Files
mxaccess/design
Joseph Doherty d149143535 [F49 steps 2 + 3] live verification: buffered recovery replay + unsubscribe skip
Step 3 (F47 buffered unsubscribe skip):
- crates/mxaccess-compat/tests/buffered_unsubscribe_skip_live.rs.
- Subscribe buffered, sleep so the engine has DataUpdates in flight,
  then call unsubscribe. Asserts Ok return without surfacing transport
  or HRESULT errors.
- Session::unsubscribe (session.rs:2261) probes the registry: if
  Buffered { .. }, it skips nmx.un_advise entirely, mirroring the .NET
  reference's `if (!subscription.IsBuffered)` guard at
  MxNativeSession.cs:361-381. If unsubscribe accidentally emitted
  UnAdvise for a buffered correlation id, the engine would return
  non-zero HRESULT (no matching plain advise to retract) — surfacing
  as a panic.

Step 2 (F45 buffered recovery replay):
- crates/mxaccess-compat/tests/buffered_recovery_replay_live.rs.
- Subscribe buffered, drain >=1 NMX subscription message
  (cmd=0x32 SubscriptionStatus + cmd=0x33 DataUpdate) to confirm the
  wire path is hot pre-recovery, install a RebuildFactory that calls
  NmxClient::create (the same auto-resolving COM-activation path
  Session::connect_nmx_auto uses), invoke recover_connection, drain
  >=1 NMX subscription message post-recovery.
- Verifies the replay branch in recover_connection_core re-issues
  RegisterReference (NOT AdviseSupervisory) for the buffered entry,
  mirroring MxNativeSession.ReAdviseSubscription (cs:538-569).
  Structural property is unit-tested; this confirms the engine
  actually picks back up after the rebuild + replay.

Both tests pass live on this Galaxy:
  cargo test -p mxaccess-compat --features live-windows-com \
      --test buffered_unsubscribe_skip_live -- --ignored --nocapture
  cargo test -p mxaccess-compat --features live-windows-com \
      --test buffered_recovery_replay_live -- --ignored --nocapture

Pulls mxaccess-nmx + mxaccess-codec into mxaccess-compat dev-deps so
the recovery test can build a RebuildFactory closure that returns
NmxClient and bind a typed broadcast Receiver.

design/followups.md F49 -> Resolved (all five steps pass live).
docs/M6-live-verification.md updated with per-step evidence + repro
commands.

F49 is fully closed out. F55 (DCOM-managed INmxSvcCallback, Path A)
and F56 (missing EnsurePublisherConnected + post-RegisterReference
AdviseSupervisory for buffered) were the two real Rust-port bugs
uncovered along the way; both resolved. Remaining post-V1 followups
(F50 Suspend/Activate Frida, F51 ASB type matrix, F52 perf, F53 doc
lint, etc.) are scoped independently and not part of F49.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 12:00:44 -04:00
..

design/ — Rust port architectural plan

This folder is the design contract for the Rust replacement of AVEVA/Wonderware MXAccess. It is the gap between the .NET reference in src/ and the Rust crates that will be written under a sibling rust/ workspace (per CLAUDE.md).

The folder is structured as a small set of focused documents. Read in order; each builds on the previous.

File Purpose
00-overview.md Mission, two-layer goal, architectural principles, non-goals
10-raw-layer.md Byte-accurate raw MXAccess layer (codec + transport + session)
20-async-layer.md Idiomatic Tokio async layer on top of the raw layer
30-crate-topology.md Cargo workspace, crates, dependencies, build/test commands
40-protocol-invariants.md Bill of materials: IIDs, opnums, envelope/handle bytes
50-error-model.md MxStatus, error types, panic/cancellation policy
60-roadmap.md Milestones M0..M6, validation strategy
70-risks-and-open-questions.md Parity gaps, unproven flows, cross-platform constraints
dependencies.md Cross- and within-milestone parallelism map; agent budget per phase
review.md Adversarial review log (BLOCKER/MAJOR/MINOR/NIT findings, all resolved)
prompt.md /loop driver prompt for autonomous M2M6 execution
followups.md Open / resolved deferred work items; auto-triaged by prompt.md Step 0 (created on first /loop run if missing)

The design is grounded in the .NET reference at src/ and the protocol artifacts in docs/, analysis/, and captures/. Do not introduce protocol behavior in these documents that is not already proven in the reference. When adding a new claim about wire format, cite either:

  • a .cs file path in src/MxNativeCodec/, src/MxNativeClient/, or src/MxAsbClient/, or
  • a docs/*.md spec file, or
  • a captures/0NN-frida-* directory or analysis/frida/*.tsv row.

This folder is documentation, not code. When the Rust workspace is created, the design here is the contract it must satisfy. When evidence in captures/ invalidates a design decision here, update the design first, then the code.

Reading order

  • New contributor: 00 → 30 → 10 → 40 → 20 → 50 → 60 → 70.
  • Protocol question: 40 first, then the relevant section of 10.
  • API question: 20 first, then 50.
  • Planning a milestone: 60 first, cross-reference 70 for blockers.
  • Scheduling concurrent work: dependencies.md for the per-phase parallelism map.
  • Driving M2M6 autonomously via /loop: prompt.md (and the followups.md triage log it maintains).