#2371 20x slower menus on windows!

[Vlad Volkov]

With the exception of the Windows Explorer (he uses own intrnal "API magic") in ALL! file managers and programs when selecting a large number of files the delay in the appearance of the menu is enormous.
For example, if you call the menu for 20000 files, without the 7-zip menu shell extension (show in context menu option) it will open in 3 seconds, and with it more than a minute! And whether I want to use 7-zip or not, such dynamic context menu extensions are always loaded and slow down the system.
The reason for this behavior is obviously a buggy extension.

Here is the code profiling that creates the delay:

[Vlad Volkov]

Forgot details
7-Zip 22.01 (2022-07-15)
Windows 10 21H2 x64

[Vlad Volkov]

I've looked more closely at what's causing the problem and hope it helps you in some way.
Here is a link (to a Russian-language resource) with a more detailed description.

[Igor Pavlov]

Thanks for report.
I'll look that problem. The case is pretty complicated. That code in 7-Zip is old, but with many updates that were not tested for performance with big number of files. So many ineffective parts are possible in that code. I'll try to fix at least some of these things.