+sub update_vmd {
+ my ($self, $docid, $vmd_mod) = @_;
+ begin_txn_lazy($self);
+ my $doc = _get_doc($self, $docid) or return;
+ my $updated = 0;
+ my @x = @VMD_MAP;
+ while (my ($field, $pfx) = splice(@x, 0, 2)) {
+ # field: "label" or "kw"
+ for my $val (@{$vmd_mod->{"-$field"} // []}) {
+ eval {
+ $doc->remove_term($pfx . $val);
+ ++$updated;
+ };
+ }
+ for my $val (@{$vmd_mod->{"+$field"} // []}) {
+ $doc->add_boolean_term($pfx . $val);
+ ++$updated;
+ }
+ }
+ $self->{xdb}->replace_document($docid, $doc) if $updated;
+ $updated;
+}
+