Updated rlp encoding. (requires verification!)

This commit is contained in:
obscuren 2013-12-27 22:32:55 +01:00
parent df0fe67fce
commit 323ba36869
2 changed files with 95 additions and 16 deletions

91
rlp.go
View File

@ -6,29 +6,51 @@ import (
"math"
)
func EncodeSlice(slice []interface{}) []byte {
var buff bytes.Buffer
func BinaryLength(n uint64) uint64 {
if n == 0 { return 0 }
for _, val := range slice {
switch t := val.(type) {
case []interface{}, []string:
buff.Write(Encode(t))
}
return 1 + BinaryLength(n / 256)
}
func ToBinarySlice(n uint64, length uint64) []uint64 {
if length == 0 {
length = BinaryLength(n)
}
return buff.Bytes()
if n == 0 { return make([]uint64, 1) }
slice := ToBinarySlice(n / 256, 0)
slice = append(slice, n % 256)
return slice
}
func ToBin(n uint64, length uint64) string {
var buf bytes.Buffer
for _, val := range ToBinarySlice(n, length) {
buf.WriteString(string(val))
}
return buf.String()
}
func FromBin(data []byte) uint64 {
if len(data) == 0 { return 0 }
return FromBin(data[:len(data)-1]) * 256 + uint64(data[len(data)-1])
}
func Decode(data []byte, pos int) {
char := int(data[pos])
switch {
case char < 24:
}
}
func Encode(object interface{}) []byte {
var buff bytes.Buffer
switch t := object.(type) {
case string:
if len(t) < 56 {
buff.WriteString(string(len(t) + 64) + t)
} else {
}
case uint32, uint64:
var num uint64
if _num, ok := t.(uint64); ok {
@ -40,12 +62,49 @@ func Encode(object interface{}) []byte {
if num >= 0 && num < 24 {
buff.WriteString(string(num))
} else if num <= uint64(math.Pow(2, 256)) {
b := ToBin(num, 0)
buff.WriteString(string(len(b) + 23) + b)
} else {
b := ToBin(num, 0)
b2 := ToBin(uint64(len(b)), 0)
buff.WriteString(string(len(b2) + 55) + b2 + b)
}
case string:
if len(t) < 56 {
buff.WriteString(string(len(t) + 64) + t)
} else {
b2 := ToBin(uint64(len(t)), 0)
buff.WriteString(string(len(b2) + 119) + b2 + t)
}
case []byte:
// Cast the byte slice to a string
buff.Write(Encode(string(t)))
case []interface{}:
buff.Write(EncodeSlice(t))
case []interface{}, []string:
// Inline function for writing the slice header
WriteSliceHeader := func(length int) {
if length < 56 {
buff.WriteString(string(length + 128))
} else {
b2 := ToBin(uint64(length), 0)
buff.WriteString(string(len(b2) + 183) + b2)
}
}
// FIXME How can I do this "better"?
if interSlice, ok := t.([]interface{}); ok {
WriteSliceHeader(len(interSlice))
for _, val := range interSlice {
buff.Write(Encode(val))
}
} else if stringSlice, ok := t.([]string); ok {
WriteSliceHeader(len(stringSlice))
for _, val := range stringSlice {
buff.Write(Encode(val))
}
}
}
return buff.Bytes()

20
rlp_test.go Normal file
View File

@ -0,0 +1,20 @@
package main
import (
"testing"
"fmt"
)
func TestEncode(t *testing.T) {
strRes := "Cdog"
str := string(Encode("dog"))
if str != strRes {
t.Error(fmt.Sprintf("Expected %q, got %q", strRes, str))
}
sliceRes := "\u0083CdogCgodCcat"
slice := string(Encode([]string{"dog", "god", "cat"}))
if slice != sliceRes {
t.Error(fmt.Sprintf("Expected %q, got %q", sliceRes, slice))
}
}