Invoke deep-cloned the whole MxCommandRequest — including its command
payload, potentially a large bulk-write graph — only to overwrite the
cloned command with commandToInvoke and discard it. MapCommand then did
the one clone actually needed. Net cost: a full wasted command deep-clone
per Invoke, worst for exactly the bulk writes that are largest.
Adds a MapCommand(MxCommand) overload (MapCommand reads nothing else off
the request) and has Invoke pass commandToInvoke directly; the request
overload delegates so other callers are untouched.
The remaining clone inside MapCommand stays and is now documented as
required rather than incidental: commandToInvoke may be the gRPC-owned
request.Command, and the caller reads it again after dispatch via
TrackCommandReply, so ownership transfer (à la GWC-07) is not safe here.
That clone is what keeps WorkerClient.CreateCommandEnvelope's no-aliasing
invariant true.
Tests: MxAccessGrpcMapperTests.MapCommandFromCommandClonesPayload
(mutating the input leaves the mapped command untouched; both overloads
produce equal results under a fixed TimeProvider).
Joseph Doherty
a044f92c5d