1 files changed, 66 insertions, 0 deletions
diff --git a/pow/ar/rnd.go b/pow/ar/rnd.go
new file mode 100644
index 000000000..7dbd99373
--- /dev/null
+++ b/pow/ar/rnd.go
@@ -0,0 +1,66 @@
+package ar
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/ethcrypto"
+	"github.com/ethereum/go-ethereum/ethutil"
+)
+
+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))
+}