Re: [PATCH 7/7] btrfs-progs: subvol show: implement json format output

[David Sterba <dsterba@suse.cz>]

On Sun, Aug 13, 2023 at 11:45:02AM +0200, Christoph Heiss wrote:
> Implements JSON-formatted output for the `subvolume list` command using
> the `--format json` global option, much like it is implemented for other
> commands.
> 
> Signed-off-by: Christoph Heiss <christoph@c8h4.io>
> ---
>  cmds/subvolume.c | 108 ++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 98 insertions(+), 10 deletions(-)
> 
> diff --git a/cmds/subvolume.c b/cmds/subvolume.c
> index f7076655..1f513a4a 100644
> --- a/cmds/subvolume.c
> +++ b/cmds/subvolume.c
> @@ -1375,6 +1375,64 @@ static void print_subvolume_show_quota_text(const struct btrfs_util_subvolume_in
>  			pretty_size_mode(stats->info.exclusive, unit_mode));
>  }
>  
> +static void print_subvolume_show_json(struct format_ctx *fctx,
> +				      const struct btrfs_util_subvolume_info *subvol,
> +				      const char *subvol_path, const char *subvol_name)
> +{
> +	fmt_print(fctx, "name", subvol_name);
> +
> +	if (!uuid_is_null(subvol->uuid))
> +		fmt_print(fctx, "uuid", subvol->uuid);

Regarding the "more is better" approach, no conditionals for similar
data.

> +	if (!uuid_is_null(subvol->parent_uuid))
> +		fmt_print(fctx, "parent_uuid", subvol->parent_uuid);
> +	if (!uuid_is_null(subvol->received_uuid))
> +		fmt_print(fctx, "received_uuid", subvol->received_uuid);
> +
> +	fmt_print(fctx, "otime", subvol->otime);
> +	fmt_print(fctx, "ID", subvol->id);
> +	fmt_print(fctx, "gen", subvol->generation);
> +	fmt_print(fctx, "cgen", subvol->otransid);
> +	fmt_print(fctx, "parent", subvol->parent_id);
> +	fmt_print(fctx, "top level", subvol->parent_id);
> +
> +	fmt_print_start_group(fctx, "flags", JSON_TYPE_ARRAY);
> +	if (subvol->flags & BTRFS_ROOT_SUBVOL_RDONLY)
> +		fmt_print(fctx, "flag-list-item", "readonly");
> +	fmt_print_end_group(fctx, "flags");
> +
> +	if (subvol->stransid)
> +		fmt_print(fctx, "stransid", subvol->stransid);
> +
> +	if (subvol->stime.tv_sec)
> +		fmt_print(fctx, "stime", subvol->stime);
> +
> +	if (subvol->rtransid)
> +		fmt_print(fctx, "rtransid", subvol->rtransid);
> +
> +	if (subvol->rtime.tv_sec)
> +		fmt_print(fctx, "rtime", subvol->rtime);
> +}