Symbol navigation is slow in large project with python venv

[zjjott]

Environment data

• VS Code version: 1.23.1
• Extension version (available under the Extensions sidebar): 2018.4.0
• OS and version: MacOS 10.13.4
• Python version (& distribution if applicable, e.g. Anaconda): Python3.6
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): venv
• Relevant/affected Python packages and their versions: tensorflow

Actual behavior

Symbol navigation is slow,about 5 seconds after open symbol navigation every time
large gif here:5.7M ,here is a compress gif,it's speed up

Expected behavior

faster as it in small project

Steps to reproduce:

1. install some package such as tensorflow in venv
2. use Symbol navigation

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

[2018-05-23 15:18:15.484] [exthost2] [info] ExtensionService#_doActivateExtension vscode.python {"startup":false,"activationEvent":"onLanguage:python"}
[2018-05-23 15:18:15.484] [exthost2] [info] ExtensionService#loadCommonJSModule /Applications/Visual Studio Code.app/Contents/Resources/app/extensions/python/out/pythonMain
[2018-05-23 15:18:15.486] [exthost2] [info] ExtensionService#_doActivateExtension ms-python.python {"startup":false,"activationEvent":"onLanguage:python"}
[2018-05-23 15:18:15.486] [exthost2] [info] ExtensionService#loadCommonJSModule /Users/zhutou/.vscode/extensions/ms-python.python-2018.4.0/out/client/extension

How can I profile this behavior?I have enable vscode profile but there is nothing about this extensions

[zjjott]

@brettcannon I have add profile in completion.py,here is result:
https://gist.github.com/zjjott/90edffc72d4aa06972150d79d86618ba

[brettcannon]

So this is on initial load only. What kind of performance would you expect? Without constantly scanning a file for it to be preloaded, there will always be a cost.

[brettcannon]

Regardless, this would require Jedi to become faster.

[zjjott]

@brettcannon but actually,everytime the same file open the navigation,it's slow
I don't know,why a file with less than 100 lines cost so long time.
as I know ,Symbol navigation should only load once?

[zjjott]

In my memory, this feature in history is faster than now

[brettcannon]

@zjjott it might be a performance regression in Jedi from our 0.12.0 upgrade we did recently. But once again, it would be an issue in Jedi and they would need to make the changes to speed it up.

[brettcannon]

Closing as this is an upstream issue which we don't have direct control or influence over.