aboutsummaryrefslogtreecommitdiffstats
path: root/pow/ar/pow.go
diff options
context:
space:
mode:
Diffstat (limited to 'pow/ar/pow.go')
-rw-r--r--pow/ar/pow.go122
1 files changed, 122 insertions, 0 deletions
diff --git a/pow/ar/pow.go b/pow/ar/pow.go
new file mode 100644
index 000000000..8991a674b
--- /dev/null
+++ b/pow/ar/pow.go
@@ -0,0 +1,122 @@
+package ar
+
+import (
+ "math/big"
+
+ "github.com/ethereum/go-ethereum/ethutil"
+)
+
+type Entry struct {
+ op OpsFunc
+ i, j *big.Int
+}
+
+type Tape struct {
+ tape []Entry
+ block Block
+}
+
+func NewTape(block Block) *Tape {
+ return &Tape{nil, block}
+}
+
+func (self *Tape) gen(w, h int64, gen NumberGenerator) {
+ self.tape = nil
+
+ for v := int64(0); v < h; v++ {
+ op := ops[gen.rand64(lenops).Int64()]
+ r := gen.rand64(100).Uint64()
+
+ var j *big.Int
+ if r < 20 && v > 20 {
+ j = self.tape[len(self.tape)-1].i
+ } else {
+ j = gen.rand64(w)
+ }
+
+ i := gen.rand64(w)
+ self.tape = append(self.tape, Entry{op, i, j})
+ }
+}
+
+func (self *Tape) runTape(w, h int64, gen NumberGenerator) *big.Int {
+ var mem []*big.Int
+ for i := int64(0); i < w; i++ {
+ mem = append(mem, gen.rand(ethutil.BigPow(2, 64)))
+ }
+
+ set := func(i, j int) Entry {
+ entry := self.tape[i*100+j]
+ mem[entry.i.Uint64()] = entry.op(entry.i, entry.j)
+
+ return entry
+ }
+
+ dir := true
+ for i := 0; i < int(h)/100; i++ {
+ var entry Entry
+ if dir {
+ for j := 0; j < 100; j++ {
+ entry = set(i, j)
+ }
+ } else {
+ for j := 99; i >= 0; j-- {
+ entry = set(i, j)
+ }
+ }
+
+ t := mem[entry.i.Uint64()]
+ if big.NewInt(2).Cmp(new(big.Int).Mod(t, big.NewInt(37))) < 0 {
+ dir = !dir
+ }
+ }
+
+ return Sha3(mem)
+}
+
+func (self *Tape) Verify(header, nonce []byte) bool {
+ n := ethutil.BigD(nonce)
+
+ var w int64 = 10000
+ var h int64 = 150000
+ gen := Rnd(Sha3([]interface{}{header, new(big.Int).Div(n, big.NewInt(1000))}))
+ self.gen(w, h, gen)
+
+ gen = Rnd(Sha3([]interface{}{header, new(big.Int).Mod(n, big.NewInt(1000))}))
+ hash := self.runTape(w, h, gen)
+
+ it := self.block.Trie().Iterator()
+ next := it.Next(string(new(big.Int).Mod(hash, ethutil.BigPow(2, 160)).Bytes()))
+
+ req := ethutil.BigPow(2, 256)
+ req.Div(req, self.block.Diff())
+ return Sha3([]interface{}{hash, next}).Cmp(req) < 0
+}
+
+func (self *Tape) Run(header []byte) []byte {
+ nonce := big.NewInt(0)
+ var w int64 = 10000
+ var h int64 = 150000
+
+ req := ethutil.BigPow(2, 256)
+ req.Div(req, self.block.Diff())
+
+ for {
+ if new(big.Int).Mod(nonce, b(1000)).Cmp(b(0)) == 0 {
+ gen := Rnd(Sha3([]interface{}{header, new(big.Int).Div(nonce, big.NewInt(1000))}))
+ self.gen(w, h, gen)
+ }
+
+ gen := Rnd(Sha3([]interface{}{header, new(big.Int).Mod(nonce, big.NewInt(1000))}))
+ hash := self.runTape(w, h, gen)
+
+ it := self.block.Trie().Iterator()
+ next := it.Next(string(new(big.Int).Mod(hash, ethutil.BigPow(2, 160)).Bytes()))
+
+ if Sha3([]interface{}{hash, next}).Cmp(req) < 0 {
+ return nonce.Bytes()
+ } else {
+ nonce.Add(nonce, ethutil.Big1)
+ }
+ }
+}