view: speed up homepage loading time with date clamp

[public-inbox.git] / lib / PublicInbox / View.pm

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index ec0434335d8919e73009f415fa6bb8edb52e518a..60fc1df17f9e5e242d55a7f05a00ca2e7943c07e 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -1069,17 +1069,31 @@ sub index_nav { # callback for WwwStream
 sub index_topics {
        my ($ctx) = @_;
        my ($off) = (($ctx->{qp}->{o} || '0') =~ /(\d+)/);
-       my $opts = { offset => $off, limit => 200 };
+       my $lim = 200;
+       my $opts = { offset => $off, limit => $lim };
 
        $ctx->{order} = [];
        my $srch = $ctx->{srch};
-       my $sres = $srch->query('', $opts);
+
+       my $qs = '';
+       # this complicated bit cuts loading time by over 400ms on my system:
+       if ($off == 0) {
+               my ($min, $max) = $ctx->{-inbox}->mm->minmax;
+               my $n = $max - $lim;
+               $n = $min if $n < $min;
+               for (; $qs eq '' && $n >= $min; --$n) {
+                       my $smsg = $srch->lookup_article($n) or next;
+                       $qs = POSIX::strftime('d:%Y%m%d..', gmtime($smsg->ts));
+               }
+       }
+
+       my $sres = $srch->query($qs, $opts);
        my $nr = scalar @{$sres->{msgs}};
        if ($nr) {
                $sres = load_results($srch, $sres);
                walk_thread(thread_results($ctx, $sres), $ctx, *acc_topic);
        }
-       $ctx->{-next_o} = $off+ $nr;
+       $ctx->{-next_o} = $off + $nr;
        $ctx->{-cur_o} = $off;
        PublicInbox::WwwStream->response($ctx, dump_topics($ctx), *index_nav);
 }