|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
namespace SchulzeFelix\Stat; |
|
4
|
|
|
|
|
5
|
|
|
/** |
|
6
|
|
|
* Exponential backoff implementation. |
|
7
|
|
|
*/ |
|
8
|
|
|
class ExponentialBackoff |
|
9
|
|
|
{ |
|
10
|
|
|
const MAX_DELAY_MICROSECONDS = 30000000; |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* @var int |
|
14
|
|
|
*/ |
|
15
|
|
|
private $retries; |
|
16
|
|
|
|
|
17
|
|
|
/** |
|
18
|
|
|
* @var callable |
|
19
|
|
|
*/ |
|
20
|
|
|
private $retryFunction; |
|
21
|
|
|
|
|
22
|
|
|
/** |
|
23
|
|
|
* @var callable |
|
24
|
|
|
*/ |
|
25
|
|
|
private $delayFunction; |
|
26
|
|
|
|
|
27
|
|
|
/** |
|
28
|
|
|
* @param int $retries [optional] Number of retries for a failed request. |
|
29
|
|
|
* @param callable $retryFunction [optional] returns bool for whether or not to retry |
|
30
|
|
|
*/ |
|
31
|
|
|
public function __construct($retries = null, callable $retryFunction = null) |
|
32
|
|
|
{ |
|
33
|
|
|
$this->retries = $retries !== null ? (int) $retries : 3; |
|
34
|
|
|
$this->retryFunction = $retryFunction; |
|
35
|
|
|
$this->delayFunction = function ($delay) { |
|
36
|
|
|
usleep($delay); |
|
37
|
|
|
}; |
|
38
|
|
|
} |
|
39
|
|
|
|
|
40
|
|
|
/** |
|
41
|
|
|
* Executes the retry process. |
|
42
|
|
|
* |
|
43
|
|
|
* @param callable $function |
|
44
|
|
|
* @param array $arguments [optional] |
|
45
|
|
|
* @return mixed |
|
46
|
|
|
* @throws \Exception The last exception caught while retrying. |
|
47
|
|
|
*/ |
|
48
|
|
|
public function execute(callable $function, array $arguments = []) |
|
49
|
|
|
{ |
|
50
|
|
|
$delayFunction = $this->delayFunction; |
|
51
|
|
|
$retryAttempt = 0; |
|
52
|
|
|
$exception = null; |
|
53
|
|
|
|
|
54
|
|
|
while (true) { |
|
55
|
|
|
try { |
|
56
|
|
|
return call_user_func_array($function, $arguments); |
|
57
|
|
|
} catch (\Exception $exception) { |
|
58
|
|
|
if ($this->retryFunction) { |
|
59
|
|
|
if (! call_user_func($this->retryFunction, $exception)) { |
|
60
|
|
|
throw $exception; |
|
61
|
|
|
} |
|
62
|
|
|
} |
|
63
|
|
|
|
|
64
|
|
|
if($exception->getCode() !== 429) { |
|
65
|
|
|
break; |
|
66
|
|
|
} |
|
67
|
|
|
|
|
68
|
|
|
if ($retryAttempt >= $this->retries) { |
|
69
|
|
|
break; |
|
70
|
|
|
} |
|
71
|
|
|
|
|
72
|
|
|
$delayFunction($this->calculateDelay($retryAttempt)); |
|
73
|
|
|
$retryAttempt++; |
|
74
|
|
|
} |
|
75
|
|
|
} |
|
76
|
|
|
|
|
77
|
|
|
throw $exception; |
|
78
|
|
|
} |
|
79
|
|
|
|
|
80
|
|
|
/** |
|
81
|
|
|
* @param callable $delayFunction |
|
82
|
|
|
* @return void |
|
83
|
|
|
*/ |
|
84
|
|
|
public function setDelayFunction(callable $delayFunction) |
|
85
|
|
|
{ |
|
86
|
|
|
$this->delayFunction = $delayFunction; |
|
87
|
|
|
} |
|
88
|
|
|
|
|
89
|
|
|
/** |
|
90
|
|
|
* Calculates exponential delay. |
|
91
|
|
|
* |
|
92
|
|
|
* @param int $attempt |
|
93
|
|
|
* @return int |
|
94
|
|
|
*/ |
|
95
|
|
|
private function calculateDelay($attempt) |
|
96
|
|
|
{ |
|
97
|
|
|
return min( |
|
98
|
|
|
mt_rand(0, 1000000) + (pow(2, $attempt) * 1000000), |
|
99
|
|
|
self::MAX_DELAY_MICROSECONDS |
|
100
|
|
|
); |
|
101
|
|
|
} |
|
102
|
|
|
} |
|
103
|
|
|
|