// Perform a PUT request at path, with data (as JSON) in the request
// body.
func (srv *KeepService) put(c *arvados.Client, path string, data interface{}) error {
// We'll start a goroutine to do the JSON encoding, so we can
// stream it to the http client through a Pipe, rather than
// keeping the entire encoded version in memory.
jsonR, jsonW := io.Pipe()
// errC communicates any encoding errors back to our main
// goroutine.
errC := make(chan error, 1)
go func() {
enc := json.NewEncoder(jsonW)
errC <- enc.Encode(data)
jsonW.Close()
}()
url := srv.URLBase() + "/" + path
req, err := http.NewRequest("PUT", url, ioutil.NopCloser(jsonR))
if err != nil {
return fmt.Errorf("building request for %s: %v", url, err)
}
err = c.DoAndDecode(nil, req)
// If there was an error encoding the request body, report
// that instead of the response: obviously we won't get a
// useful response if our request wasn't properly encoded.
if encErr := <-errC; encErr != nil {
return fmt.Errorf("encoding data for %s: %v", url, encErr)
}
return err
}
