Files
go-mc/net/packet/types.go
2021-07-05 00:58:41 +08:00

511 lines
10 KiB
Go

package packet
import (
"bytes"
"errors"
"io"
"math"
"github.com/google/uuid"
"github.com/Tnze/go-mc/nbt"
)
// A Field is both FieldEncoder and FieldDecoder
type Field interface {
FieldEncoder
FieldDecoder
}
// A FieldEncoder can be encode as minecraft protocol used.
type FieldEncoder io.WriterTo
// A FieldDecoder can Decode from minecraft protocol
type FieldDecoder io.ReaderFrom
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.
// Deprecated: Use chat.Message
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 Byte
//UUID encoded as an unsigned 128-bit integer
UUID uuid.UUID
//ByteArray is []byte with prefix VarInt as length
ByteArray []byte
//PluginMessageData is only used in LoginPlugin,and it will read all left bytes
PluginMessageData []byte
)
const MaxVarIntLen = 5
const MaxVarLongLen = 10
//Encode a Boolean
func (b Boolean) WriteTo(w io.Writer) (int64, error) {
var v byte
if b {
v = 0x01
} else {
v = 0x00
}
nn, err := w.Write([]byte{v})
return int64(nn), err
}
//Decode a Boolean
func (b *Boolean) ReadFrom(r io.Reader) (n int64, err error) {
v, err := readByte(r)
if err != nil {
return 1, err
}
*b = v != 0
return 1, nil
}
// Encode a String
func (s String) WriteTo(w io.Writer) (int64, error) {
byteStr := []byte(s)
n1, err := VarInt(len(byteStr)).WriteTo(w)
if err != nil {
return n1, err
}
n2, err := w.Write(byteStr)
return n1 + int64(n2), err
}
//Decode a String
func (s *String) ReadFrom(r io.Reader) (n int64, err error) {
var l VarInt //String length
nn, err := l.ReadFrom(r)
if err != nil {
return nn, err
}
n += nn
bs := make([]byte, l)
if _, err := io.ReadFull(r, bs); err != nil {
return n, err
}
n += int64(l)
*s = String(bs)
return n, nil
}
// readByte read one byte from io.Reader
func readByte(r io.Reader) (byte, error) {
if r, ok := r.(io.ByteReader); ok {
return r.ReadByte()
}
var v [1]byte
_, err := io.ReadFull(r, v[:])
return v[0], err
}
//Encode a Byte
func (b Byte) WriteTo(w io.Writer) (n int64, err error) {
nn, err := w.Write([]byte{byte(b)})
return int64(nn), err
}
//Decode a Byte
func (b *Byte) ReadFrom(r io.Reader) (n int64, err error) {
v, err := readByte(r)
if err != nil {
return 0, err
}
*b = Byte(v)
return 1, nil
}
//Encode a UnsignedByte
func (u UnsignedByte) WriteTo(w io.Writer) (n int64, err error) {
nn, err := w.Write([]byte{byte(u)})
return int64(nn), err
}
//Decode a UnsignedByte
func (u *UnsignedByte) ReadFrom(r io.Reader) (n int64, err error) {
v, err := readByte(r)
if err != nil {
return 0, err
}
*u = UnsignedByte(v)
return 1, nil
}
// Encode a Signed Short
func (s Short) WriteTo(w io.Writer) (int64, error) {
n := uint16(s)
nn, err := w.Write([]byte{byte(n >> 8), byte(n)})
return int64(nn), err
}
//Decode a Short
func (s *Short) ReadFrom(r io.Reader) (n int64, err error) {
var bs [2]byte
if nn, err := io.ReadFull(r, bs[:]); err != nil {
return int64(nn), err
} else {
n += int64(nn)
}
*s = Short(int16(bs[0])<<8 | int16(bs[1]))
return
}
// Encode a Unsigned Short
func (us UnsignedShort) WriteTo(w io.Writer) (int64, error) {
n := uint16(us)
nn, err := w.Write([]byte{byte(n >> 8), byte(n)})
return int64(nn), err
}
//Decode a UnsignedShort
func (us *UnsignedShort) ReadFrom(r io.Reader) (n int64, err error) {
var bs [2]byte
if nn, err := io.ReadFull(r, bs[:]); err != nil {
return int64(nn), err
} else {
n += int64(nn)
}
*us = UnsignedShort(int16(bs[0])<<8 | int16(bs[1]))
return
}
// Encode a Int
func (i Int) WriteTo(w io.Writer) (int64, error) {
n := uint32(i)
nn, err := w.Write([]byte{byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n)})
return int64(nn), err
}
//Decode a Int
func (i *Int) ReadFrom(r io.Reader) (n int64, err error) {
var bs [4]byte
if nn, err := io.ReadFull(r, bs[:]); err != nil {
return int64(nn), err
} else {
n += int64(nn)
}
*i = Int(int32(bs[0])<<24 | int32(bs[1])<<16 | int32(bs[2])<<8 | int32(bs[3]))
return
}
// Encode a Long
func (l Long) WriteTo(w io.Writer) (int64, error) {
n := uint64(l)
nn, err := w.Write([]byte{
byte(n >> 56), byte(n >> 48), byte(n >> 40), byte(n >> 32),
byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n),
})
return int64(nn), err
}
//Decode a Long
func (l *Long) ReadFrom(r io.Reader) (n int64, err error) {
var bs [8]byte
if nn, err := io.ReadFull(r, bs[:]); err != nil {
return int64(nn), err
} else {
n += int64(nn)
}
*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
}
//Encode a VarInt
func (v VarInt) WriteTo(w io.Writer) (n int64, err error) {
var vi = make([]byte, 0, MaxVarIntLen)
num := uint32(v)
for {
b := num & 0x7F
num >>= 7
if num != 0 {
b |= 0x80
}
vi = append(vi, byte(b))
if num == 0 {
break
}
}
nn, err := w.Write(vi)
return int64(nn), err
}
//Decode a VarInt
func (v *VarInt) ReadFrom(r io.Reader) (n int64, err error) {
var V uint32
for sec := byte(0x80); sec&0x80 != 0; n++ {
if n > MaxVarIntLen {
return n, errors.New("VarInt is too big")
}
sec, err = readByte(r)
if err != nil {
return n, err
}
V |= uint32(sec&0x7F) << uint32(7*n)
}
*v = VarInt(V)
return
}
//Encode a VarLong
func (v VarLong) WriteTo(w io.Writer) (n int64, err error) {
var vi = make([]byte, 0, MaxVarLongLen)
num := uint64(v)
for {
b := num & 0x7F
num >>= 7
if num != 0 {
b |= 0x80
}
vi = append(vi, byte(b))
if num == 0 {
break
}
}
nn, err := w.Write(vi)
return int64(nn), err
}
//Decode a VarLong
func (v *VarLong) ReadFrom(r io.Reader) (n int64, err error) {
var V uint64
for sec := byte(0x80); sec&0x80 != 0; n++ {
if n >= MaxVarLongLen {
return n, errors.New("VarLong is too big")
}
sec, err = readByte(r)
if err != nil {
return
}
V |= uint64(sec&0x7F) << uint64(7*n)
}
*v = VarLong(V)
return
}
//Encode a Position
func (p Position) WriteTo(w io.Writer) (n int64, err error) {
var b [8]byte
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
}
nn, err := w.Write(b[:])
return int64(nn), err
}
// Decode a Position
func (p *Position) ReadFrom(r io.Reader) (n int64, err error) {
var v Long
nn, err := v.ReadFrom(r)
if err != nil {
return nn, err
}
n += nn
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
}
// ToDeg convert Angle to Degree
func (a Angle) ToDeg() float64 {
return 360 * float64(a) / 256
}
// ToRad convert Angle to Radian
func (a Angle) ToRad() float64 {
return 2 * math.Pi * float64(a) / 256
}
func (a Angle) WriteTo(w io.Writer) (int64, error) {
return Byte(a).WriteTo(w)
}
func (a *Angle) ReadFrom(r io.Reader) (int64, error) {
return (*Byte)(a).ReadFrom(r)
}
//Encode a Float
func (f Float) WriteTo(w io.Writer) (n int64, err error) {
return Int(math.Float32bits(float32(f))).WriteTo(w)
}
// Decode a Float
func (f *Float) ReadFrom(r io.Reader) (n int64, err error) {
var v Int
n, err = v.ReadFrom(r)
if err != nil {
return
}
*f = Float(math.Float32frombits(uint32(v)))
return
}
//Encode a Double
func (d Double) WriteTo(w io.Writer) (n int64, err error) {
return Long(math.Float64bits(float64(d))).WriteTo(w)
}
// Decode a Double
func (d *Double) ReadFrom(r io.Reader) (n int64, err error) {
var v Long
n, err = v.ReadFrom(r)
if err != nil {
return
}
*d = Double(math.Float64frombits(uint64(v)))
return
}
//NBT encode a value as Named Binary Tag
func NBT(v interface{}, optionalTagName ...string) Field {
if len(optionalTagName) > 0 {
return nbtField{V: v, FieldName: optionalTagName[0]}
}
return nbtField{V: v}
}
type nbtField struct {
V interface{}
FieldName string
}
func (n nbtField) WriteTo(w io.Writer) (int64, error) {
var buf bytes.Buffer
if n.V == nil {
buf.WriteByte(nbt.TagEnd)
} else if err := nbt.NewEncoder(&buf).Encode(n.V, n.FieldName); err != nil {
return 0, err
}
return buf.WriteTo(w)
}
func (n nbtField) ReadFrom(r io.Reader) (int64, error) {
// LimitReader is used to count reader length
lr := &io.LimitedReader{R: r, N: math.MaxInt64}
_, err := nbt.NewDecoder(lr).Decode(n.V)
if err != nil && errors.Is(err, nbt.ErrEND) {
err = nil
}
return math.MaxInt64 - lr.N, err
}
// Encode a ByteArray
func (b ByteArray) WriteTo(w io.Writer) (n int64, err error) {
n1, err := VarInt(len(b)).WriteTo(w)
if err != nil {
return n1, err
}
n2, err := w.Write(b)
return n1 + int64(n2), err
}
// Decode a ByteArray
func (b *ByteArray) ReadFrom(r io.Reader) (n int64, err error) {
var Len VarInt
n1, err := Len.ReadFrom(r)
if err != nil {
return n1, err
}
buf := bytes.NewBuffer(*b)
buf.Reset()
n2, err := io.CopyN(buf, r, int64(Len))
*b = buf.Bytes()
return n1 + n2, err
}
// Encode a UUID
func (u UUID) WriteTo(w io.Writer) (n int64, err error) {
nn, err := w.Write(u[:])
return int64(nn), err
}
// Decode a UUID
func (u *UUID) ReadFrom(r io.Reader) (n int64, err error) {
nn, err := io.ReadFull(r, (*u)[:])
return int64(nn), err
}
// Encode a PluginsMessageData
func (p *PluginMessageData) WriteTo(w io.Writer) (n int64, err error) {
nn, err := w.Write(*p)
return int64(nn), err
}
// Decode a PluginsMessageData
func (p *PluginMessageData) ReadFrom(r io.Reader) (n int64, err error) {
*p, err = io.ReadAll(r)
return int64(len(*p)), err
}