Ale: Implement background virtualenv detection

Created on 26 Oct 2018 · 3Comments · Source: dense-analysis/ale

Information

VIM version
VIM - Vi IMproved 8.1 (2018 May 18, compiled Oct 26 2018 12:36:32)
Included patches: 1-497

Operating System: Ubuntu 18.04.1 LTS

What went wrong

Vim is slowed down in following cases:

When it's started.
In insert mode
Change to normal mode from insert mode and move the cursor

Reproducing the bug

I profiled vim as following:

:profile ~/vim_profile.log
:profile file *
:profile func *

Here is part of the log.

FUNCTIONS SORTED ON TOTAL TIME
count  total (s)   self (s)  function
   30   9.368570   0.002536  ale#CallWithCooldown()
    5   9.348243   0.000459  ale#Lint()
    5   9.347211   0.000537  <SNR>15_ALELintImpl()
    5   9.341646   0.001122  ale#engine#RunLinters()
    5   9.339271   0.000471  <SNR>44_RunLinter()
   10   9.319802   0.000230  ale_linters#python#pyflakes#GetExecutable()
   10   9.319572   0.000880  ale#python#FindExecutable()
   10   9.317714   9.300010  ale#python#FindVirtualenv()
    5   5.011503   0.000321  <SNR>44_InvokeChain()
    5   4.994441   0.000740  ale#engine#ProcessChain()
    5   4.993701   0.000222  ale#linter#GetCommand()
    5   4.993406   0.000259  ale_linters#python#pyflakes#GetCommand()
    5   4.327129   0.000226  ale#linter#GetExecutable()
    5   0.016741   0.002560  <SNR>44_RunJob()
    5   0.016297   0.000936  <SNR>49_VimCloseCallback()
    5   0.015099   0.000683  <SNR>49_VimExitCallback()
   10   0.014274   0.000846  <SNR>44_HandleExit()
   10   0.012996   0.000600  ale#Queue()
  730   0.012694             ale#path#Simplify()
    3   0.011843   0.000387  ale#engine#HandleLoclist()

FUNCTIONS SORTED ON SELF TIME
count  total (s)   self (s)  function
   10   9.317714   9.300010  ale#python#FindVirtualenv()
  730              0.012694  ale#path#Simplify()
  176              0.008408  ale#Var()
   15   0.011010   0.007305  ale#linter#Get()
    5              0.005921  ale#util#Writefile()
   26              0.004477  <SNR>21_Highlight_Matching_Pair()
    5   0.004629   0.004302  ale#job#Start()
   30   0.008141   0.003983  ale#ShouldDoNothing()
    3   0.006079   0.002900  ale#sign#SetSigns()
    5   0.016741   0.002560  <SNR>44_RunJob()
   30   9.368570   0.002536  ale#CallWithCooldown()
   10   0.002446   0.002157  ale#path#Upwards()
    5   0.007417   0.001431  <SNR>44_CreateTemporaryFileForJob()
   10   0.011469   0.001346  <SNR>15_ALEQueueImpl()
   15   0.006979   0.001340  <SNR>50_EchoImpl()
   11   0.002096   0.001298  ale#cursor#EchoCursorWarningWithDelay()
   15              0.001271  <SNR>35_GetAliasedFiletype()
   15              0.001186  ale#linter#GetAll()
    5   9.341646   0.001122  ale#engine#RunLinters()
    3   0.001098   0.001040  ale#engine#RemoveManagedFiles()

FUNCTION  ale#python#FindVirtualenv()
    Defined: ~/.vim/bundle/ale/autoload/ale/python.vim line 57
Called 10 times
Total time:   9.317714
 Self time:   9.300010

count  total (s)   self (s)
   70   0.004882   0.002436     for l:path in ale#path#Upwards(expand('#' . a:buffer . ':p:
h'))
                                    " Skip empty path components returned in MSYS.
   60              0.000219         if empty(l:path)
                                        continue
   60              0.000075         endif

  420   0.004772   0.001919         for l:dirname in ale#Var(a:buffer, 'virtualenv_dir_name
s')
  360   0.015215   0.008383             let l:venv_dir = ale#path#Simplify(   join([l:path,
 l:dirname], s:sep))
  360   0.012649   0.007076             let l:script_filename = ale#path#Simplify(   join([
l:venv_dir, s:bin_dir, 'activate'], s:sep))

  360              9.275185             if filereadable(l:script_filename)
                                            return l:venv_dir
  360              0.000497             endif
  420              0.000597         endfor
   70              0.000098     endfor

   10              0.000086     return $VIRTUAL_ENV

I'm not sure, but maybe it's similar to https://github.com/w0rp/ale/issues/563#issue-229379398

I still don't know why filereadable is so time consuming, but currently I just updated if filereadable(l:script_filename) to if !empty(l:script_filename), and it works well for me, for now.

enhancement

Source

catbaron0

Most helpful comment

You can disable this behavior with let g:ale_virtualenv_dir_names = [], if accessing your filesystem is slow. Then you will have to set VIRTUAL_ENV yourself if you want to use a virtualenv directory.