make spartan.Client.RoundTrip match the API of other clients.

- Request.Meta is already used as an *io.LimitedReader in spartan
  servers, so by following this convention the RoundTrip method doesn't
  need anything more than the *Request.
- Make a new public method for setting the body on a spartan request.

1 files changed, 6 insertions, 9 deletions

diff --git a/spartan/client.go b/spartan/client.go
index e571c14..40c9dd6 100644
--- a/spartan/client.go
+++ b/spartan/client.go
@@ -18,7 +18,7 @@ import (
 type Client struct{}
 
 // RoundTrip sends a single spartan request and returns its response.
-func (c Client) RoundTrip(request *sr.Request, body io.Reader) (*sr.Response, error) {
+func (c Client) RoundTrip(request *sr.Request) (*sr.Response, error) {
 	if request.Scheme != "spartan" && request.Scheme != "" {
 		return nil, errors.New("non-spartan protocols not supported")
 	}
@@ -38,20 +38,17 @@ func (c Client) RoundTrip(request *sr.Request, body io.Reader) (*sr.Response, er
 
 	request.RemoteAddr = conn.RemoteAddr()
 
-	var bodyBytes []byte = nil
-	if body != nil {
-		bodyBytes, err = io.ReadAll(body)
-		if err != nil {
-			return nil, err
-		}
+	rdr, ok := request.Meta.(*io.LimitedReader)
+	if !ok {
+		return nil, errors.New("request body must be an *io.LimitedReader")
 	}
 
-	requestLine := host + " " + request.EscapedPath() + " " + strconv.Itoa(len(bodyBytes)) + "\r\n"
+	requestLine := host + " " + request.EscapedPath() + " " + strconv.Itoa(int(rdr.N)) + "\r\n"
 
 	if _, err := conn.Write([]byte(requestLine)); err != nil {
 		return nil, err
 	}
-	if _, err := conn.Write(bodyBytes); err != nil {
+	if _, err := io.Copy(conn, rdr); err != nil {
 		return nil, err
 	}