else {
+ finishReadData(path, returnFuture);
+ }
+ }
+ };
+
+ combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ return MappingCheckedFuture.create(returnFuture, ReadFailedException.MAPPER);
+ }
+
+ private void finishReadData(final YangInstanceIdentifier path,
+ final SettableFuture<Optional<NormalizedNode<?, ?>>> returnFuture) {
+
+ LOG.debug("Tx {} finishReadData called path = {}", identifier, path);
+
+ OnComplete<Object> onComplete = new OnComplete<Object>() {
+ @Override
+ public void onComplete(Throwable failure, Object readResponse) throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} read operation failed: {}", identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "Error reading data for path " + path, failure));
+
+ } else {
+ LOG.debug("Tx {} read operation succeeded", identifier, failure);
+
+ if (readResponse instanceof ReadDataReply) {
+ ReadDataReply reply = (ReadDataReply) readResponse;
+ returnFuture.set(Optional.<NormalizedNode<?, ?>>fromNullable(reply.getNormalizedNode()));
+
+ } else if (readResponse.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)) {
+ ReadDataReply reply = ReadDataReply.fromSerializable(schemaContext, path, readResponse);
+ returnFuture.set(Optional.<NormalizedNode<?, ?>>fromNullable(reply.getNormalizedNode()));
+
+ } else {
+ returnFuture.setException(new ReadFailedException(
+ "Invalid response reading data for path " + path));
+ }
+ }
+ }
+ };
+
+ ReadData readData = new ReadData(path);
+ Future<Object> readFuture = actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? readData : readData.toSerializable());
+
+ readFuture.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> dataExists(
+ final YangInstanceIdentifier path) {
+
+ LOG.debug("Tx {} dataExists called path = {}", identifier, path);
+
+ final SettableFuture<Boolean> returnFuture = SettableFuture.create();
+
+ // If there were any previous recorded put/merge/delete operation reply Futures then we
+ // must wait for them to successfully complete. This is necessary to honor the read
+ // uncommitted semantics of the public API contract. If any one fails then fail this
+ // request.
+
+ if(recordedOperationFutures.isEmpty()) {
+ finishDataExists(path, returnFuture);
+ } else {
+ LOG.debug("Tx {} dataExists: verifying {} previous recorded operations",
+ identifier, recordedOperationFutures.size());
+
+ // Note: we make a copy of recordedOperationFutures to be on the safe side in case
+ // Futures#sequence accesses the passed List on a different thread, as
+ // recordedOperationFutures is not synchronized.
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(
+ Lists.newArrayList(recordedOperationFutures),
+ actorContext.getActorSystem().dispatcher());
+ OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
+ @Override
+ public void onComplete(Throwable failure, Iterable<Object> notUsed)
+ throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} dataExists: a recorded operation failed: {}",
+ identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "The data exists could not be performed because a previous "
+ + "put, merge, or delete operation failed", failure));
+ } else {
+ finishDataExists(path, returnFuture);
+ }
+ }
+ };
+
+ combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ return MappingCheckedFuture.create(returnFuture, ReadFailedException.MAPPER);
+ }
+
+ private void finishDataExists(final YangInstanceIdentifier path,
+ final SettableFuture<Boolean> returnFuture) {
+
+ LOG.debug("Tx {} finishDataExists called path = {}", identifier, path);
+
+ OnComplete<Object> onComplete = new OnComplete<Object>() {
+ @Override
+ public void onComplete(Throwable failure, Object response) throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} dataExists operation failed: {}", identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "Error checking data exists for path " + path, failure));
+ } else {
+ LOG.debug("Tx {} dataExists operation succeeded", identifier, failure);
+
+ if (response instanceof DataExistsReply) {
+ returnFuture.set(Boolean.valueOf(((DataExistsReply) response).exists()));
+
+ } else if (response.getClass().equals(DataExistsReply.SERIALIZABLE_CLASS)) {
+ returnFuture.set(Boolean.valueOf(DataExistsReply.fromSerializable(response).exists()));
+
+ } else {
+ returnFuture.setException(new ReadFailedException(
+ "Invalid response checking exists for path " + path));
+ }
+ }
+ }
+ };
+
+ DataExists dataExists = new DataExists(path);
+ Future<Object> future = actorContext.executeOperationAsync(getActor(),
+ isTxActorLocal ? dataExists : dataExists.toSerializable());
+
+ future.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+ }
+
+ private static class NoOpTransactionContext extends AbstractTransactionContext {
+
+ private final Logger LOG = LoggerFactory.getLogger(NoOpTransactionContext.class);
+
+ private final Throwable failure;
+
+ public NoOpTransactionContext(Throwable failure, TransactionIdentifier identifier){
+ super(identifier);
+ this.failure = failure;
+ }
+
+ @Override
+ public void closeTransaction() {
+ LOG.debug("NoOpTransactionContext {} closeTransaction called", identifier);
+ }
+
+ @Override
+ public Future<ActorSelection> readyTransaction() {
+ LOG.debug("Tx {} readyTransaction called", identifier);
+ return akka.dispatch.Futures.failed(failure);
+ }
+
+ @Override
+ public void deleteData(YangInstanceIdentifier path) {
+ LOG.debug("Tx {} deleteData called path = {}", identifier, path);
+ }
+
+ @Override
+ public void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} mergeData called path = {}", identifier, path);
+ }
+
+ @Override
+ public void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} writeData called path = {}", identifier, path);
+ }
+
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ YangInstanceIdentifier path) {
+ LOG.debug("Tx {} readData called path = {}", identifier, path);
+ return Futures.immediateFailedCheckedFuture(new ReadFailedException(
+ "Error reading data for path " + path, failure));
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> dataExists(
+ YangInstanceIdentifier path) {
+ LOG.debug("Tx {} dataExists called path = {}", identifier, path);
+ return Futures.immediateFailedCheckedFuture(new ReadFailedException(
+ "Error checking exists for path " + path, failure));
+ }