initial commit

packet.go

@@ -0,0 +1,50 @@
+package main
+
+var r *requestHeader
+
+const VBAN_PROTOCOL_TXT = 0x40
+
+// requestHeader represents a single request header
+type requestHeader struct {
+	name         string
+	bpsIndex     int
+	channel      int
+	framecounter []byte
+}
+
+// newRequestHeader returns a pointer to a requestHeader struct as a singleton
+func newRequestHeader(streamname string, bpsI, channel int) *requestHeader {
+	if r != nil {
+		return r
+	}
+	return &requestHeader{streamname, bpsI, channel, make([]byte, 4)}
+}
+
+// sr defines the samplerate for the request
+func (r *requestHeader) sr() byte {
+	return byte(VBAN_PROTOCOL_TXT + r.bpsIndex)
+}
+
+// nbc defines the channel of the request
+func (r *requestHeader) nbc() byte {
+	return byte(r.channel)
+}
+
+// streamname defines the stream name of the text request
+func (r *requestHeader) streamname() []byte {
+	b := make([]byte, 16)
+	copy(b, r.name)
+	return b
+}
+
+// header returns a fully formed text request packet header
+func (t *requestHeader) header() []byte {
+	h := []byte("VBAN")
+	h = append(h, t.sr())
+	h = append(h, byte(0))
+	h = append(h, t.nbc())
+	h = append(h, byte(0x10))
+	h = append(h, t.streamname()...)
+	h = append(h, t.framecounter...)
+	return h
+}