neo-go/pkg/util/uint256.go

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package util
import (
"bytes"
"encoding/hex"
"encoding/json"
"fmt"
"strings"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/util/slice"
)
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// Uint256Size is the size of Uint256 in bytes.
const Uint256Size = 32
// Uint256 is a 32 byte long unsigned integer.
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type Uint256 [Uint256Size]uint8
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// Uint256DecodeStringLE attempts to decode the given string (in LE representation) into an Uint256.
func Uint256DecodeStringLE(s string) (u Uint256, err error) {
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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
}
slice.Reverse(b)
return Uint256DecodeBytesBE(b)
}
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// Uint256DecodeStringBE attempts to decode the given string (in BE representation)
// into an Uint256.
func Uint256DecodeStringBE(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 Uint256DecodeBytesBE(b)
}
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// Uint256DecodeBytesBE attempts to decode the given string (in BE representation) into an Uint256.
func Uint256DecodeBytesBE(b []byte) (u Uint256, err error) {
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if len(b) != Uint256Size {
return u, fmt.Errorf("expected []byte of size %d got %d", Uint256Size, len(b))
}
copy(u[:], b)
return u, nil
}
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// Uint256DecodeBytesLE attempts to decode the given string (in LE representation) into an Uint256.
func Uint256DecodeBytesLE(b []byte) (u Uint256, err error) {
b = slice.CopyReverse(b)
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return Uint256DecodeBytesBE(b)
}
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// BytesBE returns a byte slice representation of u.
func (u Uint256) BytesBE() []byte {
return u[:]
}
// Reverse reverses the Uint256 object.
func (u Uint256) Reverse() Uint256 {
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res, _ := Uint256DecodeBytesLE(u.BytesBE())
return res
}
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// BytesLE return a little-endian byte representation of u.
func (u Uint256) BytesLE() []byte {
return slice.CopyReverse(u.BytesBE())
}
// 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 {
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return u.StringBE()
}
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// StringBE produces string representation of Uint256 with BE byte order.
func (u Uint256) StringBE() string {
return hex.EncodeToString(u.BytesBE())
}
// StringLE produces string representation of Uint256 with LE byte order.
func (u Uint256) StringLE() string {
return hex.EncodeToString(u.BytesLE())
}
// 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")
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*u, err = Uint256DecodeStringLE(js)
return err
}
// MarshalJSON implements the json marshaller interface.
func (u Uint256) MarshalJSON() ([]byte, error) {
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return []byte(`"0x` + u.StringLE() + `"`), 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[:]) }
// EncodeBinary implements io.Serializable interface.
func (u *Uint256) EncodeBinary(w *io.BinWriter) {
w.WriteBytes(u[:])
}
// DecodeBinary implements io.Serializable interface.
func (u *Uint256) DecodeBinary(r *io.BinReader) {
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r.ReadBytes(u[:])
}