forked from TrueCloudLab/neoneo-go
b257a06f3e
* added seperate folders for cmd packages. * Fix netmodes in test + reverse bigint bytes * glide get deps * add, sub, mul, div * booleans * strings * binary expressions * if statements * function calls * composite literals (slice, array) * Added lots of test cases and update readme.
87 lines
1.8 KiB
Go
87 lines
1.8 KiB
Go
package util
|
|
|
|
import (
|
|
"encoding/hex"
|
|
"fmt"
|
|
)
|
|
|
|
const uint256Size = 32
|
|
|
|
// Uint256 is a 32 byte long unsigned integer.
|
|
type Uint256 [uint256Size]uint8
|
|
|
|
// Uint256DecodeFromString returns an Uint256 from a (hex) string.
|
|
func Uint256DecodeFromString(s string) (Uint256, error) {
|
|
var val Uint256
|
|
|
|
if len(s) != uint256Size*2 {
|
|
return val, fmt.Errorf("expected string size of %d got %d", uint256Size*2, len(s))
|
|
}
|
|
|
|
b, err := hex.DecodeString(s)
|
|
if err != nil {
|
|
return val, err
|
|
}
|
|
|
|
b = ToArrayReverse(b)
|
|
|
|
return Uint256DecodeFromBytes(b)
|
|
}
|
|
|
|
// Uint256DecodeFromBytes return an Uint256 from a byte slice.
|
|
func Uint256DecodeFromBytes(b []byte) (Uint256, error) {
|
|
var val Uint256
|
|
|
|
if len(b) != uint256Size {
|
|
return val, fmt.Errorf("expected []byte of size %d got %d", uint256Size, len(b))
|
|
}
|
|
|
|
for i := 0; i < uint256Size; i++ {
|
|
val[i] = b[i]
|
|
}
|
|
|
|
return val, nil
|
|
}
|
|
|
|
// ToArrayReverse return a reversed version of the given byte slice.
|
|
func ToArrayReverse(b []byte) []byte {
|
|
// Protect from big.Ints that have 1 len bytes.
|
|
if len(b) < 2 {
|
|
return b
|
|
}
|
|
|
|
dest := make([]byte, len(b))
|
|
for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
|
|
dest[i], dest[j] = b[j], b[i]
|
|
}
|
|
|
|
return dest
|
|
}
|
|
|
|
// ToSlice returns a byte slice of u.
|
|
func (u Uint256) ToSlice() []byte {
|
|
b := make([]byte, uint256Size)
|
|
for i := 0; i < uint256Size; i++ {
|
|
b[i] = byte(u[i])
|
|
}
|
|
return b
|
|
}
|
|
|
|
// ToSliceReverse returns a reversed byte slice of u.
|
|
func (u Uint256) ToSliceReverse() []byte {
|
|
b := make([]byte, uint256Size)
|
|
for i, j := 0, uint256Size-1; i < j; i, j = i+1, j-1 {
|
|
b[i], b[j] = byte(u[j]), byte(u[i])
|
|
}
|
|
return b
|
|
}
|
|
|
|
// Equals returns true if both Uint256 values are the same.
|
|
func (u Uint256) Equals(other Uint256) bool {
|
|
return u.String() == other.String()
|
|
}
|
|
|
|
// String implements the stringer interface.
|
|
func (u Uint256) String() string {
|
|
return hex.EncodeToString(u.ToSliceReverse())
|
|
}
|