Subject: Re: [PATCH] index-pack: show chain length histogram as graph for better visual

From: Junio C Hamano <[email-masked]>
Date: Mon, 24 Feb 2014 09:27:42 -0800

Nguyễn Thái Ngọc Duy  <[email-masked]> writes:

> Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
> ---
>  definitely better than raw numbers but not really important

I would appreciate if it were an optional feature.  

> diff --git a/diff.c b/diff.c
> index 8e4a6a9..ca2b92a 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -1489,7 +1489,8 @@ int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
>  	return ret;
>  }
>  
> -static void show_stats(struct diffstat_t *data, struct diff_options *options)
> +static void show_stats(struct diffstat_t *data, struct diff_options *options,
> +		       int summary)
>  {
>  	int i, len, add, del, adds = 0, dels = 0;
>  	uintmax_t max_change = 0, max_len = 0;
> @@ -1729,10 +1730,40 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
>  			fprintf(options->file, "%s ...\n", line_prefix);
>  		extra_shown = 1;
>  	}
> +	if (!summary)
> +		return;

Yuck.

>  	fprintf(options->file, "%s", line_prefix);
>  	print_stat_summary(options->file, total_files, adds, dels);
>  }
>  
> +void show_histogram_graph(const char *label, unsigned long *data, int nr)
> +{
> +	struct diffstat_t diffstat;
> +	struct diff_options options;
> +	struct diffstat_file *files;
> +	char buf[64];
> +	int i;
> +
> +	memset(&options, 0, sizeof(options));
> +	options.file = stdout;
> +	options.use_color = diff_use_color_default;
> +	options.stat_width = -1;
> +	diffstat.nr = nr;
> +	diffstat.files = xmalloc(nr * sizeof(*diffstat.files));

Double yuck for an incomplete refactoring.  Why should a generic
histogram-drawer know about *diff*-anything (and if this is still
a diff-specific histogram-drawer, verify-pack has no business
calling it)?

I like the idea very much, but not this particular execution.

> +	files = xcalloc(nr, sizeof(*files));
> +	for (i = 0; i < nr; i++) {
> +		diffstat.files[i] = files + i;
> +		sprintf(buf, "%s %d", label, i);
> +		files[i].name = xstrdup(buf);
> +		files[i].added = data[i];
> +	}
> +	show_stats(&diffstat, &options, 0);