Audit: Quality & Diversity Baseline
Scope
Security, correctness, and operational audit of the brief ranking profile and associated pipeline fixes.
Findings
1. Security
| # |
Check |
Status |
Notes |
| S1 |
No user input in profile definition |
PASS |
Profile is code-defined with hardcoded constants. No injection surface. |
| S2 |
No new network or I/O surface |
PASS |
Pure in-process ranking. No external calls. |
| S3 |
No credential or secret handling |
PASS |
Not applicable. |
| S4 |
No unsafe code |
PASS |
All changes are safe Rust. |
2. Correctness
| # |
Check |
Status |
Notes |
| C1 |
Gate thresholds are >= (not >) |
PASS |
passes_gates() uses >= comparison. Items at exactly the threshold are included. |
| C2 |
Exploration disabled for gate safety |
PASS |
BRIEF_EXPLORATION = 0.0. inject_exploration() bypasses gates; disabling it preserves the quality floor invariant. |
| C3 |
Format enrichment populates correctly |
PASS |
Format populated from meta.get("format") only when candidate.format.is_none(). No double-write risk. |
| C4 |
Metadata loading trigger complete |
PASS |
needs_metadata_for_creator_grouping now checks `max_per_creator |
| C5 |
Gate signal names match schema |
PASS |
Gates reference "view" and "completion". If schema lacks these, read_agg returns 0.0, failing the gate. All items excluded — safe degradation (no garbage surfaced). |
| C6 |
No integer overflow risk |
PASS |
Gate thresholds are f64. Windowed counts are u64 cast to f64 internally. No overflow at the quantities involved. |
3. Performance
| # |
Check |
Status |
Notes |
| P1 |
Gate evaluation cost |
PASS |
Two additional read_agg calls per candidate. read_agg is O(1) DashMap lookup + constant-time BucketedCounter read. Negligible overhead. |
| P2 |
Metadata loading for format |
PASS |
Metadata was already being loaded when max_per_creator was set. The format enrichment adds one HashMap::get per candidate per iteration — negligible. |
| P3 |
Integration test speed |
PASS |
All 6 tests complete in 0.01s. No sleeps, no I/O. |
4. Operational
| # |
Check |
Status |
Notes |
| O1 |
Profile is registered at startup |
PASS |
Added to register_builtins(). Available immediately on TidalDb::open(). |
| O2 |
No migration required |
PASS |
No schema changes, no storage changes, no WAL format changes. |
| O3 |
Backward compatible |
PASS |
New profile is additive. Existing profiles unaffected. Format enrichment fix is backward compatible (format was always None before, so format-based diversity was a no-op). |
5. Known Limitations
| # |
Limitation |
Severity |
Notes |
| L1 |
DiversitySelector operates on full scored set |
Low |
Diversity is applied to the full scored set, then pagination takes a slice. At the page level, creator distribution depends on scoring order. Tests account for this. Not a bug — it's the architectural design. |
| L2 |
Exploration permanently disabled |
Low |
Cannot be re-enabled without also adding gate re-evaluation to inject_exploration(). This is a deliberate trade-off for this profile. |
Verdict
PASS. No security, correctness, or performance concerns. The implementation is clean, well-documented, and all changes are backward compatible. The two pipeline fixes (format enrichment and metadata loading trigger) are improvements that benefit the entire ranking system, not just the brief profile.
