1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
package ar
import (
"math/big"
"github.com/ethereum/eth-go/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)
}
}
}
|
