fix client/server protocol

1 files changed, 55 insertions, 0 deletions

diff --git a/pkg/netstring/netstring.go b/pkg/netstring/netstring.go
new file mode 100644
index 0000000..01b179a
--- /dev/null
+++ b/pkg/netstring/netstring.go
@@ -0,0 +1,55 @@
+package netstring
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+type Encoder struct {
+	w io.Writer
+}
+
+type Decoder struct {
+	r io.Reader
+}
+
+var errBadFormat = errors.New("netstring: bad format")
+
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{w: w}
+}
+
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{r: r}
+}
+
+func (e *Encoder) Encode(s string) error {
+	_, err := fmt.Fprintf(e.w, "%d:%s,", len(s), s)
+	return err
+}
+
+func (d *Decoder) Decode() (out string, err error) {
+	var n int
+
+	_, err = fmt.Fscanf(d.r, "%d:", &n)
+	if err != nil {
+		return
+	}
+
+	buf := make([]byte, n + 1)
+
+	_, err = io.ReadFull(d.r, buf)
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return
+	}
+
+	if buf[n] != ',' {
+		return "", errBadFormat
+	}
+
+	return string(buf[:n]), nil
+}