Files
mxaccess/design
Joseph Doherty fb40e4c20b
rust / build / test / clippy / fmt (push) Has been cancelled
[F34 partial] mxaccess-asb: fix collect_asbidata_payloads + add Active flag
Investigation via examples/asb-relay.rs middleman captured the full
S→C bytes of a working PublishResponse from the .NET probe against
MxDataProvider. Decoder fix verified by regression test against the
captured fixture; one further wire-format gap surfaced and is filed.

Closed in this commit:

1. collect_asbidata_payloads filtered out empty <ASBIData/> elements
   so positional payload[N] indexing collapsed when Status was
   empty-but-present. The wire form for PublishResponse is:
     <Status><ASBIData/></Status>          ← empty placeholder
     <Values><ASBIData>{bytes}</ASBIData></Values>
   Our decoder lost the positional info and read Values as Status,
   then panicked on the malformed parse. Fix: always push every
   <ASBIData> element (empty or not) so payloads[0]=Status and
   payloads[1]=Values stay aligned. New regression test
   tests/publish_capture.rs runs the full decode chain over the
   captured wire bytes (305-byte frame at
   tests/fixtures/publish-response-with-value.bin) and asserts
   values.len() == 1.

2. MinimalMonitoredItem.active: Option<bool> + new with_active()
   constructor. The .NET reference's MxAsbDataClient.AddMonitoredItems
   defaults to active: true (cs:441). Without <Active>true</Active>
   on the wire, MxDataProvider treats the subscription as inactive
   and Publish polls return empty Values. Both binary build and
   canonical XML emitters now conditionally emit <Active> when
   active.is_some(). Shared push_monitored_item_body helper
   eliminates the duplicate MonitoredItem encoder between
   AddMonitoredItems and DeleteMonitoredItems builders.

3. SampleInterval unit: clarified as **milliseconds** in
   MinimalMonitoredItem.sample_interval doc + the example
   (sample_interval_ticks → sample_interval_ms = 1000). Matches the
   .NET reference's `ulong sampleInterval = 1000` default.

Open: F34's deeper finding — `MonitoredItem`'s wire schema is
DataContract field-suffix names (`activeField`, `bufferedField`,
`itemField`, `sampleIntervalField`, etc., per the per-session NBFX
dictionary the .NET probe declares), NOT XmlSerializer property
names (`Active`, `Buffered`, `Item`, `SampleInterval`). Our binary
NBFX builder still uses the property names, so MxDataProvider
silently fails to register monitored items — successField=true with
a 0-length Status array. The fix needs a complete rebuild of
build_add_monitored_items_request_body and
build_delete_monitored_items_request_body to use the field-suffix
names plus emit the *Specified siblings (activeFieldSpecified,
idFieldSpecified, etc.) as their own elements. The HMAC canonical
XML side is unaffected (XmlSerializer naming is correct there;
verified byte-equal to .NET via the F28 fixtures). Detailed in
design/followups.md F34's "Open" section.

Live verification of the F34-partial bonus context:
  - Read still returns 99 end-to-end via canonical XML signing.
  - AddMonitoredItems still returns Status[0] = 0 items
    (server doesn't recognize our DataContract-misnamed payload).
  - Publish still returns 0 values (the F34-open consequence).
  - All other 13 canonical-XML signed ops succeed at the request
    level (no SOAP faults, no HMAC rejections).

Workspace: mxaccess-asb 95 → 96 (+1 capture-driven decoder test);
default-feature clippy clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 02:49:11 -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).