[PATCH 16/23] searchview: speed up search summary by ~10%

[Eric Wong <e@yhbt.net>]

Instead of loading one article at-a-time from over.sqlite3, we
can use SQL to mass-load IN (?,?, ...) all results with a single
SQLite query.  Despite SQLite being in-process and having no
network latency, the reduction in SQL query executions from
loading multiple rows at once speeds things up significantly.

We'll keep the over->get_art optimizations from the previous
commit, since it still speeds up long-lived responses, slightly.
---
 lib/PublicInbox/Over.pm       |  9 +++++++++
 lib/PublicInbox/SearchView.pm | 12 ++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index 80e57e62..a055b4cd 100644
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -104,6 +104,15 @@ ORDER BY num ASC
 
 }
 
+sub get_all {
+	my $self = shift;
+	my $nr = scalar(@_) or return [];
+	my $in = '?' . (',?' x ($nr - 1));
+	do_get($self, <<"", { cull => 1, limit => $nr }, @_);
+SELECT num,ds,ddd FROM over WHERE num IN ($in)
+
+}
+
 sub nothing () { wantarray ? (0, []) : [] };
 
 sub get_thread {
diff --git a/lib/PublicInbox/SearchView.pm b/lib/PublicInbox/SearchView.pm
index 61534c25..a3527057 100644
--- a/lib/PublicInbox/SearchView.pm
+++ b/lib/PublicInbox/SearchView.pm
@@ -91,22 +91,22 @@ sub mset_summary {
 	my $pfx = ' ' x $pad;
 	my $res = \($ctx->{-html_tip});
 	my $ibx = $ctx->{-inbox};
-	my $over = $ibx->over;
 	my $nshard = $ibx->search->{nshard} // 1;
 	my $obfs_ibx = $ibx->{obfuscate} ? $ibx : undef;
+	my @nums = map { mdocid($nshard, $_) } $mset->items;
+	my %num2msg = map { $_->{num} => $_ } @{$ibx->over->get_all(@nums)};
+
 	foreach my $m ($mset->items) {
 		my $rank = sprintf("%${pad}d", $m->get_rank + 1);
 		my $pct = get_pct($m);
-		my $num = mdocid($nshard, $m);
-		my $smsg = $over->get_art($num, 1);
-		unless ($smsg) {
+		my $num = shift @nums;
+		my $smsg = delete($num2msg{$num}) or do {
 			eval {
 				$m = "$m $num expired\n";
 				$ctx->{env}->{'psgi.errors'}->print($m);
 			};
 			next;
-		}
-		PublicInbox::Smsg::psgi_cull($smsg);
+		};
 		my $s = ascii_html($smsg->{subject});
 		my $f = ascii_html($smsg->{from_name});
 		if ($obfs_ibx) {