[Bug]: Slow hot reload about rspack

[hardfist]

thank you for your detailed report similar issue with #7490, it seems a performance bug of watchpack, can you help provide the input of the slow Function(the x and regex value) and help us find whether it's slow in x.replace(/\\/g, "/") or regexp.test

[escaton]

The regex is compiled once from the watchOptions.ignored that I provided, and x is each of the watched files (45k in my case).

The problem is not the performance of x => regex.test(x), but the fact that it is called at least 45k times (see filter() calls in watch method).

[hardfist]

thanks that's really helpful, and we will consider reuse watch across different compilation

[escaton]

Maybe I can help with it? I thought about some early bailout in packages/rspack/src/Watching.ts

[hardfist]

Maybe I can help with it? I thought about some early bailout in packages/rspack/src/Watching.ts

#7503 (comment) you can try whether this works for you?

[escaton]

Oh, this issue is actually a duplicate of #7490. That one was posted by my colleague :) Let's proceed in that issue.