Well-localised perf fixes across 8 modules.
Lock decoupling / SQL streaming:
- AuditLog-005: SqliteAuditWriter gains dedicated read-only _readConnection
(+ _readLock) backed by WAL journal mode. GetBacklogStatsAsync,
ReadPendingAsync, ReadPendingSinceAsync, ReadForwardedAsync no longer
contend with the hot-path INSERT lock — backlog probes on a 30s timer
can't stall the writer under multi-hundred-K Pending backlog.
- SEL-022: dropped Cache=Shared from SiteEventLogger's default connection
string (single-connection logger; mode was dormant config).
Memory / streaming:
- CLI-019: bundle export streams base64 in 1 MB-aligned chunks via
Convert.TryFromBase64Chars straight into the FileStream — no more
full-bundle byte[] allocation.
- CentralUI-031: TransportImport now stages the upload to a per-session
temp file under Path.GetTempPath() (replaces in-memory byte[] field);
page implements IDisposable to delete the temp file on reset / new
upload / dispose. Per-circuit working set drops from ~100 MB to ~80 KB.
N+1 hoisting:
- Transport-008: added ITemplateEngineRepository.GetTemplatesWithChildrenAsync
bulk method; BundleImporter.PreviewAsync calls it once instead of per-
template-name. Single query with .Include(...).AsSplitQuery().
- DM-023: BuildDeployArtifactsCommandAsync's per-site loop now references
a pre-fetched GlobalArtifactSnapshot (shared scripts, external systems,
DB connections, notification lists, SMTP) instead of re-querying per site.
- MgmtSvc-023: HandleQueryDeployments unfiltered branch uses one
GetAllInstancesAsync bulk load + Dictionary<int,int?> lookup (was a
GetInstanceByIdAsync per record).
Small allocations / per-tick rebuilds:
- InboundAPI-019: AuditWriteMiddleware gates EnableBuffering() on
RequestHasBody() so GET/HEAD/DELETE/TRACE/OPTIONS and Content-Length:0
requests skip the FileBufferingReadStream allocation.
- NotifOutbox-006: ResolveAdapters dictionary now cached on
_adaptersCache (built lazily on first sweep) + actor-lifetime
_adaptersScope; ResolveAdapters no longer rebuilds per dispatch tick.
Verify-only:
- Comm-017: Confirmed _inProgressDeployments was deleted by Comm-016 in
commit ac96b83 — marked Resolved with that attribution. No code change.
Doc-correction:
- NS-022: Updated MailKitSmtpClientWrapper XML doc to spell out single-
connection / per-delivery-factory contract (option (b) — transient
client per Send — rejected because it re-handshakes TLS per email).
10+ new regression tests across 8 test projects. Build clean; affected
suites all green. README regenerated: 54 open (was 65).
- NavMenu: move Import Bundle out of the nested RequireDesign/RequireAdmin
double-gate into the top-level Admin section so an Admin-only user sees it
without needing the Design role; Export Bundle stays in the Design section.
- TransportImport: inject IAuditService + ScadaLinkDbContext; emit a
BundleImportUnlockFailed audit row (best-effort, swallowed on failure) on
every wrong-passphrase attempt in SubmitPassphraseAsync, with attempt
number and error reason in afterState.
- docker central-node-a/b appsettings: add ScadaLink:Transport section with
SourceEnvironment = "docker-cluster" so the importer picks up a non-null
environment name in the audit trail.
- CentralUI.Tests: register IAuditService mock + SQLite in-memory
ScadaLinkDbContext in TransportImportPageTests to satisfy the two new injects.
Implements Task T21 of the Transport feature. A four-step Blazor wizard
(Select → Review → Encrypt → Download) under /design/transport/export,
gated on AuthorizationPolicies.RequireDesign:
1. Select — TemplateFolderTree (checkbox-mode) plus flat checkbox
lists for shared scripts, external systems, DB connections,
notification lists, SMTP configs, API keys, API methods.
2. Review — runs DependencyResolver, surfaces seed vs auto-included.
"Include all dependencies" toggle re-resolves on flip.
3. Encrypt — passphrase + confirm with strength meter, secret-count
warning over the resolved closure, explicit unencrypted
opt-out path (calls BundleExporter with passphrase=null
so the audit row tags UnencryptedBundleExport).
4. Download— calls IBundleExporter.ExportAsync, streams bytes to the
browser via JS interop (wwwroot/js/transport.js), displays
filename + size + SHA-256 + encryption status.
Source environment is sourced from new TransportOptions.SourceEnvironment
(bound from ScadaLink:Transport:SourceEnvironment, defaults "scadalink"),
filename pattern scadabundle-{env}-{yyyy-MM-dd-HHmmss}.scadabundle.
Tests (bUnit + policy): step 1 group rendering, step 2 dependency
expansion (Pump composes Motor), step 4 full walkthrough verifying
ExportAsync receives the selected ids + authenticated identity, and a
RequireDesign policy-deny test for users without the Design role. Also
unit-pins the filename-sanitisation contract.
Joseph Doherty