lei_mail_sync: rely on flock(2), avoid IPC

Since 44917fdd24a8bec1 ("lei_mail_sync: do not use transactions"),
relying on lei/store to serialize access was a pointless endeavor.

Rely on flock(2) to serialize multiple writers since (in my
experience) it's the easiest way to deal with parallel writers
when using SQLite.  This allows us to simplify existing callers
while speeding up 'lei refresh-mail-sync --all=local' by 5% or
so.

1 files changed, 3 insertions, 4 deletions

diff --git a/lib/PublicInbox/LeiImport.pm b/lib/PublicInbox/LeiImport.pm
index b1cb3940..9084d771 100644
--- a/lib/PublicInbox/LeiImport.pm
+++ b/lib/PublicInbox/LeiImport.pm
@@ -36,7 +36,7 @@ sub pmdir_cb { # called via wq_io_do from LeiPmdir->each_mdir_fn
         my $kw = PublicInbox::MdirReader::flags2kw($fl);
         substr($folder, 0, 0) = 'maildir:'; # add prefix
         my $lse = $self->{lse} //= $self->{lei}->{sto}->search;
-        my $lms = $self->{-lms_ro} //= $lse->lms; # may be 0 or undef
+        my $lms = $self->{-lms_ro} //= $self->{lei}->lms; # may be 0 or undef
         my $oidbin = $lms ? $lms->name_oidbin($folder, $bn) : undef;
         my @docids = defined($oidbin) ? $lse->over->oidbin_exists($oidbin) : ();
         my $vmd = $self->{-import_kw} ? { kw => $kw } : undef;
@@ -83,7 +83,7 @@ sub do_import_index ($$@) {
                 # $j = $net->net_concurrency($j); TODO
                 if ($lei->{opt}->{incremental} // 1) {
                         $net->{incremental} = 1;
-                        $net->{-lms_ro} = $sto->search->lms // 0;
+                        $net->{-lms_ro} = $lei->lms // 0;
                         if ($self->{-import_kw} && $net->{-lms_ro} &&
                                         !$lei->{opt}->{'new-only'} &&
                                         $net->{imap_order}) {
@@ -120,8 +120,7 @@ sub _complete_import {
         my $match_cb = $lei->complete_url_prepare(\@argv);
         my @m = map { $match_cb->($_) } $lei->url_folder_cache->keys;
         my %f = map { $_ => 1 } @m;
-        my $sto = $lei->_lei_store;
-        if (my $lms = $sto ? $sto->search->lms : undef) {
+        if (my $lms = $lei->lms) {
                 @m = map { $match_cb->($_) } $lms->folders;
                 @f{@m} = @m;
         }