feat: add realistic broadcasting (throttle)

internal/udp/header.go

@@ -0,0 +1,32 @@
+package udp
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+type Header struct {
+	PacketFormat            uint16  // 2021
+	GameMajorVersion        uint8   // Game major version - "X.00"
+	GameMinorVersion        uint8   // Game minor version - "1.XX"
+	PacketVersion           uint8   // Version of this packet type, all start from 1
+	PacketID                uint8   // Identifier for the packet type, see below
+	SessionUID              uint64  // Unique identifier for the session
+	SessionTime             float32 // Session timestamp
+	FrameIdentifier         uint32  // Identifier for the frame the data was retrieved on
+	PlayerCarIndex          uint8   // Index of player's car in the array
+	SecondaryPlayerCarIndex uint8   // Index of secondary player's car in the array (split screen)
+}
+
+func (h *Header) Read(buf []byte) error {
+	reader := bytes.NewReader(buf)
+	if err := binary.Read(reader, binary.LittleEndian, h); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (h *Header) Second() int32 {
+	return int32(h.SessionTime)
+}

pkg/broadcaster/broadcaster.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"os"
+	"time"
 )
 
 type Broadcaster struct {
@@ -48,6 +49,7 @@ func (b *Broadcaster) Start(file string) error {
 	defer f.Close()
 
 	offset := int64(0)
+	t := 0
 	for {
 		select {
 		case <-b.ctx.Done():
@@ -70,6 +72,19 @@ func (b *Broadcaster) Start(file string) error {
 
 		offset += int64(n)
 
+		header := new(udp.Header)
+		if header.Read(buf) != nil {
+			if opts.Verbose {
+				printer.PrintError("header read error: %s", err.Error())
+			}
+		}
+
+		d := int(header.SessionTime * 100000)
+		if d != t {
+			time.Sleep(time.Nanosecond * time.Duration(d))
+			t = d
+		}
+
 		err = b.serv.WriteSocket(buf)
 		if err != nil {
 			if opts.Verbose {