Reputation: 3318
I'm currently trying to communicate using websockets and my code is the following (im using gorilla)
buff := bytes.NewBuffer([]byte{})
binary.Write(buff, binary.LittleEndian, uint64(1))
binary.Write(buff, binary.LittleEndian, len(message))
binary.Write(buff, binary.LittleEndian, message)
client.Write <- buff.Bytes()
The c.Write channel its inside a for select loop
case msg := <-client.Write:
buffer := &bytes.Buffer{}
err := binary.Write(buffer, binary.LittleEndian, msg)
if err != nil {
return
}
err = client.Ws.WriteMessage(websocket.BinaryMessage, buffer.Bytes())
if err != nil {
return
}
buffer.Reset()
And client is just a struct
type Client struct {
Ws *websocket.Conn
Read chan []byte
Write chan []byte
Account *models.Account
}
The message is sent successfully and I read it like this
b, err := conn.Read(buff)
if err != nil {
utils.Log("Error while reading from socket " + err.Error())
return
}
buffer := bytes.NewBuffer(buff[:b])
t, err := binary.ReadUvarint(buffer)
utils.Log(t)
if err != nil {
utils.Log("Error while reading from socket " + err.Error())
return
}
switch t {
case 1:
roomsLen, err := binary.ReadUvarint(buffer)
if err != nil {
utils.Log("Error while reading rooms len " + err.Error())
return
}
utils.Log(roomsLen)
roomsBytes := make([]byte, roomsLen)
binary.Read(buffer, binary.LittleEndian, roomsBytes)
rooms := []*Room{}
err = json.Unmarshal(roomsBytes, rooms)
if err != nil {
utils.Log("Error while unmarshaling room list " + err.Error())
return
}
utils.Log(rooms)
The utils.Log function is just this
func Log(msg interface{}) {
n := time.Now()
console.Call("log", fmt.Sprintf("[%v:%v:%v] %v", n.Hour(), n.Minute(), n.Second(), msg))
}
Thing is the first uint64 is the one im waiting (1) but the second uint64 im reading is always 0 while loggin it (len(message)) gives me 52
And since its always 0 I cant unmarshal it properly
So I'm not sure what I am doing wrong or if this is not a correct way to use websockets.
Upvotes: 0
Views: 211
Reputation: 9359
Small error. You're writing uint64 but using "ReadUvarint" to read it (a varint is a different type of data).
package main
import (
"bytes"
"encoding/binary"
"fmt"
)
func main() {
b := bytes.NewBuffer([]byte{})
e1 := binary.Write(b, binary.LittleEndian, uint64(10))
e2 := binary.Write(b, binary.LittleEndian, uint64(20))
fmt.Println("writing 10 and 20", e1, e2)
{
r := bytes.NewBuffer(b.Bytes())
res, e := binary.ReadUvarint(r)
res2, e2 := binary.ReadUvarint(r)
fmt.Println("using readuvarint here :", res, res2, e, e2, b.Bytes())
}
{
r := bytes.NewBuffer(b.Bytes())
var res, res2 uint64
e := binary.Read(r, binary.LittleEndian, &res)
e2 := binary.Read(r, binary.LittleEndian, &res2)
fmt.Println("using read into uint64's here :", res, res2, e, e2, b.Bytes())
}
}
Upvotes: 1