view: improve grouping for topic view

This reduces the amount of mbox/Atom links while keeping
better track of overall thread count.  We no longer loop
to fill up slots to simplify the code a bit and hopefully
get better grouping.

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 275fed43d23526adf48ea4c4cca12bbecfe32320..5a312d84ba8d14e45cee9fac410440736aefca47 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -839,84 +839,82 @@ sub _tryload_ghost ($$) {
 }
 
 # accumulate recent topics if search is supported
-# returns 1 if done, undef if not
-sub add_topic {
+# returns 200 if done, 404 if not
+sub acc_topic {
        my ($ctx, $level, $node) = @_;
        my $srch = $ctx->{srch};
        my $mid = $node->messageid;
        my $x = $node->message || _tryload_ghost($srch, $mid);
        my ($subj, $ts);
+       my $topic;
        if ($x) {
                $x = $x->header_obj;
-               $subj = $x->header('Subject');
+               $subj = $x->header('Subject') || '';
                $subj = $srch->subject_normalized($subj);
                $ts = $x->header('X-PI-TS');
-       } else { # ghost message, do not bump level
-               $ts = -666;
-               $subj = "<$mid>";
-       }
-       if (++$ctx->{subjs}->{$subj} == 1) {
-               push @{$ctx->{order}}, [ $level, $subj ];
-       }
-       my $exist = $ctx->{latest}->{$subj};
-       if (!$exist || $exist->[1] < $ts) {
-               $ctx->{latest}->{$subj} = [ $mid, $ts ];
+               if ($level == 0) {
+                       $topic = [ $ts, 1, { $subj => $mid }, $subj ];
+                       $ctx->{-cur_topic} = $topic;
+                       push @{$ctx->{order}}, $topic;
+                       return;
+               }
+
+               $topic = $ctx->{-cur_topic}; # should never be undef
+               $topic->[0] = $ts if $ts > $topic->[0];
+               $topic->[1]++;
+               my $seen = $topic->[2];
+               if (scalar(@$topic) == 3) { # parent was a ghost
+                       push @$topic, $subj;
+               } elsif (!$seen->{$subj}) {
+                       push @$topic, $level, $subj;
+               }
+               $seen->{$subj} = $mid; # latest for subject
+       } else { # ghost message
+               return if $level != 0; # ignore child ghosts
+               $topic = [ -666, 0, {} ];
+               $ctx->{-cur_topic} = $topic;
+               push @{$ctx->{order}}, $topic;
        }
 }
 
-sub topics {
+sub dump_topics {
        my ($ctx) = @_;
-       my $order = $ctx->{order};
-       my $subjs = $ctx->{subjs};
-       my $latest = $ctx->{latest};
+       my $order = $ctx->{order}; # [ ts, subj1, subj2, subj3, ... ]
        if (!@$order) {
                $ctx->{-html_tip} = '<pre>[No topics in range]</pre>';
                return 404;
        }
-       my $pfx;
-       my $prev = 0;
-       my $prev_attr = '';
-       my $cur;
-       my @recent;
-       while (defined(my $info = shift @$order)) {
-               my ($level, $subj) = @$info;
-               my $n = delete $subjs->{$subj};
-               my ($mid, $ts) = @{delete $latest->{$subj}};
-               my $href = PublicInbox::Hval->new_msgid($mid)->as_href;
-               $pfx = indent_for($level);
-               my $nl = $level == $prev ? "\n" : '';
-               if ($nl && $cur) {
-                       push @recent, $cur;
-                       $cur = undef;
-               }
-               $cur ||= [ $ts, '' ];
-               $cur->[0] = $ts if $ts > $cur->[0];
-               $cur->[1] .= $nl . $pfx . th_pfx($level);
-               if ($ts == -666) { # ghost
-                       $cur->[1] .= ghost_parent('', $mid) . "\n";
-                       next; # child will have mbox / atom link
-               }
 
-               $subj = PublicInbox::Hval->new($subj)->as_html;
-               $cur->[1] .= "<a\nhref=\"$href/T/#u\"><b>$subj</b></a>\n";
+       my @out;
+       foreach my $topic (@$order) {
+               my ($ts, $n, $seen, $top, @ex) = @$topic;
+               @$topic = ();
+               next unless defined $top;  # ghost topic
+               my $mid = delete $seen->{$top};
+               my $href = PublicInbox::Hval->new_msgid($mid)->as_href;
+               $top = PublicInbox::Hval->new($top)->as_html;
                $ts = fmt_ts($ts);
-               my $attr = " $ts UTC";
 
                # $n isn't the total number of posts on the topic,
                # just the number of posts in the current results window
                $n = $n == 1 ? '' : " ($n+ messages)";
 
-               if ($level == 0 || $attr ne $prev_attr) {
-                       my $mbox = qq(<a\nhref="$href/t.mbox.gz">mbox.gz</a>);
-                       my $atom = qq(<a\nhref="$href/t.atom">Atom</a>);
-                       $pfx .= INDENT if $level > 0;
-                       $cur->[1] .= $pfx . $attr . $n . " - $mbox / $atom\n";
-                       $prev_attr = $attr;
+               my $mbox = qq(<a\nhref="$href/t.mbox.gz">mbox.gz</a>);
+               my $atom = qq(<a\nhref="$href/t.atom">Atom</a>);
+               my $s = "<a\nhref=\"$href/T/#t\"><b>$top</b></a>\n" .
+                       " $ts UTC $n - $mbox / $atom\n";
+               for (my $i = 0; $i < scalar(@ex); $i += 2) {
+                       my $level = $ex[$i];
+                       my $sub = $ex[$i + 1];
+                       $mid = delete $seen->{$sub};
+                       $sub = PublicInbox::Hval->new($sub)->as_html;
+                       $href = PublicInbox::Hval->new_msgid($mid)->as_href;
+                       $s .= indent_for($level) . TCHILD;
+                       $s .= "<a\nhref=\"$href/T/#u\">$sub</a>\n";
                }
+               push @out, $s;
        }
-       push @recent, $cur if $cur;
-       @recent = map { $_->[1] } sort { $b->[0] <=> $a->[0] } @recent;
-       $ctx->{-html_tip} = join('', '<pre>', @recent, '</pre>');
+       $ctx->{-html_tip} = '<pre>' . join("\n", @out) . '</pre>';
        200;
 }
 
@@ -947,21 +945,18 @@ sub index_nav { # callback for WwwStream
 sub index_topics {
        my ($ctx) = @_;
        my ($off) = (($ctx->{qp}->{o} || '0') =~ /(\d+)/);
-       my $order = $ctx->{order} = [];
-       $ctx->{subjs} = {};
-       $ctx->{latest} = {};
-       my $max = 25;
-       my %opts = ( offset => $off, limit => $max * 4 );
-       while (scalar @{$ctx->{order}} < $max) {
-               my $sres = $ctx->{srch}->query('', \%opts);
-               my $nr = scalar @{$sres->{msgs}} or last;
+       my $opts = { offset => $off, limit => 200 };
+
+       $ctx->{order} = [];
+       my $sres = $ctx->{srch}->query('', $opts);
+       my $nr = scalar @{$sres->{msgs}};
+       if ($nr) {
                $sres = load_results($sres);
-               walk_thread(thread_results($sres), $ctx, *add_topic);
-               $opts{offset} += $nr;
+               walk_thread(thread_results($sres), $ctx, *acc_topic);
        }
-       $ctx->{-next_o} = $opts{offset};
+       $ctx->{-next_o} = $off+ $nr;
        $ctx->{-cur_o} = $off;
-       PublicInbox::WwwStream->response($ctx, topics($ctx), *index_nav);
+       PublicInbox::WwwStream->response($ctx, dump_topics($ctx), *index_nav);
 }
 
 sub thread_adj_level {