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add support for nonarray lists, fix bugs with structs, make compliant with bigtest.nbt

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This commit is contained in:
Mark Asp
2020-09-17 22:38:48 -05:00
parent 610cb0c7d5
commit 95b9ba9360
5 changed files with 246 additions and 152 deletions
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1
nbt/README.md
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@ -1,4 +1,5 @@
# NBT
This is copied from [mc-go](https://github.com/Tnze/go-mc) until PRs to add support for needed features is merged in.
This package implement the Named Binary Tag format of Minecraft.
# Docs
[![GoDoc](https://godoc.org/github.com/Tnze/go-mc/nbt?status.svg)](https://godoc.org/github.com/Tnze/go-mc/nbt)

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nbt/bigtest.nbt Normal file
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272
nbt/marshal.go
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@ -5,12 +5,26 @@ import (
"io"
"math"
"reflect"
"strings"
)
var (
ErrMustBeStruct = errors.New("a compound can only be a struct")
)
func Marshal(w io.Writer, v interface{}) error {
return NewEncoder(w).Encode(v)
}
func MarshalCompound(w io.Writer, v interface{}, rootTagName string) error {
enc := NewEncoder(w)
val := reflect.ValueOf(v)
if val.Kind() != reflect.Struct {
return ErrMustBeStruct
}
return enc.marshal(val, TagCompound, rootTagName)
}
type Encoder struct {
w io.Writer
}
@ -21,166 +35,86 @@ func NewEncoder(w io.Writer) *Encoder {
func (e *Encoder) Encode(v interface{}) error {
val := reflect.ValueOf(v)
return e.marshal(val, "")
return e.marshal(val, getTagType(val.Type()), "")
}
func (e *Encoder) marshal(val reflect.Value, tagName string) error {
switch vk := val.Kind(); vk {
default:
return errors.New("unknown type " + vk.String())
func (e *Encoder) marshal(val reflect.Value, tagType byte, tagName string) (err error) {
err = e.writeHeader(val, tagType, tagName)
err = e.writeValue(val, tagType)
return err
}
case reflect.Uint8:
if err := e.writeTag(TagByte, tagName); err != nil {
return err
}
func (e *Encoder) writeHeader(val reflect.Value, tagType byte, tagName string) (err error) {
if tagType == TagList {
eleType := getTagType(val.Type().Elem())
err = e.writeListHeader(eleType, tagName, val.Len())
} else {
err = e.writeTag(tagType, tagName)
}
return err
}
func (e *Encoder) writeValue(val reflect.Value, tagType byte) error {
switch tagType {
default:
return errors.New("unsupported type " + val.Type().Kind().String())
case TagByte:
_, err := e.w.Write([]byte{byte(val.Uint())})
return err
case reflect.Int16, reflect.Uint16:
if err := e.writeTag(TagShort, tagName); err != nil {
return err
}
case TagShort:
return e.writeInt16(int16(val.Int()))
case reflect.Int32, reflect.Uint32:
if err := e.writeTag(TagInt, tagName); err != nil {
return err
}
case TagInt:
return e.writeInt32(int32(val.Int()))
case reflect.Float32:
if err := e.writeTag(TagFloat, tagName); err != nil {
return err
}
case TagFloat:
return e.writeInt32(int32(math.Float32bits(float32(val.Float()))))
case reflect.Int64, reflect.Uint64:
if err := e.writeTag(TagLong, tagName); err != nil {
return err
}
return e.writeInt64(int64(val.Int()))
case reflect.Float64:
if err := e.writeTag(TagDouble, tagName); err != nil {
return err
}
case TagLong:
return e.writeInt64(val.Int())
case TagDouble:
return e.writeInt64(int64(math.Float64bits(val.Float())))
case reflect.Array, reflect.Slice:
case TagByteArray, TagIntArray, TagLongArray:
n := val.Len()
switch val.Type().Elem().Kind() {
case reflect.Uint8: // []byte
if err := e.writeTag(TagByteArray, tagName); err != nil {
return err
}
if err := e.writeInt32(int32(val.Len())); err != nil {
return err
}
if err := e.writeInt32(int32(n)); err != nil {
return err
}
if tagType == TagByteArray {
_, err := e.w.Write(val.Bytes())
return err
} else {
for i := 0; i < n; i++ {
v := val.Index(i).Int()
case reflect.Int32:
if err := e.writeTag(TagIntArray, tagName); err != nil {
return err
}
if err := e.writeInt32(int32(n)); err != nil {
return err
}
for i := 0; i < n; i++ {
if err := e.writeInt32(int32(val.Index(i).Int())); err != nil {
return err
var err error
if tagType == TagIntArray {
err = e.writeInt32(int32(v))
} else if tagType == TagLongArray {
err = e.writeInt64(v)
}
}
case reflect.Int64:
if err := e.writeTag(TagLongArray, tagName); err != nil {
return err
}
if err := e.writeInt32(int32(n)); err != nil {
return err
}
for i := 0; i < n; i++ {
if err := e.writeInt64(val.Index(i).Int()); err != nil {
return err
}
}
case reflect.Int16:
if err := e.writeListHeader(TagShort, tagName, val.Len()); err != nil {
return err
}
for i := 0; i < n; i++ {
if err := e.writeInt16(int16(val.Index(i).Int())); err != nil {
return err
}
}
case reflect.Float32:
if err := e.writeListHeader(TagFloat, tagName, val.Len()); err != nil {
return err
}
for i := 0; i < n; i++ {
if err := e.writeInt32(int32(math.Float32bits(float32(val.Index(i).Float())))); err != nil {
return err
}
}
case reflect.Float64:
if err := e.writeListHeader(TagDouble, tagName, val.Len()); err != nil {
return err
}
for i := 0; i < n; i++ {
if err := e.writeInt64(int64(math.Float64bits(val.Index(i).Float()))); err != nil {
return err
}
}
case reflect.String:
if err := e.writeListHeader(TagString, tagName, n); err != nil {
return err
}
for i := 0; i < n; i++ {
// Write length of this string
s := val.Index(i).String()
if err := e.writeInt16(int16(len(s))); err != nil {
return err
}
// Write string
if _, err := e.w.Write([]byte(s)); err != nil {
return err
}
}
case reflect.Struct, reflect.Interface:
if err := e.writeListHeader(TagCompound, tagName, n); err != nil {
return err
}
for i := 0; i < n; i++ {
elemVal := val.Index(i)
if val.Type().Elem().Kind() == reflect.Interface {
elemVal = reflect.ValueOf(elemVal.Interface())
}
err := e.marshal(elemVal, "")
if err != nil {
return err
}
}
default:
return errors.New("unknown type " + val.Type().String() + " slice")
}
case reflect.String:
if err := e.writeTag(TagString, tagName); err != nil {
return err
case TagList:
for i := 0; i < val.Len(); i++ {
arrVal := val.Index(i)
err := e.writeValue(arrVal, getTagType(arrVal.Type()))
if err != nil {
return err
}
}
case TagString:
if err := e.writeInt16(int16(val.Len())); err != nil {
return err
}
_, err := e.w.Write([]byte(val.String()))
return err
case reflect.Struct:
if err := e.writeTag(TagCompound, ""); err != nil {
return err
case TagCompound:
if val.Kind() == reflect.Interface {
val = reflect.ValueOf(val.Interface())
}
n := val.NumField()
@ -191,12 +125,8 @@ func (e *Encoder) marshal(val reflect.Value, tagName string) error {
continue // Private field
}
tagName := f.Name
if tag != "" {
tagName = tag
}
err := e.marshal(val.Field(i), tagName)
tagProps := parseTag(f, tag)
err := e.marshal(val.Field(i), tagProps.Type, tagProps.Name)
if err != nil {
return err
}
@ -207,6 +137,65 @@ func (e *Encoder) marshal(val reflect.Value, tagName string) error {
return nil
}
func getTagType(vk reflect.Type) byte {
switch vk.Kind() {
case reflect.Uint8:
return TagByte
case reflect.Int16, reflect.Uint16:
return TagShort
case reflect.Int32, reflect.Uint32:
return TagInt
case reflect.Float32:
return TagFloat
case reflect.Int64, reflect.Uint64:
return TagLong
case reflect.Float64:
return TagDouble
case reflect.String:
return TagString
case reflect.Struct, reflect.Interface:
return TagCompound
case reflect.Array, reflect.Slice:
switch vk.Elem().Kind() {
case reflect.Uint8: // Special types for these values
return TagByteArray
case reflect.Int32:
return TagIntArray
case reflect.Int64:
return TagLongArray
default:
return TagList
}
default:
return TagNone
}
}
type tagProps struct {
Name string
Type byte
}
func parseTag(f reflect.StructField, tagName string) tagProps {
result := tagProps{}
result.Name = tagName
if result.Name == "" {
result.Name = f.Name
}
nbtType := f.Tag.Get("nbt_type")
result.Type = getTagType(f.Type)
if strings.Contains(nbtType, "noarray") {
if IsArrayTag(result.Type) {
result.Type = TagList // for expanding the array to a standard list
} else {
panic("noarray is only supported for array types (byte, int, long)")
}
}
return result
}
func (e *Encoder) writeTag(tagType byte, tagName string) error {
if _, err := e.w.Write([]byte{tagType}); err != nil {
return err
@ -233,11 +222,6 @@ func (e *Encoder) writeListHeader(elementType byte, tagName string, n int) (err
return nil
}
func (e *Encoder) writeNamelessTag(tagType byte, tagName string) error {
_, err := e.w.Write([]byte{tagType})
return err
}
func (e *Encoder) writeInt16(n int16) error {
_, err := e.w.Write([]byte{byte(n >> 8), byte(n)})
return err

120
nbt/marshal_test.go
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@ -2,6 +2,7 @@ package nbt
import (
"bytes"
"io/ioutil"
"math"
"testing"
)
@ -56,6 +57,19 @@ func TestMarshal_FloatArray(t *testing.T) {
}
}
func TestMarshal_String(t *testing.T) {
v := "Test"
out := []byte{TagString, 0x00, 0x00, 0, 4,
'T', 'e', 's', 't'}
var buf bytes.Buffer
if err := Marshal(&buf, v); err != nil {
t.Error(err)
} else if !bytes.Equal(buf.Bytes(), out) {
t.Errorf("output binary not right: got % 02x, want % 02x ", buf.Bytes(), out)
}
}
func TestMarshal_InterfaceArray(t *testing.T) {
type Struct1 struct {
Val int32
@ -76,16 +90,15 @@ func TestMarshal_InterfaceArray(t *testing.T) {
want: []byte{
TagList, 0x00, 0x00 /*no name*/, TagCompound, 0, 0, 0, 2,
// 1st element
TagCompound, 0x00, 0x00, /*no name*/
TagInt, 0x00, 0x03, 'V', 'a', 'l', 0x00, 0x00, 0x00, 0x03, // 3
TagEnd,
// 2nd element
TagCompound, 0x00, 0x00, /*no name*/
TagFloat, 0x00, 0x03, 'V', 'a', 'l', 0x3e, 0x99, 0x99, 0x9a, // 0.3
TagEnd,
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
w := &bytes.Buffer{}
@ -105,24 +118,39 @@ func TestMarshal_StructArray(t *testing.T) {
Val int32
}
type Struct2 struct {
T int32
Ele Struct1
}
type StructCont struct {
V []Struct2
}
tests := []struct {
name string
args []Struct1
args StructCont
want []byte
}{
{
name: "One element struct array",
args: []Struct1{{3}, {-10}},
args: StructCont{[]Struct2{{3, Struct1{3}}, {-10, Struct1{-10}}}},
want: []byte{
TagList, 0x00, 0x00 /*no name*/, TagCompound, 0, 0, 0, 2,
// 1st element
TagCompound, 0x00, 0x00, /*no name*/
TagCompound, 0x00, 0x00,
TagList, 0x00, 0x01, 'V', TagCompound, 0, 0, 0, 2,
// Struct2
TagInt, 0x00, 0x01, 'T', 0x00, 0x00, 0x00, 0x03,
TagCompound, 0x00, 0x03, 'E', 'l', 'e',
TagInt, 0x00, 0x03, 'V', 'a', 'l', 0x00, 0x00, 0x00, 0x03, // 3
TagEnd,
TagEnd,
// 2nd element
TagCompound, 0x00, 0x00, /*no name*/
TagInt, 0x00, 0x01, 'T', 0xff, 0xff, 0xff, 0xf6,
TagCompound, 0x00, 0x03, 'E', 'l', 'e',
TagInt, 0x00, 0x03, 'V', 'a', 'l', 0xff, 0xff, 0xff, 0xf6, // -10
TagEnd,
TagEnd,
TagEnd,
},
},
}
@ -139,3 +167,79 @@ func TestMarshal_StructArray(t *testing.T) {
})
}
}
// This test is for compliance with the "bigtest.dat" described in detail here:
// https://wiki.vg/NBT#bigtest.nbt
func TestMarshal_BigTest(t *testing.T) {
byteValues := make([]byte, 1000)
for n := 0; n < 1000; n++ {
byteValues[n] = byte((n*n*255 + n*7) % 100)
}
type NestedCompound struct {
Name string `nbt:"name"`
Value float32 `nbt:"value"`
}
type NestedCompoundCont struct {
Ham NestedCompound `nbt:"ham"`
Egg NestedCompound `nbt:"egg"`
}
type ListCompound struct {
Name string `nbt:"name"`
CreatedOn int64 `nbt:"created-on"`
}
val := struct {
LongTest int64 `nbt:"longTest"`
ShortTest int16 `nbt:"shortTest"`
StringTest string `nbt:"stringTest"`
FloatTest float32 `nbt:"floatTest"`
IntTest int32 `nbt:"intTest"`
NestedCompoundTest NestedCompoundCont `nbt:"nested compound test"`
ListTestLong []int64 `nbt:"listTest (long)" nbt_type:"noarray"`
ListTestCompound []ListCompound `nbt:"listTest (compound)"`
ByteTest byte `nbt:"byteTest"`
ByteArrayTest []byte `nbt:"byteArrayTest (the first 1000 values of (n*n*255+n*7)%100, starting with n=0 (0, 62, 34, 16, 8, ...))"`
DoubleTest float64 `nbt:"doubleTest"`
}{
LongTest: 9223372036854775807,
ShortTest: 32767,
StringTest: "HELLO WORLD THIS IS A TEST STRING \xc3\x85\xc3\x84\xc3\x96!",
FloatTest: 0.49823147058486938,
IntTest: 2147483647,
NestedCompoundTest: NestedCompoundCont{
NestedCompound{"Hampus", 0.75},
NestedCompound{"Eggbert", 0.5},
},
ListTestLong: []int64{11, 12, 13, 14, 15},
ListTestCompound: []ListCompound{
{"Compound tag #0", 1264099775885},
{"Compound tag #1", 1264099775885},
},
ByteTest: 127,
ByteArrayTest: byteValues,
DoubleTest: 0.49312871321823148,
}
var b bytes.Buffer
err := MarshalCompound(&b, val, "Level")
if err != nil {
t.Error(err)
}
want, err := ioutil.ReadFile("bigtest.nbt")
if err != nil {
t.Error(err)
}
err = ioutil.WriteFile("bigtest_got.nbt", b.Bytes(), 0644)
if err != nil {
t.Error(err)
}
if !bytes.Equal(b.Bytes(), want) {
t.Errorf("got:\n[% 2x]\nwant:\n[% 2x]", b.Bytes(), want)
}
}

5
nbt/nbt.go
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@ -22,8 +22,13 @@ const (
TagCompound
TagIntArray
TagLongArray
TagNone = 0xFF
)
func IsArrayTag(ty byte) bool {
return ty == TagByteArray || ty == TagIntArray || ty == TagLongArray
}
type DecoderReader = interface {
io.ByteScanner
io.Reader