| 1 | <?php |
| 2 | /* |
| 3 | +--------------------------------------------------------------------+ |
| 4 | | Copyright CiviCRM LLC. All rights reserved. | |
| 5 | | | |
| 6 | | This work is published under the GNU AGPLv3 license with some | |
| 7 | | permitted exceptions and without any warranty. For full license | |
| 8 | | and copyright information, see https://civicrm.org/licensing | |
| 9 | +--------------------------------------------------------------------+ |
| 10 | */ |
| 11 | |
| 12 | /** |
| 13 | * The queue service provides an interface for creating or locating |
| 14 | * queues. Note that this approach hides the details of data-storage: |
| 15 | * different queue-providers may store the queue content in different |
| 16 | * ways (in memory, in SQL, or in an external service). |
| 17 | * |
| 18 | * @code |
| 19 | * $queue = CRM_Queue_Service::singleton()->create(array( |
| 20 | * 'type' => 'interactive', |
| 21 | * 'name' => 'upgrade-tasks', |
| 22 | * )); |
| 23 | * $queue->createItem($myData); |
| 24 | * |
| 25 | * // Some time later... |
| 26 | * $item = $queue->claimItem(); |
| 27 | * if ($item) { |
| 28 | * if (my_process($item->data)) { |
| 29 | * $queue->deleteItem($item); |
| 30 | * } else { |
| 31 | * $queue->releaseItem($item); |
| 32 | * } |
| 33 | * } |
| 34 | * @endcode |
| 35 | */ |
| 36 | class CRM_Queue_Service { |
| 37 | |
| 38 | protected static $_singleton; |
| 39 | |
| 40 | /** |
| 41 | * FIXME: Singleton pattern should be removed when dependency-injection |
| 42 | * becomes available. |
| 43 | * |
| 44 | * @param bool $forceNew |
| 45 | * TRUE if a new instance must be created. |
| 46 | * |
| 47 | * @return \CRM_Queue_Service |
| 48 | */ |
| 49 | public static function &singleton($forceNew = FALSE) { |
| 50 | if ($forceNew || !self::$_singleton) { |
| 51 | self::$_singleton = new CRM_Queue_Service(); |
| 52 | } |
| 53 | return self::$_singleton; |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Queues. |
| 58 | * |
| 59 | * Format is (string $queueName => CRM_Queue_Queue). |
| 60 | * |
| 61 | * @var array |
| 62 | */ |
| 63 | public $queues; |
| 64 | |
| 65 | /** |
| 66 | * Class constructor. |
| 67 | */ |
| 68 | public function __construct() { |
| 69 | $this->queues = []; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Create a queue. If one already exists, then it will be reused. |
| 74 | * |
| 75 | * @param array $queueSpec |
| 76 | * Array with keys: |
| 77 | * - type: string, required, e.g. "interactive", "immediate", "stomp", |
| 78 | * "beanstalk" |
| 79 | * - name: string, required, e.g. "upgrade-tasks" |
| 80 | * - reset: bool, optional; if a queue is found, then it should be |
| 81 | * flushed; default to TRUE |
| 82 | * - (additional keys depending on the queue provider). |
| 83 | * |
| 84 | * @return CRM_Queue_Queue |
| 85 | */ |
| 86 | public function create($queueSpec) { |
| 87 | if (@is_object($this->queues[$queueSpec['name']]) && empty($queueSpec['reset'])) { |
| 88 | return $this->queues[$queueSpec['name']]; |
| 89 | } |
| 90 | |
| 91 | $queue = $this->instantiateQueueObject($queueSpec); |
| 92 | $exists = $queue->existsQueue(); |
| 93 | if (!$exists) { |
| 94 | $queue->createQueue(); |
| 95 | } |
| 96 | elseif (@$queueSpec['reset']) { |
| 97 | $queue->deleteQueue(); |
| 98 | $queue->createQueue(); |
| 99 | } |
| 100 | else { |
| 101 | $queue->loadQueue(); |
| 102 | } |
| 103 | $this->queues[$queueSpec['name']] = $queue; |
| 104 | return $queue; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Look up an existing queue. |
| 109 | * |
| 110 | * @param array $queueSpec |
| 111 | * Array with keys: |
| 112 | * - type: string, required, e.g. "interactive", "immediate", "stomp", |
| 113 | * "beanstalk" |
| 114 | * - name: string, required, e.g. "upgrade-tasks" |
| 115 | * - (additional keys depending on the queue provider). |
| 116 | * |
| 117 | * @return CRM_Queue_Queue |
| 118 | */ |
| 119 | public function load($queueSpec) { |
| 120 | if (is_object($this->queues[$queueSpec['name']])) { |
| 121 | return $this->queues[$queueSpec['name']]; |
| 122 | } |
| 123 | $queue = $this->instantiateQueueObject($queueSpec); |
| 124 | $queue->loadQueue(); |
| 125 | $this->queues[$queueSpec['name']] = $queue; |
| 126 | return $queue; |
| 127 | } |
| 128 | |
| 129 | /** |
| 130 | * Convert a queue "type" name to a class name. |
| 131 | * |
| 132 | * @param string $type |
| 133 | * E.g. "interactive", "immediate", "stomp", "beanstalk". |
| 134 | * |
| 135 | * @return string |
| 136 | * Class-name |
| 137 | */ |
| 138 | protected function getQueueClass($type) { |
| 139 | $type = preg_replace('/[^a-zA-Z0-9]/', '', $type); |
| 140 | $className = 'CRM_Queue_Queue_' . $type; |
| 141 | // FIXME: when used with class-autoloader, this may be unnecessary |
| 142 | if (!class_exists($className)) { |
| 143 | $classFile = 'CRM/Queue/Queue/' . $type . '.php'; |
| 144 | require_once $classFile; |
| 145 | } |
| 146 | return $className; |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * @param array $queueSpec |
| 151 | * See create(). |
| 152 | * |
| 153 | * @return CRM_Queue_Queue |
| 154 | */ |
| 155 | protected function instantiateQueueObject($queueSpec) { |
| 156 | // note: you should probably never do anything else here |
| 157 | $class = new ReflectionClass($this->getQueueClass($queueSpec['type'])); |
| 158 | return $class->newInstance($queueSpec); |
| 159 | } |
| 160 | |
| 161 | } |