Read path scaffold + the byte→uint quality mapping table that the parity
matrix (PR 5.x) pins. PR 4.4 supplies the production GW-backed reader; this
PR ships the abstraction and the supporting infrastructure so 4.4 just
plugs the implementation in.
Files:
- Runtime/StatusCodeMap.cs — explicit OPC DA quality byte → OPC UA
StatusCode uint mapping. Extends the legacy Galaxy.Host
HistorianQualityMapper with named constants (Good / GoodLocalOverride,
Uncertain + 4 substatuses, Bad + 7 substatuses, BadInternalError) and an
MxStatusProxy → uint helper that honors success flag → detail byte →
detected_by transport-error fallback. Unknown bytes fall back to category
bucket with a once-per-session diagnostic log so field captures can
extend the table.
- Runtime/MxValueDecoder.cs — gateway MxValue → boxed CLR value for the
seven Galaxy data types (Boolean, Int32, Int64, Float32, Float64, String,
DateTime) plus their array variants. Honors MxValue.IsNull and
RawValue passthrough.
- Runtime/IGalaxyDataReader.cs — driver-side seam for one-shot reads. PR
4.4 ships the production wrapper around MxGatewaySession.SubscribeBulk +
StreamEvents + UnsubscribeBulk; this PR exposes the contract so
GalaxyDriver.ReadAsync wires through it.
- Runtime/GalaxyMxSession.cs — wrapper around MxGatewaySession that owns
the Register handle. ConnectAsync opens session + Register; AttachForTests
lets tests bypass real gw construction. PR 4.3/4.4/4.5 add write,
subscribe, and reconnect surfaces.
GalaxyDriver:
- Implements IReadable. ReadAsync routes through the injected
IGalaxyDataReader (test seam) when present; production path throws
NotSupportedException pointing at PR 4.4 — protects deployments running
this PR from silent wrong reads while signaling that the legacy-host
backend (Galaxy:Backend=legacy-host) handles reads in the meantime.
- Internal ctor extended with optional dataReader parameter (default null,
preserves PR 4.0/4.1 callers).
Tests: 42 new — exhaustive byte→uint table for StatusCodeMap (15 known
codes + category-bucket fallback for unknowns + MxStatusProxy precedence
rules + OPC UA top-byte invariants), every MxValue oneof case for the
decoder (bool/int32/int64/float/double/string/timestamp/3 array variants/
raw bytes/null), GalaxyDriver IReadable wiring (route-through, empty-
request, no-reader-throws, post-dispose-throws, status-code preservation).
62 Galaxy tests total pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
