Joseph Doherty
a31237d1d0
F15 step 2/2 lands the per-Subscription routing on top of step 1's broadcast layer. Subscription is now a working data-change stream. Subscription type - Now impls futures_util::Stream<Item = Result<DataChange, Error>> via tokio_stream::wrappers::BroadcastStream + a per-message filter. - No longer Clone (broadcast::Receiver isn't Clone). Consumers that want fanout subscribe twice or share via Arc<Mutex<...>>. - Holds the broadcast::Receiver subscribed BEFORE AdviseSupervisory fires — guarantees no updates between advise and stream-creation are dropped. - pending VecDeque buffers records from the current message so each poll_next yields at most one DataChange (Stream contract). Filter logic (records_to_data_changes, mirrors cs:333-343) - 0x32 SubscriptionStatus: keep when msg.item_correlation_id == subscription.correlation_id; drop otherwise. - 0x33 DataUpdate: keep ALL — codec exposes no per-record correlation field, and the .NET filter only checks item_correlation_id (which 0x33 doesn't carry), so DataUpdates fan out to every active subscription. Matches .NET behavior verbatim. - Records with value: None drop silently (mirrors evt.Record.Value is null filter at cs:337). - BroadcastStream Lagged(n) maps to Error::Configuration with the lag count in the detail string. Helpers - filetime_to_system_time(i64) -> SystemTime: inverse of system_time_to_filetime; saturates at Unix epoch for FILETIMEs before 1970 since SystemTime can't portably represent pre-epoch. - record_to_data_change(record, reference) -> Option<DataChange>: builds DataChange from one record, returns None for unparseable value (the codec couldn't decode the wire kind). - Status currently hardcoded to MxStatus::DATA_CHANGE_OK (mirrors NmxSubscriptionRecord.ToDataChangeStatus at NmxSubscriptionMessage.cs:22-25 which the .NET reference itself stubs to the OK constant). Cargo.toml additions: futures-util (workspace) + tokio-stream (0.1 with sync feature for BroadcastStream). Tests (5 new in mxaccess; total 40) - subscription_stream_yields_data_change_for_matching_correlation: build a 0x32 SubscriptionStatus with one Int32 record and the subscription's correlation id, inject through test_inject_sender, observe the DataChange (reference, value, quality match) on the Stream. - subscription_stream_filters_out_mismatched_correlation_for_status: inject 0x32 with wrong correlation id, assert the stream stays pending (timeout-as-success). - subscription_stream_keeps_data_update_regardless_of_correlation: inject 0x33 DataUpdate with one Int32 record (no correlation field on the message); stream still yields the DataChange. - filetime_to_system_time_round_trip: build a SystemTime with .005s precision, round-trip through both helpers, assert equality. - filetime_to_system_time_pre_unix_epoch_saturates: FILETIME 0 (year 1601) → SystemTime::UNIX_EPOCH (saturating clamp). design/followups.md: F15 moved to Resolved with both step commits referenced. Open list: 9 items (was 10). Test count delta: 511 -> 516 (+5). All four DoD gates green. 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).