Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Queue often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Queue, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
48 | class Queue implements QueueInterface |
||
49 | { |
||
50 | |||
51 | const PRIORITY_HIGH = 'high'; |
||
52 | const PRIORITY_LOW = 'low'; |
||
53 | |||
54 | const NS_QUEUE = 'queue'; |
||
55 | const NS_QUEUE_STOP = 'queue2stop'; |
||
56 | const NS_MESSAGE = 'message'; |
||
57 | const NS_MESSAGE_TO_QUEUE = 'message2queue'; |
||
58 | const NS_MESSAGE_TO_STATE = 'message2state'; |
||
59 | |||
60 | // State |
||
61 | const STATE_READY = 'ready'; |
||
62 | const STATE_DELAYED = 'delayed'; |
||
63 | const STATE_RESERVED = 'reserved'; |
||
64 | const STATE_BURIED = 'buried'; |
||
65 | |||
66 | // Stats |
||
67 | const STATS_QUEUES_LIST = 'queues'; |
||
68 | const STATS_QUEUES = 'queues'; |
||
69 | const STATS_MESSAGE_TOTAL = 'total'; |
||
70 | const STATS_MESSAGE_READY = 'ready'; |
||
71 | const STATS_MESSAGE_RESERVED = 'reserved'; |
||
72 | const STATS_MESSAGE_DELAYED = 'delayed'; |
||
73 | const STATS_MESSAGE_BURIED = 'buried'; |
||
74 | const STATS_QUEUE_STOP = 'stop'; |
||
75 | |||
76 | /** |
||
77 | * @var \Predis\Client |
||
78 | */ |
||
79 | protected $redis; |
||
80 | |||
81 | /** |
||
82 | * @var string |
||
83 | */ |
||
84 | protected $namespace; |
||
85 | |||
86 | /** |
||
87 | * Queue constructor. |
||
88 | * |
||
89 | * @param mixed $redis |
||
90 | * @param string $namespace |
||
91 | */ |
||
92 | 35 | public function __construct($redis, $namespace = 'Quedis') |
|
97 | |||
98 | /** |
||
99 | * @return \Predis\Client |
||
100 | */ |
||
101 | 35 | public function getRedis() |
|
105 | |||
106 | /** |
||
107 | * @return string |
||
108 | */ |
||
109 | 1 | public function getNamespace() |
|
113 | |||
114 | /** |
||
115 | * @param string $queue |
||
116 | * @param mixed $data |
||
117 | * @param int $delay |
||
118 | * @param string $priority |
||
119 | * |
||
120 | * @return MessageInterface |
||
121 | * @throws \Exception |
||
122 | */ |
||
123 | 28 | public function put($queue, $data, $delay = 0, $priority = self::PRIORITY_LOW) |
|
152 | |||
153 | /** |
||
154 | * @param string $queue |
||
155 | * @param int $timeout |
||
156 | * |
||
157 | * @return mixed|null|Queue |
||
158 | */ |
||
159 | 11 | public function pop($queue, $timeout = 0) |
|
169 | |||
170 | /** |
||
171 | * @param string $queue |
||
172 | * @param int $timeout |
||
173 | * |
||
174 | * @return MessageInterface|null |
||
175 | */ |
||
176 | 22 | public function reserve($queue, $timeout = 0) |
|
199 | |||
200 | /** |
||
201 | * @param string $queue |
||
202 | * @param int $timeout |
||
203 | * |
||
204 | * @return null|string |
||
205 | */ |
||
206 | 21 | protected function reserveToken($queue, $timeout = 0) |
|
221 | |||
222 | /** |
||
223 | * @param string|null $token |
||
224 | * |
||
225 | * @return null|MessageInterface |
||
226 | */ |
||
227 | 21 | protected function restoreMessage($token) |
|
238 | |||
239 | /** |
||
240 | * @param string|MessageInterface $mixed |
||
241 | * |
||
242 | * @return $this |
||
243 | * @throws QueueException |
||
244 | */ |
||
245 | 3 | View Code Duplication | public function bury($mixed) |
261 | |||
262 | /** |
||
263 | * @param string|MessageInterface $mixed |
||
264 | * |
||
265 | * @return $this |
||
266 | * @throws QueueException |
||
267 | */ |
||
268 | 20 | public function delete($mixed) |
|
285 | |||
286 | /** |
||
287 | * @param MessageInterface|string $mixed |
||
288 | * |
||
289 | * @return $this |
||
290 | * @throws QueueException |
||
291 | */ |
||
292 | 3 | View Code Duplication | public function kick($mixed) |
308 | |||
309 | /** |
||
310 | * @param MessageInterface|string $mixed |
||
311 | * @param int $delay |
||
312 | * |
||
313 | * @return $this |
||
314 | * @throws FlowException |
||
315 | * @throws QueueException |
||
316 | */ |
||
317 | 3 | public function release($mixed, $delay = 0) |
|
340 | |||
341 | /** |
||
342 | * @return array |
||
343 | */ |
||
344 | 4 | public function getQueueList() |
|
353 | |||
354 | /** |
||
355 | * @param null|string $queue |
||
356 | * |
||
357 | * @return $this |
||
358 | */ |
||
359 | 22 | public function migrate($queue = null) |
|
395 | |||
396 | |||
397 | /** |
||
398 | * @param string $queue |
||
399 | * @param array $options |
||
400 | * |
||
401 | * @return Iterator |
||
402 | */ |
||
403 | 1 | public function iterator($queue, array $options = []) |
|
409 | |||
410 | /** |
||
411 | * @param string $queue |
||
412 | * |
||
413 | * @return $this |
||
414 | */ |
||
415 | 1 | public function start($queue) |
|
421 | |||
422 | /** |
||
423 | * @param string $queue |
||
424 | * |
||
425 | * @return $this |
||
426 | */ |
||
427 | 2 | public function stop($queue) |
|
433 | |||
434 | /** |
||
435 | * @param string $queue |
||
436 | * |
||
437 | * @return bool |
||
438 | */ |
||
439 | 25 | public function isStop($queue) |
|
443 | |||
444 | /** |
||
445 | * @param string $queue |
||
446 | * |
||
447 | * @return array |
||
448 | */ |
||
449 | 4 | protected function queueStats($queue) |
|
463 | |||
464 | /** |
||
465 | * @param null|string $queue |
||
466 | * |
||
467 | * @return array |
||
468 | */ |
||
469 | 6 | public function stats($queue = null) |
|
504 | |||
505 | /** |
||
506 | * @param string $queue |
||
507 | * @param string $state |
||
508 | * |
||
509 | * @return int|string |
||
510 | * @throws QueueException |
||
511 | */ |
||
512 | 5 | public function size($queue, $state = self::STATE_READY) |
|
524 | |||
525 | |||
526 | /** |
||
527 | * @param null|string $queue |
||
528 | * |
||
529 | * @return $this |
||
530 | */ |
||
531 | 35 | public function clean($queue = null) |
|
547 | |||
548 | /** |
||
549 | * @param mixed $mixed |
||
550 | * |
||
551 | * @return MessageInterface |
||
552 | */ |
||
553 | 28 | protected function createMessage($mixed) |
|
561 | |||
562 | /** |
||
563 | * @param string $type |
||
564 | * |
||
565 | * @return string |
||
566 | */ |
||
567 | 29 | protected function ns($type) |
|
571 | |||
572 | |||
573 | /** |
||
574 | * @param string $queue |
||
575 | * @param string $state |
||
576 | * |
||
577 | * @return string |
||
578 | */ |
||
579 | 28 | protected function getKey($queue, $state) |
|
583 | |||
584 | /** |
||
585 | * @param int|\DateTime $mixed |
||
586 | * |
||
587 | * @return int |
||
588 | */ |
||
589 | 28 | protected function parseDelay($mixed) |
|
599 | |||
600 | /** |
||
601 | * @param string $currentState |
||
602 | * @param string $action |
||
603 | * |
||
604 | * @return $this |
||
605 | * @throws FlowException |
||
606 | */ |
||
607 | 25 | protected function checkMessageFlow($currentState, $action) |
|
622 | |||
623 | /** |
||
624 | * @param array $result |
||
625 | * @param string $action |
||
626 | * |
||
627 | * @return $this |
||
628 | * @throws QueueException |
||
629 | */ |
||
630 | 29 | protected function checkTransactionResult($result, $action) |
|
638 | |||
639 | /** |
||
640 | * @param string|MessageInterface $mixed |
||
641 | * |
||
642 | * @return Payload |
||
643 | * @throws QueueException |
||
644 | */ |
||
645 | 25 | protected function payload($mixed) |
|
654 | |||
655 | } |
||
656 |
If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check:
If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue.