This commit is contained in:
JunDao
2019-05-01 15:22:42 +08:00
parent 2b58eb07b5
commit 0d436609ce
21 changed files with 91491 additions and 0 deletions

141
net/packet/packet.go Normal file
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package packet
import (
"bytes"
"compress/zlib"
"fmt"
"io"
)
// Packet define a net data package
type Packet struct {
ID byte
Data []byte
}
//Marshal generate Packet with the ID and Fields
func Marshal(ID byte, fields ...FieldEncoder) (pk Packet) {
pk.ID = ID
for _, v := range fields {
pk.Data = append(pk.Data, v.Encode()...)
}
return
}
//Scan decode the packet and fill data into fields
func (p Packet) Scan(fields ...FieldDecoder) error {
r := bytes.NewReader(p.Data)
for _, v := range fields {
err := v.Decode(r)
if err != nil {
return err
}
}
return nil
}
// Pack 打包一个数据包
func (p *Packet) Pack(threshold int) (pack []byte) {
data := []byte{p.ID} //data
data = append(data, p.Data...) //data
if threshold > 0 { //是否启用了压缩
if len(data) > threshold { //是否需要压缩
Len := len(data)
VarLen := VarInt(Len).Encode()
data = Compress(data)
pack = append(pack, VarInt(len(VarLen)+len(data)).Encode()...)
pack = append(pack, VarLen...)
pack = append(pack, data...)
} else {
pack = append(pack, VarInt(int32(len(data)+1)).Encode()...)
pack = append(pack, 0x00)
pack = append(pack, data...)
}
} else {
pack = append(pack, VarInt(int32(len(data))).Encode()...) //len
pack = append(pack, data...)
}
return
}
// RecvPacket recive a packet from server
func RecvPacket(r io.ByteReader, useZlib bool) (*Packet, error) {
var len int
for i := 0; i < 5; i++ { //读数据前的长度标记
b, err := r.ReadByte()
if err != nil {
return nil, fmt.Errorf("read len of packet fail: %v", err)
}
len |= (int(b&0x7F) << uint(7*i))
if b&0x80 == 0 {
break
}
}
if len < 1 {
return nil, fmt.Errorf("packet length too short")
}
data := make([]byte, len) //读包内容
var err error
for i := 0; i < len; i++ {
data[i], err = r.ReadByte()
if err != nil {
return nil, fmt.Errorf("read content of packet fail: %v", err)
}
}
//解压数据
if useZlib {
return UnCompress(data)
}
return &Packet{
ID: data[0],
Data: data[1:],
}, nil
}
// UnCompress 读取一个压缩的包
func UnCompress(data []byte) (*Packet, error) {
reader := bytes.NewReader(data)
var sizeUncompressed VarInt
if err := sizeUncompressed.Decode(reader); err != nil {
return nil, err
}
uncompressData := make([]byte, sizeUncompressed)
if sizeUncompressed != 0 { // != 0 means compressed, let's decompress
r, err := zlib.NewReader(reader)
if err != nil {
return nil, fmt.Errorf("decompress fail: %v", err)
}
_, err = io.ReadFull(r, uncompressData)
if err != nil {
return nil, fmt.Errorf("decompress fail: %v", err)
}
r.Close()
} else {
uncompressData = data[1:]
}
return &Packet{
ID: uncompressData[0],
Data: uncompressData[1:],
}, nil
}
// Compress 压缩数据
func Compress(data []byte) []byte {
var b bytes.Buffer
w := zlib.NewWriter(&b)
w.Write(data)
w.Close()
return b.Bytes()
}

62
net/packet/packet_test.go Normal file
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package packet
import (
"bytes"
"testing"
)
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},
}
func TestPackInt(t *testing.T) {
for i, v := range VarInts {
p := v.Encode()
if !bytes.Equal(p, PackedVarInts[i]) {
t.Errorf("pack int %d should be \"% x\", get \"% x\"", v, PackedVarInts[i], p)
}
}
}
func TestUnpackInt(t *testing.T) {
for i, v := range PackedVarInts {
var vi VarInt
if err := vi.Decode(bytes.NewReader(v)); err != nil {
t.Errorf("unpack \"% x\" error: %v", v, err)
}
if vi != VarInts[i] {
t.Errorf("unpack \"% x\" should be %d, get %d", v, VarInts[i], vi)
}
}
}
func TestPositionPack(t *testing.T) {
// x (-33554432 to 33554431), y (-2048 to 2047), z (-33554432 to 33554431)
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)
}
if pos1 != pos2 {
t.Errorf("cannot pack %v", pos2)
}
}
}
}
}

335
net/packet/types.go Normal file
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package packet
import (
"io"
"math"
)
type Field interface {
FieldEncoder
FieldDecoder
}
type FieldEncoder interface {
Encode() []byte
}
type FieldDecoder interface {
Decode(r io.ByteReader) error
}
type (
//Boolean of True is encoded as 0x01, false as 0x00.
Boolean bool
//Byte is signed 8-bit integer, two's complement
Byte int8
//UnsignedByte is unsigned 8-bit integer
UnsignedByte uint8
//Short is signed 16-bit integer, two's complement
Short int16
//UnsignedShort is unsigned 16-bit integer
UnsignedShort uint16
//Int is signed 32-bit integer, two's complement
Int int32
//Long is signed 64-bit integer, two's complement
Long int64
//A Float is a single-precision 32-bit IEEE 754 floating point number
Float float32
//A Double is a double-precision 64-bit IEEE 754 floating point number
Double float64
//String is sequence of Unicode scalar values
String string
//Chat is encoded as a String with max length of 32767.
Chat = String
//Identifier is encoded as a String with max length of 32767.
Identifier = String
//VarInt is variable-length data encoding a two's complement signed 32-bit integer
VarInt int32
//VarLong is variable-length data encoding a two's complement signed 64-bit integer
VarLong int64
//Position x as a 26-bit integer, followed by y as a 12-bit integer, followed by z as a 26-bit integer (all signed, two's complement)
Position struct {
X, Y, Z int
}
//Angle is rotation angle in steps of 1/256 of a full turn
Angle int8
//UUID encoded as an unsigned 128-bit integer
UUID [16]byte
)
//ReadNBytes read N bytes from bytes.Reader
func ReadNBytes(r io.ByteReader, n int) (bs []byte, err error) {
bs = make([]byte, n)
for i := 0; i < n; i++ {
bs[i], err = r.ReadByte()
if err != nil {
return
}
}
return
}
//Encode a Boolean
func (b Boolean) Encode() []byte {
if b {
return []byte{0x01}
}
return []byte{0x00}
}
//Decode a Boolean
func (b *Boolean) Decode(r io.ByteReader) error {
v, err := r.ReadByte()
if err != nil {
return err
}
*b = Boolean(v != 0)
return nil
}
// Encode a String
func (s String) Encode() (p []byte) {
byteString := []byte(s)
p = append(p, VarInt(len(byteString)).Encode()...) //len
p = append(p, byteString...) //data
return
}
//Decode a String
func (s *String) Decode(r io.ByteReader) error {
var l VarInt //String length
if err := l.Decode(r); err != nil {
return err
}
bs, err := ReadNBytes(r, int(l))
if err != nil {
return err
}
*s = String(bs)
return nil
}
//Encode a Byte
func (b Byte) Encode() []byte {
return []byte{byte(b)}
}
//Decode a Byte
func (b *Byte) Decode(r io.ByteReader) error {
v, err := r.ReadByte()
if err != nil {
return err
}
*b = Byte(v)
return nil
}
//Encode a UnsignedByte
func (ub UnsignedByte) Encode() []byte {
return []byte{byte(ub)}
}
//Decode a UnsignedByte
func (ub *UnsignedByte) Decode(r io.ByteReader) error {
v, err := r.ReadByte()
if err != nil {
return err
}
*ub = UnsignedByte(v)
return nil
}
// Encode a Signed Short
func (s Short) Encode() []byte {
n := uint16(s)
return []byte{
byte(n >> 8),
byte(n),
}
}
//Decode a Short
func (s *Short) Decode(r io.ByteReader) error {
bs, err := ReadNBytes(r, 2)
if err != nil {
return err
}
*s = Short(int16(bs[0])<<8 | int16(bs[1]))
return nil
}
// Encode a Unsigned Short
func (us UnsignedShort) Encode() []byte {
n := uint16(us)
return []byte{
byte(n >> 8),
byte(n),
}
}
//Decode a UnsignedShort
func (us *UnsignedShort) Decode(r io.ByteReader) error {
bs, err := ReadNBytes(r, 2)
if err != nil {
return err
}
*us = UnsignedShort(int16(bs[0])<<8 | int16(bs[1]))
return nil
}
// Encode a Int
func (i Int) Encode() []byte {
n := uint32(i)
return []byte{
byte(n >> 24), byte(n >> 16),
byte(n >> 8), byte(n),
}
}
//Decode a Int
func (i *Int) Decode(r io.ByteReader) error {
bs, err := ReadNBytes(r, 4)
if err != nil {
return err
}
*i = Int(int32(bs[0])<<24 | int32(bs[1])<<16 | int32(bs[2])<<8 | int32(bs[3]))
return nil
}
// Encode a Long
func (l Long) Encode() []byte {
n := uint64(l)
return []byte{
byte(n >> 56), byte(n >> 48), byte(n >> 40), byte(n >> 32),
byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n),
}
}
//Decode a Long
func (l *Long) Decode(r io.ByteReader) error {
bs, err := ReadNBytes(r, 8)
if err != nil {
return err
}
*l = Long(int64(bs[0])<<56 | int64(bs[1])<<48 | int64(bs[2])<<40 | int64(bs[3])<<32 |
int64(bs[4])<<24 | int64(bs[5])<<16 | int64(bs[6])<<8 | int64(bs[7]))
return nil
}
//Encode a VarInt
func (v VarInt) Encode() (vi []byte) {
num := uint32(v)
for {
b := num & 0x7F
num >>= 7
if num != 0 {
b |= 0x80
}
vi = append(vi, byte(b))
if num == 0 {
break
}
}
return
}
//Decode a VarInt
func (v *VarInt) Decode(r io.ByteReader) error {
var n uint32
for i := 0; i < 5; i++ { //读数据前的长度标记
sec, err := r.ReadByte()
if err != nil {
return err
}
n |= (uint32(sec&0x7F) << uint32(7*i))
if sec&0x80 == 0 {
break
}
}
*v = VarInt(n)
return nil
}
//Encode a Position
func (p Position) Encode() []byte {
b := make([]byte, 8)
position := (uint64(p.X&0x3FFFFFF)<<38 | uint64((p.Z&0x3FFFFFF)<<12) | uint64(p.Y&0xFFF))
for i := 7; i >= 0; i-- {
b[i] = byte(position)
position >>= 8
}
return b
}
// Decode a Position
func (p *Position) Decode(r io.ByteReader) error {
var v Long
if err := v.Decode(r); err != nil {
return err
}
x := int(v >> 38)
y := int(v & 0xFFF)
z := int(v << 26 >> 38)
//处理负数
if x >= 1<<25 {
x -= 1 << 26
}
if y >= 1<<11 {
y -= 1 << 12
}
if z >= 1<<25 {
z -= 1 << 26
}
p.X, p.Y, p.Z = x, y, z
return nil
}
//Encode a Float
func (f Float) Encode() []byte {
return Int(math.Float32bits(float32(f))).Encode()
}
// Decode a Float
func (f *Float) Decode(r io.ByteReader) error {
var v Int
if err := v.Decode(r); err != nil {
return err
}
*f = Float(math.Float32frombits(uint32(v)))
return nil
}
//Encode a Double
func (d Double) Encode() []byte {
return Long(math.Float64bits(float64(d))).Encode()
}
// Decode a Double
func (d *Double) Decode(r io.ByteReader) error {
var v Long
if err := v.Decode(r); err != nil {
return err
}
*d = Double(math.Float64frombits(uint64(v)))
return nil
}