reflector.go/dht/bitmap.go

135 lines
2.3 KiB
Go

package dht
import (
"crypto/rand"
"encoding/hex"
"github.com/lbryio/errors.go"
"github.com/lyoshenka/bencode"
)
type Bitmap [nodeIDLength]byte
func (b Bitmap) RawString() string {
return string(b[:])
}
func (b Bitmap) Hex() string {
return hex.EncodeToString(b[:])
}
func (b Bitmap) HexShort() string {
return hex.EncodeToString(b[:4])
}
func (b Bitmap) Equals(other Bitmap) bool {
for k := range b {
if b[k] != other[k] {
return false
}
}
return true
}
func (b Bitmap) Less(other interface{}) bool {
for k := range b {
if b[k] != other.(Bitmap)[k] {
return b[k] < other.(Bitmap)[k]
}
}
return false
}
func (b Bitmap) Xor(other Bitmap) Bitmap {
var ret Bitmap
for k := range b {
ret[k] = b[k] ^ other[k]
}
return ret
}
// PrefixLen returns the number of leading 0 bits
func (b Bitmap) PrefixLen() int {
for i := range b {
for j := 0; j < 8; j++ {
if (b[i]>>uint8(7-j))&0x1 != 0 {
return i*8 + j
}
}
}
return numBuckets
}
func (b Bitmap) MarshalBencode() ([]byte, error) {
str := string(b[:])
return bencode.EncodeBytes(str)
}
func (b *Bitmap) UnmarshalBencode(encoded []byte) error {
var str string
err := bencode.DecodeBytes(encoded, &str)
if err != nil {
return err
}
if len(str) != nodeIDLength {
return errors.Err("invalid bitmap length")
}
copy(b[:], str)
return nil
}
func BitmapFromBytes(data []byte) (Bitmap, error) {
var bmp Bitmap
if len(data) != len(bmp) {
return bmp, errors.Err("invalid bitmap of length %d", len(data))
}
copy(bmp[:], data)
return bmp, nil
}
func BitmapFromBytesP(data []byte) Bitmap {
bmp, err := BitmapFromBytes(data)
if err != nil {
panic(err)
}
return bmp
}
func BitmapFromString(data string) (Bitmap, error) {
return BitmapFromBytes([]byte(data))
}
func BitmapFromStringP(data string) Bitmap {
bmp, err := BitmapFromString(data)
if err != nil {
panic(err)
}
return bmp
}
func BitmapFromHex(hexStr string) (Bitmap, error) {
decoded, err := hex.DecodeString(hexStr)
if err != nil {
return Bitmap{}, errors.Err(err)
}
return BitmapFromBytes(decoded)
}
func BitmapFromHexP(hexStr string) Bitmap {
bmp, err := BitmapFromHex(hexStr)
if err != nil {
panic(err)
}
return bmp
}
func RandomBitmapP() Bitmap {
var id Bitmap
_, err := rand.Read(id[:])
if err != nil {
panic(err)
}
return id
}