aweisberg commented on code in PR #80: URL: https://github.com/apache/cassandra-accord/pull/80#discussion_r1501081497
########## accord-core/src/main/java/accord/coordinate/CoordinateEphemeralRead.java: ########## @@ -0,0 +1,124 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package accord.coordinate; + +import java.util.ArrayList; +import java.util.List; +import java.util.Set; + +import accord.api.Result; +import accord.coordinate.tracking.QuorumTracker; +import accord.local.CommandStore; +import accord.local.Node; +import accord.messages.Callback; +import accord.messages.GetEphemeralReadDeps; +import accord.messages.GetEphemeralReadDeps.GetEphemeralReadDepsOk; +import accord.primitives.Deps; +import accord.primitives.FullRoute; +import accord.primitives.Txn; +import accord.primitives.TxnId; +import accord.topology.Topologies; +import accord.utils.async.AsyncResult; +import accord.utils.async.AsyncResults; + +import static accord.coordinate.tracking.RequestStatus.Failed; +import static accord.coordinate.tracking.RequestStatus.Success; + +public class CoordinateEphemeralRead extends AbstractCoordinatePreAccept<Result, GetEphemeralReadDepsOk> +{ + public static AsyncResult<Result> coordinate(Node node, FullRoute<?> route, TxnId txnId, Txn txn) + { + TopologyMismatch mismatch = TopologyMismatch.checkForMismatch(node.topology().globalForEpoch(txnId.epoch()), txnId, route.homeKey(), txn.keys()); + if (mismatch != null) + return AsyncResults.failure(mismatch); + + Topologies topologies = node.topology().withUnsyncedEpochs(route, txnId, txnId); + CoordinateEphemeralRead coordinate = new CoordinateEphemeralRead(node, topologies, route, txnId, txn); + coordinate.start(); + return coordinate; + } + + private final QuorumTracker tracker; + private final List<GetEphemeralReadDepsOk> oks; + private long executeAtEpoch; + + CoordinateEphemeralRead(Node node, Topologies topologies, FullRoute<?> route, TxnId txnId, Txn txn) + { + super(node, route, txnId, txn); + this.tracker = new QuorumTracker(topologies); + this.executeAtEpoch = txnId.epoch(); + this.oks = new ArrayList<>(topologies.estimateUniqueNodes()); + } + + @Override + void contact(Set<Node.Id> nodes, Topologies topologies, Callback<GetEphemeralReadDepsOk> callback) + { + CommandStore commandStore = CommandStore.maybeCurrent(); + if (commandStore == null) commandStore = node.commandStores().select(route.homeKey()); + node.send(nodes, to -> new GetEphemeralReadDeps(to, topologies, route, txnId, txn.keys(), executeAtEpoch), commandStore, callback); + } + + @Override + long executeAtEpoch() + { + return executeAtEpoch; + } + + @Override + public void onSuccessInternal(Node.Id from, GetEphemeralReadDepsOk ok) + { + oks.add(ok); + if (ok.latestEpoch > executeAtEpoch) + executeAtEpoch = ok.latestEpoch; + + if (tracker.recordSuccess(from) == Success) + onPreAcceptedOrNewEpoch(); + } + + @Override + boolean onExtraSuccessInternal(Node.Id from, GetEphemeralReadDepsOk ok) + { + if (ok.latestEpoch > executeAtEpoch) + executeAtEpoch = ok.latestEpoch; + + oks.add(ok); + return true; + } + + @Override + public void onFailureInternal(Node.Id from, Throwable failure) + { + if (tracker.recordFailure(from) == Failed) + setFailure(new Timeout(txnId, route.homeKey())); + } + + @Override + void onNewEpochTopologyMismatch(TopologyMismatch mismatch) + { + accept(null, mismatch); + } + + @Override + void onPreAccepted(Topologies topologies) + { + Deps deps = Deps.merge(oks, ok -> ok.deps); + new ExecuteEphemeralRead(node, topologies, route, txnId, txn, executeAtEpoch, deps, this).start(); Review Comment: To close the loop on this. Ephemeral reads *do* execute in their `executeAt` epoch, it's validated according to Benedict. I haven't found where yet though. So that means the code in `TxnQuery` that validates things will be able to work. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
