process_outgoing_message
Description:
Process a message before it's sent.
If the payload isn't changed the given payload
is just returned, otherwise [method@Glib.Bytes.unref] is called on the given
payload
and a new [struct@GLib.Bytes] is returned with the new data.
Extensions using reserved bits of the header will change them in header
.
Parameters:
this | |
header |
the message header |
payload |
the payload data |
Returns:
the message payload data, or null in case of error |