Three M6 sub-followups landed in this wave (sub-agent worktrees +
manual reconciliation in main):
**F36 — Session::subscribe_buffered (NMX) per R2 single-sample**
- `BufferedOptions::rounded_update_interval_ms()` — 100ms rounding
helper mirroring MxNativeCompatibilityServer.cs:638
((updateInterval + 99) / 100) * 100, saturating on overflow.
- `Session::subscribe_buffered` (public, lib.rs:604) delegates to
the new private `subscribe_buffered_nmx` which uses the buffered
RegisterReference path: item_definition suffixed with
`.property(buffer)`, subscribe=true (no separate
AdviseSupervisory follow-up — verified against capture 082).
- Per R2 verified at wwtools/mxaccesscli/docs/api-notes.md the wire
semantic is single-sample-per-event with a server-side cadence
knob; rounded_ms is held client-side only (native MXAccess does
not emit a separate SetBufferedUpdateInterval RPC, verified by
absence in 079/082 captures).
- New crates/mxaccess/examples/subscribe-buffered.rs.
- New crates/mxaccess-codec/tests/buffered_register_reference_parity.rs:
4 tests (capture 079/082 round-trip, suffix helper, constructive
forward-build vs capture 082).
**F40 — Optional metrics feature**
- New crates/mxaccess/src/metrics.rs (275 lines): `pub(crate)`
thin wrappers (`record_write_latency`, `record_read_latency`,
`inc_writes`, `inc_reads`, `inc_advises`, `inc_recovery_*`,
`set_active_subscriptions`, etc.) that compile to no-ops under
`#[cfg(not(feature = "metrics"))]`. Call sites in session.rs +
asb_session.rs invoke them unconditionally; the gate is inside
the wrapper.
- `metrics = { version = "0.24", optional = true }` added to
workspace + mxaccess crate Cargo.toml.
- Default build: zero metrics dep, zero runtime cost.
**F44 — Buffered batch + suspend capture decode evidence**
- New docs/M6-buffered-evidence.md: per-capture summary for
077, 079, 080, 081, 082, 094 — call sequence, key wire bytes,
R2/R5 verdict.
- R2 confirmed silently as "not a real risk" — single-sample
observed across 079/080/082/094.
- R5 trigger conditions documented from capture 077: AdviseSupervisory
+ Suspend pair, 1-second intervals, succeeds on enum attributes.
- design/70-risks-and-open-questions.md R2/R5 status updated.
Workspace: 759 → 792 tests, clippy clean, rustdoc -D warnings clean.
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).