Choose appropriate containers

Select data structures based on expected collection size and usage patterns. For small collections (typically fewer than 30 elements), consider using ordered containers like std::map instead of hash-based ones like std::unordered_map. With small collections, the theoretical O(log n) vs O(1) lookup time difference becomes negligible in practice, while ordered containers avoid hash function computation overhead and potential collision handling.

// Instead of using unordered_map for small collections:
std::unordered_map<ModuleRequest, ModuleWrap*> module_requests;

// Consider using an ordered map:
std::map<ModuleRequest, ModuleWrap*> module_requests;

When working with hash-based containers, reuse precomputed hash values when available (like V8’s GetIdentityHash()) instead of recomputing hashes with std::hash. This avoids unnecessary computation and improves performance, especially for string data that might already have an identity hash from the JavaScript engine.