bdeggleston commented on code in PR #49: URL: https://github.com/apache/cassandra-accord/pull/49#discussion_r1223293448
########## accord-core/src/main/java/accord/impl/AbstractFetchCoordinator.java: ########## @@ -0,0 +1,288 @@ +/* + * 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.impl; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import javax.annotation.Nullable; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import accord.api.Data; +import accord.api.DataStore; +import accord.coordinate.FetchCoordinator; +import accord.local.CommandStore; +import accord.local.Node; +import accord.local.Status; +import accord.messages.Callback; +import accord.messages.MessageType; +import accord.messages.ReadData; +import accord.messages.WaitAndReadData; +import accord.primitives.PartialDeps; +import accord.primitives.PartialTxn; +import accord.primitives.Ranges; +import accord.primitives.SyncPoint; +import accord.primitives.Timestamp; +import accord.primitives.TxnId; +import accord.utils.Invariants; +import accord.utils.async.AsyncChains; +import accord.utils.async.AsyncResult; +import accord.utils.async.AsyncResults; + +import static accord.primitives.Routables.Slice.Minimal; + +public abstract class AbstractFetchCoordinator extends FetchCoordinator +{ + private static final Logger logger = LoggerFactory.getLogger(AbstractFetchCoordinator.class); + + static class FetchResult extends AsyncResults.SettableResult<Ranges> implements DataStore.FetchResult + { + final AbstractFetchCoordinator coordinator; + + FetchResult(AbstractFetchCoordinator coordinator) + { + this.coordinator = coordinator; + } + + @Override + public void abort(Ranges abort) + { + coordinator.abort(abort); + } + } + + static class Key + { + final Node.Id id; + final Ranges ranges; + + Key(Node.Id id, Ranges ranges) + { + this.id = id; + this.ranges = ranges; + } + + @Override + public int hashCode() + { + return id.hashCode() + ranges.hashCode(); + } + + @Override + public boolean equals(Object obj) + { + if (this == obj) return true; + if (!(obj instanceof Key)) return false; + Key that = (Key) obj; + return id.equals(that.id) && ranges.equals(that.ranges); + } + } + + final DataStore.FetchRanges fetchRanges; + final CommandStore commandStore; + final Map<Key, DataStore.StartingRangeFetch> inflight = new HashMap<>(); + final FetchResult result = new FetchResult(this); + final List<AsyncResult<Void>> persisting = new ArrayList<>(); + + protected AbstractFetchCoordinator(Node node, Ranges ranges, SyncPoint syncPoint, DataStore.FetchRanges fetchRanges, CommandStore commandStore) + { + super(node, ranges, syncPoint, fetchRanges); + this.fetchRanges = fetchRanges; + this.commandStore = commandStore; + } + + protected abstract PartialTxn rangeReadTxn(Ranges ranges); + + protected abstract void onReadOk(Node.Id from, CommandStore commandStore, Data data, Ranges ranges); + + @Override + public void contact(Node.Id to, Ranges ranges) + { + Key key = new Key(to, ranges); + inflight.put(key, starting(to, ranges)); + Ranges ownedRanges = ownedRangesForNode(to); + Invariants.checkArgument(ownedRanges.containsAll(ranges)); + PartialDeps partialDeps = syncPoint.waitFor.slice(ownedRanges, ranges); + node.send(to, new FetchRequest(syncPoint.sourceEpoch(), syncPoint.syncId, ranges, partialDeps, rangeReadTxn(ranges)), new Callback<ReadData.ReadReply>() + { + @Override + public void onSuccess(Node.Id from, ReadData.ReadReply reply) + { + if (!reply.isOk()) + { + fail(to, new RuntimeException(reply.toString())); + inflight.remove(key).cancel(); + switch ((ReadData.ReadNack) reply) + { + default: throw new AssertionError("Unhandled enum"); + case Invalid: + case Redundant: + case NotCommitted: + throw new AssertionError(); + case Error: + // TODO (required): ensure errors are propagated to coordinators and can be logged + } + return; + } + + FetchResponse ok = (FetchResponse) reply; + Ranges received; + if (ok.unavailable != null) + { + unavailable(to, ok.unavailable); + if (ok.data == null) + { + inflight.remove(key).cancel(); + return; + } + received = ranges.difference(ok.unavailable); + } + else + { + received = ranges; + } + + // TODO (now): make sure it works if invoked in either order + inflight.remove(key).started(ok.maxApplied); + onReadOk(to, commandStore, ok.data, received); + // received must be invoked after submitting the persistence future, as it triggers onDone + // which creates a ReducingFuture over {@code persisting} + } + + @Override + public void onFailure(Node.Id from, Throwable failure) + { + inflight.remove(key).cancel(); + fail(from, failure); + } + + @Override + public void onCallbackFailure(Node.Id from, Throwable failure) + { + // TODO (soon) + logger.error("Fetch coordination failure from " + from, failure); + } + }); + } + + @Override + protected synchronized void success(Node.Id to, Ranges ranges) + { + super.success(to, ranges); + } + + @Override + protected synchronized void fail(Node.Id to, Ranges ranges, Throwable failure) + { + super.fail(to, ranges, failure); + } Review Comment: I don't think I did that, but I imagine it would have been done to avoid imposing a concurrency strategy on the base class. We can move it up to FetchCoordinator if you'd like -- 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]
