123 lines
2.5 KiB
Go
123 lines
2.5 KiB
Go
package ar
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import (
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"math/big"
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"github.com/ethereum/eth-go/ethutil"
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)
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type Entry struct {
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op OpsFunc
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i, j *big.Int
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}
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type Tape struct {
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tape []Entry
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block Block
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}
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func NewTape(block Block) *Tape {
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return &Tape{nil, block}
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}
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func (self *Tape) gen(w, h int64, gen NumberGenerator) {
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self.tape = nil
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for v := int64(0); v < h; v++ {
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op := ops[gen.rand64(lenops).Int64()]
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r := gen.rand64(100).Uint64()
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var j *big.Int
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if r < 20 && v > 20 {
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j = self.tape[len(self.tape)-1].i
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} else {
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j = gen.rand64(w)
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}
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i := gen.rand64(w)
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self.tape = append(self.tape, Entry{op, i, j})
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}
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}
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func (self *Tape) runTape(w, h int64, gen NumberGenerator) *big.Int {
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var mem []*big.Int
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for i := int64(0); i < w; i++ {
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mem = append(mem, gen.rand(ethutil.BigPow(2, 64)))
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}
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set := func(i, j int) Entry {
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entry := self.tape[i*100+j]
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mem[entry.i.Uint64()] = entry.op(entry.i, entry.j)
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return entry
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}
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dir := true
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for i := 0; i < int(h)/100; i++ {
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var entry Entry
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if dir {
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for j := 0; j < 100; j++ {
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entry = set(i, j)
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}
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} else {
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for j := 99; i >= 0; j-- {
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entry = set(i, j)
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}
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}
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t := mem[entry.i.Uint64()]
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if big.NewInt(2).Cmp(new(big.Int).Mod(t, big.NewInt(37))) < 0 {
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dir = !dir
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}
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}
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return Sha3(mem)
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}
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func (self *Tape) Verify(header, nonce []byte) bool {
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n := ethutil.BigD(nonce)
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var w int64 = 10000
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var h int64 = 150000
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gen := Rnd(Sha3([]interface{}{header, new(big.Int).Div(n, big.NewInt(1000))}))
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self.gen(w, h, gen)
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gen = Rnd(Sha3([]interface{}{header, new(big.Int).Mod(n, big.NewInt(1000))}))
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hash := self.runTape(w, h, gen)
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it := self.block.Trie().Iterator()
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next := it.Next(string(new(big.Int).Mod(hash, ethutil.BigPow(2, 160)).Bytes()))
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req := ethutil.BigPow(2, 256)
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req.Div(req, self.block.Diff())
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return Sha3([]interface{}{hash, next}).Cmp(req) < 0
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}
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func (self *Tape) Run(header []byte) []byte {
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nonce := big.NewInt(0)
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var w int64 = 10000
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var h int64 = 150000
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req := ethutil.BigPow(2, 256)
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req.Div(req, self.block.Diff())
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for {
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if new(big.Int).Mod(nonce, b(1000)).Cmp(b(0)) == 0 {
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gen := Rnd(Sha3([]interface{}{header, new(big.Int).Div(nonce, big.NewInt(1000))}))
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self.gen(w, h, gen)
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}
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gen := Rnd(Sha3([]interface{}{header, new(big.Int).Mod(nonce, big.NewInt(1000))}))
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hash := self.runTape(w, h, gen)
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it := self.block.Trie().Iterator()
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next := it.Next(string(new(big.Int).Mod(hash, ethutil.BigPow(2, 160)).Bytes()))
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if Sha3([]interface{}{hash, next}).Cmp(req) < 0 {
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return nonce.Bytes()
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} else {
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nonce.Add(nonce, ethutil.Big1)
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}
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}
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}
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