Files
mxaccess/rust
Joseph Doherty f2f22dfcd1
rust / build / test / clippy / fmt (push) Has been cancelled
[F26 stream] mxaccess: AsbSession::subscribe — Stream<Item = MonitoredItemValue>
Closes the last F26 stub from the M5 status block. New
AsbSession::subscribe(subscription_id) returns an AsbSubscription
that impls Stream<Item = Result<MonitoredItemValue, Error>>. An
internal tokio::spawn'd publish-loop drains the subscription queue
via the existing AsbSession::publish() and fans each
PublishResponse's `values` array out as individual stream items.

Termination semantics:
  - Drop of AsbSubscription calls JoinHandle::abort() — the publish
    task stops draining the server-side queue (the .NET reference
    pattern at MxAsbDataClient.cs uses the same task-cancellation
    shape).
  - Transport error from publish() is delivered as the final stream
    item; the loop returns and the channel closes.
  - Receiver-drop (consumer stops polling) is detected when
    tx.send returns Err — the loop exits without making more
    publish calls.

The inner publish_loop helper takes any FnMut() -> Future<Result<...>>
so it's testable in isolation (no live ASB endpoint required).

Per-item ItemStatus from the server is intentionally not surfaced
on the stream: the field is opaque per-item and rarely actionable
for the streaming consumer. A richer struct can wrap each value if
that need surfaces.

3 new tests pin:
  - asb_subscription_is_stream_send_unpin (compile-time bounds);
  - publish_loop_delivers_values_then_terminates_on_error
    (3 Ok values from 2 batches, then 1 terminal Err);
  - publish_loop_exits_when_consumer_drops_channel.

New deps used (already in mxaccess Cargo.toml): futures_util::Stream,
tokio::sync::mpsc, tokio_stream::wrappers::ReceiverStream,
tokio::task::JoinHandle.

Workspace: 718 → 721 tests. Default-feature clippy clean.
mxaccess crate-level doc updated to drop the "stubbed for next F26
iteration" note for the subscription stream.

design/followups.md F18 M5 status block updated: F26 stream
subscription marked resolved.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 01:10:22 -04:00
..

mxaccess (Rust port)

Native Rust replacement for AVEVA / Wonderware MXAccess. See ../design/ for the architectural specification, ../src/ for the .NET reference (the executable spec), and ../CLAUDE.md for project-wide rules.

Status

M0 — Workspace skeleton. Stub types compile; nothing is implemented yet. See ../design/60-roadmap.md for the M0M6 milestone plan.

Layout

rust/
  Cargo.toml                 workspace root
  rust-toolchain.toml        1.85 stable
  crates/
    mxaccess-codec/          pure protocol codec, no I/O
    mxaccess-galaxy/         Galaxy SQL resolver (tiberius)
    mxaccess-rpc/            DCE/RPC + NTLMv2 + OXID + OBJREF
    mxaccess-callback/       INmxSvcCallback RPC server
    mxaccess-nmx/            INmxService2 client
    mxaccess-asb-nettcp/     net.tcp framing (MC-NMF + MC-NBFX/NBFS)
    mxaccess-asb/            IASBIDataV2 client
    mxaccess/                async session + Transport trait + public API
    mxaccess-compat/         LMXProxyServer-shaped facade

Build

cargo build --workspace
cargo test --workspace
cargo clippy --workspace -- -D warnings
cargo fmt --check

Live probes

. ..\tools\Setup-LiveProbeEnv.ps1
cargo test -p mxaccess --features live -- --ignored

The setup script fetches credentials from Infisical via wwtools/secrets/Get-Secret.ps1. Never inline plaintext credentials.

License

MIT — see ../LICENSE.