Autocomplete from our data source

I have a data source that contains a large number of postal codes and cities throughout the world. I am trying to create an auto-complete for either the city or postal code or both after selecting the Country.

Ideally it would be similar to the auto complete frappe uses for accounts, customers, etc, but this would be from our own data source. The file itself is about 30MB of text.

I created a doc type and uploaded the data source, but when using it in a document as either auto complete or either as a drop down list, it is drastically slow while everything loads.

Any suggestions as to how to do this?

bump any help on this?

does anyone have any input on this at all?