Re: [PATCH v1 1/1] dir: teach status to show ignored directories

[Brandon Williams <bmwill@google.com>]

On 08/10, Jameson Miller wrote:
> Teach Git to optionally show ignored directories when showing all
> untracked files. The git status command exposes the options to report
> ignored and/or untracked files. However, when reporting all untracked
> files (--untracked-files=all), all individual ignored files are reported
> as well. It is not currently possible to get the reporting behavior of
> the --ignored flag, while also reporting all untracked files. This
> change exposes a flag to report all untracked files while not showing
> individual files in ignored directories.
> 
> Motivation:
> Our application (Visual Studio) needs all untracked files listed
> individually, but does not need all ignored files listed individually.
> Reporting all ignored files can affect the time it takes for status
> to run. For a representative repository, here are some measurements
> showing a large perf improvement for this scenario:
> 
> | Command | Reported ignored entries | Time (s) |
> | ------- | ------------------------ | -------- |
> | 1       | 0                        | 1.3      |
> | 2       | 1024                     | 4.2      |
> | 3       | 174904                   | 7.5      |
> | 4       | 1046                     | 1.6      |
> 
> Commands:
>  1) status
>  2) status --ignored
>  3) status --ignored --untracked-files=all
>  4) status --ignored --untracked-files=all --show-ignored-directory
> 
> This changes exposes a --show-ignored-directory flag to the git status
> command. This flag is utilized when running git status with the
> --ignored and --untracked-files options to not list ignored individual
> ignored files contained in directories that match an ignore pattern.

I can't help feeling that there is a better way express this with a
better UI.  I'm not saying this is wrong, I'm just not sure how
--show-ignored-directory would work when not paired with --ignored and
--untracked-files.  Does it require --ignored to also be given?

> 
> Part of the perf improvement comes from the tweak to
> read_directory_recursive to stop scanning the file system after it
> encounters the first file. When a directory is ignored, all it needs to
> determine is if the directory is empty or not. The logic currently keeps
> scanning the file system until it finds an untracked file. However, as
> the directory is ignored, all the contained contents are also marked
> excluded. For ignored directories that contain a large number of files,
> this can take some time.
> 
> Signed-off-by: Jameson Miller <jamill@microsoft.com>

-- 
Brandon Williams