Re: [pve-devel] [PATCH manager] vzdump mail: Refactor text part

["Dominic Jäger" <d.jaeger@proxmox.com>]

On Mon, Nov 16, 2020 at 06:12:37PM +0100, Thomas Lamprecht wrote:
> 
> Or move out even more than just the format string generation out, so that it
> becomes a simple loop calling
> 
> $text .= render_task_plain($vmid, $task);
> 
> or something similar to that.

my $namelength = 20;
$text .= sprintf ("%-10s %-${namelength}s %-6s %10s %10s  %s\n",
    qw(VMID NAME STATUS TIME SIZE FILENAME));
my $render_task_plain = sub {
    my ($vmid, $task) = @_;
    my $successful = $task->{state} eq 'ok';
    $text .= sprintf("%-10s %-${namelength}s %-6s %10s " .
	($successful ? "%10s": "%8.2fMB")."  %s\n", $task->{vmid},
	$name, $task->{state}, format_time($task->{backuptime}), $size,
	$filename);
};
foreach my $task (@$tasklist) {
    $text .= render_task_plain($vmid, $task);
}

Not sure about this, we cannot move the heading into render_task_plain => Still
two format strings? So I don't really see how we would benefit from the
additional sub.

> we could avoid the sub and the if by using the $size_conversion directly in
> the format string?

I personally would prefer this idea. Then we can still decide if we prefer
 1. Short, but two format strings written out

my $namelength = 20;
$text .= sprintf ("%-10s %-${namelength}s %-6s %10s %10s  %s\n",
    qw(VMID NAME STATUS TIME SIZE FILENAME));
foreach my $task (@$tasklist) {
    my $successful = $task->{state} eq 'ok';
    $text .= sprintf("%-10s %-${namelength}s %-6s %10s " . 
	($successful ? "%10s": "%8.2fMB")."  %s\n", $task->{vmid}, $name,
	$task->{state}, format_time($task->{backuptime}), $size, $filename);
    }

 2. or a longer version. We could put all the decisions into the $fmt sub (idea
thanks to Hannes). Then it's a little longer, but relatively easy to read I
think, and has no two written out format strings.

my $namelength = 20;
my $fmt = sub {
    my ($successful) = @_;
    my $fmt = "%-10s %-${namelength}s %-6s %10s ";
    $fmt .= $successful ? "%10s": "%8.2fMB";
    $fmt .= "  %s\n";
    return $fmt;
};
$text .= sprintf ($fmt->(1), qw(VMID NAME STATUS TIME SIZE FILENAME));
foreach my $task (@$tasklist) {
    my $name = substr($task->{hostname}, 0, $namelength);
    my $successful = $task->{state} eq 'ok';
    my $size = $successful ? format_size ($task->{size}) : 0;
    my $filename = $successful ? $task->{target} : '-';
    $text .= sprintf($fmt->($successful), $task->{vmid}, $name,
	$task->{state}, format_time($task->{backuptime}), $size, $filename);
}