write a quick set of functions to pack and unpack byte arrays

pkg/utilfn/binpack.go

@@ -0,0 +1,34 @@
+package utilfn
+
+import (
+	"bufio"
+	"encoding/binary"
+	"io"
+)
+
+func PackValue(w io.Writer, barr []byte) error {
+	viBuf := make([]byte, binary.MaxVarintLen64)
+	viLen := binary.PutUvarint(viBuf, uint64(len(barr)))
+	_, err := w.Write(viBuf[0:viLen])
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(barr)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func UnpackValue(r *bufio.Reader) ([]byte, error) {
+	lenVal, err := binary.ReadUvarint(r)
+	if err != nil {
+		return nil, err
+	}
+	rtnBuf := make([]byte, int(lenVal))
+	_, err = io.ReadFull(r, rtnBuf)
+	if err != nil {
+		return nil, err
+	}
+	return rtnBuf, nil
+}