Closes the highest-value remaining IASBIDataV2 op. With Write landed,
the read+write+subscribe path is functionally complete in-memory.
API additions:
* `MinimalWriteValue { value: AsbVariant }` — carries just the Value
payload. Optional ArrayElementIndex / Comment / HasQT / Status /
Timestamp fields are deferred to a later iteration once a live
capture confirms the WCF DataContract XML form.
* `build_write_request_body(items, values, write_handle)` per
`AsbContracts.cs:181-194`:
```xml
<WriteBasicRequest xmlns="urn:msg.data.asb.iom:2">
<Items><ASBIData>{ItemIdentity[] binary}</ASBIData></Items>
<Values>
<WriteValue><Value><ASBIData>{Variant binary}</ASBIData></Value></WriteValue>
...
</Values>
<WriteHandle>{i32}</WriteHandle>
</WriteBasicRequest>
```
Items array uses the IAsbCustomSerializableType binary fast-path;
each Value's inner Variant also uses the fast-path. WriteHandle is
an Int32 (opaque correlation echoed in PublishWriteComplete).
* `decode_write_response` — per-item Status array (mirrors the
unregister/register pattern).
* `AsbClient::write(items, values, write_handle)` — thin wrapper.
4 new tests:
* `write_request_body_carries_items_values_and_write_handle` — body
shape sanity (WriteHandle = 7 Int32, WriteValue element present).
* `write_request_body_pairs_items_and_values_arrays` — 2 items + 2
values produces 2 WriteValue elements.
* `write_response_round_trips_status_array` — Status decode.
* `write_response_missing_status_fails` — graceful MissingField
error.
Workspace: 695 tests pass (was 691, +4).
Stubbed for next F25 iterations:
* `PublishWriteComplete` — empty request, `ItemWriteComplete[]`
response.
* `DeleteMonitoredItems` — mirrors AddMonitoredItems pattern.
* Optional WriteValue fields (Comment / Timestamp / etc.) once a
live capture confirms the wire-byte layout.
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).