Add Len method for VarInt and VarLong.

net/packet/packet_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	_ "embed"
 	"fmt"
+	"io"
 	"testing"
 
 	pk "github.com/Tnze/go-mc/net/packet"
@@ -60,6 +61,22 @@ func TestVarInt_ReadFrom_tooLongData(t *testing.T) {
 	}
 }
 
+func FuzzVarInt_Len(f *testing.F) {
+	for _, v := range VarInts {
+		f.Add(int32(v))
+	}
+	var buf bytes.Buffer
+	f.Fuzz(func(t *testing.T, v int32) {
+		defer buf.Reset()
+		if _, err := pk.VarInt(v).WriteTo(&buf); err != nil {
+			t.Fatal(err)
+		}
+		if a, b := buf.Len(), pk.VarInt(v).Len(); a != b {
+			t.Errorf("%#v Length calculation error: calculated to be %d, actually %d", pk.VarInt(v), b, a)
+		}
+	})
+}
+
 var VarLongs = []pk.VarLong{0, 1, 2, 127, 128, 255, 2147483647, 9223372036854775807, -1, -2147483648, -9223372036854775808}
 
 var PackedVarLongs = [][]byte{
@@ -101,6 +118,22 @@ func TestVarLong_ReadFrom(t *testing.T) {
 	}
 }
 
+func FuzzVarLong_Len(f *testing.F) {
+	for _, v := range VarLongs {
+		f.Add(int64(v))
+	}
+	var buf bytes.Buffer
+	f.Fuzz(func(t *testing.T, v int64) {
+		defer buf.Reset()
+		if _, err := pk.VarLong(v).WriteTo(&buf); err != nil {
+			t.Fatal(err)
+		}
+		if a, b := buf.Len(), pk.VarLong(v).Len(); a != b {
+			t.Errorf("%#v Length calculation error: calculated to be %d, actually %d", pk.VarLong(v), b, a)
+		}
+	})
+}
+
 //go:embed joingame_test.bin
 var testJoinGameData []byte
 
@@ -171,3 +204,13 @@ func ExampleMarshal_setSlot() {
 	// 15 00 00 05 01 01 01 00
 	// 15 00 00 05 01 01 01 03 00 00 12 34 56 78
 }
+
+func BenchmarkPacket_Pack(b *testing.B) {
+	p := pk.Packet{ID: 0, Data: make([]byte, 64)}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		if err := p.Pack(io.Discard, -1); err != nil {
+			b.Fatal(err)
+		}
+	}
+}