[PATCH 16/38] view: attach_link: reduce obuf manipulation

[Eric Wong]

This is another steep towards reducing the maximum size of
an obuf by eventually doing compression earlier while we
render messages as HTML.

And do some golfing while we're at it...
---
 lib/PublicInbox/View.pm | 30 +++++++++++-------------------
 1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 1b55fe77..0fe645ca 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -524,7 +524,6 @@ sub attach_link ($$$$;$) {
        # downloads for 0-byte multipart attachments
        return unless $part->{bdy};
 
-       my $nl = $idx eq '1' ? '' : "\n"; # like join("\n", ...)
        my $size = length($part->body);
        delete $part->{bdy}; # save memory
 
@@ -540,23 +539,17 @@ sub attach_link ($$$$;$) {
        } else {
                $sfn = 'a.bin';
        }
-       my $rv = $ctx->{obuf};
-       $$rv .= qq($nl<a\nhref="$ctx->{mhref}$idx-$sfn">);
-       if ($err) {
-               $$rv .= <<EOF;
+       my $rv = $idx eq '1' ? '' : "\n"; # like join("\n", ...)
+       $rv .= qq(<a\nhref="$ctx->{mhref}$idx-$sfn">);
+       $rv .= <<EOF if $err;
 [-- Warning: decoded text below may be mangled, UTF-8 assumed --]
 EOF
-       }
-       $$rv .= "[-- Attachment #$idx: ";
-       my $ts = "Type: $ct, Size: $size bytes";
+       $rv .= "[-- Attachment #$idx: ";
        my $desc = $part->header('Content-Description') // $fn // '';
-       $desc = ascii_html($desc);
-       $$rv .= ($desc eq '') ? "$ts --]" : "$desc --]\n[-- $ts --]";
-       $$rv .= "</a>\n";
-
-       $$rv .= submsg_hdr($ctx, $part) if $part->{is_submsg};
-
-       undef;
+       $rv .= ascii_html($desc)." --]\n[-- " if $desc ne '';
+       $rv .= "Type: $ct, Size: $size bytes --]</a>\n";
+       $rv .= submsg_hdr($ctx, $part) if $part->{is_submsg};
+       $rv;
 }
 
 sub add_text_body { # callback for each_part
@@ -568,10 +561,9 @@ sub add_text_body { # callback for each_part
        my ($part, $depth, $idx) = @$p;
        my $ct = $part->content_type || 'text/plain';
        my $fn = $part->filename;
-       my ($s, $err) = msg_part_text($part, $ct);
-       return attach_link($ctx, $ct, $p, $fn) unless defined $s;
-
        my $rv = $ctx->{obuf};
+       my ($s, $err) = msg_part_text($part, $ct);
+       $s // return $$rv .= (attach_link($ctx, $ct, $p, $fn) // '');
        if ($part->{is_submsg}) {
                $$rv .= submsg_hdr($ctx, $part);
                $$rv .= "\n";
@@ -623,7 +615,7 @@ sub add_text_body { # callback for each_part
        undef $s; # free memory
        if (defined($fn) || ($depth > 0 && !$part->{is_submsg}) || $err) {
                # badly-encoded message with $err? tell the world about it!
-               attach_link($ctx, $ct, $p, $fn, $err);
+               $$rv .= attach_link($ctx, $ct, $p, $fn, $err);
                $$rv .= "\n";
        }
        delete $part->{bdy}; # save memory