reduced allocations

README.md

@@ -3,7 +3,7 @@ Simple SDK to interact with BeamNG.drive OutGauge data.
 
 ## Development
 ### Performance
-`go test -bench=BenchmarkReadData -benchmem -memprofile=mem.pprof`
+`go test -bench=BenchmarkUpdate -benchmem -memprofile=mem.pprof`
 replace the function to be tested
 
 Use `go tool pprof` to analyze the results
@@ -15,18 +15,17 @@ goos: linux
 goarch: amd64
 pkg: github.com/ESilva15/gobngsdk
 cpu: AMD Ryzen 7 5800X3D 8-Core Processor
-BenchmarkReadData-16    	 320931	     4058 ns/op	    100 B/op	      2 allocs/op
+BenchmarkReadData-16    	 362514	     3188 ns/op	      4 B/op	      1 allocs/op
 PASS
-ok  	github.com/ESilva15/gobngsdk	1.345s
+ok  	github.com/ESilva15/gobngsdk	1.194s
 
 # New footprint
 goos: linux
 goarch: amd64
 pkg: github.com/ESilva15/gobngsdk
 cpu: AMD Ryzen 7 5800X3D 8-Core Processor
-BenchmarkReadData-16    	 362514	     3188 ns/op	      4 B/op	      1 allocs/op
+BenchmarkUpdate-16    	 159170	     7287 ns/op	      4 B/op	      1 allocs/op
 PASS
-ok  	github.com/ESilva15/gobngsdk	1.194s
-
+ok  	github.com/ESilva15/gobngsdk	1.241s
 # Pretty good enough. I can finally go be productive instead of "procrastinating" here
 ```

bngsdk_test.go

@@ -3,35 +3,51 @@ package bngsdk
 import (
 	"bytes"
 	"encoding/binary"
+	"io"
+	"log/slog"
 	"net"
 	"testing"
 )
 
-func BenchmarkReadData(b *testing.B) {
-	// Spin up an UDP server
-	sdk, err := Init("127.0.0.1", 0)
+func BenchmarkUpdate(b *testing.B) {
+	// Silence logging output so slog calls don't pollute benchmark stats
+	slogger := slog.New(slog.NewTextHandler(io.Discard, nil))
+
+	// Initialize the SDK with port 0 to bind to an OS-assigned ephemeral port
+	sdk, err := NewBngSDK(Options{
+		Logger:           slogger,
+		SourceType:       UDPData,
+		ImportUDPAddress: "127.0.0.1",
+		ImportUDPPort:    0,
+	})
 	if err != nil {
 		b.Fatalf("Failed to initialize SDK: %v", err)
 	}
 	defer sdk.Close()
 
-	// Retrieve the actual assigned UDP address
-	localAddr := sdk.Conn.LocalAddr().(*net.UDPAddr)
+	// Access the underlying reader connection to determine the dynamically bound port
+	ogReader, ok := sdk.reader.(*OgUDPReader)
+	if !ok || ogReader.udpConnection == nil || ogReader.udpConnection.connection == nil {
+		b.Fatalf("Failed to retrieve underlying UDP connection")
+	}
 
-	// Start a client to stream data
-	clientConn, err := net.DialUDP("udp", nil, localAddr)
+	serverAddr := ogReader.udpConnection.connection.LocalAddr().(*net.UDPAddr)
+
+	// Dial the UDP socket as a client to send test data
+	clientConn, err := net.DialUDP("udp", nil, serverAddr)
 	if err != nil {
-		b.Fatalf("Failed to dial local UDP socket: %v", err)
+		b.Fatalf("Failed to dial UDP server: %v", err)
 	}
 	defer clientConn.Close()
 
-	// Pre serialize some data
+	// Pre-serialize a dummy Outgauge struct matching the required byte layout
 	dummyOutgauge := Outgauge{
 		Time:  424242,
 		Car:   [4]byte{'P', 'E', 'R', 'F'},
 		Speed: 45.2,
 		RPM:   3500.0,
 	}
+
 	var buf bytes.Buffer
 	if err := binary.Write(&buf, binary.LittleEndian, dummyOutgauge); err != nil {
 		b.Fatalf("Failed to serialize dummy struct: %v", err)
@@ -42,16 +58,16 @@ func BenchmarkReadData(b *testing.B) {
 	b.ReportAllocs()
 
 	for i := 0; i < b.N; i++ {
-		// Feed a packet into the network buffer right before reading it
+		// Feed a packet into the network transport socket
 		_, err := clientConn.Write(packetBytes)
 		if err != nil {
 			b.Fatalf("Failed to write to UDP socket: %v", err)
 		}
 
-		// Execute the target function
-		err = sdk.ReadData()
+		// Run the main API loop method
+		_, err = sdk.Update()
 		if err != nil {
-			b.Fatalf("ReadData failed at iteration %d: %v", i, err)
+			b.Fatalf("Update failed at iteration %d: %v", i, err)
 		}
 	}
 }

transport.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"log/slog"
 	"net"
+	"sync"
 	"time"
 	"unsafe"
 )
@@ -12,12 +13,25 @@ import (
 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 []byte
+	dataChan   chan frame
 }
 
 func NewUDPReader(ip string, port int) (*UDPTransport, error) {
@@ -35,7 +49,7 @@ func NewUDPReader(ip string, port int) (*UDPTransport, error) {
 	udpT := UDPTransport{
 		address:    addr,
 		connection: conn,
-		dataChan:   make(chan []byte, 1),
+		dataChan:   make(chan frame, 1),
 	}
 
 	go udpT.udpSink()
@@ -69,17 +83,28 @@ func (ut *UDPTransport) udpSink() {
 	for {
 		ut.connection.SetReadDeadline(time.Now().Add(readTimeout))
 
-		buf := make([]byte, unsafe.Sizeof(Outgauge{}))
-		nBytes, _, err := ut.connection.ReadFromUDP(buf)
+		bufPtr := packetPool.Get().(*packetBuffer)
+
+		nBytes, _, err := ut.connection.ReadFromUDP(bufPtr[:])
 		if err != nil {
 			return
 		}
 
+		frame := frame{
+			Buf: bufPtr,
+			Len: nBytes,
+		}
+
 		select {
-		case ut.dataChan <- buf[:nBytes]:
+		case ut.dataChan <- frame:
+			// Packet sent successfuly
 		default:
-			<-ut.dataChan
-			ut.dataChan <- buf[:nBytes]
+			select {
+			case oldFrame := <-ut.dataChan:
+				packetPool.Put(oldFrame.Buf)
+			default:
+			}
+			ut.dataChan <- frame
 		}
 	}
 }
@@ -89,13 +114,16 @@ func (ut *UDPTransport) Write(data []byte) (int, error) {
 }
 
 func (ut *UDPTransport) Read(buffer []byte) (int, error) {
-	data, ok := <-ut.dataChan
+	latestFrame, ok := <-ut.dataChan
 	if !ok {
 		slog.Error(ErrNoData.Error())
 		return 0, ErrNoData
 	}
 
-	return copy(buffer, data), nil
+	nBytes := copy(buffer, latestFrame.Buf[:latestFrame.Len])
+	packetPool.Put(latestFrame.Buf)
+
+	return nBytes, nil
 }
 
 func (ut *UDPTransport) Close() error {