index: use message threading if search is available

This lets us merge topics with different subjects with a common parent
(common in "[PATCH 0/X]" threads).  This also lets us avoid forking for
the HTML index page, too.

1 files changed, 108 insertions, 2 deletions

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 129aa895..ee5ba20e 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -656,11 +656,12 @@ sub msg_timestamp {
 }
 
 sub thread_results {
-        my ($msgs) = @_;
+        my ($msgs, $nosubject) = @_;
         require PublicInbox::Thread;
         my $th = PublicInbox::Thread->new(@$msgs);
-        $th->thread;
         no warnings 'once';
+        $Mail::Thread::nosubject = $nosubject;
+        $th->thread;
         $th->order(*PublicInbox::Thread::sort_ts);
         $th
 }
@@ -746,4 +747,109 @@ sub inline_dump {
         inline_dump($dst, $state, $upfx, $node->next, $level);
 }
 
+sub rsort_ts {
+        sort {
+                (eval { $b->topmost->message->header('X-PI-TS') } || 0) <=>
+                (eval { $a->topmost->message->header('X-PI-TS') } || 0)
+        } @_;
+}
+
+# accumulate recent topics if search is supported
+# returns 1 if done, undef if not
+sub add_topic {
+        my ($state, $node, $level) = @_;
+        return unless $node;
+
+        if (my $x = $node->message) {
+                $x = $x->header_obj;
+                my ($topic, $subj);
+
+                $subj = $x->header('Subject');
+                $subj = $state->{srch}->subject_normalized($subj);
+                $topic = $subj;
+
+                # kill "[PATCH v2]" etc. for summarization
+                $topic =~ s/\A\s*\[[^\]]+\]\s*//g;
+                $topic = substr($topic, 0, 30);
+
+                if (++$state->{subjs}->{$topic} == 1) {
+                        push @{$state->{order}}, [ $level, $subj, $topic ];
+                }
+
+                my $mid = mid_clean($x->header('Message-ID'));
+
+                my $u = $x->header('X-PI-From');
+                my $ts = $x->header('X-PI-TS');
+                $state->{latest}->{$topic} = [ $mid, $u, $ts ];
+        } # else { } # ghost ignored...
+
+        add_topic($state, $node->child, $level + 1);
+        add_topic($state, $node->next, $level);
+}
+
+sub dump_topics {
+        my ($state) = @_;
+        my $order = $state->{order};
+        my $subjs = $state->{subjs};
+        my $latest = $state->{latest};
+        return "\n[No recent topics]</pre>" unless (scalar @$order);
+        my $dst = '';
+        my $pfx;
+        my $prev = 0;
+        my $prev_attr = '';
+        while (defined(my $info = shift @$order)) {
+                my ($level, $subj, $topic) = @$info;
+                my $n = delete $subjs->{$topic};
+                my ($mid, $u, $ts) = @{delete $latest->{$topic}};
+                $mid = PublicInbox::Hval->new($mid)->as_href;
+                $subj = PublicInbox::Hval->new($subj)->as_html;
+                $u = PublicInbox::Hval->new($u)->as_html;
+                $pfx = INDENT x $level;
+                my $nl = $level == $prev ? "\n" : '';
+                my $dot = $level == 0 ? '' : '`';
+                $dst .= "$nl$pfx$dot<a\nhref=\"$mid/t/#u\"><b>$subj</b></a>\n";
+
+                my $attr;
+                $ts = POSIX::strftime('%Y-%m-%d %H:%M', gmtime($ts));
+                if ($n == 1) {
+                        $attr = "created by $u @ $ts UTC";
+                        $n = "\n";
+                } else {
+                        # $n isn't the total number of posts on the topic,
+                        # just the number of posts in the current results
+                        # window, so leave it unlabeled
+                        $attr = "updated by $u @ $ts UTC";
+                        $n = " ($n)\n";
+                }
+                if ($level == 0 || $attr ne $prev_attr) {
+                        $dst .= "$pfx - ". $attr . $n;
+                        $prev_attr = $attr;
+                }
+        }
+        $dst .= '</pre>';
+}
+
+sub emit_index_topics {
+        my ($state, $fh) = @_;
+        my $off = $state->{ctx}->{cgi}->param('o');
+        $off = 0 unless defined $off;
+        $state->{order} = [];
+        $state->{subjs} = {};
+        $state->{latest} = {};
+        my $max = 25;
+        my %opts = ( offset => int $off, limit => $max * 4 );
+        while (scalar @{$state->{order}} < $max) {
+                my $res = $state->{srch}->query('', \%opts);
+                my $nr = scalar @{$res->{msgs}} or last;
+
+                for (rsort_ts(thread_results(load_results($res), 1)->rootset)) {
+                        add_topic($state, $_, 0);
+                }
+                $opts{offset} += $nr;
+        }
+
+        $fh->write(dump_topics($state));
+        $opts{offset};
+}
+
 1;