C1 (CRITICAL). AuthoredTable routed any wildcard-authored tag into `Wildcards`
and never into the concrete topic index. But the two paths that reconstruct
state from a SUBSCRIBED FILTER STRING — OnReconnectedAsync's re-subscribe set
and DegradeTopic — both looked up that concrete-only index, and
`_subscribedTopics` keys on the wildcard PATTERN ("f/+/temp"). So:
- reconnect resolved zero filters for a wildcard tag, hit a silent early
return, and issued NO subscribe. The cache keeps its last Good value, so the
tag never turns Bad — it just stops updating forever behind a connection
reporting healthy. Exactly the silent-death mode MqttConnection's own remarks
warn about, left unguarded for wildcards.
- DegradeTopic missed too, so a SUBACK rejection of a wildcard filter degraded
nothing and left the tag at BadWaitingForInitialData.
Fix: AuthoredTable now carries `ByFilter` (EVERY def, keyed by its authored
topic filter, wildcards included) alongside `ByExactTopic` (concrete only) and
`Wildcards`. Delivery matches an incoming published topic — which never carries
a wildcard — so it keeps using ByExactTopic + the comparer scan. Every path
keyed on a filter string uses ByFilter. The distinction is documented on the
record. The silent early return is now a Warning naming the orphaned topics.
Also in this pass:
- I2: bounded decode on the dispatcher thread. A body over `MaxPayloadBytes`
(default 1 MiB, ctor-settable) is refused BEFORE any GetString/JsonDocument
parse and degrades its own tags. Unbounded decode on the shared dispatcher is
paid by every subscription, not just the offending topic. NOTE: promoting this
to an operator-facing MqttDriverOptions key (+ WithMaximumPacketSize) needs a
.Contracts edit this task is scoped out of; flagged in the XML docs.
- I3: integral-valued reals now coerce to integer tags. JS/Python edge gateways
serialize an integer as 5.0, and TryGetInt32/int.TryParse are syntactic — an
Int32 tag fed by such a gateway silently never received data. Parsed via
decimal so integrality and range are exact across Int64/UInt64. A genuinely
fractional 5.5 is still refused, never rounded.
- I4: the JSON document is parsed ONCE per message and shared across the whole
fan-out (the documented "one document, one JSONPath per signal" shape was
re-parsing per tag). Zero-alloc via a ref struct when no Json tag matches.
- I5: pinned the documented JSON-string-holding-a-number coercion end-to-end.
- Minor: Register now prunes `_subscribedTopics` / `_handleByRawPath` entries for
tags a redeploy dropped, so a deleted topic stops being re-subscribed forever.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
MqttSubscriptionManager is the P1 plain-MQTT ingest path: it holds the authored
RawPath → MqttTagDefinition table behind the shared EquipmentTagRefResolver,
establishes one SUBSCRIBE per distinct authored topic, and turns each inbound
message into a LastValueCache update plus an OnDataChange notification.
Load-bearing choices, each pinned by a falsified test:
- The published reference IS the RawPath (def.Name), never the topic and never
the TagConfig blob — DriverHostActor's dual-namespace fan-out is RawPath-keyed,
so any other key passes every unit test and delivers nothing in production.
- One message fans out to EVERY tag on its topic; several tags routinely share a
topic with different jsonPaths, and stopping at the first match silently starves
the rest.
- An unauthored topic raises nothing: MQTT ingest never auto-provisions.
- Wildcard-authored topics (accepted by the parser, warned at deploy) match via
MQTTnet's own MqttTopicFilterComparer, so '+'/'#' behave as a broker would.
Concrete topics stay a single lookup; the wildcard scan runs only when one exists.
- Retained seeds are honoured natively on MQTT 5.0 (retain handling) AND filtered
client-side on the retain flag, because 3.1.1 brokers always replay.
- Nothing throws on MQTTnet's dispatcher thread: a malformed payload degrades that
tag (BadDecodingError / BadTypeMismatch), and a throwing OnDataChange subscriber
is contained without starving the tags behind it.
- The manager issues the FIRST subscribe itself — Reconnected deliberately does not
fire after the initial ConnectAsync.
- Reconnect re-subscribe: total failure THROWS (MqttConnection then tears the
session down and retries under backoff, rather than serving a connected-but-deaf
driver); a partial SUBACK rejection degrades only the denied refs, because
retrying forever over one ACL-denied topic would take every tag dark.
MqttConnection gains a MessageReceived observer (fired on the dispatcher, throwing
observers contained) and a bounded SubscribeAsync under its own linked-CTS deadline
— deliberately not MqttClientOptions.Timeout, which already governs every MQTTnet
op. A refused filter is an outcome, not an exception; only the SUBSCRIBE itself
failing throws. Classify() is parameterised by operation name (messages unchanged
for connect).
JSONPath is a documented subset ($, $.a.b, $['a'], $.a[0]); filters/slices/
recursive descent report a miss rather than pulling in a JSONPath package for an
expression form that selects a set where a tag needs one scalar.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Closes the connect-vs-connect defect: MQTTnet throws (and raises no DisconnectedAsync)
on a connect-while-connected, so a caller's ConnectAsync and the reconnect supervisor
corrupted each other in both directions. Both paths now check first; when the supervisor
finds the session already restored it stands down WITHOUT firing Reconnected.
Reconnected becomes Func<CancellationToken, Task>, fed from the lifetime token and capped
at ConnectTimeoutSeconds, so a hung re-subscribe can no longer park the supervisor.
Connected is published only after the re-subscribe succeeds; a supervisor that dies now
reports Faulted instead of Reconnecting forever.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
LastValueCache bridges MQTT's subscribe-first push model to the OPC UA
server's polled IReadable.ReadAsync: the subscription path calls Update()
per RawPath, the read path calls Read(). Read never throws; an unseen
RawPath returns BadWaitingForInitialData (0x80320000) rather than an
exception or null, so a batch covering many references degrades per-ref
instead of failing wholesale.
Deviates from the plan's GoodNoData snippet: GoodNoData is reserved
repo-wide for "the historian window held no samples" (NullHistorianDataSource,
OtOpcUaNodeManager HistoryRead paths); BadWaitingForInitialData is the
established convention for "no live value observed yet" (CalculationDriver,
VirtualTagEngine, FOCAS, AddressSpaceApplier). Keyed by RawPath per the v3
driver-reference identity, not a topic/JSON-path-derived key.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Review follow-ups on MqttConnection (Task 3):
- Every certificate test asserted rejection, so the accept branch was
unreachable-by-regression. Adds a leaf genuinely issued by the pinned CA and
asserts acceptance.
- ValidateAgainstPinnedCa never seeded ChainPolicy.ExtraStore from the incoming
chain, so a leaf behind an intermediate delivered during the handshake failed
despite a legitimate path to the pinned root. Seeds from both the incoming
chain's elements and its ExtraStore; CustomRootTrust still means only the
pinned roots may terminate the chain.
- A DisposeAsync racing an in-flight connect escaped as an unclassified
exception; it now folds into ObjectDisposedException.
- Promotes the single-caller concurrency invariant into the type remarks, with
the accurate blast radius (a leaked live connection, not a benign throw).
Serialising the lifecycle remains Task 4's job.
- X509Chain.Build can throw; an exception escaping a TLS validation callback is
an opaque handshake crash, so it is caught and refused.
- Adds a connect-retry test (Task 4's reconnect loop reuses the instance) and a
disposed-then-connect test.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty