initial spartan client support

1 files changed, 70 insertions, 0 deletions

diff --git a/spartan/client.go b/spartan/client.go
new file mode 100644
index 0000000..154b18a
--- /dev/null
+++ b/spartan/client.go
@@ -0,0 +1,70 @@
+package spartan
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+
+	"tildegit.org/tjp/gus"
+)
+
+// Client is used for sending spartan requests and receiving responses.
+//
+// It carries no state and is reusable simultaneously by multiple goroutines.
+//
+// The zero value is immediately usabble.
+type Client struct{}
+
+// RoundTrip sends a single spartan request and returns its response.
+func (c Client) RoundTrip(request *gus.Request, body io.Reader) (*gus.Response, error) {
+	if request.Scheme != "spartan" && request.Scheme != "" {
+		return nil, errors.New("non-spartan protocols not supported")
+	}
+
+	host, port, _ := net.SplitHostPort(request.Host)
+	if port == "" {
+		host = request.Host
+		port = "300"
+	}
+	addr := net.JoinHostPort(host, port)
+
+	conn, err := net.Dial("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	request.RemoteAddr = conn.RemoteAddr()
+
+	var bodyBytes []byte = nil
+	if body != nil {
+		bodyBytes, err = io.ReadAll(body)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	requestLine := host + " " + request.EscapedPath() + " " + strconv.Itoa(len(bodyBytes)) + "\r\n"
+
+	if _, err := conn.Write([]byte(requestLine)); err != nil {
+		return nil, err
+	}
+	if _, err := conn.Write(bodyBytes); err != nil {
+		return nil, err
+	}
+
+	response, err := ParseResponse(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	bodybuf, err := io.ReadAll(response.Body)
+	if err != nil {
+		return nil, err
+	}
+	response.Body = bytes.NewBuffer(bodybuf)
+
+	return response, nil
+}