147 lines
2.6 KiB
Go
147 lines
2.6 KiB
Go
package bngsdk
|
|
|
|
import (
|
|
"errors"
|
|
"log/slog"
|
|
"net"
|
|
"sync"
|
|
"time"
|
|
"unsafe"
|
|
)
|
|
|
|
// ErrReaderDisabled = errors.New("reader is currently turned off")
|
|
var (
|
|
ErrNoData = errors.New("no new data available")
|
|
readTimeout = (time.Second / 60) * 5 // N missed frames at 60fps
|
|
packetPool = sync.Pool{
|
|
New: func() any {
|
|
var b packetBuffer
|
|
return &b
|
|
},
|
|
}
|
|
)
|
|
|
|
type packetBuffer [unsafe.Sizeof(Outgauge{})]byte
|
|
|
|
type frame struct {
|
|
Buf *packetBuffer
|
|
Len int
|
|
}
|
|
|
|
type UDPTransport struct {
|
|
address *net.UDPAddr
|
|
connection *net.UDPConn
|
|
dataChan chan frame
|
|
totalBytes int64 // returns total bytes read in case of reader and written in case of writer
|
|
}
|
|
|
|
func NewUDPReader(ip string, port int) (*UDPTransport, error) {
|
|
// Define the IP address and port to listen on
|
|
addr := &net.UDPAddr{
|
|
IP: net.ParseIP(ip),
|
|
Port: port,
|
|
}
|
|
|
|
conn, err := net.ListenUDP("udp", addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
udpT := UDPTransport{
|
|
address: addr,
|
|
connection: conn,
|
|
dataChan: make(chan frame, 1),
|
|
}
|
|
|
|
go udpT.udpSink()
|
|
|
|
return &udpT, nil
|
|
}
|
|
|
|
func NewUDPWriter(ip string, port int) (*UDPTransport, error) {
|
|
// Define the IP address and port to listen on
|
|
addr := &net.UDPAddr{
|
|
IP: net.ParseIP(ip),
|
|
Port: port,
|
|
}
|
|
|
|
conn, err := net.DialUDP("udp", nil, addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &UDPTransport{
|
|
address: addr,
|
|
connection: conn,
|
|
}, nil
|
|
}
|
|
|
|
// udpSink is a loop that will consume the most recent packets on the port
|
|
// instead of letting them pile up
|
|
func (ut *UDPTransport) udpSink() {
|
|
defer close(ut.dataChan)
|
|
|
|
for {
|
|
ut.connection.SetReadDeadline(time.Now().Add(readTimeout))
|
|
|
|
bufPtr := packetPool.Get().(*packetBuffer)
|
|
|
|
nBytes, _, err := ut.connection.ReadFromUDP(bufPtr[:])
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
frame := frame{
|
|
Buf: bufPtr,
|
|
Len: nBytes,
|
|
}
|
|
|
|
select {
|
|
case ut.dataChan <- frame:
|
|
// Packet sent successfuly
|
|
default:
|
|
select {
|
|
case oldFrame := <-ut.dataChan:
|
|
packetPool.Put(oldFrame.Buf)
|
|
default:
|
|
}
|
|
ut.dataChan <- frame
|
|
}
|
|
}
|
|
}
|
|
|
|
func (ut *UDPTransport) Write(data []byte) (int, error) {
|
|
nBytes, err := ut.connection.Write(data)
|
|
|
|
ut.totalBytes += int64(nBytes)
|
|
|
|
return nBytes, err
|
|
}
|
|
|
|
func (ut *UDPTransport) Read(buffer []byte) (int, error) {
|
|
latestFrame, ok := <-ut.dataChan
|
|
if !ok {
|
|
slog.Error(ErrNoData.Error())
|
|
return 0, ErrNoData
|
|
}
|
|
|
|
nBytes := copy(buffer, latestFrame.Buf[:latestFrame.Len])
|
|
packetPool.Put(latestFrame.Buf)
|
|
|
|
ut.totalBytes += int64(nBytes)
|
|
|
|
return nBytes, nil
|
|
}
|
|
|
|
func (ut *UDPTransport) Close() error {
|
|
if ut.connection != nil {
|
|
return ut.connection.Close()
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (ut *UDPTransport) GetTotalBytes() int64 {
|
|
return ut.totalBytes
|
|
}
|