Initial upload

fcast/raw.go

@@ -0,0 +1,54 @@
+package fcast
+
+import (
+	"encoding/binary"
+	"errors"
+)
+
+type OpCode uint8
+
+type MessageHeader struct {
+	Size   uint32 // little endian (4) 0-3
+	OpCode OpCode // (1) 4-4
+}
+
+type RawMessage struct {
+	Header MessageHeader // 0-4
+	Body   []byte        // 5-
+}
+
+func NewMessage(op OpCode, body []byte) *RawMessage {
+	return &RawMessage{
+		Header: MessageHeader{
+			Size:   uint32(len(body) + 1),
+			OpCode: op,
+		},
+		Body: body,
+	}
+}
+
+func SerializeRaw(message *RawMessage) []byte {
+	buf := make([]byte, 4+message.Header.Size)
+	binary.LittleEndian.PutUint32(buf[0:4], message.Header.Size)
+	buf[4] = byte(message.Header.OpCode)
+	copy(buf[5:], message.Body)
+
+	return buf
+}
+
+var (
+	ErrHeaderTooShort = errors.New("header is too short")
+	ErrBodyTooShort   = errors.New("body is too short")
+)
+
+func DeserializeRaw(bodyLen, opCode, body []byte) (*RawMessage, error) {
+
+	var msg RawMessage
+
+	msg.Header.Size = binary.LittleEndian.Uint32(bodyLen)
+	msg.Header.OpCode = OpCode(uint8(opCode[0]))
+	msg.Body = body
+
+	return &msg, nil
+
+}