+/*
+ * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.datastore;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Verify;
+import com.google.common.primitives.UnsignedLong;
+import com.google.common.util.concurrent.FutureCallback;
+import java.util.ArrayDeque;
+import java.util.Iterator;
+import java.util.Queue;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
+import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.ModifyTransactionSuccess;
+import org.opendaylight.controller.cluster.access.commands.OutOfOrderRequestException;
+import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
+import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionAbortSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionCanCommitSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionCommitSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionDelete;
+import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionMerge;
+import org.opendaylight.controller.cluster.access.commands.TransactionModification;
+import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
+import org.opendaylight.controller.cluster.access.commands.TransactionWrite;
+import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
+import org.opendaylight.controller.cluster.access.concepts.RequestException;
+import org.opendaylight.controller.cluster.access.concepts.RuntimeRequestException;
+import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
+import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Frontend transaction state as observed by the shard leader.
+ *
+ * @author Robert Varga
+ */
+@NotThreadSafe
+final class FrontendTransaction {
+ private static final Logger LOG = LoggerFactory.getLogger(FrontendTransaction.class);
+
+ private final AbstractFrontendHistory history;
+ private final TransactionIdentifier id;
+
+ /**
+ * It is possible that after we process a request and send a response that response gets lost and the client
+ * initiates a retry. Since subsequent requests can mutate transaction state we need to retain the response until
+ * it is acknowledged by the client.
+ */
+ private final Queue<Object> replayQueue = new ArrayDeque<>();
+ private long firstReplaySequence;
+ private Long lastPurgedSequence;
+ private long expectedSequence;
+
+ private ReadWriteShardDataTreeTransaction openTransaction;
+ private ModifyTransactionSuccess cachedModifySuccess;
+ private DataTreeModification sealedModification;
+ private ShardDataTreeCohort readyCohort;
+
+ private FrontendTransaction(final AbstractFrontendHistory history, final TransactionIdentifier id,
+ final ReadWriteShardDataTreeTransaction transaction) {
+ this.history = Preconditions.checkNotNull(history);
+ this.id = Preconditions.checkNotNull(id);
+ this.openTransaction = Preconditions.checkNotNull(transaction);
+ }
+
+ private FrontendTransaction(final AbstractFrontendHistory history, final TransactionIdentifier id,
+ final DataTreeModification mod) {
+ this.history = Preconditions.checkNotNull(history);
+ this.id = Preconditions.checkNotNull(id);
+ this.sealedModification = Preconditions.checkNotNull(mod);
+ }
+
+ static FrontendTransaction createOpen(final AbstractFrontendHistory history,
+ final ReadWriteShardDataTreeTransaction transaction) {
+ return new FrontendTransaction(history, transaction.getIdentifier(), transaction);
+ }
+
+ static FrontendTransaction createReady(final AbstractFrontendHistory history, final TransactionIdentifier id,
+ final DataTreeModification mod) {
+ return new FrontendTransaction(history, id, mod);
+ }
+
+ java.util.Optional<TransactionSuccess<?>> replaySequence(final long sequence) throws RequestException {
+ // Fast path check: if the requested sequence is the next request, bail early
+ if (expectedSequence == sequence) {
+ return java.util.Optional.empty();
+ }
+
+ // Check sequencing: we do not need to bother with future requests
+ if (Long.compareUnsigned(expectedSequence, sequence) < 0) {
+ throw new OutOfOrderRequestException(expectedSequence);
+ }
+
+ // Sanity check: if we have purged sequences, this has to be newer
+ if (lastPurgedSequence != null && Long.compareUnsigned(lastPurgedSequence.longValue(), sequence) >= 0) {
+ // Client has sent a request sequence, which has already been purged. This is a hard error, which should
+ // never occur. Throwing an IllegalArgumentException will cause it to be wrapped in a
+ // RuntimeRequestException (which is not retriable) and report it back to the client.
+ throw new IllegalArgumentException(String.format("Invalid purged sequence %s (last purged is %s)",
+ sequence, lastPurgedSequence));
+ }
+
+ // At this point we have established that the requested sequence lies in the open interval
+ // (lastPurgedSequence, expectedSequence). That does not actually mean we have a response, as the commit
+ // machinery is asynchronous, hence a reply may be in the works and not available.
+
+ long replaySequence = firstReplaySequence;
+ final Iterator<?> it = replayQueue.iterator();
+ while (it.hasNext()) {
+ final Object replay = it.next();
+ if (replaySequence == sequence) {
+ if (replay instanceof RequestException) {
+ throw (RequestException) replay;
+ }
+
+ Verify.verify(replay instanceof TransactionSuccess);
+ return java.util.Optional.of((TransactionSuccess<?>) replay);
+ }
+
+ replaySequence++;
+ }
+
+ // Not found
+ return java.util.Optional.empty();
+ }
+
+ void purgeSequencesUpTo(final long sequence) {
+ // FIXME: implement this
+
+ lastPurgedSequence = sequence;
+ }
+
+ // Sequence has already been checked
+ @Nullable TransactionSuccess<?> handleRequest(final TransactionRequest<?> request, final RequestEnvelope envelope)
+ throws RequestException {
+ if (request instanceof ModifyTransactionRequest) {
+ return handleModifyTransaction((ModifyTransactionRequest) request, envelope);
+ } else if (request instanceof CommitLocalTransactionRequest) {
+ handleCommitLocalTransaction((CommitLocalTransactionRequest) request, envelope);
+ return null;
+ } else if (request instanceof ExistsTransactionRequest) {
+ return handleExistsTransaction((ExistsTransactionRequest) request);
+ } else if (request instanceof ReadTransactionRequest) {
+ return handleReadTransaction((ReadTransactionRequest) request);
+ } else if (request instanceof TransactionPreCommitRequest) {
+ handleTransactionPreCommit((TransactionPreCommitRequest) request, envelope);
+ return null;
+ } else if (request instanceof TransactionDoCommitRequest) {
+ handleTransactionDoCommit((TransactionDoCommitRequest) request, envelope);
+ return null;
+ } else if (request instanceof TransactionAbortRequest) {
+ handleTransactionAbort((TransactionAbortRequest) request, envelope);
+ return null;
+ } else {
+ throw new UnsupportedRequestException(request);
+ }
+ }
+
+ private void recordResponse(final long sequence, final Object response) {
+ if (replayQueue.isEmpty()) {
+ firstReplaySequence = sequence;
+ }
+ replayQueue.add(response);
+ expectedSequence++;
+ }
+
+ private <T extends TransactionSuccess<?>> T recordSuccess(final long sequence, final T success) {
+ recordResponse(sequence, success);
+ return success;
+ }
+
+ private void recordAndSendSuccess(final RequestEnvelope envelope, final TransactionSuccess<?> success) {
+ recordResponse(success.getSequence(), success);
+ envelope.sendSuccess(success);
+ }
+
+ private void recordAndSendFailure(final RequestEnvelope envelope, final RuntimeRequestException failure) {
+ recordResponse(envelope.getMessage().getSequence(), failure);
+ envelope.sendFailure(failure);
+ }
+
+ private void handleTransactionPreCommit(final TransactionPreCommitRequest request,
+ final RequestEnvelope envelope) throws RequestException {
+ readyCohort.preCommit(new FutureCallback<DataTreeCandidate>() {
+ @Override
+ public void onSuccess(final DataTreeCandidate result) {
+ recordAndSendSuccess(envelope, new TransactionPreCommitSuccess(readyCohort.getIdentifier(),
+ request.getSequence()));
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("Precommit failed", failure));
+ readyCohort = null;
+ }
+ });
+ }
+
+ private void handleTransactionDoCommit(final TransactionDoCommitRequest request, final RequestEnvelope envelope)
+ throws RequestException {
+ readyCohort.commit(new FutureCallback<UnsignedLong>() {
+ @Override
+ public void onSuccess(final UnsignedLong result) {
+ successfulCommit(envelope);
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("Commit failed", failure));
+ readyCohort = null;
+ }
+ });
+ }
+
+ private void handleTransactionAbort(final TransactionAbortRequest request, final RequestEnvelope envelope)
+ throws RequestException {
+ readyCohort.abort(new FutureCallback<Void>() {
+ @Override
+ public void onSuccess(final Void result) {
+ readyCohort = null;
+ recordAndSendSuccess(envelope, new TransactionAbortSuccess(id, request.getSequence()));
+ LOG.debug("Transaction {} aborted", id);
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ readyCohort = null;
+ LOG.warn("Transaction {} abort failed", id, failure);
+ recordAndSendFailure(envelope, new RuntimeRequestException("Abort failed", failure));
+ }
+ });
+ }
+
+ private void coordinatedCommit(final RequestEnvelope envelope) {
+ readyCohort.canCommit(new FutureCallback<Void>() {
+ @Override
+ public void onSuccess(final Void result) {
+ recordAndSendSuccess(envelope, new TransactionCanCommitSuccess(readyCohort.getIdentifier(),
+ envelope.getMessage().getSequence()));
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("CanCommit failed", failure));
+ readyCohort = null;
+ }
+ });
+ }
+
+ private void directCommit(final RequestEnvelope envelope) {
+ readyCohort.canCommit(new FutureCallback<Void>() {
+ @Override
+ public void onSuccess(final Void result) {
+ successfulDirectCanCommit(envelope);
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("CanCommit failed", failure));
+ readyCohort = null;
+ }
+ });
+
+ }
+
+ private void successfulDirectCanCommit(final RequestEnvelope envelope) {
+ readyCohort.preCommit(new FutureCallback<DataTreeCandidate>() {
+ @Override
+ public void onSuccess(final DataTreeCandidate result) {
+ successfulDirectPreCommit(envelope);
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("PreCommit failed", failure));
+ readyCohort = null;
+ }
+ });
+ }
+
+ private void successfulDirectPreCommit(final RequestEnvelope envelope) {
+ readyCohort.commit(new FutureCallback<UnsignedLong>() {
+
+ @Override
+ public void onSuccess(final UnsignedLong result) {
+ successfulCommit(envelope);
+ }
+
+ @Override
+ public void onFailure(final Throwable failure) {
+ recordAndSendFailure(envelope, new RuntimeRequestException("DoCommit failed", failure));
+ readyCohort = null;
+ }
+ });
+ }
+
+ private void successfulCommit(final RequestEnvelope envelope) {
+ recordAndSendSuccess(envelope, new TransactionCommitSuccess(readyCohort.getIdentifier(),
+ envelope.getMessage().getSequence()));
+ readyCohort = null;
+ }
+
+ private void handleCommitLocalTransaction(final CommitLocalTransactionRequest request,
+ final RequestEnvelope envelope) throws RequestException {
+ if (sealedModification.equals(request.getModification())) {
+ readyCohort = history.createReadyCohort(id, sealedModification);
+
+ if (request.isCoordinated()) {
+ coordinatedCommit(envelope);
+ } else {
+ directCommit(envelope);
+ }
+ } else {
+ throw new UnsupportedRequestException(request);
+ }
+ }
+
+ private ExistsTransactionSuccess handleExistsTransaction(final ExistsTransactionRequest request)
+ throws RequestException {
+ final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
+ return recordSuccess(request.getSequence(), new ExistsTransactionSuccess(id, request.getSequence(),
+ data.isPresent()));
+ }
+
+ private ReadTransactionSuccess handleReadTransaction(final ReadTransactionRequest request) throws RequestException {
+ final Optional<NormalizedNode<?, ?>> data = openTransaction.getSnapshot().readNode(request.getPath());
+ return recordSuccess(request.getSequence(), new ReadTransactionSuccess(id, request.getSequence(), data));
+ }
+
+ private ModifyTransactionSuccess replyModifySuccess(final long sequence) {
+ if (cachedModifySuccess == null) {
+ cachedModifySuccess = new ModifyTransactionSuccess(id, sequence);
+ }
+
+ return recordSuccess(sequence, cachedModifySuccess);
+ }
+
+ private @Nullable TransactionSuccess<?> handleModifyTransaction(final ModifyTransactionRequest request,
+ final RequestEnvelope envelope) throws RequestException {
+
+ final DataTreeModification modification = openTransaction.getSnapshot();
+ for (TransactionModification m : request.getModifications()) {
+ if (m instanceof TransactionDelete) {
+ modification.delete(m.getPath());
+ } else if (m instanceof TransactionWrite) {
+ modification.write(m.getPath(), ((TransactionWrite) m).getData());
+ } else if (m instanceof TransactionMerge) {
+ modification.merge(m.getPath(), ((TransactionMerge) m).getData());
+ } else {
+ LOG.warn("{}: ignoring unhandled modification {}", history.persistenceId(), m);
+ }
+ }
+
+ final java.util.Optional<PersistenceProtocol> maybeProto = request.getPersistenceProtocol();
+ if (!maybeProto.isPresent()) {
+ return replyModifySuccess(request.getSequence());
+ }
+
+ switch (maybeProto.get()) {
+ case ABORT:
+ openTransaction.abort();
+ openTransaction = null;
+ return replyModifySuccess(request.getSequence());
+ case SIMPLE:
+ readyCohort = openTransaction.ready();
+ openTransaction = null;
+ directCommit(envelope);
+ return null;
+ case THREE_PHASE:
+ readyCohort = openTransaction.ready();
+ openTransaction = null;
+ coordinatedCommit(envelope);
+ return null;
+ default:
+ throw new UnsupportedRequestException(request);
+ }
+ }
+}
Code Review / controller.git / commitdiff