Introduce pgproto3 package

pgproto3 will wrap the message encoding and decoding for the PostgreSQL frontend/backend protocol version 3.
2017-04-29 10:02:38 -05:00
commit 4e2900b774
25 changed files with 1473 additions and 0 deletions
@@ -0,0 +1,70 @@
+package pgproto3
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/jackc/pgx/chunkreader"
+)
+
+type Frontend struct {
+	cr *chunkreader.ChunkReader
+	w  io.Writer
+}
+
+func NewFrontend(r io.Reader, w io.Writer) (*Frontend, error) {
+	cr := chunkreader.NewChunkReader(r)
+	return &Frontend{cr: cr, w: w}, nil
+}
+
+func (b *Frontend) Send(msg FrontendMessage) error {
+	return errors.New("not implemented")
+}
+
+func (b *Frontend) Receive() (BackendMessage, error) {
+	backendMessages := map[byte]BackendMessage{
+		'1': &ParseComplete{},
+		'2': &BindComplete{},
+		'3': &CloseComplete{},
+		'A': &NotificationResponse{},
+		'C': &CommandComplete{},
+		'd': &CopyData{},
+		'D': &DataRow{},
+		'E': &ErrorResponse{},
+		'G': &CopyInResponse{},
+		'H': &CopyOutResponse{},
+		'I': &EmptyQueryResponse{},
+		'K': &BackendKeyData{},
+		'n': &NoData{},
+		'N': &NoticeResponse{},
+		'R': &Authentication{},
+		'S': &ParameterStatus{},
+		't': &ParameterDescription{},
+		'T': &RowDescription{},
+		'V': &FunctionCallResponse{},
+		'W': &CopyBothResponse{},
+		'Z': &ReadyForQuery{},
+	}
+
+	header, err := b.cr.Next(5)
+	if err != nil {
+		return nil, err
+	}
+
+	msgType := header[0]
+	bodyLen := int(binary.BigEndian.Uint32(header[1:])) - 4
+
+	msgBody, err := b.cr.Next(bodyLen)
+	if err != nil {
+		return nil, err
+	}
+
+	if msg, ok := backendMessages[msgType]; ok {
+		err = msg.UnmarshalBinary(msgBody)
+		return msg, err
+	}
+
+	return nil, fmt.Errorf("unknown message type: %c", msgType)
+}