Commit Graph

4 Commits

Author SHA1 Message Date
Joseph Doherty b29623cf99 feat(mtconnect): IWritable via agent observation writes
MTConnectDriver now implements IWritable over the Task-1 agent-client seam
(WriteObservationAsync -> the Agent's AllowPut POST surface). A write is
OBSERVATION INJECTION, not machine command: it sets what the Agent reports for
a DataItem, is visible to every consumer of that Agent, and is overwritten by
the next adapter/SHDR update. Off at two independent gates, both off by default
- the Agent's own AllowPut and the driver's write.enabled (Task 0).

Per-slot refusal order (never throws, strict N-in/N-out batch shape):
  write disabled          -> BadNotWritable
  no live client          -> BadNotConnected  (ReadAsync's existing convention)
  reference unresolved    -> BadNodeIdUnknown
  no resolvable device    -> BadNodeIdUnknown
  CONDITION category      -> BadNotWritable
  null / non-scalar value -> BadTypeMismatch
  agent refusal OR throw  -> BadCommunicationError
OperationCanceledException fills the remaining slots and returns. The Agent's
refusal text is logged at Warning and never enters DriverHealth.LastError
(type-only discipline); a refused write leaves health untouched.

Device-name resolution: TagBinding gains WriteTargetsByDataItemId, built in
BuildBinding from a probe-model walk that remembers which device each DataItem
was declared under (name, or id when nameless) plus its category. Falls back to
options.DeviceName; unresolvable -> BadNodeIdUnknown rather than a guess.
Values render via Convert.ToString(..., InvariantCulture) - so a Boolean writes
the invariant string "True"/"False", NOT "1"/"0". Arrays are refused rather
than rendered: Convert.ToString would emit the literal "System.Double[]", which
the Agent stores happily and which is invisible until read-back.

FINDING - the CurrentWrite bit does NOT key on SecurityClassification, and the
discovery stamping below is therefore cosmetic. Traced end to end: a browsed
leaf's SecurityClass survives into the browse session's AttributeInfo
(CapturedTreeBrowseSession.cs:53) and stops there - RawBrowseModal never reads
it, RawBrowseCommitMapper.MapLeaf hardcodes TagAccessLevel.Read, and Tag has no
SecurityClass column. AddressSpaceComposer:746/:809 sets Writable purely from
Tag.AccessLevel == ReadWrite; AddressSpaceApplier ANDs !IsArray;
OtOpcUaNodeManager.ComposeAccessLevel:2002 composes CurrentWrite from that
alone. Driver capability is never consulted at compose time either - IWritable
is checked only at runtime in DriverInstanceActor:755. Consequences: (a) raw
tags already committed keep their authored AccessLevel, so nothing this commit
does makes an existing node writable; (b) an operator must still set the tag to
ReadWrite for an MTConnect write to be reachable over OPC UA; (c) conversely a
ReadWrite tag on a non-IWritable driver has always advertised CurrentWrite and
failed only at the actor - pre-existing, not touched here.

Discovery stamps CanWrite(writeEnabled, dataItem) = write.enabled && !CONDITION
-> Operate, else ViewOnly - kept honest so the browse never advertises a tier
the write path would refuse (MQTT's CanWrite principle), with the caveat above
recorded verbatim at the call site.

Status-code constants are spelled WITHOUT MqttDriver's "Status" prefix, to
match the two this file already declares (BadCommunicationError,
BadNotConnected). StatusCodeParityTests strips either spelling and passes.

TDD: WriteAsync landed first as a NotImplementedException scaffold - 19 of 20
new tests red on behaviour, 1 (the capability assertion) green on the scaffold
- then implemented. MTConnectFactoryTests' "not_writable" characterization test
is rewritten to pin the new truth, and is the guard for the concrete-return
contract the factory remark explains.

Tests: 532 passed / 0 failed (was ~509). Full solution build: 0 errors,
0 warnings; OTOPCUA0001 clean.
2026-08-05 06:36:08 -04:00
Joseph Doherty b815446940 refactor(drivers): delete GetMemoryFootprint / FlushOptionalCachesAsync (#525)
Both `IDriver` members had no production call site. Their only consumer was
`MemoryTracking`, deleted with the driver-tier recycle machinery in #522, and
`GetMemoryFootprint`'s doc-comment claimed "polled every 30s by Core" — which
had not been true since v3, even before #522 removed the poller.

Owner decision on #525 was (a) delete rather than (b) build the process-wide
watchdog that would consume them. The driver-side implementations are in git
history and were mostly reusable; what was always missing is the trigger, and a
member nobody calls is how the misleading doc-comment survived this long.

Removed from `IDriver`, all 12 driver implementations, and every test stub —
plus the support code that existed only to feed them, which is the part a
member-only deletion would have left behind as dead weight:

- MTConnect's three per-entry byte-weight constants, its cached
  `ProbeModelDataItemCount`, and `CountDataItems` — a full device-tree walk run
  on every cache fill to populate a number with no remaining reader.
- OpcUaClient's `_discoveredNodeCount` field and the discovery-pass write to it.
- MQTT's `ApproxBytesPerAuthoredTag`.

Two behavioural notes, neither a change in what the software does:

- `AbCipTemplateCache` now has no production reset path. Its only caller was
  AB CIP's flush, which itself had no caller — so nothing changes except how
  visible the fact is. Recorded on the type, along with the correction that its
  comment's claim about a device `ReinitializeAsync` also flushing it was never
  true. A UDT redefined on a live controller keeps its stale shape until the
  driver instance is rebuilt.
- MTConnect's `/probe` cache is still dropped, by `InvalidateProbeModel()` on an
  Agent restart. That is now `internal` rather than `private` so the tests which
  used the flush purely to empty the cache drive the real path instead — they
  now cover a case that actually occurs in production. Several unrelated doc
  comments cited `FlushOptionalCachesAsync` as the canonical CAS example and are
  repointed to it.

Tests: the ones that existed only to assert on the removed members are deleted
(3 OpcUaClient, 3 Galaxy, 2 MQTT, 1 MTConnect, 1 AbCip). Worth noting one was
vacuous — `FlushOptionalCachesAsync_resets_footprint_counter` asserted a
footprint of 0 before the flush and 0 after with no discovery in between, so it
would have passed against a flush that did nothing at all.

Full suite green except 7 failures verified identical on master before and
after (4 AbLegacy integration with the compose profile down, 3
Host.IntegrationTests), checked by name rather than assumed.

Docs corrected where they described this as live: `DriverLifecycle.md` (which
carried the #525 placeholder), `drivers/AbCip.md`, `drivers/AbLegacy.md`, and
`v2/driver-stability.md` — whose "polls this every 30 s" + per-driver
`DriverConfig` memory budget were never built as written and are now banner-ed
as design intent rather than description.

Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
2026-07-31 09:07:11 -04:00
Joseph Doherty dfbcb0e7f0 fix(mtconnect): close the silent-refusal + teardown-wedge defects in the pump (Task 11 review)
C1 (critical): a latched "this endpoint cannot stream" verdict could end with a
GREEN driver holding a permanently silent subscription. DriverInstanceActor
handles a tag-set change as Unsubscribe-then-Subscribe with no re-initialize;
the unsubscribe cleared the stream-degraded flag, the resubscribe was refused by
the latch without a word, and one successful read then reported Healthy.
StartSampleStreamCore now re-asserts the degradation and logs a Warning naming
the remedy, and teardown no longer clears the flag while the latch is set.

NOT promoted to Faulted: DriverHealthReport maps any Faulted driver to a /readyz
503, so that would de-ready the whole node over one misconfigured Agent whose
reads are perfectly healthy. Faulted stays for the case that earns it.

I1: teardown waits are bounded (5 s) and honour the caller's token. They were
unbounded and ignored it, so DriverInstanceActor's 5 s budget was inert and
PostStop — which blocks a dispatcher thread on ShutdownAsync while holding the
lifecycle semaphore — could be wedged forever by one blocking subscriber. The
cancellation source is disposed only when the loop is provably gone. Applied to
StopProbeLoopAsync too: Task 13 reproduced the identical shape, and closing the
class in one method while leaving the other as the pattern to copy is worse than
not closing it.

I2: the reconnect ladder was monotonic for the process lifetime, so ~9 unrelated
drops pinned the driver at MaxBackoffMs forever. A stream that delivered before
dropping now starts a fresh ladder (at attempt 1, not 0, so MinBackoffMs is
still honoured).

I3: MaxBackoffMs <= 0 clamped every delay to zero — an operator-authorable
reconnect spin. Treated as unset, like a multiplier that cannot grow.

I4: the session published instanceId without NextSequence, so after a restart it
held the new agent's id beside the dead one's cursor, and a gap/OUT_OF_RANGE
re-baseline (id unchanged) never published the cursor at all. Both move in one
CAS, and the pump publishes its cursor as it exits.

I5: OnDataChange was a multicast Invoke — the first throwing handler aborted the
rest of the list, starving every later subscriber. Now walked by hand with the
catch inside the loop. The test that claimed to cover this registered the
recorder BEFORE the thrower, so it passed regardless; swapped, it was red.
Faults are latched to one Warning per stream generation (Debug thereafter) so a
consistently-throwing consumer cannot flood the log.

Also: the pump restarts after an unexpected fault (IsCompleted, not null); a
device-scope that matches nothing is a Warning, not a Debug tally; a device or
component with neither name nor id is skipped rather than emitting a blank path
segment; DiscoverAsync's remark no longer claims DriverInstanceActor retries
(it does not for a Once driver, and injection is dormant in v3); and two flake
seeds in the fake are gone (Dispose re-read its own counter; _disposeCts was
disposed under a racing SampleAsync).

439/439. Every changed behaviour falsified by mutation.
2026-07-27 13:57:46 -04:00
Joseph Doherty 13dd9fcd70 feat(mtconnect): ITagDiscovery streams tree + SupportsOnlineDiscovery opt-in (Task 12) 2026-07-27 13:57:46 -04:00