Files
mxaccess/design
Joseph Doherty b66f5bb018
rust / build / test / clippy / fmt (push) Has been cancelled
[F34 evidence] capture AddMonitoredItems request wire + decoder trace
Investigation continued via examples/asb-relay.rs middleman:
captured the .NET probe's verbatim AddMonitoredItems request bytes
(695 bytes with the 3-byte NMF SizedEnvelope header). Saved at
rust/crates/mxaccess-asb/tests/fixtures/add-monitored-items-request-wire.bin
as the ground-truth shape MxDataProvider actually accepts.

New tests/add_monitored_items_request_capture.rs runs decode_envelope
over the capture and dumps every NBFX token to stderr for inspection.

Decoded trace surfaces a SECOND, deeper issue:

The F30 dynamic-dict-resolution post-pass at
envelope.rs::resolve_dict_names_in_tokens mis-maps per-session dict
ids. Decoding the captured request renders namespace-URL slots as
field-name strings:

  body[1]=DefaultNamespace { value: Chars("nameField") }   ← bogus
  body[7]=NamespaceDeclaration { prefix: "i",
                                 value: Chars("activeField") }  ← bogus

and leaves most element names as `Static(NN)` instead of resolving
to inline names like `activeField` / `bufferedField` / `itemField`.

This blocks F34's substantive fix (rewrite
build_add_monitored_items_request_body to use DataContract
field-suffix names matching the wire). We can't validate the
rewritten builder against the captured fixture until the dict
post-pass produces the right strings.

design/followups.md F34 updated with two-prerequisite resolution
plan:
  1. Fix the F30 dynamic-dict resolution so the captured request
     decodes to recognisable inline names.
  2. Rewrite the AddMonitoredItems / DeleteMonitoredItems builders
     against the now-readable structure (DataContract field names
     + namespace prefixes for ASBIDataV2Contract / ASBContract +
     nested DataContract serialization of ItemIdentity inside
     `<itemField>` and Variants inside userDataField /
     valueDeadbandField).

Workspace: mxaccess-asb 96 → 97 (+1 capture-driven analysis test);
default-feature clippy clean. The HMAC canonical-XML signing path
remains correct (F28 fixtures are byte-equal to .NET); only the
binary NBFX wire body needs the rewrite.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 02:58:25 -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).