Tab completion in large folders is very slow #4797
Description
Steps to reproduce
Get a folder with a decent number of files (65k will do)
Try to do autocompletion on file name in this folder
Expected behavior
Respond time comparable with bash completion (about a second)
Actual behavior
No response for 12 seconds (appears like a hang)
For comparisons, ls | measure in the same folder takes about 4 seconds (3 times faster), which hints that there is a room for improvements even without a big rewrite for the completion logic.
Environment data
> $PSVersionTable
Name Value
---- -----
PSVersion 6.0.0-beta
PSEdition Core
GitCommitId v6.0.0-beta.5
OS Darwin 16.7.0 Darwin Kernel Version 16.7.0: T...
Platform Unix
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0