cleanly separate version handling

packer/packer.go

@@ -46,10 +46,18 @@ func splitHeader(header []byte, names []string) (map[string]string, error) {
 	return result, nil
 }
 
-//ReadMessage -
+// ReadMessage checks the protocol and switches accordingly
 func ReadMessage(b []byte) (*Packer, error) {
 	// Detect protocol in use
 	if b[0] == packerV1 {
+		return ReadV1Message(b)
+	}
+
+	return nil, fmt.Errorf("Version %d not supported", 255-b[0])
+}
+
+// ReadV1Message parses a v1-formatted message
+func ReadV1Message(b []byte) (*Packer, error) {
 	// Separate the header and body using the header length in the second byte.
 	p := NewPacker(nil)
 	header := b[2 : b[1]+2]
@@ -98,9 +106,6 @@ func ReadMessage(b []byte) (*Packer, error) {
 	//handle payload
 	p.Data.AppendBytes(data)
 	return p, nil
-	}
-
-	return nil, fmt.Errorf("Version %d not supported", 255-b[0])
 }
 
 //PackV1 -- Outputs version 1 of packer