CRM/Queue/Runner.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 4.4                                                |
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   6  | Copyright CiviCRM LLC (c) 2004-2013                                |
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   8  | This file is a part of CiviCRM.                                    |
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  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
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  12  | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
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  17  | See the GNU Affero General Public License for more details.        |
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  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
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  24  | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
  25  +--------------------------------------------------------------------+
  26 */
  27
  28 /**
  29  * The queue runner is a helper which runs all jobs in a queue.
  30  *
  31  * The queue runner is most useful for one-off queues (such as an upgrade);
  32  * if the intention is to develop a dedicated, long-running worker thread,
  33  * then one should consider writing a new queue consumer.
  34  */
  35 class CRM_Queue_Runner {
  36
  37   /**
  38    * The failed task should be discarded, and queue processing should continue
  39    */
  40   CONST ERROR_CONTINUE = 1;
  41
  42   /**
  43    * The failed task should be kept in the queue, and queue processing should abort
  44    */
  45   CONST ERROR_ABORT = 2;
  46
  47   /**
  48    * @var string
  49    */
  50   var $title;
  51
  52   /**
  53    * @var CRM_Queue_Queue
  54    */
  55   var $queue;
  56   var $errorMode;
  57   var $isMinimal;
  58   var $onEnd;
  59   var $onEndUrl;
  60   var $pathPrefix;
  61   // queue-runner id; used for persistence
  62   var $qrid;
  63
  64   /**
  65    * @var array whether to display buttons, eg ('retry' => TRUE, 'skip' => FALSE)
  66    */
  67   var $buttons;
  68
  69   /**
  70    * @var CRM_Queue_TaskContext
  71    */
  72   var $taskCtx;
  73
  74   /**
  75    * Locate a previously-created instance of the queue-runner
  76    *
  77    * @param $qrid string, the queue-runner ID
  78    *
  79    * @return CRM_Queue_Runner or NULL
  80    */
  81   static function instance($qrid) {
  82     if (!empty($_SESSION['queueRunners'][$qrid])) {
  83       return unserialize($_SESSION['queueRunners'][$qrid]);
  84     }
  85     else {
  86       return NULL;
  87     }
  88   }
  89
  90   /**
  91    *
  92    * FIXME: parameter validation
  93    * FIXME: document signature of onEnd callback
  94    *
  95    * @param $runnerSpec array with keys:
  96    *   - queue: CRM_Queue_Queue
  97    *   - errorMode: int, ERROR_CONTINUE or ERROR_ABORT
  98    *   - onEnd: mixed, a callback to update the UI after running; should be both callable and serializable
  99    *   - onEndUrl: string, the URL to which one redirects
 100    *   - pathPrefix: string, prepended to URLs for the web-runner; default: 'civicrm/queue'
 101    */
 102   public function __construct($runnerSpec) {
 103     $this->title      = CRM_Utils_Array::value('title', $runnerSpec, ts('Queue Runner'));
 104     $this->queue      = $runnerSpec['queue'];
 105     $this->errorMode  = CRM_Utils_Array::value('errorMode', $runnerSpec, self::ERROR_ABORT);
 106     $this->isMinimal  = CRM_Utils_Array::value('isMinimal', $runnerSpec, FALSE);
 107     $this->onEnd      = CRM_Utils_Array::value('onEnd', $runnerSpec, NULL);
 108     $this->onEndUrl   = CRM_Utils_Array::value('onEndUrl', $runnerSpec, NULL);
 109     $this->pathPrefix = CRM_Utils_Array::value('pathPrefix', $runnerSpec, 'civicrm/queue');
 110     $this->buttons    = CRM_Utils_Array::value('buttons', $runnerSpec, array('retry' => TRUE,'skip' => TRUE));
 111     // perhaps this value should be randomized?
 112     $this->qrid = $this->queue->getName();
 113   }
 114
 115   function __sleep() {
 116     // exclude taskCtx
 117     return array('title', 'queue', 'errorMode', 'isMinimal', 'onEnd', 'onEndUrl', 'pathPrefix', 'qrid', 'buttons');
 118   }
 119
 120   /**
 121    * Redirect to the web-based queue-runner and evaluate all tasks in a queue.
 122    */
 123   public function runAllViaWeb() {
 124     $_SESSION['queueRunners'][$this->qrid] = serialize($this);
 125     $url = CRM_Utils_System::url($this->pathPrefix . '/runner', 'reset=1&qrid=' . urlencode($this->qrid));
 126     CRM_Utils_System::redirect($url);
 127     // TODO: evaluate items incrementally via AJAX polling, cleanup session, call
 128   }
 129
 130   /**
 131    * Immediately run all tasks in a queue (until either reaching the end
 132    * of the queue or encountering an error)
 133    *
 134    * If the runner has an onEndUrl, then this function will not return
 135    *
 136    * @return mixed, TRUE if all tasks complete normally; otherwise, an array describing the failed task
 137    */
 138   public function runAll() {
 139     $taskResult = $this->formatTaskResult(TRUE);
 140     while ($taskResult['is_continue']) {
 141       // setRaiseException should't be necessary here, but there's a bug
 142       // somewhere which causes this setting to be lost.  Observed while
 143       // upgrading 4.0=>4.2.  This preference really shouldn't be a global
 144       // setting -- it should be more of a contextual/stack-based setting.
 145       // This should be appropriate because queue-runners are not used with
 146       // basic web pages -- they're used with CLI/REST/AJAX.
 147       $errorScope = CRM_Core_TemporaryErrorScope::useException();
 148       $taskResult = $this->runNext();
 149       $errorScope = NULL;
 150     }
 151
 152     if ($taskResult['numberOfItems'] == 0) {
 153       $result = $this->handleEnd();
 154       if (!empty($result['redirect_url'])) {
 155         CRM_Utils_System::redirect($result['redirect_url']);
 156       }
 157       return TRUE;
 158     }
 159     else {
 160       return $taskResult;
 161     }
 162   }
 163
 164   /**
 165    * Take the next item from the queue and attempt to run it.
 166    *
 167    * Individual tasks may also throw exceptions -- caller should watch for exceptions
 168    *
 169    * @param $useSteal bool, whether to steal active locks
 170    *
 171    * @return array(is_error => bool, is_continue => bool, numberOfItems => int, 'last_task_title' => $, 'exception' => $)
 172    */
 173   public function runNext($useSteal = FALSE) {
 174     if ($useSteal) {
 175       $item = $this->queue->stealItem();
 176     }
 177     else {
 178       $item = $this->queue->claimItem();
 179     }
 180
 181     if ($item) {
 182       $this->lastTaskTitle = $item->data->title;
 183
 184       $exception = NULL;
 185       try {
 186         $isOK = $item->data->run($this->getTaskContext());
 187         if (!$isOK) {
 188           $exception = new Exception('Task returned false');
 189       }
 190       }
 191       catch(Exception$e) {
 192         $isOK = FALSE;
 193         $exception = $e;
 194         }
 195
 196       if ($isOK) {
 197         $this->queue->deleteItem($item);
 198       }
 199       else {
 200         $this->releaseErrorItem($item);
 201       }
 202
 203       return $this->formatTaskResult($isOK, $exception);
 204     }
 205     else {
 206       return $this->formatTaskResult(FALSE, new Exception('Failed to claim next task'));
 207     }
 208   }
 209
 210   /**
 211    * Take the next item from the queue and attempt to run it.
 212    *
 213    * Individual tasks may also throw exceptions -- caller should watch for exceptions
 214    *
 215    * @param $useSteal bool, whether to steal active locks
 216    *
 217    * @return array(is_error => bool, is_continue => bool, numberOfItems => int)
 218    */
 219   public function skipNext($useSteal = FALSE) {
 220     if ($useSteal) {
 221       $item = $this->queue->stealItem();
 222     }
 223     else {
 224       $item = $this->queue->claimItem();
 225     }
 226
 227     if ($item) {
 228       $this->lastTaskTitle = $item->data->title;
 229       $this->queue->deleteItem($item);
 230       return $this->formatTaskResult(TRUE);
 231     }
 232     else {
 233       return $this->formatTaskResult(FALSE, new Exception('Failed to claim next task'));
 234     }
 235   }
 236
 237   protected function releaseErrorItem($item) {
 238     switch ($this->errorMode) {
 239       case self::ERROR_CONTINUE:
 240         $this->queue->deleteItem($item);
 241       case self::ERROR_ABORT:
 242       default:
 243         $this->queue->releaseItem($item);
 244     }
 245   }
 246
 247   /**
 248    *
 249    * @return array(is_error => bool, is_continue => bool, numberOfItems => int, redirect_url => string)
 250    */
 251   public function handleEnd() {
 252     if (is_callable($this->onEnd)) {
 253       call_user_func($this->onEnd, $this->getTaskContext());
 254     }
 255     // Don't remove queueRunner until onEnd succeeds
 256     if (!empty($_SESSION['queueRunners'][$this->qrid])) {
 257       unset($_SESSION['queueRunners'][$this->qrid]);
 258     }
 259
 260     // Fallback; web UI does redirect in Javascript
 261     $result = array();
 262     $result['is_error'] = 0;
 263     $result['numberOfItems'] = 0;
 264     $result['is_continue'] = 0;
 265     if (!empty($this->onEndUrl)) {
 266       $result['redirect_url'] = $this->onEndUrl;
 267     }
 268     return $result;
 269   }
 270
 271   /**
 272    *
 273    * @return array(is_error => bool, is_continue => bool, numberOfItems => int)
 274    */
 275   function formatTaskResult($isOK, $exception = NULL) {
 276     $numberOfItems = $this->queue->numberOfItems();
 277
 278     $result = array();
 279     $result['is_error'] = $isOK ? 0 : 1;
 280     $result['exception'] = $exception;
 281     $result['last_task_title'] = isset($this->lastTaskTitle) ? $this->lastTaskTitle : '';
 282     $result['numberOfItems'] = $this->queue->numberOfItems();
 283     if ($result['numberOfItems'] <= 0) {
 284       // nothing to do
 285       $result['is_continue'] = 0;
 286     }
 287     elseif ($isOK) {
 288       // more tasks remain, and this task succeeded
 289       $result['is_continue'] = 1;
 290     }
 291     elseif ($this->errorMode == CRM_Queue_Runner::ERROR_CONTINUE) {
 292       // more tasks remain, and we can disregard this error
 293       $result['is_continue'] = 1;
 294     }
 295     else {
 296       // more tasks remain, but we can't disregard the error
 297       $result['is_continue'] = 0;
 298     }
 299
 300     return $result;
 301   }
 302
 303   protected function getTaskContext() {
 304     if (!is_object($this->taskCtx)) {
 305       $this->taskCtx = new CRM_Queue_TaskContext();
 306       $this->taskCtx->queue = $this->queue;
 307       // $this->taskCtx->log = CRM_Core_Config::getLog();
 308       $this->taskCtx->log = CRM_Core_Error::createDebugLogger();
 309     }
 310     return $this->taskCtx;
 311   }
 312 }
 313