Improve the performance of creating null terminated byte strings

filechooser/open.go

@@ -36,7 +36,7 @@ func OpenFile(parentWindow, title string, options *OpenFileOptions) ([]string, e
 	}
 
 	if options.CurrentFolder != "" {
-		data["current_folder"] = convert.ToNullTerminatedString(options.CurrentFolder)
+		data["current_folder"] = dbus.MakeVariant(convert.ToNullTerminated(options.CurrentFolder))
 	}
 
 	obj := conn.Object(apis.ObjectName, apis.ObjectPath)

filechooser/save.go

@@ -40,7 +40,7 @@ func SaveFile(parentWindow, title string, options *SaveFileOptions) ([]string, e
 	}
 
 	if options.CurrentFolder != "" {
-		data["current_folder"] = convert.ToNullTerminatedString(options.CurrentFolder)
+		data["current_folder"] = dbus.MakeVariant(convert.ToNullTerminated(options.CurrentFolder))
 	}
 
 	obj := conn.Object(apis.ObjectName, apis.ObjectPath)
@@ -76,7 +76,7 @@ func SaveFiles(parentWindow, title string, options *SaveFilesOptions) ([]string,
 	}
 
 	if options.CurrentFolder != "" {
-		data["current_folder"] = convert.ToNullTerminatedString(options.CurrentFolder)
+		data["current_folder"] = dbus.MakeVariant(convert.ToNullTerminated(options.CurrentFolder))
 	}
 
 	obj := conn.Object(apis.ObjectName, apis.ObjectPath)

internal/convert/nullstr.go

@@ -1,8 +1,8 @@
 package convert
 
-import "github.com/godbus/dbus/v5"
-
-// ToNullTerminatedString connverts a regular string into a null terminated dbus variant string.
-func ToNullTerminatedString(input string) dbus.Variant {
-	return dbus.MakeVariant([]byte(input + "\000"))
+// ToNullTerminated connverts a regular string into a null terminated byte string.
+func ToNullTerminated(input string) []byte {
+	terminated := make([]byte, len(input)+1)
+	copy(terminated, input)
+	return terminated
 }

internal/convert/nullstr_test.go

@@ -0,0 +1,28 @@
+package convert
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestToNullTerminated(t *testing.T) {
+	input := "test"
+
+	got := ToNullTerminated(input)
+	expect := []byte{'t', 'e', 's', 't', '\000'}
+	if !bytes.Equal(got, expect) {
+		t.Fatalf("Got %v, expected %v", got, expect)
+	}
+}
+
+var benchResult []byte
+
+func BenchmarkToNullTerminated(b *testing.B) {
+	var result []byte
+
+	for i := 0; i < b.N; i++ {
+		result = ToNullTerminated("long_input_string")
+	}
+
+	benchResult = result
+}