func getDescriptor(
txn *client.Txn, plainKey sqlbase.DescriptorKey, descriptor sqlbase.DescriptorProto,
) (bool, error) {
gr, err := txn.Get(plainKey.Key())
if err != nil {
return false, err
}
if !gr.Exists() {
return false, nil
}
descKey := sqlbase.MakeDescMetadataKey(sqlbase.ID(gr.ValueInt()))
desc := &sqlbase.Descriptor{}
if err := txn.GetProto(descKey, desc); err != nil {
return false, err
}
switch t := descriptor.(type) {
case *sqlbase.TableDescriptor:
table := desc.GetTable()
if table == nil {
return false, errors.Errorf("%q is not a table", plainKey.Name())
}
table.MaybeUpgradeFormatVersion()
// TODO(dan): Write the upgraded TableDescriptor back to kv. This will break
// the ability to use a previous version of cockroach with the on-disk data,
// but it's worth it to avoid having to do the upgrade every time the
// descriptor is fetched. Our current test for this enforces compatibility
// backward and forward, so that'll have to be extended before this is done.
if err := table.Validate(txn); err != nil {
return false, err
}
*t = *table
case *sqlbase.DatabaseDescriptor:
database := desc.GetDatabase()
if database == nil {
return false, errors.Errorf("%q is not a database", plainKey.Name())
}
if err := database.Validate(); err != nil {
return false, err
}
*t = *database
}
return true, nil
}
