core: USB function properties do not change dynamically, don't claim so

poettering · poettering · commit b4525804a149 · 2018-11-28T10:29:51.000+01:00
This reduces our PropertiesChanged signals a bit in size as we don't
keep out blasting properties that cannot change anyway all the time.
diff --git a/src/core/dbus-service.c b/src/core/dbus-service.c
@@ -120,8 +120,8 @@ const sd_bus_vtable bus_service_vtable[] = {
         SD_BUS_PROPERTY("StatusText", "s", NULL, offsetof(Service, status_text), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("StatusErrno", "i", bus_property_get_int, offsetof(Service, status_errno), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("Result", "s", property_get_result, offsetof(Service, result), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
-        SD_BUS_PROPERTY("USBFunctionDescriptors", "s", NULL, offsetof(Service, usb_function_descriptors), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
-        SD_BUS_PROPERTY("USBFunctionStrings", "s", NULL, offsetof(Service, usb_function_strings), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+        SD_BUS_PROPERTY("USBFunctionDescriptors", "s", NULL, offsetof(Service, usb_function_descriptors), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("USBFunctionStrings", "s", NULL, offsetof(Service, usb_function_strings), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("UID", "u", bus_property_get_uid, offsetof(Unit, ref_uid), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("GID", "u", bus_property_get_gid, offsetof(Unit, ref_gid), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("NRestarts", "u", bus_property_get_unsigned, offsetof(Service, n_restarts), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
