Improve Packet Listener Performance

[twisti-dev]

What Needs Improvement?

The current packet listener system lacks optimal performance and does not take advantage of modern Spring features or low-level performance enhancements. It uses a more traditional listener pattern which can become a bottleneck, especially under high concurrency or frequent packet event conditions.

Proposed Improvement

Enhance the packet listener system by integrating:

1. Spring’s Event System:

   • Use a modified version of springs @EventListener annotations for event handling.
   • Enable conditional listeners using SpEL expressions.
   • Leverage Spring’s automatic bean registration and AOP support for clean, modular handling.

2. LambdaEvents Library:

   • Use LambdaEvents for ASM-based bytecode generation of listener dispatchers.
   • Replace or wrap the current event dispatch mechanism to benefit from significantly faster runtime performance.
   • Maintain event lifecycle integration with Spring to preserve consistency and manageability.

3. Hybrid Dispatcher:

   • Create a dispatcher that supports both Spring-managed and LambdaEvents-managed listeners.
   • Allow configuration to toggle ASM optimization per event type or globally.

Benefits of the Improvement

• Improved Performance: LambdaEvents significantly reduces the overhead of event dispatch via bytecode rewriting.
• Enhanced Flexibility: Spring’s system supports filtering, conditional execution, and async handling natively.
• Cleaner Architecture: AOP and DI features from Spring improve separation of concerns and testability.
• Scalability: The hybrid system allows for modular event handling, scaling efficiently for both light and heavy event traffic scenarios.

Additional Context

• LambdaEvents GitHub: https://github.com/Lenni0451/LambdaEvents/
• Consider combining listener registration with a Spring @Configuration class and integrating a custom ApplicationEventMulticaster if needed for custom dispatch logic.