Support ascii format

frame_test.go

@@ -51,7 +51,9 @@ func TestFrameConn(t *testing.T) {
 							return
 						}
 					}
-					fmt.Println(string(b))
+					if len(string(b)) > 3 {
+						fmt.Println(string(b))
+					}
 				}
 			}(c)
 		}
@@ -70,3 +72,67 @@ func TestFrameConn(t *testing.T) {
 
 	time.Sleep(1 * time.Second)
 }
+
+func TestFrameConnAsciiFormat(t *testing.T) {
+	//server
+	l, err := net.Listen("tcp", ":9983")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	encoderConfig := EncoderConfig{
+		ByteOrder:                       binary.BigEndian,
+		LengthFieldLength:               2,
+		LengthAdjustment:                0,
+		LengthIncludesLengthFieldLength: false,
+		Format:                          ASCII,
+	}
+
+	decoderConfig := DecoderConfig{
+		ByteOrder:           binary.BigEndian,
+		LengthFieldLength:   2,
+		LengthFieldOffset:   0,
+		LengthAdjustment:    0,
+		InitialBytesToStrip: 2,
+		Format:              ASCII,
+	}
+
+	go func() {
+		for {
+			conn, err := l.Accept()
+			if err != nil {
+				log.Println(err)
+				return
+			}
+
+			c := NewLengthFieldBasedFrameConn(encoderConfig, decoderConfig, conn)
+			go func(conn FrameConn) {
+				for {
+					b, err := c.ReadFrame()
+					if err != nil {
+						if err == io.EOF {
+							return
+						}
+					}
+					if len(string(b)) > 3 {
+						fmt.Println(string(b))
+					}
+				}
+			}(c)
+		}
+
+	}()
+
+	conn, err := net.Dial("tcp", "127.0.0.1:9983")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+
+	fc := NewLengthFieldBasedFrameConn(encoderConfig, decoderConfig, conn)
+	fc.WriteFrame([]byte("hello"))
+	fc.WriteFrame([]byte("world"))
+
+	time.Sleep(1 * time.Second)
+}

length_field_based_frameconn.go

@@ -5,6 +5,14 @@ import (
 	"encoding/binary"
 	"fmt"
 	"net"
+	"strconv"
+)
+
+const (
+	// ASCII is ASCII encoding
+	ASCII = iota
+	// BINARY encoding
+	BINARY
 )
 
 type lengthFieldBasedFrameConn struct {
@@ -25,6 +33,8 @@ type EncoderConfig struct {
 	LengthAdjustment int
 	// LengthIncludesLengthFieldLength is true, the length of the prepended length field is added to the value of the prepended length field
 	LengthIncludesLengthFieldLength bool
+	// Format is the message length data format
+	Format int
 }
 
 // DecoderConfig config for decoder.
@@ -39,6 +49,8 @@ type DecoderConfig struct {
 	LengthAdjustment int
 	// InitialBytesToStrip is the number of first bytes to strip out from the decoded frame
 	InitialBytesToStrip int
+	// Format is the message length data format
+	Format int
 }
 
 // NewLengthFieldBasedFrameConn returns a wrapped Frame conn based on the length field.
@@ -85,6 +97,16 @@ func (fc *lengthFieldBasedFrameConn) ReadFrame() ([]byte, error) {
 }
 
 func (fc *lengthFieldBasedFrameConn) getUnadjustedFrameLength() (lenBuf []byte, n uint64, err error) {
+	if fc.decoderConfig.Format == ASCII {
+		lenBuf := make([]byte, fc.decoderConfig.LengthFieldLength)
+		_, err = fc.r.Read(lenBuf)
+		i, err := strconv.ParseUint(string(lenBuf), 10, 64)
+		if err != nil {
+			return nil, 0, err
+		}
+		return lenBuf, i, nil
+	}
+	// Default assume format is binary
 	switch fc.decoderConfig.LengthFieldLength {
 	case 1:
 		b, err := fc.r.ReadByte()
@@ -147,6 +169,9 @@ func (fc *lengthFieldBasedFrameConn) WriteFrame(p []byte) error {
 		if length >= 256 {
 			return fmt.Errorf("length does not fit into a byte: %d", length)
 		}
+		if fc.encoderConfig.Format == ASCII {
+			return fmt.Errorf("Ascii format not allowed for LengthFieldLength = 1")
+		}
 		err = fc.w.WriteByte(byte(length))
 		if err != nil {
 			return err
@@ -156,7 +181,11 @@ func (fc *lengthFieldBasedFrameConn) WriteFrame(p []byte) error {
 			return fmt.Errorf("length does not fit into a short integer: %d", length)
 		}
 		buf := make([]byte, 2)
-		fc.encoderConfig.ByteOrder.PutUint16(buf, uint16(length))
+		if fc.encoderConfig.Format == ASCII {
+			copy(buf, []byte(fmt.Sprintf("%02d", length)))
+		} else {
+			fc.encoderConfig.ByteOrder.PutUint16(buf, uint16(length))
+		}
 		_, err = fc.w.Write(buf)
 		if err != nil {
 			return err
@@ -165,21 +194,34 @@ func (fc *lengthFieldBasedFrameConn) WriteFrame(p []byte) error {
 		if length >= 16777216 {
 			return fmt.Errorf("length does not fit into a medium integer: %d", length)
 		}
-		buf := writeUint24(fc.encoderConfig.ByteOrder, length)
+		buf := make([]byte, 3)
+		if fc.encoderConfig.Format == ASCII {
+			copy(buf, []byte(fmt.Sprintf("%03d", length)))
+		} else {
+			buf = writeUint24(fc.encoderConfig.ByteOrder, length)
+		}
 		_, err = fc.w.Write(buf)
 		if err != nil {
 			return err
 		}
 	case 4:
 		buf := make([]byte, 4)
-		fc.encoderConfig.ByteOrder.PutUint32(buf, uint32(length))
+		if fc.encoderConfig.Format == ASCII {
+			copy(buf, []byte(fmt.Sprintf("%04d", length)))
+		} else {
+			fc.encoderConfig.ByteOrder.PutUint32(buf, uint32(length))
+		}
 		_, err = fc.w.Write(buf)
 		if err != nil {
 			return err
 		}
 	case 8:
 		buf := make([]byte, 8)
-		fc.encoderConfig.ByteOrder.PutUint64(buf, uint64(length))
+		if fc.encoderConfig.Format == ASCII {
+			copy(buf, []byte(fmt.Sprintf("%08d", length)))
+		} else {
+			fc.encoderConfig.ByteOrder.PutUint64(buf, uint64(length))
+		}
 		_, err = fc.w.Write(buf)
 		if err != nil {
 			return err