check-hotpath

name	check-hotpath
description	Scan hot-path code for allocation violations, lock misuse, and performance anti-patterns. Zero-tolerance audit.

Hot path invariant checker for moon.

Hot Path Files

• src/command/*.rs — command dispatch
• src/protocol/*.rs — RESP parsing
• src/shard/event_loop.rs — shard event loop
• src/shard/spsc_handler.rs — cross-shard message handling
• src/io/*.rs — I/O drivers
• src/storage/dashtable/*.rs — hash table lookups

Checks

1. Allocation Violations

Grep for forbidden patterns in hot-path files:

grep -rn 'Box::new\|Vec::new()\|String::new()\|Arc::new\|\.clone()\|format!\|\.to_string()\|\.to_owned()' src/command/ src/protocol/ src/shard/event_loop.rs src/io/

Exceptions: Vec::with_capacity() at end of command path is acceptable.

2. Lock Violations

grep -rn 'Mutex::new\|RwLock::new\|\.lock()\|\.read()\.\|\.write()\.' src/command/ src/shard/event_loop.rs src/io/

Flag: any lock held across .await, any std::sync lock (should be parking_lot).

3. Syscall Violations

grep -rn 'Instant::now()\|SystemTime::now()\|std::time' src/command/ src/shard/event_loop.rs

Should use shard-cached timestamp instead.

4. Copy Violations

grep -rn '\.to_vec()\|\.to_owned()\|copy_from_slice' src/protocol/ src/io/

Should use Bytes::slice() for zero-copy where possible.

5. Branch Density

Find match arms with excessive cases:

grep -c '^\s*"' src/command/registry.rs 2>/dev/null || echo "Check PHF table"

Output

For each violation:

[ALLOC|LOCK|SYSCALL|COPY|BRANCH] file.rs:line
  Pattern: <what was found>
  Severity: HIGH|MEDIUM|LOW
  Fix: <suggested change>

Summary: total violations by category.