Free SKILL.md scraped from GitHub. Clone the repo or copy the file directly into your Claude Code skills directory.
npx versuz@latest install audit-performancegit clone https://github.com/ben-manes/caffeine.gitcp caffeine/.claude/skills/audit-performance/SKILL.md ~/.claude/skills/audit-performance/SKILL.md--- name: audit-performance description: Audit hot paths for performance inefficiencies (allocations, contention, layout) context: fork agent: auditor disable-model-invocation: true --- Audit the Caffeine cache for performance inefficiencies. Context: Caffeine runs in high-throughput, low-latency JVM services where cache operations occur millions of times per second. The library is already heavily optimized — generic textbook advice is not useful. ## Rules 1. **Read the actual source code** before analyzing. 2. **Only report findings traceable to specific lines.** 3. **Account for JIT compilation.** C2 eliminates many apparent inefficiencies: escape analysis, inlining, dead code elimination. Don't flag JIT-optimized issues. 4. **Ignore correctness, style, and API design.** This is purely runtime performance. 5. **Quality over quantity.** Five real findings beat twenty speculative ones. ## Analysis Areas (priority order) ### 1. Get Fast Path (highest priority) Trace get()/getIfPresent() from entry to return. Count volatile/opaque reads, method calls, branches, allocations. Even one saved volatile read matters. ### 2. Allocation and GC Pressure Identify allocations surviving escape analysis on hot paths. Frequency, size, lifetime. Do not flag JIT-eliminated allocations. ### 3. Contention and Cache-Line Effects CAS retry rates, cache-line bouncing, graceful vs catastrophic degradation for read buffer, evictionLock, CHM bins, node field updates. ### 4. FrequencySketch Counter layout locality, hash computation, reset cost. Accessed every read/write. ### 5. Maintenance Work Worst-case work per write, latency spikes, eviction cascades, timer wheel scan cost. ### 6. Memory Layout Node object size, pointer indirection depth, false sharing, @Contended opportunities. ## Output Format For each finding: ``` ## [Category] Title **Location:** file:method (lines X-Y) **Severity:** negligible | moderate | high **What happens:** (trace the code path) **Why it matters:** (quantify) **JIT considerations:** (will C2 handle this?) **Proposed fix:** (specific code change) **Expected benchmark impact:** (JMH prediction) ``` If fewer than 3 real issues, the code is well-optimized. Do not pad the output.