pub trait Migration {
// Required method
fn migrate_rev0(&self, userdata: &[u8]) -> Result<(u32, Vec<u8>), String>;
}
Required Methods§
Sourcefn migrate_rev0(&self, userdata: &[u8]) -> Result<(u32, Vec<u8>), String>
fn migrate_rev0(&self, userdata: &[u8]) -> Result<(u32, Vec<u8>), String>
Migration of a revision 0 header.
You you have a revision 0 header, then this function is called. You
must extract the top-id
from the given userdata
record. The concept
of userdata
was removed with the revision 1. The top-id
is directly
stored in the header.
On success the extracted top-id
should be returned, otherwise return
an error-description.