Re: [RFC/PATCH 5/3] Alternative --dirstat implementation, based on diffstat analysis

[Junio C Hamano <gitster@pobox.com>]

Johan Herland <johan@herland.net> writes:

> This patch adds an alternative implementation of show_dirstat(), called
> show_dirstat_based_on_diffstat(), which uses the more expensive diffstat
> analysis (as opposed to --dirstat's own (inexpensive) analysis) to derive
> the numbers from which the --dirstat output is computed.
> ...
> diff --git a/diff.c b/diff.c
> index 5376d01..a496ba6 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -31,6 +31,7 @@ static const char *external_diff_cmd_cfg;
>  int diff_auto_refresh_index = 1;
>  static int diff_mnemonic_prefix;
>  static int diff_no_prefix;
> +static int dirstat_based_on_diffstat;
>  static struct diff_options default_diff_options;
>  
>  static char diff_colors[][COLOR_MAXLEN] = {
> @@ -103,6 +104,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
>  		diff_no_prefix = git_config_bool(var, value);
>  		return 0;
>  	}
> +	if (!strcmp(var, "diff.dirstatbasedondiffstat")) {
> +		dirstat_based_on_diffstat = git_config_bool(var, value);
> +		return 0;
> +	}

People may think of other damage calculator, so the variable shouldn't be
a boolean that says "dirstat-based-on-diffstat" but rather an enum.

We would need a command line interface for this.  How about something like
"--dirstat=lines" vs "--dirstat=changes", and default "--dirstat" without
an explicit type to traditional "--dirstat=changes"?