Performance issue of VSCode extension

[pshao25]

Repro step:

1. Go to branch https://github.com/Azure/azure-rest-api-specs/tree/feature/cplat-typespecTest/
2. Go to this operation for example, press F12. It takes a long time to jump. Sometimes it just cannot jump
3. When I edit something and press save, it will call format. This format process takes long. Sometimes it just cannot save because format cannot finish.

I could provide log/trace if you let me know how to collect.

[timotheeguerin]

@pshao25 are you still reproing this, checkedout this branch and everything works fast.
I know we have(At least had) performance issue for large azure specs but can't seem to get this one to repro. Been trying to find example so we can try to see what can be done in the compiler

[pshao25]

Yes, I'm still reproing and it happens in many services.

[timotheeguerin]

@pshao25 could you run node --cpu-prof node_modules/@typespec/compiler/entrypoints/cli.js compile ./specification/path/to/slow-spec on a few and share the cpuprofile file?

Is this happening immediatelly if you make a fresh window or the performance slowly degrade?

[RodgeFu]

vscode perf optimization: #8346