|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
declare(strict_types=1); |
|
4
|
|
|
|
|
5
|
|
|
namespace BitWasp\Bitcoin\Chain; |
|
6
|
|
|
|
|
7
|
|
|
use BitWasp\Bitcoin\Block\BlockHeaderInterface; |
|
8
|
|
|
use BitWasp\Bitcoin\Math\Math; |
|
9
|
|
|
use BitWasp\Buffertools\Buffer; |
|
10
|
|
|
use BitWasp\Buffertools\BufferInterface; |
|
11
|
|
|
|
|
12
|
|
|
class ProofOfWork |
|
13
|
|
|
{ |
|
14
|
|
|
const DIFF_PRECISION = 12; |
|
15
|
|
|
const POW_2_256 = '115792089237316195423570985008687907853269984665640564039457584007913129639936'; |
|
16
|
|
|
|
|
17
|
|
|
/** |
|
18
|
|
|
* @var Math |
|
19
|
|
|
*/ |
|
20
|
|
|
private $math; |
|
21
|
|
|
|
|
22
|
|
|
/** |
|
23
|
|
|
* @var ParamsInterface |
|
24
|
|
|
*/ |
|
25
|
|
|
private $params; |
|
26
|
|
|
|
|
27
|
|
|
/** |
|
28
|
|
|
* @param Math $math |
|
29
|
|
|
* @param ParamsInterface $params |
|
30
|
|
|
*/ |
|
31
|
4 |
|
public function __construct(Math $math, ParamsInterface $params) |
|
32
|
|
|
{ |
|
33
|
4 |
|
$this->math = $math; |
|
34
|
4 |
|
$this->params = $params; |
|
35
|
4 |
|
} |
|
36
|
|
|
|
|
37
|
|
|
/** |
|
38
|
|
|
* @param int $bits |
|
39
|
|
|
* @return \GMP |
|
40
|
|
|
*/ |
|
41
|
190 |
|
public function getTarget(int $bits): \GMP |
|
42
|
|
|
{ |
|
43
|
190 |
|
$negative = false; |
|
44
|
190 |
|
$overflow = false; |
|
45
|
190 |
|
return $this->math->decodeCompact($bits, $negative, $overflow); |
|
46
|
|
|
} |
|
47
|
|
|
|
|
48
|
|
|
/** |
|
49
|
|
|
* @return \GMP |
|
50
|
|
|
*/ |
|
51
|
189 |
|
public function getMaxTarget(): \GMP |
|
52
|
|
|
{ |
|
53
|
189 |
|
return $this->getTarget($this->params->powBitsLimit()); |
|
54
|
|
|
} |
|
55
|
|
|
|
|
56
|
|
|
/** |
|
57
|
|
|
* @param int $bits |
|
58
|
|
|
* @return BufferInterface |
|
59
|
|
|
*/ |
|
60
|
1 |
|
public function getTargetHash(int $bits): BufferInterface |
|
61
|
|
|
{ |
|
62
|
1 |
|
return Buffer::int(gmp_strval($this->getTarget($bits), 10), 32); |
|
63
|
|
|
} |
|
64
|
|
|
|
|
65
|
|
|
/** |
|
66
|
|
|
* @param int $bits |
|
67
|
|
|
* @return string |
|
68
|
|
|
*/ |
|
69
|
1 |
|
public function getDifficulty(int $bits): string |
|
70
|
|
|
{ |
|
71
|
1 |
|
$target = $this->getTarget($bits); |
|
72
|
1 |
|
$lowest = $this->getMaxTarget(); |
|
73
|
1 |
|
$lowest = $this->math->mul($lowest, $this->math->pow(gmp_init(10, 10), self::DIFF_PRECISION)); |
|
74
|
|
|
|
|
75
|
1 |
|
$difficulty = str_pad($this->math->toString($this->math->div($lowest, $target)), self::DIFF_PRECISION + 1, '0', STR_PAD_LEFT); |
|
76
|
|
|
|
|
77
|
1 |
|
$intPart = substr($difficulty, 0, 0 - self::DIFF_PRECISION); |
|
78
|
1 |
|
$decPart = substr($difficulty, 0 - self::DIFF_PRECISION, self::DIFF_PRECISION); |
|
79
|
|
|
|
|
80
|
1 |
|
return $intPart . '.' . $decPart; |
|
81
|
|
|
} |
|
82
|
|
|
|
|
83
|
|
|
/** |
|
84
|
|
|
* @param BufferInterface $hash |
|
85
|
|
|
* @param int $nBits |
|
86
|
|
|
* @return bool |
|
87
|
|
|
*/ |
|
88
|
189 |
|
public function checkPow(BufferInterface $hash, int $nBits): bool |
|
89
|
|
|
{ |
|
90
|
189 |
|
$negative = false; |
|
91
|
189 |
|
$overflow = false; |
|
92
|
|
|
|
|
93
|
189 |
|
$target = $this->math->decodeCompact($nBits, $negative, $overflow); |
|
94
|
189 |
|
if ($negative || $overflow || $this->math->cmp($target, gmp_init(0)) === 0 || $this->math->cmp($target, $this->getMaxTarget()) > 0) { |
|
|
|
|
|
|
95
|
1 |
|
throw new \RuntimeException('nBits below minimum work'); |
|
96
|
|
|
} |
|
97
|
|
|
|
|
98
|
188 |
|
if ($this->math->cmp($hash->getGmp(), $target) > 0) { |
|
99
|
1 |
|
return false; |
|
100
|
|
|
} |
|
101
|
|
|
|
|
102
|
187 |
|
return true; |
|
103
|
|
|
} |
|
104
|
|
|
|
|
105
|
|
|
/** |
|
106
|
|
|
* @param BlockHeaderInterface $header |
|
107
|
|
|
* @return bool |
|
108
|
|
|
* @throws \Exception |
|
109
|
|
|
*/ |
|
110
|
187 |
|
public function checkHeader(BlockHeaderInterface $header): bool |
|
111
|
|
|
{ |
|
112
|
187 |
|
return $this->checkPow($header->getHash(), $header->getBits()); |
|
113
|
|
|
} |
|
114
|
|
|
|
|
115
|
|
|
/** |
|
116
|
|
|
* @param int $bits |
|
117
|
|
|
* @return \GMP |
|
118
|
|
|
*/ |
|
119
|
1 |
|
public function getWork(int $bits): \GMP |
|
120
|
|
|
{ |
|
121
|
1 |
|
$target = gmp_strval($this->getTarget($bits), 10); |
|
122
|
1 |
|
return gmp_init(bcdiv(self::POW_2_256, $target), 10); |
|
123
|
|
|
} |
|
124
|
|
|
} |
|
125
|
|
|
|
Bit-Wasp /
bitcoin-php
Loading history...