Performance Analyzer

Analyze performance-critical code in this secret scanning engine.

When to Use

• •After writing hot-path code (scanning, decoding, validation)
• •Before committing changes to src/engine/ modules
• •When benchmark results show unexpected regressions
• •During optimization work on data structures in src/stdx/

Analysis Checklist

Memory & Allocation

• • Unnecessary allocations in loops (Vec, String, Box)
• • Missing with_capacity() for known-size collections
• • Cloning where borrowing would suffice
• • Large structs passed by value instead of reference

CPU & Cache

• • False sharing in concurrent data structures
• • Cache-unfriendly access patterns (strided, random)
• • Missing #[inline(always)] on hot functions
• • Branch-heavy code that could use branchless alternatives

Async & Concurrency

• • Blocking operations in async contexts
• • Lock contention patterns
• • Oversized futures (check with std::mem::size_of)
• • Unnecessary Arc when Rc or ownership would work

Rust-Specific

• • Bounds checks in hot loops (consider get_unchecked with proof)
• • Iterator vs manual loop performance
• • &str vs String in function signatures
• • Zero-cost abstraction violations

Project-Specific Patterns

This codebase uses these performance patterns:

• •NONE_U32 = u32::MAX as sentinel (avoid Option overhead)
• •#[inline(always)] on hot-path functions
• •debug_assert! for invariant checks (zero cost in release)
• •Const generics (G) for compile-time granularity selection

Output Format

## Performance Analysis: [file/function]

### Findings

| Severity | Issue | Location | Impact |
|----------|-------|----------|--------|
| HIGH | Allocation in hot loop | line:XX | ~Xns per call |
| MEDIUM | Missing inline hint | line:XX | Potential call overhead |

### Recommendations

1. **[Issue]**: [Specific fix with code example]
   ```rust
   // Before
   // After

Validation

Run these benchmarks to verify:

• •cargo bench --bench <relevant_bench>

## Related Skills

- `/bench-compare` - Before/after measurement
- `/rust-hotspot-finder` - Systematic hotspot scanning
- `/perf-regression` - Full regression workflow