[PATCH] v2writable: only load Xapian when a shard is found

[Eric Wong <e@yhbt.net>]

We don't need to load Xapian until we have a directory
which looks like a shard, otherwise we're wasting cycles
on memory when running short-lived processes.
---
 lib/PublicInbox/V2Writable.pm | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 513e9f23..b393b31f 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -75,11 +75,14 @@ sub count_shards ($) {
 	# Also, shard count may change while -watch is running
 	# due to "xcpdb --reshard"
 	if (-d $xpfx) {
-		require PublicInbox::Search;
-		PublicInbox::Search::load_xapian();
-		my $XapianDatabase = $PublicInbox::Search::X{Database};
+		my $XapianDatabase;
 		foreach my $shard (<$xpfx/*>) {
 			-d $shard && $shard =~ m!/[0-9]+\z! or next;
+			$XapianDatabase //= do {
+				require PublicInbox::Search;
+				PublicInbox::Search::load_xapian();
+				$PublicInbox::Search::X{Database};
+			};
 			eval {
 				$XapianDatabase->new($shard)->close;
 				$n++;