|
1
|
|
|
<?php |
|
2
|
|
|
namespace Ackintosh; |
|
3
|
|
|
|
|
4
|
|
|
use Ackintosh\Ganesha\Exception\StorageException; |
|
5
|
|
|
use Ackintosh\Ganesha\StrategyInterface; |
|
6
|
|
|
|
|
7
|
|
|
class Ganesha |
|
8
|
|
|
{ |
|
9
|
|
|
/** |
|
10
|
|
|
* @var string |
|
11
|
|
|
*/ |
|
12
|
|
|
const EVENT_TRIPPED = 'tripped'; |
|
13
|
|
|
|
|
14
|
|
|
/** |
|
15
|
|
|
* @var string |
|
16
|
|
|
*/ |
|
17
|
|
|
const EVENT_CALMED_DOWN = 'calmed_down'; |
|
18
|
|
|
|
|
19
|
|
|
/** |
|
20
|
|
|
* @var string |
|
21
|
|
|
*/ |
|
22
|
|
|
const EVENT_STORAGE_ERROR = 'storage_error'; |
|
23
|
|
|
|
|
24
|
|
|
/** |
|
25
|
|
|
* the status between failure count 0 and trip. |
|
26
|
|
|
* @var int |
|
27
|
|
|
*/ |
|
28
|
|
|
const STATUS_CALMED_DOWN = 1; |
|
29
|
|
|
|
|
30
|
|
|
/** |
|
31
|
|
|
* the status between trip and calm down. |
|
32
|
|
|
* @var int |
|
33
|
|
|
*/ |
|
34
|
|
|
const STATUS_TRIPPED = 2; |
|
35
|
|
|
|
|
36
|
|
|
/** |
|
37
|
|
|
* @var StrategyInterface |
|
38
|
|
|
*/ |
|
39
|
|
|
private $strategy; |
|
40
|
|
|
|
|
41
|
|
|
/** |
|
42
|
|
|
* @var callable[] |
|
43
|
|
|
*/ |
|
44
|
|
|
private $subscribers = []; |
|
45
|
|
|
|
|
46
|
|
|
/** |
|
47
|
|
|
* @var bool |
|
48
|
|
|
*/ |
|
49
|
|
|
private static $disabled = false; |
|
50
|
|
|
|
|
51
|
|
|
/** |
|
52
|
|
|
* Ganesha constructor. |
|
53
|
|
|
* |
|
54
|
|
|
* @param StrategyInterface $strategy |
|
55
|
|
|
*/ |
|
56
|
|
|
public function __construct($strategy) |
|
57
|
|
|
{ |
|
58
|
|
|
$this->strategy = $strategy; |
|
59
|
|
|
} |
|
60
|
|
|
|
|
61
|
|
|
/** |
|
62
|
|
|
* records failure |
|
63
|
|
|
* |
|
64
|
|
|
* @param string $service |
|
65
|
|
|
* @return void |
|
66
|
|
|
*/ |
|
67
|
|
|
public function failure($service): void |
|
68
|
|
|
{ |
|
69
|
|
|
try { |
|
70
|
|
|
if ($this->strategy->recordFailure($service) === self::STATUS_TRIPPED) { |
|
71
|
|
|
$this->notify(self::EVENT_TRIPPED, $service, ''); |
|
72
|
|
|
} |
|
73
|
|
|
} catch (StorageException $e) { |
|
74
|
|
|
$this->notify(self::EVENT_STORAGE_ERROR, $service, 'failed to record failure : ' . $e->getMessage()); |
|
75
|
|
|
} |
|
76
|
|
|
} |
|
77
|
|
|
|
|
78
|
|
|
/** |
|
79
|
|
|
* records success |
|
80
|
|
|
* |
|
81
|
|
|
* @param string $service |
|
82
|
|
|
* @return void |
|
83
|
|
|
*/ |
|
84
|
|
|
public function success($service): void |
|
85
|
|
|
{ |
|
86
|
|
|
try { |
|
87
|
|
|
if ($this->strategy->recordSuccess($service) === self::STATUS_CALMED_DOWN) { |
|
88
|
|
|
$this->notify(self::EVENT_CALMED_DOWN, $service, ''); |
|
89
|
|
|
} |
|
90
|
|
|
} catch (StorageException $e) { |
|
91
|
|
|
$this->notify(self::EVENT_STORAGE_ERROR, $service, 'failed to record success : ' . $e->getMessage()); |
|
92
|
|
|
} |
|
93
|
|
|
} |
|
94
|
|
|
|
|
95
|
|
|
/** |
|
96
|
|
|
* @param string $service |
|
97
|
|
|
* @return bool |
|
98
|
|
|
*/ |
|
99
|
|
|
public function isAvailable($service): bool |
|
100
|
|
|
{ |
|
101
|
|
|
if (self::$disabled) { |
|
102
|
|
|
return true; |
|
103
|
|
|
} |
|
104
|
|
|
|
|
105
|
|
|
try { |
|
106
|
|
|
return $this->strategy->isAvailable($service); |
|
107
|
|
|
} catch (StorageException $e) { |
|
108
|
|
|
$this->notify(self::EVENT_STORAGE_ERROR, $service, 'failed to isAvailable : ' . $e->getMessage()); |
|
109
|
|
|
// fail-silent |
|
110
|
|
|
return true; |
|
111
|
|
|
} |
|
112
|
|
|
} |
|
113
|
|
|
|
|
114
|
|
|
/** |
|
115
|
|
|
* @param callable $callable |
|
116
|
|
|
* @return void |
|
117
|
|
|
*/ |
|
118
|
|
|
public function subscribe(callable $callable): void |
|
119
|
|
|
{ |
|
120
|
|
|
$this->subscribers[] = $callable; |
|
121
|
|
|
} |
|
122
|
|
|
|
|
123
|
|
|
/** |
|
124
|
|
|
* @param string $event |
|
125
|
|
|
* @param string $service |
|
126
|
|
|
* @param string $message |
|
127
|
|
|
* @return void |
|
128
|
|
|
*/ |
|
129
|
|
|
private function notify(string $event, string $service, string $message): void |
|
130
|
|
|
{ |
|
131
|
|
|
foreach ($this->subscribers as $s) { |
|
132
|
|
|
call_user_func_array($s, [$event, $service, $message]); |
|
133
|
|
|
} |
|
134
|
|
|
} |
|
135
|
|
|
|
|
136
|
|
|
/** |
|
137
|
|
|
* disable |
|
138
|
|
|
* |
|
139
|
|
|
* @return void |
|
140
|
|
|
*/ |
|
141
|
|
|
public static function disable(): void |
|
142
|
|
|
{ |
|
143
|
|
|
self::$disabled = true; |
|
144
|
|
|
} |
|
145
|
|
|
|
|
146
|
|
|
/** |
|
147
|
|
|
* enable |
|
148
|
|
|
* |
|
149
|
|
|
* @return void |
|
150
|
|
|
*/ |
|
151
|
|
|
public static function enable(): void |
|
152
|
|
|
{ |
|
153
|
|
|
self::$disabled = false; |
|
154
|
|
|
} |
|
155
|
|
|
|
|
156
|
|
|
/** |
|
157
|
|
|
* resets all counts |
|
158
|
|
|
* |
|
159
|
|
|
* @return void |
|
160
|
|
|
*/ |
|
161
|
|
|
public function reset(): void |
|
162
|
|
|
{ |
|
163
|
|
|
$this->strategy->reset(); |
|
164
|
|
|
} |
|
165
|
|
|
} |
|
166
|
|
|
|
ackintosh /
ganesha
