view: reply threading adjustment

Give changes in subject their own line to reduce line wrapping,
but avoid showing any redundant subjects by maintaining a hash
of subjects already displayed.

1 files changed, 19 insertions, 10 deletions

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index dcdb3109..fe4f2dfd 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -9,6 +9,7 @@ use Encode::MIME::Header;
 use Email::MIME::ContentType qw/parse_content_type/;
 use PublicInbox::Hval;
 use PublicInbox::MID qw/mid_clean mid_compressed/;
+use Digest::SHA;
 require POSIX;
 
 # TODO: make these constants tunable
@@ -393,37 +394,45 @@ sub anchor_for {
 
 sub simple_dump {
         my ($dst, $root, $node, $level) = @_;
-        $$dst .= '  ' x $level;
+        my $pfx = '  ' x $level;
+        $$dst .= $pfx;
         if (my $x = $node->message) {
                 my $mid = $x->header('Message-ID');
                 if ($root->[0] ne $mid) {
-                        my $s = clean_subj($x->header('Subject'));
-                        if ($root->[1] eq $s) {
-                                $s = '  ';
+                        my $s = $x->header('Subject');
+                        my $h = hash_subj($s);
+                        if ($root->[1]->{$h}) {
+                                $s = '';
                         } else {
+                                $root->[1]->{$h} = 1;
                                 $s = PublicInbox::Hval->new($s);
-                                $s = $s->as_html . ' ';
+                                $s = $s->as_html;
                         }
                         my $m = PublicInbox::Hval->new_msgid($mid);
                         my $f = PublicInbox::Hval->new($x->header('X-PI-From'));
                         my $d = PublicInbox::Hval->new($x->header('X-PI-Date'));
                         $m = $m->as_href . '.html';
                         $f = $f->as_html;
-                        $d = $d->as_html;
-                        $$dst .= "` <a\nhref=\"$m\">$s$f @ $d UTC</a>\n";
+                        $d = $d->as_html . ' UTC';
+                        if (length($s) == 0) {
+                                $$dst .= "` <a\nhref=\"$m\">$f @ $d</a>\n";
+                        } else {
+                                $$dst .= "` <a\nhref=\"$m\">$s</a>\n" .
+                                     "$pfx  by $f @ $d\n";
+                        }
                 }
         }
         simple_dump($dst, $root, $node->child, $level + 1) if $node->child;
         simple_dump($dst, $root, $node->next, $level) if $node->next;
 }
 
-sub clean_subj {
+sub hash_subj {
         my ($subj) = @_;
         $subj =~ s/\A\s+//;
         $subj =~ s/\s+\z//;
         $subj =~ s/^(?:re|aw):\s*//i; # remove reply prefix (aw: German)
         $subj =~ s/\s+/ /;
-        $subj;
+        Digest::SHA::sha1($subj);
 }
 
 sub thread_replies {
@@ -435,7 +444,7 @@ sub thread_replies {
         $th->thread;
         $th->order(*PublicInbox::Thread::sort_ts);
         $root = [ $root->header('Message-ID'),
-                  clean_subj($root->header('Subject')) ];
+                  { hash_subj($root->header('Subject')) => 1 } ];
         simple_dump($dst, $root, $_, 0) for $th->rootset;
 }