Bash completion for show/config commands has gotten slow

[jleveque]

It appears as though the slowdown is present on both the master and 201803 branches. Need to find what caused the slowdown and fix it.

[ishidawataru]

One of the reasons of the slowness is this

Original show command takes 1.376s for the execution.
Using https://github.com/ninjaaron/fast-entry_points reduced that to 0.760s.

I'll open a PR for this.

[jleveque]

Confirmed the slowdown is caused by the line from pkg_resources import load_entry_point as below:

root@str-s6000-acs-9:/# env 'COMP_WORDS=show ' COMP_CWORD=1 _SHOW_COMPLETE=complete pdb /usr/bin/show 
> /usr/bin/show(3)<module>()
-> __requires__ = 'sonic-utilities==1.2'
(Pdb) n
> /usr/bin/show(4)<module>()
-> import sys
(Pdb) 
> /usr/bin/show(5)<module>()
-> from pkg_resources import load_entry_point

[ishidawataru]

@jleveque Correct.

With #426, fastentrypoints doesn't import pkg_resources, which can speed up the tab completion.

Here is the show command script after applying #426

root@100310f19a75:/data# cat /usr/local/bin/show
#!/usr/local/bin/python
# -*- coding: utf-8 -*-
# EASY-INSTALL-ENTRY-SCRIPT: 'sonic-utilities==1.2','console_scripts','show'
__requires__ = 'sonic-utilities==1.2'
import re
import sys

from show.main import cli

if __name__ == '__main__':
    sys.argv[0] = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv[0])
    sys.exit(cli())

[jleveque]

@ishidawataru: Is that output from an image built on the master branch? Why is your show wrapper file located at /usr/local/bin/show? I'm running a build off the head of the master branch as of yesterday, and my show wrapper is at /usr/bin/show and still contains the import statement:

root@sonic:~# cat /usr/bin/show
#! /usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'sonic-utilities==1.2','console_scripts','show'
__requires__ = 'sonic-utilities==1.2'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('sonic-utilities==1.2', 'console_scripts', 'show')()
    )

What's different between our builds?

[ishidawataru]

I ran the following at the top directory of sonic-utilities repo.

$ docker run -v `pwd`:/data -w /data python:3.7.2 sh -c 'python3 setup.py install && cat `which show`'

It seems the build system is installing this repo differently?
I'll investigate.

[jleveque]

Yes. The build system builds the sonic-utilities Python package into a .deb package and installs it using dpkg -i.

[wait2035]

will you address this ?