chore(buffer): add a parent directory field in z.Buffer (#215)
chore(buffer): add a parent directory field in z.Buffer (#215)

This PR adds a dir field inside z.Buffer. This field is the parent directory for the mmaped buffers created. If the field is not specified(i.e., it is ""), then it uses /tmp (default).
dgraph-io/ristretto,dgraph-io/ristretto