Re: [PATCH] Remove StGit patch detection from vcs_info

[Mikael Magnusson <mikachu@gmail.com>]

On 11/14/22, Peter Grayson <pete@jpgrayson.net> wrote:
> On Sat, Nov 12, 2022, at 11:30 PM, Daniel Shahaf wrote:
>> Peter Grayson wrote on Sat, Nov 12, 2022 at 09:46:02 -0500:
>>> On Fri, Nov 11, 2022, at 6:49 AM, Daniel Shahaf wrote:
>>> > [re #2]: It sounds like StGit 2.x support can be implemented at the
>>> > cost
>>> > of one fork(2) for those who don't use StGit and under a microsecond
>>> > for
>>> > those who do.  That doesn't sound like a deal breaker at all.
>>>
>>> Running `stg series` with StGit 2.0 takes about 12ms in my environment.
>>> StGit 1.5 it is about 32ms. Not a microsecond, but perhaps acceptable
>>> nonetheless.
>>>
>>
>> To be clear, are these figures the duration of the «stg series
>> --noprefix --applied» invocation?
>
> Yes.
>
>> What's the impact on people who don't have stg(1) installed, or who have
>> stg(1) installed but are currently in a worktree that doesn't use StGit?
>> I.e., are those figures immediately after `git init`, or in a worktree
>> that has a StGit patch stack, or?
>
> Without stg(1) installed, the cost would be however long it takes zsh to
> determine that the executable is not available in $path, which is
> ostensibly very fast (microseconds?).
>
> If stg(1) is installed, but run in a repo with a branch that has not been
> initialized with `stg init`, it's still about 12ms. Almost all that time
> is taken just to initialize a libgit2 Repository structure, which is
> used to interrogate the object database to determine whether a StGit
> stack is initialized.

fwiw, vcs_info lets you configure which vcs systems it looks for,
whether or not you have them installed. eg, I use:
  zstyle ':vcs_info:*:*' enable git hg svn
although these days i could surely set that to just git...

-- 
Mikael Magnusson