net_reader: mic_get: reuse connections if cache enabled

We only enable {mic_cached} in WQ workers, and those
aren't expected to fork again going forward.  So cache
here avoid a penalty for the non-augmenting (imap_delete_all)
call with "lei q"

diff --git a/lib/PublicInbox/NetReader.pm b/lib/PublicInbox/NetReader.pm
index c29e09c190a6159c9c1a442e110ee5c4ffe018ff..ff90468b0652fb62d5f3ef3c3505f61bdbc73e21 100644 (file)
--- a/lib/PublicInbox/NetReader.pm
+++ b/lib/PublicInbox/NetReader.pm
@@ -426,7 +426,8 @@ sub mic_get {
        my ($self, $uri) = @_;
        my $sec = uri_section($uri);
        # see if caller saved result of imap_common_init
-       if (my $cached = $self->{mics_cached}) {
+       my $cached = $self->{mics_cached};
+       if ($cached) {
                my $mic = $cached->{$sec};
                return $mic if $mic && $mic->IsConnected;
                delete $cached->{$sec};
@@ -439,7 +440,8 @@ sub mic_get {
                }
        }
        my $mic = PublicInbox::IMAPClient->new(%$mic_arg);
-       $mic && $mic->IsConnected ? $mic : undef;
+       $cached //= {}; # invalid placeholder if no cache enabled
+       $mic && $mic->IsConnected ? ($cached->{$sec} = $mic) : undef;
 }
 
 sub imap_each {