bug#19390: 25.0.50; `package-activate' is too slow

[Dmitry Gutov]

On 12/16/2014, Artur Malabarba wrote:

> I didn't notice anything as aggravating as the report, but I agree my
> latest patch is a performance concern.

Do you maybe have fewer packages installed?

> avoid a lot of
> calls to `file-truename'. This, I suspect, is the bigger performance
> issue.

Any particular reason you're using `file-truename', instead of 
`expand-file-name'? Replacing the former with the latter already gives 
~twofold performance improvement.

> 2. Creating the `history' variable as below is a problem.
>
> (mapcar (lambda (x) (file-name-sans-extension
>                                    (file-truename (car x))))
>                      load-history)

With the above change, this piece of code is relatively fast.

For instance, (package--list-loaded-files default-directory) in the Helm 
directory takes 140 ms here, whereas

            (mapcar (lambda (x) (file-name-sans-extension
                                 (expand-file-name (car x))))
             load-history)

only takes ~10 ms. Still not fast enough not to need the other patch, of 
course.