plugeth/pow/ar/rnd.go

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2014-10-10 20:44:20 +00:00
package ar
import (
"math/big"
"github.com/ethereum/go-ethereum/ethcrypto"
"github.com/ethereum/go-ethereum/ethutil"
2014-10-10 20:44:20 +00:00
)
var b = big.NewInt
type Node interface {
Big() *big.Int
}
type ByteNode []byte
func (self ByteNode) Big() *big.Int {
return ethutil.BigD(ethutil.Encode([]byte(self)))
}
func Sha3(v interface{}) *big.Int {
if b, ok := v.(*big.Int); ok {
return ethutil.BigD(ethcrypto.Sha3(b.Bytes()))
} else if b, ok := v.([]interface{}); ok {
return ethutil.BigD(ethcrypto.Sha3(ethutil.Encode(b)))
} else if s, ok := v.([]*big.Int); ok {
v := make([]interface{}, len(s))
for i, b := range s {
v[i] = b
}
return ethutil.BigD(ethcrypto.Sha3(ethutil.Encode(v)))
}
return nil
}
type NumberGenerator interface {
rand(r *big.Int) *big.Int
rand64(r int64) *big.Int
}
type rnd struct {
seed *big.Int
}
func Rnd(s *big.Int) rnd {
return rnd{s}
}
func (self rnd) rand(r *big.Int) *big.Int {
o := b(0).Mod(self.seed, r)
self.seed.Div(self.seed, r)
if self.seed.Cmp(ethutil.BigPow(2, 64)) < 0 {
self.seed = Sha3(self.seed)
}
return o
}
func (self rnd) rand64(r int64) *big.Int {
return self.rand(b(r))
}