Transfering file using tcp golang - go

Question

I'm trying to make a music app that sends file through tcp protocol using go and microservice architecture. Now I'm creating a player service that should:
Get user token and get claims from it
Check is user exists using claims and user_service microservice
Get song from redis
Check is song exists using music_service
Read file by chunks and send it to client using tcp
Redis data looks like this:
{
"user_id": [{
"song_id": "<song_id>"
}]
}
But I faced with a small problem. My music files stored in a flac format and when I receive it on the client, my player doesn't play it. I don't really know what can be the problem. So here's my code:
SERVER
service_setup.go
//this function is called in main function
func setService() {
ln, err := net.Listen("tcp", config.TCPAddress)
if err != nil {
panic("couldn't start tcp server")
}
defer ln.Close()
for {
conn, err := ln.Accept()
if err != nil {
logger.ErrorLog(fmt.Sprintf("Error: couldn't accept connection. Details: %v", err))
return
}
service.DownloadSong(conn)
}
}
downloader_service.go
func DownloadSong(conn net.Conn) {
token, err := bufio.NewReader(conn).ReadString('\n')
if err != nil {
logger.ErrorLog(fmt.Sprintf("Error: couldn't get token. Details: %v", token))
conn.Close()
return
}
claims, err := jwt_funcs.DecodeJwt(token)
if err != nil {
conn.Close()
return
}
songs, err := redis_repo.Get(claims.Id)
if err != nil {
conn.Close()
return
}
for _, song := range songs {
download(song, conn)
}
}
func download(song models.SongsModel, conn net.Conn) {
filePath, err := filepath.Abs(fmt.Sprintf("./songs/%s.flac", song.SongId))
if err != nil {
logger.ErrorLog(fmt.Sprintf("Errror: couldn't create filepath. Details: %v", err))
conn.Close()
return
}
file, err := os.Open(filePath)
defer file.Close()
if err != nil {
logger.ErrorLog(fmt.Sprintf("Errror: couldn't open file. Details: %v", err))
conn.Close()
return
}
read(file, conn)
}
func read(file *os.File, conn net.Conn) {
reader := bufio.NewReader(file)
buf := make([]byte, 15)
defer conn.Close()
for {
_, err := reader.Read(buf)
if err != nil && err == io.EOF {
logger.InfoLog(fmt.Sprintf("Details: %v", err))
fmt.Println()
return
}
conn.Write(buf)
}
}
CLIENT
main.go
func main() {
conn, _ := net.Dial("tcp", "127.0.0.1:6060")
var glMessage []byte
text := "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjYzYzlhNmE1OWI3ZmQyNTQ2ZjA4ZWEyYSIsInVzZXJuYW1lIjoiMTIiLCJleHAiOjE2NzQyMTE5ODl9.aarSDhrFF1df3i2pIRyjNxTfSHKObqLU3kHJiPreredIhLNCzs7z7jMgRHQIcLaIvCOECN7bX0OaSvKdW7VKsQ\n"
fmt.Fprint(conn, text)
reader := bufio.NewReader(conn)
b := make([]byte, 15)
c := 0
for i, _ := reader.Read(b); int(i) != 0; i, _ = reader.Read(b) {
c += i
glMessage = append(glMessage, b...)
}
os.WriteFile("./test.flac", glMessage, 0644)
}
If you know what can be the problem, please tell me. I'd really appreciate it!

Answer 1

It looks like you're trying to send the music file over the network in 15 byte chunks, which is likely not enough to play the song on the client side.
You can try increasing the chunk size, for example, to 8192 bytes. To do this, replace buf := make([]byte, 15) with buf := make([]byte, 8192).
Also, it's better to write the received data directly to the file rather than storing it in memory. You can do this by creating a file and using os.Create to write the received data to it:
file, err := os.Create("./test.flac")
if err != nil {
fmt.Println("Error: couldn't create file")
return
}
defer file.Close()
for {
i, err := reader.Read(buf)
if err != nil && err == io.EOF {
break
}
file.Write(buf[:i])
}
I believe that this can solve the issue.