exponentially slow when run source .zshrc several times

[ewen-goisot]

I use ZSH with a few plugins including zsh-syntax-highlighting,
I sometimes run source ~/.zshrc several times, for example when I edit the prompt theme (in oh-my-zsh).
First time I source, it takes approximately 0.14 seconds, so it's not so slow,
but if I run it 10 times on the same shell, it takes 0.26 seconds
20 times, 1.31 seconds
30 times, 10.89 seconds
40 times, 40.61 seconds
50 times, 111.55 seconds (and I didn't tried more).
.
The time does not increases if I use only other scripts (I use git, z, zsh-autosuggestion),
and time increases (twice faster but increases the same way) if I use only zsh-syntax-highlighting and no other plugin.

[danielshahaf]

When you `source zsh-syntax-highlighting.zsh`, the widget wrappers are installed on top of whatever plugins you activated previously. If you activate (source) z-sy-h twice, the wrappers will be installed twice. This was intentionally implemented this way to allow you to do — source z-sy-h source some-other-plugin source z-sy-h — and still have correct syntax highlighting. Therefore, _some_ slowness in this use-case is expected. Workarounds include: - Source z-sy-h just once, at the end, as recommended in the docs. - Implement your own guard preventing z-sy-h from being sourced multiple times if it's already activated. - Try the feature/redrawhook branch (see issue #245) - Use `exec zsh` instead of re-sourcing .zshrc Your data shows a roughly quadratic dependence of runtime on number of iterations. I would have expected the dependence to be linear. This might be an interesting issue to dig into — if it can be reproduced without omz.

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I use ZSH with a few plugins including zsh-syntax-highlighting, I sometimes run `source ~/.zshrc` several times, for example when I edit the prompt theme (in oh-my-zsh). First time I source, it takes approximately 0.14 seconds, so it's not so slow, but if I run it 10 times on the same shell, it takes 0.26 seconds 20 times, 1.31 seconds 30 times, 10.89 seconds 40 times, 40.61 seconds 50 times, 111.55 seconds (and I didn't tried more). . The time does not increases if I use only other scripts (I use git, z, zsh-autosuggestion), and time increases (twice faster but increases the same way) if I use only zsh-syntax-highlighting and no other plugin. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#625?email_source=notifications&email_token=AAQK5UAT7R7XCK3RA5S5LVLP6QWPPA5CNFSM4H7CB7B2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4G6AN2UQ>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAQK5UFGOONU42QHA3MYHMDP6QWPPANCNFSM4H7CB7BQ>.

[ewen-goisot]

Use exec zsh instead of re-sourcing .zshrc

exec zsh works with constant time, and I didn't noticed any other issues with it.

[danielshahaf]

Thanks for following up.

In the meantime redrawhook has been merged, which should independently address the issue.

[danielshahaf]

By the way, if anyone wants to fix the issue for pre-redrawhook zsh, look into `_zsh_highlight_bind_widgets` and its callees and make sure that if z-sy-h is registered multiple times, then all but one of the copies do no work. (Beware of causing a bottomless recursion, where a widget wraps itself, possibly through intermediate wrappers by other plugins; IIRC, that's what the unique $prefix values are for.) E.g., checking $funcstack in `_zsh_highlight_call_widget` might do the trick.