watch: avoid long transaction to IMAPTracker

With different polling intervals, multiple processes may
simultaneously write to IMAPtracker.  This ought to reduce
SQLite busy waiting and contention issues when importing
many inboxes in parallel.

diff --git a/lib/PublicInbox/WatchMaildir.pm b/lib/PublicInbox/WatchMaildir.pm
index e0caaa563b24b0f64f2aa0c6855ac6b1e5dd7197..d492e5d65b7c8ffa369b7e402b166cb0ff16deab 100644 (file)
--- a/lib/PublicInbox/WatchMaildir.pm
+++ b/lib/PublicInbox/WatchMaildir.pm
@@ -335,12 +335,12 @@ sub mic_for ($$$) { # mic = Mail::IMAPClient
        $mic;
 }
 
-sub imap_import_msg ($$$$$) {
-       my ($self, $itrk, $r_uidval, $uid, $raw) = @_;
+sub imap_import_msg ($$$$) {
+       my ($self, $url, $uid, $raw) = @_;
        # our target audience expects LF-only, save storage
        $$raw =~ s/\r\n/\n/sg;
 
-       my $inboxes = $self->{imap}->{$itrk->{url}};
+       my $inboxes = $self->{imap}->{$url};
        if (ref($inboxes)) {
                for my $ibx (@$inboxes) {
                        my $eml = PublicInbox::Eml->new($$raw);
@@ -348,12 +348,11 @@ sub imap_import_msg ($$$$$) {
                }
        } elsif ($inboxes eq 'watchspam') {
                my $eml = PublicInbox::Eml->new($raw);
-               my $arg = [ $self, $eml, "$itrk->{url} UID:$uid" ];
+               my $arg = [ $self, $eml, "$url UID:$uid" ];
                $self->{config}->each_inbox(\&remove_eml_i, $arg);
        } else {
                die "BUG: destination unknown $inboxes";
        }
-       $itrk->update_last($r_uidval, $uid);
 }
 
 sub imap_fetch_all ($$$) {
@@ -415,8 +414,8 @@ sub imap_fetch_all ($$$) {
                return if $uids->[0] < $l_uid;
 
                $l_uid = $uids->[-1] + 1; # for next search
+               my $last_uid;
 
-               $itrk->{dbh}->begin_work;
                while (defined(($uid = shift(@$uids)))) {
                        local $0 = "UID:$uid $mbx $sec";
                        my $r = $mic->fetch_hash($uid, $req);
@@ -426,11 +425,12 @@ sub imap_fetch_all ($$$) {
                        }
                        # messages get deleted, so holes appear
                        defined(my $raw = delete $r->{$uid}->{$key}) or next;
-                       imap_import_msg($self, $itrk, $r_uidval, $uid, \$raw);
+                       imap_import_msg($self, $url, $uid, \$raw);
+                       $last_uid = $uid;
                        last if $self->{quit};
                }
                _done_for_now($self);
-               $itrk->{dbh}->commit;
+               $itrk->update_last($r_uidval, $last_uid) if defined $last_uid;
        } until ($err || $self->{quit});
        $err;
 }