Caller-provided SourceNode wins (preserves reconciled rows from other nodes);
otherwise the writer fills it from the local INodeIdentityProvider.NodeName.
Reads from the provider on every write — singleton lifetime means zero overhead.
Bundle C task M5-T6 — plugs the IAuditPayloadFilter singleton into the
three audit writer entry points so every event is truncated + redacted
before persistence, regardless of which path it took to disk:
- FallbackAuditWriter (site hot path): filter runs before the primary
SQLite write AND the ring-buffer enqueue, so a recovery drain replays
rows that are already capped/redacted.
- CentralAuditWriter (central direct-write): filter runs before the
per-call IAuditLogRepository.InsertIfNotExistsAsync.
- AuditLogIngestActor (site→central telemetry):
- OnIngestAsync resolves the filter from the per-message scope and
applies it to each row before IngestedAtUtc stamping.
- OnCachedTelemetryAsync (M3 dual-write) applies the filter to the
audit half of every CachedTelemetryEntry before the audit-insert
+ site-call-upsert transaction.
Filter parameter is optional (nullable) on each constructor so the
existing test composition roots that don't pass one keep working unchanged
— production DI wiring in AddAuditLog always passes the real filter
through. ICentralAuditWriter registration switched from the open-ctor
form to a factory so the filter flows through it.
Tests: FilterIntegrationTests covers all three writer paths end-to-end
(4 tests). Full ScadaLink.AuditLog.Tests suite: 146 passed, 0 failed,
0 skipped.