[PATCH 4/5] searchidx: rename get_val to int_val and return IV

[Eric Wong <e@80x24.org>]

Values can be strings in Xapian, although we currently use
integer values exclusively.  Give the wrapper a more appropriate
name in case we start using string columns.

For future-proofing, we'll now return `undef' on missing columns
and coerce the return value to an IV (integer value) to save
memory, as sortable_unserialise returns a PV (pointer value)
scalar despite it existing to support numeric values.
---
 lib/PublicInbox/SearchIdx.pm | 9 +++++----
 t/search.t                   | 4 ++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index b731f698..cf2c2c55 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -501,17 +501,18 @@ sub remove_eidx_info {
 	$self->{xdb}->replace_document($docid, $doc);
 }
 
-sub get_val ($$) {
+sub int_val ($$) {
 	my ($doc, $col) = @_;
-	sortable_unserialise($doc->get_value($col));
+	my $val = $doc->get_value($col) or return; # undefined is '' in Xapian
+	sortable_unserialise($val) + 0; # PV => IV conversion
 }
 
 sub smsg_from_doc ($) {
 	my ($doc) = @_;
 	my $data = $doc->get_data or return;
 	my $smsg = bless {}, 'PublicInbox::Smsg';
-	$smsg->{ts} = get_val($doc, PublicInbox::Search::TS());
-	my $dt = get_val($doc, PublicInbox::Search::DT());
+	$smsg->{ts} = int_val($doc, PublicInbox::Search::TS());
+	my $dt = int_val($doc, PublicInbox::Search::DT());
 	my ($yyyy, $mon, $dd, $hh, $mm, $ss) = unpack('A4A2A2A2A2A2', $dt);
 	$smsg->{ds} = timegm($ss, $mm, $hh, $dd, $mon - 1, $yyyy);
 	$smsg->load_from_data($data);
diff --git a/t/search.t b/t/search.t
index da9acb07..11143204 100644
--- a/t/search.t
+++ b/t/search.t
@@ -332,13 +332,13 @@ $ibx->with_umask(sub {
 		like($smsg->{to}, qr/\blist\@example\.com\b/, 'to appears');
 		my $doc = $m->get_document;
 		my $col = PublicInbox::Search::BYTES();
-		my $bytes = PublicInbox::SearchIdx::get_val($doc, $col);
+		my $bytes = PublicInbox::SearchIdx::int_val($doc, $col);
 		like($bytes, qr/\A[0-9]+\z/, '$bytes stored as digit');
 		ok($bytes > 0, '$bytes is > 0');
 		is($bytes, $smsg->{bytes}, 'bytes Xapian value matches Over');
 
 		$col = PublicInbox::Search::UID();
-		my $uid = PublicInbox::SearchIdx::get_val($doc, $col);
+		my $uid = PublicInbox::SearchIdx::int_val($doc, $col);
 		is($uid, $smsg->{num}, 'UID column matches {num}');
 		is($uid, $m->get_docid, 'UID column matches docid');
 	}