neo-go/pkg/util/uint256.go

99 lines
2.7 KiB
Go

package util
import (
"bytes"
"encoding/hex"
"encoding/json"
"fmt"
"strings"
)
const uint256Size = 32
// Uint256 is a 32 byte long unsigned integer.
type Uint256 [uint256Size]uint8
// Uint256DecodeReverseString attempts to decode the given string (in LE representation) into an Uint256.
func Uint256DecodeReverseString(s string) (u Uint256, err error) {
if len(s) != uint256Size*2 {
return u, fmt.Errorf("expected string size of %d got %d", uint256Size*2, len(s))
}
b, err := hex.DecodeString(s)
if err != nil {
return u, err
}
return Uint256DecodeReverseBytes(b)
}
// Uint256DecodeBytes attempts to decode the given string (in BE representation) into an Uint256.
func Uint256DecodeBytes(b []byte) (u Uint256, err error) {
if len(b) != uint256Size {
return u, fmt.Errorf("expected []byte of size %d got %d", uint256Size, len(b))
}
copy(u[:], b)
return u, nil
}
// Uint256DecodeReverseBytes attempts to decode the given string (in LE representation) into an Uint256.
func Uint256DecodeReverseBytes(b []byte) (u Uint256, err error) {
b = ArrayReverse(b)
return Uint256DecodeBytes(b)
}
// Bytes returns a byte slice representation of u.
func (u Uint256) Bytes() []byte {
return u[:]
}
// Reverse reverses the Uint256 object
func (u Uint256) Reverse() Uint256 {
res, _ := Uint256DecodeReverseBytes(u.Bytes())
return res
}
// BytesReverse return a reversed byte representation of u.
func (u Uint256) BytesReverse() []byte {
return ArrayReverse(u.Bytes())
}
// Equals returns true if both Uint256 values are the same.
func (u Uint256) Equals(other Uint256) bool {
return u == other
}
// String implements the stringer interface.
func (u Uint256) String() string {
return hex.EncodeToString(u.Bytes())
}
// ReverseString produces string representation of Uint256 with LE byte order.
func (u Uint256) ReverseString() string {
return hex.EncodeToString(u.BytesReverse())
}
// UnmarshalJSON implements the json unmarshaller interface.
func (u *Uint256) UnmarshalJSON(data []byte) (err error) {
var js string
if err = json.Unmarshal(data, &js); err != nil {
return err
}
js = strings.TrimPrefix(js, "0x")
*u, err = Uint256DecodeReverseString(js)
return err
}
// Size returns the lenght of the bytes representation of Uint256
func (u Uint256) Size() int {
return uint256Size
}
// MarshalJSON implements the json marshaller interface.
func (u Uint256) MarshalJSON() ([]byte, error) {
return []byte(`"0x` + u.ReverseString() + `"`), nil
}
// CompareTo compares two Uint256 with each other. Possible output: 1, -1, 0
// 1 implies u > other.
// -1 implies u < other.
// 0 implies u = other.
func (u Uint256) CompareTo(other Uint256) int { return bytes.Compare(u[:], other[:]) }