Three real fixes + one architectural diagnosis:
1. Session::subscribe_buffered_nmx now sends the .NET-reference split
form on the wire:
item_definition = "<attr>.property(buffer)" (was: full reference)
item_context = "<object_tag_name>" (was: empty)
item_handle = SessionInner::next_item_handle.fetch_add(1)
(was: hardcoded 0)
Verified byte-identical against captures/082 + 094 by the existing
buffered_register_reference_parity unit tests. The
item_handle counter mirrors MxNativeCompatibilityServer's
_nextItemHandle++ at MxNativeSession.cs:613.
2. New live tests:
- tests/buffered_subscribe_live.rs (F49 step 1) — uses real Galaxy
metadata via SqlTagResolver + connect_nmx_auto, drives a
background writer at 500ms cadence to force value-changes,
drains DataChange events from Subscription.
- tests/plain_subscribe_live.rs — same harness over plain
Session::subscribe (NOT buffered), used to isolate whether
"no DataUpdate" is buffered-specific (it's not — both fail).
Both pull tracing-subscriber as a dev-dep so `RUST_LOG=trace`
surfaces dcom_sink + router activity.
3. mxaccess-galaxy/sql_resolver.rs: drop the inner-attribute
`#![cfg(feature = "galaxy-resolver")]` — the module-level cfg on
`pub mod sql_resolver` in lib.rs already handles this and Rust
1.85's clippy::duplicated_attributes lint flagged the duplicate
once mxaccess-compat dev-deps activated the feature.
4. F56 finding (diagnosis, NOT a bug fix): the engine on this Galaxy
install does not have an active value for TestChildObject.TestInt.
Confirmed by running the .NET reference's own probe:
dotnet run --project src/MxNativeClient.Probe -c Release \
-- --probe-session-subscribe --tag=TestChildObject.TestInt \
--subscribe-hold-seconds=10
...returns ONE 0x32 SubscriptionStatus (status=3 detail=3
quality=0x00C0 Uncertain value=null) and zero 0x33 DataUpdates —
matching the Rust port's symptom exactly. Not a Rust port bug,
not a wire-byte gap. F49 steps 1-3 need either an actively-
scanned tag or local Galaxy reconfiguration to scan
TestChildObject.TestInt.
Workspace tests + clippy clean under both feature configurations.
F56 entry in design/followups.md updated with the full diagnostic
chain so future-me / future-collaborators can pick it up without
re-tracing.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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 M2–M6 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
.csfile path insrc/MxNativeCodec/,src/MxNativeClient/, orsrc/MxAsbClient/, or - a
docs/*.mdspec file, or - a
captures/0NN-frida-*directory oranalysis/frida/*.tsvrow.
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.mdfor the per-phase parallelism map. - Driving M2–M6 autonomously via
/loop:prompt.md(and thefollowups.mdtriage log it maintains).