Comment by jeyjeyemem | Hacker News Reader

Comment by jeyjeyemem | Hacker News Reader

Emissary is a simple-to-use, no dependency, yet BLAZING FAST messaging library for decoupling messages (requests and events) and message handlers.

Emissary aims to take advantage of the simplicity of using the annotations for handlers (e.g. @RequestHandler/@EventHandler) without the drawbacks of reflection (slow).

What differentiates Emissary from other messaging/dispatch libraries? It takes advantage of java.lang.invoke.LambdaMetafactory to avoid the cost of invoking methods reflectively. This results in performance close to directly invoking the request handler and event handler methods.

~ 1000% more throughput compared to other similar libraries (Spring's ApplicationEventPublisher, Pipelinr, EventBus) ~ 90% faster compared to other similar libraries (Spring's ApplicationEventPublisher, Pipelinr, EventBus)

Benchmarks found on the GitHub repository: https://github.com/joel-jeremy/emissary?tab=readme-ov-file#p...

Assuming that you are the author of Emissary, this could be a Show HN, I think.

https://news.ycombinator.com/showhn.html

> To post, submit a story whose title begins with "Show HN".

I always enjoy how low-tech this website is. Not necessarily great UX, but it's quaint.

This is the only site I go to without fear of having to wait for page load.

And the only one I can think of where I can't post my comment using Ctrl+Enter.

Yes, I am the author. I didn't know that, I'll give it a try. Thank you for the tip!

Are you planning to add persistent events as well, so that events are not lost due to crashes

This a frequently requested feature. At the moment, it only handles in-process messages but allowing for persistent events is definitely in the roadmap. It's not built-in right now, but this can be achieved by implementing custom RequestHandlerInvocationStrategy and EventHandlerInvocationStrategy. For example, one can implement an invocation strategy to serialize and send certain events to Kafka, queue, or your DB of choice.

See: https://github.com/joel-jeremy/emissary/blob/main/emissary-c...

Here are the default invocation strategies built-in right now: https://github.com/joel-jeremy/emissary/tree/main/emissary-c...

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