|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
/* |
|
4
|
|
|
* This file is part of the circuit-breaker package |
|
5
|
|
|
* |
|
6
|
|
|
* Copyright (c) 2016 Guillaume Cavana |
|
7
|
|
|
* |
|
8
|
|
|
* For the full copyright and license information, please view the LICENSE |
|
9
|
|
|
* file that was distributed with this source code. |
|
10
|
|
|
* |
|
11
|
|
|
* Feel free to edit as you please, and have fun. |
|
12
|
|
|
* |
|
13
|
|
|
* @author Guillaume Cavana <[email protected]> |
|
14
|
|
|
*/ |
|
15
|
|
|
|
|
16
|
|
|
namespace Eljam\CircuitBreaker; |
|
17
|
|
|
|
|
18
|
|
|
use Doctrine\Common\Cache\ArrayCache; |
|
19
|
|
|
use Doctrine\Common\Cache\Cache; |
|
20
|
|
|
use Eljam\CircuitBreaker\Event\CircuitEvent; |
|
21
|
|
|
use Eljam\CircuitBreaker\Event\CircuitEvents; |
|
22
|
|
|
use Eljam\CircuitBreaker\Exception\CircuitOpenException; |
|
23
|
|
|
use Eljam\CircuitBreaker\Handler\Handler; |
|
24
|
|
|
use Eljam\CircuitBreaker\Handler\HandlerInterface; |
|
25
|
|
|
use Eljam\CircuitBreaker\Util\Utils; |
|
26
|
|
|
use Symfony\Component\EventDispatcher\EventDispatcher; |
|
27
|
|
|
use Symfony\Component\EventDispatcher\EventDispatcherInterface; |
|
28
|
|
|
use Symfony\Component\OptionsResolver\OptionsResolver; |
|
29
|
|
|
|
|
30
|
|
|
/** |
|
31
|
|
|
* Class Breaker. |
|
32
|
|
|
*/ |
|
33
|
|
|
class Breaker |
|
34
|
|
|
{ |
|
35
|
|
|
/** |
|
36
|
|
|
* $cache. |
|
37
|
|
|
* |
|
38
|
|
|
* @var Cache |
|
39
|
|
|
*/ |
|
40
|
|
|
protected $store; |
|
41
|
|
|
|
|
42
|
|
|
/** |
|
43
|
|
|
* $config. |
|
44
|
|
|
* |
|
45
|
|
|
* @var array |
|
46
|
|
|
*/ |
|
47
|
|
|
protected $config; |
|
48
|
|
|
|
|
49
|
|
|
/** |
|
50
|
|
|
* $handler. |
|
51
|
|
|
* |
|
52
|
|
|
* @var HandlerInterface |
|
53
|
|
|
*/ |
|
54
|
|
|
protected $handler; |
|
55
|
|
|
|
|
56
|
|
|
/** |
|
57
|
|
|
* $dispatcher. |
|
58
|
|
|
* |
|
59
|
|
|
* @var EventDispatcherInterface |
|
60
|
|
|
*/ |
|
61
|
|
|
protected $dispatcher; |
|
62
|
|
|
|
|
63
|
|
|
/** |
|
64
|
|
|
* Constructor. |
|
65
|
|
|
* |
|
66
|
|
|
* @param string $name |
|
67
|
|
|
* @param array $config |
|
68
|
|
|
* @param Cache $store |
|
69
|
|
|
* @param Handler $handler |
|
70
|
|
|
* @param EventDispatcherInterface $dispatcher |
|
71
|
|
|
*/ |
|
72
|
|
|
public function __construct( |
|
73
|
|
|
$name, |
|
74
|
|
|
array $config = [], |
|
75
|
|
|
Cache $store = null, |
|
76
|
|
|
HandlerInterface $handler = null, |
|
77
|
|
|
EventDispatcherInterface $dispatcher = null |
|
78
|
|
|
) { |
|
79
|
|
|
$resolver = new OptionsResolver(); |
|
80
|
|
|
$resolver->setDefaults([ |
|
81
|
|
|
'max_failure' => 5, |
|
82
|
|
|
'reset_timeout' => 5, |
|
83
|
|
|
'exclude_exceptions' => [], |
|
84
|
|
|
'ignore_exceptions' => false, |
|
85
|
|
|
]); |
|
86
|
|
|
|
|
87
|
|
|
$resolver->setAllowedTypes('exclude_exceptions', 'array'); |
|
88
|
|
|
$resolver->setAllowedTypes('max_failure', 'int'); |
|
89
|
|
|
$resolver->setAllowedTypes('reset_timeout', 'int'); |
|
90
|
|
|
|
|
91
|
|
|
$this->config = $resolver->resolve($config); |
|
92
|
|
|
$this->store = null !== $store ? $store : (new ArrayCache()); |
|
93
|
|
|
$this->handler = null !== $handler ? $handler($this->config) : new Handler($this->config); |
|
94
|
|
|
$this->dispatcher = null !== $dispatcher ? $dispatcher : new EventDispatcher(); |
|
95
|
|
|
$name = Utils::snakeCase($name); |
|
96
|
|
|
$this->circuit = $this->loadCircuit($name); |
|
|
|
|
|
|
97
|
|
|
} |
|
98
|
|
|
|
|
99
|
|
|
/** |
|
100
|
|
|
* protect. |
|
101
|
|
|
* |
|
102
|
|
|
* @param \Closure $closure |
|
103
|
|
|
* @throw \Exception |
|
104
|
|
|
* |
|
105
|
|
|
* @return mixed |
|
106
|
|
|
*/ |
|
107
|
|
|
public function protect(\Closure $closure) |
|
108
|
|
|
{ |
|
109
|
|
|
try { |
|
110
|
|
|
$result = null; |
|
111
|
|
|
$circuitOpenException = null; |
|
112
|
|
|
|
|
113
|
|
|
if ($this->isClosed($this->circuit) || $this->isHalfOpen($this->circuit)) { |
|
114
|
|
|
$result = $closure(); |
|
115
|
|
|
$this->success($this->circuit); |
|
116
|
|
|
} elseif ($this->isOpen($this->circuit)) { |
|
117
|
|
|
$circuitOpenException = new CircuitOpenException(); |
|
118
|
|
|
} |
|
119
|
|
|
} catch (\Exception $e) { |
|
120
|
|
|
$this->failure($this->circuit); |
|
121
|
|
|
|
|
122
|
|
|
if (!$this->config['ignore_exceptions']) { |
|
123
|
|
|
if (!in_array(get_class($e), $this->config['exclude_exceptions'])) { |
|
124
|
|
|
$result = $e; |
|
125
|
|
|
} |
|
126
|
|
|
} |
|
127
|
|
|
} |
|
128
|
|
|
|
|
129
|
|
|
// Throw circuit exception when it is opened |
|
130
|
|
|
if (null !== $circuitOpenException) { |
|
131
|
|
|
throw $circuitOpenException; |
|
132
|
|
|
} |
|
133
|
|
|
|
|
134
|
|
|
//Throw closure exception |
|
135
|
|
|
if ($result instanceof \Exception) { |
|
136
|
|
|
throw $result; |
|
137
|
|
|
} |
|
138
|
|
|
|
|
139
|
|
|
return $result; |
|
140
|
|
|
} |
|
141
|
|
|
|
|
142
|
|
|
/** |
|
143
|
|
|
* addListener. |
|
144
|
|
|
* |
|
145
|
|
|
* @param string $eventName |
|
146
|
|
|
* @param \Closure|array $listener |
|
147
|
|
|
*/ |
|
148
|
|
|
public function addListener($eventName, $listener) |
|
149
|
|
|
{ |
|
150
|
|
|
$this->dispatcher->addListener($eventName, $listener); |
|
151
|
|
|
} |
|
152
|
|
|
|
|
153
|
|
|
/** |
|
154
|
|
|
* isClosed. |
|
155
|
|
|
* |
|
156
|
|
|
* @param Circuit $circuit |
|
157
|
|
|
* |
|
158
|
|
|
* @return bool |
|
159
|
|
|
*/ |
|
160
|
|
View Code Duplication |
protected function isClosed($circuit) |
|
|
|
|
|
|
161
|
|
|
{ |
|
162
|
|
|
if ($this->handler->isClosed($circuit)) { |
|
|
|
|
|
|
163
|
|
|
$this->dispatcher->dispatch(CircuitEvents::CLOSED, (new CircuitEvent($circuit))); |
|
164
|
|
|
|
|
165
|
|
|
return true; |
|
166
|
|
|
} |
|
167
|
|
|
|
|
168
|
|
|
return; |
|
169
|
|
|
} |
|
170
|
|
|
|
|
171
|
|
|
/** |
|
172
|
|
|
* isOpen. |
|
173
|
|
|
* |
|
174
|
|
|
* @param Circuit $circuit |
|
175
|
|
|
* |
|
176
|
|
|
* @return bool |
|
177
|
|
|
*/ |
|
178
|
|
View Code Duplication |
protected function isOpen($circuit) |
|
|
|
|
|
|
179
|
|
|
{ |
|
180
|
|
|
if ($this->handler->isOpen($circuit)) { |
|
|
|
|
|
|
181
|
|
|
$this->dispatcher->dispatch(CircuitEvents::OPEN, (new CircuitEvent($circuit))); |
|
182
|
|
|
|
|
183
|
|
|
return true; |
|
184
|
|
|
} |
|
185
|
|
|
|
|
186
|
|
|
return; |
|
187
|
|
|
} |
|
188
|
|
|
|
|
189
|
|
|
/** |
|
190
|
|
|
* isHalfOpen. |
|
191
|
|
|
* |
|
192
|
|
|
* @param Circuit $circuit |
|
193
|
|
|
* |
|
194
|
|
|
* @return bool |
|
195
|
|
|
*/ |
|
196
|
|
View Code Duplication |
protected function isHalfOpen($circuit) |
|
|
|
|
|
|
197
|
|
|
{ |
|
198
|
|
|
if ($this->handler->isHalfOpen($circuit)) { |
|
|
|
|
|
|
199
|
|
|
$this->dispatcher->dispatch(CircuitEvents::HALF_OPEN, (new CircuitEvent($circuit))); |
|
200
|
|
|
|
|
201
|
|
|
return true; |
|
202
|
|
|
} |
|
203
|
|
|
|
|
204
|
|
|
return; |
|
205
|
|
|
} |
|
206
|
|
|
|
|
207
|
|
|
/** |
|
208
|
|
|
* success. |
|
209
|
|
|
* |
|
210
|
|
|
* @param Circuit $circuit |
|
211
|
|
|
*/ |
|
212
|
|
|
protected function success($circuit) |
|
213
|
|
|
{ |
|
214
|
|
|
$circuit->resetFailture(); |
|
215
|
|
|
|
|
216
|
|
|
$this->dispatcher->dispatch(CircuitEvents::SUCCESS, (new CircuitEvent($circuit))); |
|
217
|
|
|
$this->writeToStore($circuit); |
|
218
|
|
|
} |
|
219
|
|
|
|
|
220
|
|
|
/** |
|
221
|
|
|
* failure. |
|
222
|
|
|
* |
|
223
|
|
|
* @param Circuit $circuit |
|
224
|
|
|
*/ |
|
225
|
|
|
protected function failure(Circuit $circuit) |
|
226
|
|
|
{ |
|
227
|
|
|
$circuit->incrementFailure(); |
|
228
|
|
|
$circuit->setLastFailure(time()); |
|
229
|
|
|
|
|
230
|
|
|
$this->dispatcher->dispatch(CircuitEvents::FAILURE, (new CircuitEvent($circuit))); |
|
231
|
|
|
$this->writeToStore($circuit); |
|
232
|
|
|
} |
|
233
|
|
|
|
|
234
|
|
|
/** |
|
235
|
|
|
* loadCircuit. |
|
236
|
|
|
* |
|
237
|
|
|
* @param string $name |
|
238
|
|
|
* |
|
239
|
|
|
* @return Circuit |
|
240
|
|
|
*/ |
|
241
|
|
|
protected function loadCircuit($name) |
|
242
|
|
|
{ |
|
243
|
|
|
if ($this->store->contains($name)) { |
|
244
|
|
|
$circuit = $this->store->fetch($name); |
|
245
|
|
|
} else { |
|
246
|
|
|
$circuit = new Circuit($name); |
|
247
|
|
|
} |
|
248
|
|
|
|
|
249
|
|
|
$this->writeToStore($circuit); |
|
250
|
|
|
|
|
251
|
|
|
return $circuit; |
|
252
|
|
|
} |
|
253
|
|
|
|
|
254
|
|
|
protected function writeToStore(Circuit $circuit) |
|
255
|
|
|
{ |
|
256
|
|
|
$this->store->save($circuit->getName(), $circuit); |
|
257
|
|
|
} |
|
258
|
|
|
} |
|
259
|
|
|
|
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: