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package main
import (
"math/big"
"fmt"
"math/rand"
"time"
"github.com/obscuren/sha3"
)
type Dagger struct {
hash *big.Int
xn *big.Int
}
func (dag *Dagger) Search(diff *big.Int) *big.Int {
dag.hash = big.NewInt(0)
obj := BigPow(2, 256)
obj = obj.Div(obj, diff)
fmt.Println("diff", diff, "< objective", obj)
r := rand.New(rand.NewSource(time.Now().UnixNano()))
rnd := big.NewInt(r.Int63())
fmt.Println("init rnd =", rnd)
for i := 0; i < 1000; i++ {
if dag.Eval(rnd).Cmp(obj) < 0 {
fmt.Println("Found result! i = ", i)
return rnd
}
rnd = rnd.Add(rnd, big.NewInt(1))
}
return big.NewInt(0)
}
func (dag *Dagger) Node(L uint64, i uint64) *big.Int {
if L == i {
return dag.hash
}
var m *big.Int
if L == 9 {
m = big.NewInt(16)
} else {
m = big.NewInt(3)
}
sha := sha3.NewKeccak224()
sha.Reset()
d := sha3.NewKeccak224()
b := new(big.Int)
ret := new(big.Int)
for k := 0; k < int(m.Uint64()); k++ {
d.Reset()
d.Write(dag.hash.Bytes())
d.Write(dag.xn.Bytes())
d.Write(big.NewInt(int64(L)).Bytes())
d.Write(big.NewInt(int64(i)).Bytes())
d.Write(big.NewInt(int64(k)).Bytes())
b.SetBytes(d.Sum(nil))
pk := b.Uint64() & ((1 << ((L - 1) * 3)) - 1)
sha.Write(dag.Node(L - 1, pk).Bytes())
}
ret.SetBytes(sha.Sum(nil))
return ret
}
func (dag *Dagger) Eval(N *big.Int) *big.Int {
pow := BigPow(2, 26)
dag.xn = N.Div(N, pow)
sha := sha3.NewKeccak224()
sha.Reset()
ret := new(big.Int)
doneChan := make(chan bool, 3)
for k := 0; k < 4; k++ {
go func(_k int) {
d := sha3.NewKeccak224()
b := new(big.Int)
d.Reset()
d.Write(dag.hash.Bytes())
d.Write(dag.xn.Bytes())
d.Write(N.Bytes())
d.Write(big.NewInt(int64(_k)).Bytes())
b.SetBytes(d.Sum(nil))
pk := (b.Uint64() & 0x1ffffff)
sha.Write(dag.Node(9, pk).Bytes())
doneChan <- true
}(k)
}
for k := 0; k < 4; k++ {
<- doneChan
}
return ret.SetBytes(sha.Sum(nil))
}
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