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 |
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| 16 | final class Queue implements QueueInterface |
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| 17 | { |
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| 18 | /** |
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| 19 | * Maximum millisecond value to use for UTCDateTime creation. |
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| 20 | * |
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| 21 | * @var integer |
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| 22 | */ |
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| 23 | const MONGO_INT32_MAX = PHP_INT_MAX; |
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| 24 | |||
| 25 | /** |
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| 26 | * mongo collection to use for queue. |
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| 27 | * |
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| 28 | * @var \MongoDB\Collection |
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| 29 | */ |
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| 30 | private $collection; |
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| 31 | |||
| 32 | /** |
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| 33 | * Construct queue. |
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| 34 | * |
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| 35 | * @param \MongoDB\Collection|string $collectionOrUrl A MongoCollection instance or the mongo connection url. |
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| 36 | * @param string $db the mongo db name |
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| 37 | * @param string $collection the collection name to use for the queue |
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| 38 | * |
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| 39 | * @throws \InvalidArgumentException $collectionOrUrl, $db or $collection was not a string |
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| 40 | */ |
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| 41 | public function __construct($collectionOrUrl, $db = null, $collection = null) |
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| 42 | { |
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| 43 | if ($collectionOrUrl instanceof \MongoDB\Collection) { |
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| 44 | $this->collection = $collectionOrUrl; |
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| 45 | return; |
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| 46 | } |
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| 47 | |||
| 48 | if (!is_string($collectionOrUrl)) { |
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| 49 | throw new \InvalidArgumentException('$collectionOrUrl was not a string'); |
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| 50 | } |
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| 51 | |||
| 52 | if (!is_string($db)) { |
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| 53 | throw new \InvalidArgumentException('$db was not a string'); |
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| 54 | } |
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| 55 | |||
| 56 | if (!is_string($collection)) { |
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| 57 | throw new \InvalidArgumentException('$collection was not a string'); |
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| 58 | } |
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| 59 | |||
| 60 | $mongo = new \MongoDB\Client($collectionOrUrl, [], ['typeMap' => ['root' => 'array', 'document' => 'array', 'array' => 'array']]); |
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| 61 | $mongoDb = $mongo->selectDatabase($db); |
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| 62 | $this->collection = $mongoDb->selectCollection($collection); |
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| 63 | } |
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| 64 | |||
| 65 | /** |
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| 66 | * Ensure an index for the get() method. |
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| 67 | * |
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| 68 | * @param array $beforeSort Fields in get() call to index before the sort field in same format |
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| 69 | * as \MongoDB\Collection::ensureIndex() |
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| 70 | * @param array $afterSort Fields in get() call to index after the sort field in same format as |
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| 71 | * \MongoDB\Collection::ensureIndex() |
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| 72 | * |
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| 73 | * @return void |
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| 74 | * |
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| 75 | * @throws \InvalidArgumentException value of $beforeSort or $afterSort is not 1 or -1 for ascending and descending |
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| 76 | * @throws \InvalidArgumentException key in $beforeSort or $afterSort was not a string |
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| 77 | */ |
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| 78 | public function ensureGetIndex(array $beforeSort = [], array $afterSort = []) |
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| 79 | { |
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| 80 | //using general rule: equality, sort, range or more equality tests in that order for index |
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| 81 | $completeFields = ['earliestGet' => 1]; |
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| 82 | |||
| 83 | self::verifySort($beforeSort, 'beforeSort', $completeFields); |
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| 84 | |||
| 85 | $completeFields['priority'] = 1; |
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| 86 | $completeFields['created'] = 1; |
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| 87 | |||
| 88 | self::verifySort($afterSort, 'afterSort', $completeFields); |
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| 89 | |||
| 90 | //for the main query in get() |
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| 91 | $this->ensureIndex($completeFields); |
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| 92 | } |
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| 93 | |||
| 94 | /** |
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| 95 | * Ensure an index for the count() method. |
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| 96 | * Is a no-op if the generated index is a prefix of an existing one. If you have a similar ensureGetIndex call, |
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| 97 | * call it first. |
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| 98 | * |
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| 99 | * @param array $fields fields in count() call to index in same format as \MongoDB\Collection::createIndex() |
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| 100 | * @param bool $includeRunning whether to include the running field in the index |
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| 101 | * |
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| 102 | * @return void |
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| 103 | * |
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| 104 | * @throws \InvalidArgumentException $includeRunning was not a boolean |
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| 105 | * @throws \InvalidArgumentException key in $fields was not a string |
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| 106 | * @throws \InvalidArgumentException value of $fields is not 1 or -1 for ascending and descending |
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| 107 | */ |
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| 108 | public function ensureCountIndex(array $fields, $includeRunning) |
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| 109 | { |
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| 110 | if (!is_bool($includeRunning)) { |
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| 111 | throw new \InvalidArgumentException('$includeRunning was not a boolean'); |
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| 112 | } |
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| 113 | |||
| 114 | $completeFields = []; |
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| 115 | |||
| 116 | if ($includeRunning) { |
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| 117 | $completeFields['earliestGet'] = 1; |
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| 118 | } |
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| 119 | |||
| 120 | self::verifySort($fields, 'fields', $completeFields); |
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| 121 | |||
| 122 | $this->ensureIndex($completeFields); |
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| 123 | } |
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| 124 | |||
| 125 | /** |
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| 126 | * Get a non running message from the queue. |
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| 127 | * |
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| 128 | * @param array $query in same format as \MongoDB\Collection::find() where top level fields do not contain operators. |
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| 129 | * Lower level fields can however. eg: valid {a: {$gt: 1}, "b.c": 3}, |
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| 130 | * invalid {$and: [{...}, {...}]} |
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| 131 | * @param int $runningResetDuration second duration the message can stay unacked before it resets and can be |
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| 132 | * retreived again. |
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| 133 | * @param int $waitDurationInMillis millisecond duration to wait for a message. |
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| 134 | * @param int $pollDurationInMillis millisecond duration to wait between polls. |
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| 135 | * |
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| 136 | * @return array|null the message or null if one is not found |
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| 137 | * |
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| 138 | * @throws \InvalidArgumentException $runningResetDuration, $waitDurationInMillis or $pollDurationInMillis was not |
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| 139 | * an int |
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| 140 | * @throws \InvalidArgumentException key in $query was not a string |
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| 141 | */ |
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| 142 | public function get(array $query, $runningResetDuration, $waitDurationInMillis = 3000, $pollDurationInMillis = 200) |
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| 143 | { |
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| 144 | if (!is_int($runningResetDuration)) { |
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| 145 | throw new \InvalidArgumentException('$runningResetDuration was not an int'); |
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| 146 | } |
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| 147 | |||
| 148 | if (!is_int($waitDurationInMillis)) { |
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| 149 | throw new \InvalidArgumentException('$waitDurationInMillis was not an int'); |
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| 150 | } |
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| 151 | |||
| 152 | if (!is_int($pollDurationInMillis)) { |
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| 153 | throw new \InvalidArgumentException('$pollDurationInMillis was not an int'); |
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| 154 | } |
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| 155 | |||
| 156 | if ($pollDurationInMillis < 0) { |
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| 157 | $pollDurationInMillis = 0; |
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| 158 | } |
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| 159 | |||
| 160 | $completeQuery = ['earliestGet' => ['$lte' => new UTCDateTime((int)(microtime(true) * 1000))]]; |
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| 161 | foreach ($query as $key => $value) { |
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| 162 | if (!is_string($key)) { |
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| 163 | throw new \InvalidArgumentException('key in $query was not a string'); |
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| 164 | } |
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| 165 | |||
| 166 | $completeQuery["payload.{$key}"] = $value; |
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| 167 | } |
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| 168 | |||
| 169 | $resetTimestamp = time() + $runningResetDuration; |
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| 170 | //ints overflow to floats |
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| 171 | if (!is_int($resetTimestamp)) { |
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| 172 | $resetTimestamp = $runningResetDuration > 0 ? self::MONGO_INT32_MAX : 0; |
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| 173 | } |
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| 174 | |||
| 175 | $resetTimestamp = min(max(0, $resetTimestamp * 1000), self::MONGO_INT32_MAX); |
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| 176 | |||
| 177 | $update = ['$set' => ['earliestGet' => new UTCDateTime($resetTimestamp)]]; |
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| 178 | $findOneAndUpdateOptions = ['sort' => ['priority' => 1, 'created' => 1]]; |
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| 179 | $findOneOptions = ['typeMap' => ['root' => 'array', 'document' => 'array', 'array' => 'array']], |
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| 180 | |||
| 181 | //ints overflow to floats, should be fine |
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| 182 | $end = microtime(true) + ($waitDurationInMillis / 1000.0); |
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| 183 | |||
| 184 | $sleepTime = $pollDurationInMillis * 1000; |
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| 185 | //ints overflow to floats and already checked $pollDurationInMillis was positive |
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| 186 | if (!is_int($sleepTime)) { |
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| 187 | //ignore since testing a giant sleep takes too long |
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| 188 | //@codeCoverageIgnoreStart |
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| 189 | $sleepTime = PHP_INT_MAX; |
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| 190 | } //@codeCoverageIgnoreEnd |
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| 191 | |||
| 192 | while (true) { |
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| 193 | $id = $this->getIdFromMessage( |
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| 194 | $this->collection->findOneAndUpdate($completeQuery, $update, $findOneAndUpdateOptions) |
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| 195 | ); |
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| 196 | if ($id !== null) { |
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| 197 | // findOneAndUpdate does not correctly return result according to typeMap options so just refetch. |
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| 198 | $message = $this->collection->findOne(['_id' => $id], $findOneOptions); |
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| 199 | //id on left of union operator so a possible id in payload doesnt wipe it out the generated one |
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| 200 | return ['id' => $id] + $message['payload']; |
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| 201 | } |
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| 202 | |||
| 203 | if (microtime(true) >= $end) { |
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| 204 | return null; |
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| 205 | } |
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| 206 | |||
| 207 | usleep($sleepTime); |
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| 208 | } |
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| 209 | |||
| 210 | //ignore since always return from the function from the while loop |
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| 211 | //@codeCoverageIgnoreStart |
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| 212 | } |
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| 213 | //@codeCoverageIgnoreEnd |
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| 214 | |||
| 215 | private function getIdFromMessage($message) |
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| 216 | { |
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| 217 | if (is_array($message)) { |
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| 218 | return array_key_exists('_id', $message) ? $message['_id'] : null; |
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| 219 | } |
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| 220 | |||
| 221 | if (is_object($message)) { |
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| 222 | return isset($message->_id) ? $message->_id : null; |
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| 223 | } |
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| 224 | |||
| 225 | return null; |
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| 226 | } |
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| 227 | |||
| 228 | /** |
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| 229 | * Count queue messages. |
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| 230 | * |
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| 231 | * @param array $query in same format as \MongoDB\Collection::find() where top level fields do not contain operators. |
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| 232 | * Lower level fields can however. eg: valid {a: {$gt: 1}, "b.c": 3}, invalid {$and: [{...}, {...}]} |
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| 233 | * @param bool|null $running query a running message or not or all |
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| 234 | * |
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| 235 | * @return int the count |
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| 236 | * |
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| 237 | * @throws \InvalidArgumentException $running was not null and not a bool |
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| 238 | * @throws \InvalidArgumentException key in $query was not a string |
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| 239 | */ |
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| 240 | public function count(array $query, $running = null) |
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| 241 | { |
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| 242 | if ($running !== null && !is_bool($running)) { |
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| 243 | throw new \InvalidArgumentException('$running was not null and not a bool'); |
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| 244 | } |
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| 245 | |||
| 246 | $totalQuery = []; |
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| 247 | |||
| 248 | if ($running === true || $running === false) { |
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| 249 | $key = $running ? '$gt' : '$lte'; |
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| 250 | $totalQuery['earliestGet'] = [$key => new UTCDateTime((int)(microtime(true) * 1000))]; |
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| 251 | } |
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| 252 | |||
| 253 | foreach ($query as $key => $value) { |
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| 254 | if (!is_string($key)) { |
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| 255 | throw new \InvalidArgumentException('key in $query was not a string'); |
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| 256 | } |
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| 257 | |||
| 258 | $totalQuery["payload.{$key}"] = $value; |
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| 259 | } |
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| 260 | |||
| 261 | return $this->collection->count($totalQuery); |
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| 262 | } |
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| 263 | |||
| 264 | /** |
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| 265 | * Acknowledge a message was processed and remove from queue. |
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| 266 | * |
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| 267 | * @param array $message message received from get() |
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| 268 | * |
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| 269 | * @return void |
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| 270 | * |
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| 271 | * @throws \InvalidArgumentException $message does not have a field "id" that is a MongoDB\BSON\ObjectID |
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| 272 | */ |
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| 273 | public function ack(array $message) |
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| 274 | { |
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| 275 | $id = null; |
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| 276 | if (array_key_exists('id', $message)) { |
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| 277 | $id = $message['id']; |
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| 278 | } |
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| 279 | |||
| 280 | if (!(is_a($id, 'MongoDB\BSON\ObjectID'))) { |
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| 281 | throw new \InvalidArgumentException('$message does not have a field "id" that is a ObjectID'); |
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| 282 | } |
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| 283 | |||
| 284 | $this->collection->deleteOne(['_id' => $id]); |
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| 285 | } |
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| 286 | |||
| 287 | /** |
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| 288 | * Atomically acknowledge and send a message to the queue. |
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| 289 | * |
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| 290 | * @param array $message the message to ack received from get() |
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| 291 | * @param array $payload the data to store in the message to send. Data is handled same way |
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| 292 | * as \MongoDB\Collection::insertOne() |
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| 293 | * @param int $earliestGet earliest unix timestamp the message can be retreived. |
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| 294 | * @param float $priority priority for order out of get(). 0 is higher priority than 1 |
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| 295 | * @param bool $newTimestamp true to give the payload a new timestamp or false to use given message timestamp |
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| 296 | * |
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| 297 | * @return void |
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| 298 | * |
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| 299 | * @throws \InvalidArgumentException $message does not have a field "id" that is a ObjectID |
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| 300 | * @throws \InvalidArgumentException $earliestGet was not an int |
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| 301 | * @throws \InvalidArgumentException $priority was not a float |
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| 302 | * @throws \InvalidArgumentException $priority is NaN |
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| 303 | * @throws \InvalidArgumentException $newTimestamp was not a bool |
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| 304 | */ |
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| 305 | public function ackSend(array $message, array $payload, $earliestGet = 0, $priority = 0.0, $newTimestamp = true) |
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| 306 | { |
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| 307 | $id = null; |
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| 308 | if (array_key_exists('id', $message)) { |
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| 309 | $id = $message['id']; |
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| 310 | } |
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| 311 | |||
| 312 | if (!(is_a($id, 'MongoDB\BSON\ObjectID'))) { |
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| 313 | throw new \InvalidArgumentException('$message does not have a field "id" that is a ObjectID'); |
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| 314 | } |
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| 315 | |||
| 316 | if (!is_int($earliestGet)) { |
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| 317 | throw new \InvalidArgumentException('$earliestGet was not an int'); |
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| 318 | } |
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| 319 | |||
| 320 | if (!is_float($priority)) { |
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| 321 | throw new \InvalidArgumentException('$priority was not a float'); |
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| 322 | } |
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| 323 | |||
| 324 | if (is_nan($priority)) { |
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| 325 | throw new \InvalidArgumentException('$priority was NaN'); |
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| 326 | } |
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| 327 | |||
| 328 | if ($newTimestamp !== true && $newTimestamp !== false) { |
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| 329 | throw new \InvalidArgumentException('$newTimestamp was not a bool'); |
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| 330 | } |
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| 331 | |||
| 332 | //Ensure $earliestGet is between 0 and MONGO_INT32_MAX |
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| 333 | $earliestGet = min(max(0, $earliestGet * 1000), self::MONGO_INT32_MAX); |
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| 334 | |||
| 335 | $toSet = [ |
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| 336 | 'payload' => $payload, |
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| 337 | 'earliestGet' => new UTCDateTime($earliestGet), |
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| 338 | 'priority' => $priority, |
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| 339 | ]; |
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| 340 | if ($newTimestamp) { |
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| 341 | $toSet['created'] = new UTCDateTime((int)(microtime(true) * 1000)); |
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| 342 | } |
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| 343 | |||
| 344 | //using upsert because if no documents found then the doc was removed (SHOULD ONLY HAPPEN BY SOMEONE MANUALLY) |
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| 345 | //so we can just send |
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| 346 | $this->collection->updateOne(['_id' => $id], ['$set' => $toSet], ['upsert' => true]); |
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| 347 | } |
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| 348 | |||
| 349 | /** |
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| 350 | * Requeue message to the queue. Same as ackSend() with the same message. |
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| 351 | * |
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| 352 | * @param array $message message received from get(). |
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| 353 | * @param int $earliestGet earliest unix timestamp the message can be retreived. |
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| 354 | * @param float $priority priority for order out of get(). 0 is higher priority than 1 |
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| 355 | * @param bool $newTimestamp true to give the payload a new timestamp or false to use given message timestamp |
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| 356 | * |
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| 357 | * @return void |
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| 358 | * |
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| 359 | * @throws \InvalidArgumentException $message does not have a field "id" that is a ObjectID |
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| 360 | * @throws \InvalidArgumentException $earliestGet was not an int |
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| 361 | * @throws \InvalidArgumentException $priority was not a float |
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| 362 | * @throws \InvalidArgumentException priority is NaN |
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| 363 | * @throws \InvalidArgumentException $newTimestamp was not a bool |
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| 364 | */ |
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| 365 | public function requeue(array $message, $earliestGet = 0, $priority = 0.0, $newTimestamp = true) |
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| 366 | { |
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| 367 | $forRequeue = $message; |
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| 368 | unset($forRequeue['id']); |
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| 369 | $this->ackSend($message, $forRequeue, $earliestGet, $priority, $newTimestamp); |
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| 370 | } |
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| 371 | |||
| 372 | /** |
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| 373 | * Send a message to the queue. |
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| 374 | * |
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| 375 | * @param array $payload the data to store in the message. Data is handled same way as \MongoDB\Collection::insertOne() |
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| 376 | * @param int $earliestGet earliest unix timestamp the message can be retreived. |
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| 377 | * @param float $priority priority for order out of get(). 0 is higher priority than 1 |
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| 378 | * |
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| 379 | * @return void |
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| 380 | * |
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| 381 | * @throws \InvalidArgumentException $earliestGet was not an int |
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| 382 | * @throws \InvalidArgumentException $priority was not a float |
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| 383 | * @throws \InvalidArgumentException $priority is NaN |
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| 384 | */ |
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| 385 | public function send(array $payload, $earliestGet = 0, $priority = 0.0) |
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| 386 | { |
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| 387 | if (!is_int($earliestGet)) { |
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| 388 | throw new \InvalidArgumentException('$earliestGet was not an int'); |
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| 389 | } |
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| 390 | |||
| 391 | if (!is_float($priority)) { |
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| 392 | throw new \InvalidArgumentException('$priority was not a float'); |
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| 393 | } |
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| 394 | |||
| 395 | if (is_nan($priority)) { |
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| 396 | throw new \InvalidArgumentException('$priority was NaN'); |
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| 397 | } |
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| 398 | |||
| 399 | //Ensure $earliestGet is between 0 and MONGO_INT32_MAX |
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| 400 | $earliestGet = min(max(0, $earliestGet * 1000), self::MONGO_INT32_MAX); |
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| 401 | |||
| 402 | $message = [ |
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| 403 | 'payload' => $payload, |
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| 404 | 'earliestGet' => new UTCDateTime($earliestGet), |
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| 405 | 'priority' => $priority, |
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| 406 | 'created' => new UTCDateTime((int)(microtime(true) * 1000)), |
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| 407 | ]; |
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| 408 | |||
| 409 | $this->collection->insertOne($message); |
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| 410 | } |
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| 411 | |||
| 412 | /** |
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| 413 | * Ensure index of correct specification and a unique name whether the specification or name already exist or not. |
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| 414 | * Will not create index if $index is a prefix of an existing index |
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| 415 | * |
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| 416 | * @param array $index index to create in same format as \MongoDB\Collection::createIndex() |
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| 417 | * |
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| 418 | * @return void |
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| 419 | * |
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| 420 | * @throws \Exception couldnt create index after 5 attempts |
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| 421 | */ |
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| 422 | private function ensureIndex(array $index) |
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| 423 | { |
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| 424 | //if $index is a prefix of any existing index we are good |
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| 425 | foreach ($this->collection->listIndexes() as $existingIndex) { |
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| 426 | $slice = array_slice($existingIndex['key'], 0, count($index), true); |
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| 427 | if ($slice === $index) { |
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| 428 | return; |
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| 429 | } |
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| 430 | } |
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| 431 | |||
| 432 | for ($i = 0; $i < 5; ++$i) { |
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| 433 | for ($name = uniqid(); strlen($name) > 0; $name = substr($name, 0, -1)) { |
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| 434 | //creating an index with same name and different spec does nothing. |
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| 435 | //creating an index with same spec and different name does nothing. |
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| 436 | //so we use any generated name, and then find the right spec after we have called, |
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| 437 | //and just go with that name. |
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| 438 | try { |
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| 439 | $this->collection->createIndex($index, ['name' => $name, 'background' => true]); |
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| 440 | } catch (\MongoDB\Exception\Exception $e) { |
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| 441 | //this happens when the name was too long, let continue |
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| 442 | } |
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| 443 | |||
| 444 | foreach ($this->collection->listIndexes() as $existingIndex) { |
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| 445 | if ($existingIndex['key'] === $index) { |
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| 446 | return; |
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| 447 | } |
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| 448 | } |
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| 449 | } |
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| 450 | } |
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| 451 | |||
| 452 | throw new \Exception('couldnt create index after 5 attempts'); |
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| 453 | //@codeCoverageIgnoreEnd |
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| 454 | } |
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| 455 | |||
| 456 | /** |
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| 457 | * Helper method to validate keys and values for the given sort array |
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| 458 | * |
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| 459 | * @param array $sort The proposed sort for a mongo index. |
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| 460 | * @param string $label The name of the variable given to the public ensureXIndex method. |
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| 461 | * @param array &$completedFields The final index array with payload. prefix added to fields. |
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| 462 | * |
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| 463 | * @return void |
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| 464 | */ |
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| 465 | private static function verifySort(array $sort, $label, &$completeFields) |
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| 466 | { |
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| 467 | foreach ($sort as $key => $value) { |
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| 468 | if (!is_string($key)) { |
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| 482 |