dynamic module second import still slowly when has import std@0.56.0/http/server.ts

[shynome]

deno version

debian 10

deno 1.0.5
v8 8.4.300
typescript 3.9.2

report steps

you need wrk or other tools for test

• git clone https://github.com/shynome/deno-report-dynamic-module-exec-so-slowly.git
• cd deno-report-dynamic-module-exec-so-slowly
• deno run -A server.ts
• curl http://127.0.0.1:8000/b work fine
• curl http://127.0.0.1:8000/c work fine
• wrk http://127.0.0.1:8000/b my qps test result is 79
• wrk http://127.0.0.1:8000/c my qps test result is 6389

difference

the difference is b.ts has imported type import type { ServerRequest } from "https://deno.land/std@0.56.0/http/server.ts", if I remove this line, b.ts will work fine

//b.ts
import type { ServerRequest } from "https://deno.land/std@0.56.0/http/server.ts";
export default (req: ServerRequest) => {
  req.respond({ body: "bbbb" });
};

//c.ts
//import type { ServerRequest } from "https://deno.land/std@0.56.0/http/server.ts";
export default (req: any) => {
  req.respond({ body: "bbbb" });
};

[shynome]

I have update reproudce repo, the new repo has less code and make test easier

[shynome]

When I add a simple module cache to the code, both qps are close to 20k in my PC

I think import should have a cache, but I don't know the import is
whether equally slow in the browser

[shynome]

node dynamic import is also heavye, but deno dynamic import is look like have ignore the compiled files and recompile everytime

[bartlomieju]

@shynome double compilation problem was fixed in #6177. Closing as resolved, feel free to reopen if you're still experiencing problems.