func (u *Updater) fetchAndApplyPatch(old io.Reader) ([]byte, error) {
r, err := fetch(u.diffURL + u.cmdName + "/" + Version + "/" + u.info.Version + "/" + plat)
if err != nil {
return nil, err
}
defer r.Close()
var buf bytes.Buffer
err = binarydist.Patch(old, &buf, r)
return buf.Bytes(), err
}
func applyPatch(patch io.Reader, updatePath string) ([]byte, error) {
// open the file to update
old, err := os.Open(updatePath)
if err != nil {
return nil, err
}
defer old.Close()
// apply the patch
applied := new(bytes.Buffer)
if err = binarydist.Patch(old, applied, patch); err != nil {
return nil, err
}
return applied.Bytes(), nil
}