Slow startup

[yujinyuz]

I'm trying out this plugin and everything seems to be fast except during startup.

Every time I open a new terminal, it kinda slows down for awhile. I'm getting this message

direnv: loading ~/.envrc
direnv: using asdf
direnv: loading ~/.asdf/installs/direnv/2.28.0/env/310956497-1026309726-4161296171-1200834465
direnv: using asdf direnv 2.28.0
direnv: using asdf awscli 2.2.38
direnv: using asdf yarn 1.22.10
direnv: using asdf rust stable
direnv: using asdf golang 1.14
direnv: using asdf nodejs 16.4.1
direnv: using asdf python 3.8.10
direnv: export +CARGO_HOME +GOPATH +GOROOT +NPM_CONFIG_PREFIX +RUSTUP_HOME ~PATH

Is this normal or are there any things I can do for further optimizations?

I'm using fish shell if that helps

[craigfurman]

I'm new to this project so my comment might be wide of the mark, but my understanding is that the latency is mostly caused by evaluating each relevant asdf shim - a tax you'd otherwise pay every time you run the executables behind those shims.

Unfortunately I'm not sure how to use an extensive global ~/.tool-versions and avoid this problem. Not sure if this will help you, but I don't use a use asdf .envrc globally, so by default I am executing asdf shims every time I call a tool, but avoid this direnv startup tax. I put use asdf .envrcs in individual projects, so that when I pop "random system stuff" shells that aren't in those project dirs, I don't pay the startup tax - but I do pay the shim tax, if that makes any sense.

[smorimoto]

Probably I know the cause, so when I get home, I will make sure it's true and come back here. Anyway, I'm still on an aeroplane!

[jfly]

@smorimoto, did you ever figure out the cause of this?

[ericem]

A certain amount of startup latency is due to loading the direnv stdlib via the asdf shim. If you replace that line with a system installed version then startup is faster (at least for me).

# Load direnv stdlib if not already loaded
if [ -z "$(declare -f -F watch_file)" ]; then
  if [ -n "$ASDF_DIRENV_SYSTEM_BINARY" ]; then
    eval "$(direnv stdlib)"
  else
    eval "$(asdf exec direnv stdlib)"
  fi
fi

[jfly]

That's an interesting observation, @ericem! I do see a noticeable difference myself:

$ hyperfine --warmup 3 --runs 100 "$(asdf which direnv) stdlib" 'asdf exec direnv stdlib'
Benchmark 1: /home/jeremy/.asdf/installs/direnv/2.30.3/bin/direnv stdlib
  Time (mean ± σ):       1.8 ms ±   0.3 ms    [User: 1.5 ms, System: 1.4 ms]
  Range (min … max):     1.5 ms …   3.0 ms    100 runs

  Warning: Command took less than 5 ms to complete. Results might be inaccurate.

Benchmark 2: asdf exec direnv stdlib
  Time (mean ± σ):      85.6 ms ±   1.1 ms    [User: 103.3 ms, System: 28.3 ms]
  Range (min … max):    83.9 ms …  89.5 ms    100 runs

Summary
  '/home/jeremy/.asdf/installs/direnv/2.30.3/bin/direnv stdlib' ran
   46.64 ± 7.56 times faster than 'asdf exec direnv stdlib'

Running direnv stdlib directly takes under 2ms, whereas going through asdf exec takes ~80-90ms. That's a human perceptible difference, I think.

It does seem like most of that time is spent with asdf exec trying to figure out which direnv to execute. Here's a benchmark of asdf which direnv, which I would expect to be the bulk of the work that asdf exec has to do before actually executing the correct version of the relevant program:

$ hyperfine --warmup 3 --runs 100 "asdf which direnv"
Benchmark 1: asdf which direnv
  Time (mean ± σ):      70.6 ms ±   0.9 ms    [User: 85.0 ms, System: 22.7 ms]
  Range (min … max):    69.0 ms …  74.6 ms    100 runs

[vic]

Hm, interesting @ericem. Using asdf exec direnv goes thru asdf version resolution (asdf trying to determine which direnv version to use) and that seems to be slow and one of the reasons why this project was started and being able to skip version resolution done by shims.

[vic]

asdf version resolution IS slow. :/

[vic]

@ericem thank you so much for your suggestion!. There's now an ASDF_DIRENV_BIN variable inspired by your snippet and documented in main branch.

[yujinyuz]

Thanks for the recent PR for ASDF_DIRENV_BIN support. It feels much faster now compared to last time

[jfly]

@vic, thanks for working on this! Do you think we can close out this issue now?

[vic]

Closing, looks like @yujinyuz and other's issue has been solved. Let's open another issue if we find other things to improve.