Support VarLong encode/decode

This commit is contained in:
Tnze
2020-01-29 13:57:57 +08:00
parent e5004ab9c9
commit 72c389c86f
2 changed files with 85 additions and 29 deletions

View File

@ -8,15 +8,15 @@ import (
var VarInts = []VarInt{0, 1, 2, 127, 128, 255, 2147483647, -1, -2147483648}
var PackedVarInts = [][]byte{
[]byte{0x00},
[]byte{0x01},
[]byte{0x02},
[]byte{0x7f},
[]byte{0x80, 0x01},
[]byte{0xff, 0x01},
[]byte{0xff, 0xff, 0xff, 0xff, 0x07},
[]byte{0xff, 0xff, 0xff, 0xff, 0x0f},
[]byte{0x80, 0x80, 0x80, 0x80, 0x08},
{0x00},
{0x01},
{0x02},
{0x7f},
{0x80, 0x01},
{0xff, 0x01},
{0xff, 0xff, 0xff, 0xff, 0x07},
{0xff, 0xff, 0xff, 0xff, 0x0f},
{0x80, 0x80, 0x80, 0x80, 0x08},
}
func TestPackVarInt(t *testing.T) {
@ -39,24 +39,38 @@ func TestUnpackVarInt(t *testing.T) {
}
}
// func TestPositionPack(t *testing.T) {
// // This test is not good.
var VarLongs = []VarLong{0, 1, 2, 127, 128, 255, 2147483647, 9223372036854775807, -1, -2147483648, -9223372036854775808}
// for x := -33554432; x < 33554432; x += 55443 {
// for y := -2048; y < 2048; y += 48 {
// for z := -33554432; z < 33554432; z += 55443 {
// var (
// pos1 Position
// pos2 = Position{x, y, z}
// )
// if err := pos1.Decode(bytes.NewReader(pos2.Encode())); err != nil {
// t.Errorf("Position decode fail: %v", err)
// }
var PackedVarLongs = [][]byte{
{0x00},
{0x01},
{0x02},
{0x7f},
{0x80, 0x01},
{0xff, 0x01},
{0xff, 0xff, 0xff, 0xff, 0x07},
{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f},
{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
{0x80, 0x80, 0x80, 0x80, 0xf8, 0xff, 0xff, 0xff, 0xff, 0x01},
{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x01},
}
// if pos1 != pos2 {
// t.Errorf("cannot pack %v", pos2)
// }
// }
// }
// }
// }
func TestPackVarLong(t *testing.T) {
for i, v := range VarLongs {
p := v.Encode()
if !bytes.Equal(p, PackedVarLongs[i]) {
t.Errorf("pack long %d should be \"% x\", get \"% x\"", v, PackedVarLongs[i], p)
}
}
}
func TestUnpackVarLong(t *testing.T) {
for i, v := range PackedVarLongs {
var vi VarLong
if err := vi.Decode(bytes.NewReader(v)); err != nil {
t.Errorf("unpack \"% x\" error: %v", v, err)
}
if vi != VarLongs[i] {
t.Errorf("unpack \"% x\" should be %d, get %d", v, VarLongs[i], vi)
}
}
}

View File

@ -1,6 +1,7 @@
package packet
import (
"errors"
"github.com/google/uuid"
"io"
"math"
@ -268,7 +269,7 @@ func (v VarInt) Encode() (vi []byte) {
//Decode a VarInt
func (v *VarInt) Decode(r DecodeReader) error {
var n uint32
for i := 0; i < 5; i++ { //读数据前的长度标记
for i := 0; ; i++ { //读数据前的长度标记
sec, err := r.ReadByte()
if err != nil {
return err
@ -278,6 +279,8 @@ func (v *VarInt) Decode(r DecodeReader) error {
if sec&0x80 == 0 {
break
} else if i > 5 {
return errors.New("VarInt is too big")
}
}
@ -285,6 +288,45 @@ func (v *VarInt) Decode(r DecodeReader) error {
return nil
}
//Encode a VarLong
func (v VarLong) Encode() (vi []byte) {
num := uint64(v)
for {
b := num & 0x7F
num >>= 7
if num != 0 {
b |= 0x80
}
vi = append(vi, byte(b))
if num == 0 {
break
}
}
return
}
//Decode a VarLong
func (v *VarLong) Decode(r DecodeReader) error {
var n uint64
for i := 0; ; i++ { //读数据前的长度标记
sec, err := r.ReadByte()
if err != nil {
return err
}
n |= uint64(sec&0x7F) << uint64(7*i)
if sec&0x80 == 0 {
break
} else if i > 10 {
return errors.New("VarInt is too big")
}
}
*v = VarLong(n)
return nil
}
//Encode a Position
func (p Position) Encode() []byte {
b := make([]byte, 8)