Add pgproto3.Backend

parse.go

@@ -0,0 +1,82 @@
+package pgproto3
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/json"
+)
+
+type Parse struct {
+	Name          string
+	Query         string
+	ParameterOIDs []uint32
+}
+
+func (*Parse) Frontend() {}
+
+func (dst *Parse) Decode(src []byte) error {
+	buf := bytes.NewBuffer(src)
+
+	b, err := buf.ReadBytes(0)
+	if err != nil {
+		return err
+	}
+	dst.Name = string(b[:len(b)-1])
+
+	b, err = buf.ReadBytes(0)
+	if err != nil {
+		return err
+	}
+	dst.Query = string(b[:len(b)-1])
+
+	if buf.Len() < 2 {
+		return &invalidMessageFormatErr{messageType: "Parse"}
+	}
+	parameterOIDCount := int(binary.BigEndian.Uint16(buf.Next(2)))
+
+	for i := 0; i < parameterOIDCount; i++ {
+		if buf.Len() < 4 {
+			return &invalidMessageFormatErr{messageType: "Parse"}
+		}
+		dst.ParameterOIDs = append(dst.ParameterOIDs, binary.BigEndian.Uint32(buf.Next(4)))
+	}
+
+	return nil
+}
+
+func (src *Parse) MarshalBinary() ([]byte, error) {
+	var bigEndian BigEndianBuf
+	buf := &bytes.Buffer{}
+
+	buf.WriteByte('P')
+	buf.Write(bigEndian.Uint32(0))
+
+	buf.WriteString(src.Name)
+	buf.WriteByte(0)
+	buf.WriteString(src.Query)
+	buf.WriteByte(0)
+
+	buf.Write(bigEndian.Uint16(uint16(len(src.ParameterOIDs))))
+
+	for _, v := range src.ParameterOIDs {
+		buf.Write(bigEndian.Uint32(v))
+	}
+
+	binary.BigEndian.PutUint32(buf.Bytes()[1:5], uint32(buf.Len()-1))
+
+	return buf.Bytes(), nil
+}
+
+func (src *Parse) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type          string
+		Name          string
+		Query         string
+		ParameterOIDs []uint32
+	}{
+		Type:          "Parse",
+		Name:          src.Name,
+		Query:         src.Query,
+		ParameterOIDs: src.ParameterOIDs,
+	})
+}