status-go/vendor/github.com/anacrolix/dht/v2/int160/int160.go

111 lines
1.6 KiB
Go

package int160
import (
"encoding/hex"
"math"
"math/big"
)
type T struct {
bits [20]uint8
}
func (me T) String() string {
return hex.EncodeToString(me.bits[:])
}
func (me *T) AsByteArray() [20]byte {
return me.bits
}
func (me *T) ByteString() string {
return string(me.bits[:])
}
func (me *T) BitLen() int {
var a big.Int
a.SetBytes(me.bits[:])
return a.BitLen()
}
func (me *T) SetBytes(b []byte) {
n := copy(me.bits[:], b)
if n != 20 {
panic(n)
}
}
func (me *T) SetBit(index int, val bool) {
var orVal uint8
if val {
orVal = 1 << (7 - index%8)
}
var mask uint8 = ^(1 << (7 - index%8))
me.bits[index/8] = me.bits[index/8]&mask | orVal
}
func (me *T) GetBit(index int) bool {
return me.bits[index/8]>>(7-index%8)&1 == 1
}
func (me T) Bytes() []byte {
return me.bits[:]
}
func (l T) Cmp(r T) int {
for i := range l.bits {
if l.bits[i] < r.bits[i] {
return -1
} else if l.bits[i] > r.bits[i] {
return 1
}
}
return 0
}
func (me *T) SetMax() {
for i := range me.bits {
me.bits[i] = math.MaxUint8
}
}
func (me *T) Xor(a, b *T) {
for i := range me.bits {
me.bits[i] = a.bits[i] ^ b.bits[i]
}
}
func (me *T) IsZero() bool {
for _, b := range me.bits {
if b != 0 {
return false
}
}
return true
}
func FromBytes(b []byte) (ret T) {
ret.SetBytes(b)
return
}
func FromByteArray(b [20]byte) (ret T) {
ret.SetBytes(b[:])
return
}
func FromByteString(s string) (ret T) {
ret.SetBytes([]byte(s))
return
}
func Distance(a, b T) (ret T) {
ret.Xor(&a, &b)
return
}
func (a T) Distance(b T) (ret T) {
ret.Xor(&a, &b)
return
}