+sub set_keywords {
+ my ($self, $docid, @kw) = @_;
+ begin_txn_lazy($self);
+ my $doc = _get_doc($self, $docid) or return;
+ my %keep = map { $_ => 1 } @kw;
+ my %add = %keep;
+ my @rm;
+ my $end = $doc->termlist_end;
+ for (my $cur = $doc->termlist_begin; $cur != $end; $cur++) {
+ $cur->skip_to('K');
+ last if $cur == $end;
+ my $kw = $cur->get_termname;
+ $kw =~ s/\AK//s or next;
+ $keep{$kw} ? delete($add{$kw}) : push(@rm, $kw);
+ }
+ return unless (scalar(@rm) + scalar(keys %add));
+ $doc->remove_term('K'.$_) for @rm;
+ $doc->add_boolean_term('K'.$_) for (keys %add);
+ $self->{xdb}->replace_document($docid, $doc);
+}
+
+sub add_keywords {
+ my ($self, $docid, @kw) = @_;
+ begin_txn_lazy($self);
+ my $doc = _get_doc($self, $docid) or return;
+ $doc->add_boolean_term('K'.$_) for @kw;
+ $self->{xdb}->replace_document($docid, $doc);
+}
+
+sub remove_keywords {
+ my ($self, $docid, @kw) = @_;
+ begin_txn_lazy($self);
+ my $doc = _get_doc($self, $docid) or return;
+ my $replace;
+ eval {
+ $doc->remove_term('K'.$_);
+ $replace = 1
+ } for @kw;
+ $self->{xdb}->replace_document($docid, $doc) if $replace;