Added startup message

conn_test.go

@@ -0,0 +1,26 @@
+package pqx
+
+import (
+	// "encoding/binary"
+	"net"
+	"testing"
+)
+
+func TestXxx(t *testing.T) {
+	conn, err := net.Dial("tcp", "localhost:5432")
+	if err != nil {
+		// handle error
+	}
+
+	msg := newStartupMsg()
+	msg.options["user"] = "jack"
+
+	msg.WriteTo(conn)
+
+
+	buf := make([]byte, 128)
+
+	num, _ := conn.Read(buf)
+	println(string(buf[0:1]))
+	println(num)
+}

messages.go

@@ -0,0 +1,35 @@
+package pqx
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+const (
+	protocolVersionNumber = 196608 // 3.0
+)
+
+type startupMsg struct {
+	options map[string] string
+}
+
+func newStartupMsg() *startupMsg {
+	return &startupMsg{map[string] string{}}
+}
+
+func (self *startupMsg) WriteTo(w io.Writer) (n int64, err error) {
+	buf := make([]byte, 8, 128)
+	binary.BigEndian.PutUint32(buf[4:8], uint32(protocolVersionNumber))
+	for key, value := range self.options {
+		buf = append(buf, key...)
+		buf = append(buf, 0)
+		buf = append(buf, value...)
+		buf = append(buf, 0)
+	}
+	buf = append(buf, ("\000")...)
+	binary.BigEndian.PutUint32(buf[0:4], uint32(len(buf)))
+
+	var n32 int
+	n32, err = w.Write(buf)
+	return int64(n32), err
+}