first import

sites/all/modules/job_scheduler/JobScheduler.inc

@@ -0,0 +1,226 @@
+<?php
+
+/**
+ * @file
+ * JobScheduler class.
+ */
+
+/**
+ * Use to make Job Scheduler exceptions identifiable by type.
+ */
+class JobSchedulerException extends Exception {}
+
+/**
+ * Manage scheduled jobs.
+ */
+class JobScheduler {
+  /**
+   * The name of this scheduler.
+   */
+  protected $name;
+
+  /**
+   * Produces a single instance of JobScheduler for a schedule name.
+   */
+  public static function get($name) {
+    static $schedulers;
+    // Instantiante a new scheduler for $name if we haven't done so yet.
+    if (!isset($schedulers[$name])) {
+      $class = variable_get('job_scheduler_class_' . $name, 'JobScheduler');
+      $schedulers[$name] = new $class($name);
+    }
+    return $schedulers[$name];
+  }
+
+  /**
+   * Creates a JobScheduler object.
+   */
+  protected function __construct($name) {
+    $this->name = $name;
+  }
+
+  /**
+   * Returns scheduler info.
+   *
+   * @see hook_cron_job_scheduler_info()
+   *
+   * @throws JobSchedulerException.
+   */
+  public function info() {
+    if ($info = job_scheduler_info($this->name)) {
+      return $info;
+    }
+    throw new JobSchedulerException('Could not find Job Scheduler cron information for ' . check_plain($this->name));
+  }
+
+  /**
+   * Add a job to the schedule, replace any existing job.
+   *
+   * A job is uniquely identified by $job = array(type, id).
+   *
+   * @param $job
+   *   An array that must contain the following keys:
+   *   'type'     - A string identifier of the type of job.
+   *   'id'       - A numeric identifier of the job.
+   *   'period'   - The time when the task should be executed.
+   *   'periodic' - True if the task should be repeated periodically.
+   *
+   * @code
+   * function worker_callback($job) {
+   *   // Work off job.
+   *   // Set next time to be called. If this portion of the code is not
+   *   // reached for some reason, the scheduler will keep periodically invoking
+   *   // the callback() with the period value initially specified.
+   *   $scheduler->set($job);
+   * }
+   * @endcode
+   */
+  public function set($job) {
+    $job['name'] = $this->name;
+    $job['last'] = REQUEST_TIME;
+    if (!empty($job['crontab'])) {
+      $crontab = new JobSchedulerCronTab($job['crontab']);
+      $job['next'] = $crontab->nextTime(REQUEST_TIME);
+    }
+    else {
+      $job['next'] = REQUEST_TIME + $job['period'];
+    }
+    $job['scheduled'] = 0;
+    $this->remove($job);
+    drupal_write_record('job_schedule', $job);
+  }
+
+  /**
+   * Reserve a job.
+   */
+  protected function reserve($job) {
+    $job['name'] = $this->name;
+    $job['scheduled'] =
+    $job['last'] = REQUEST_TIME;
+    $job['next'] = $job['period'] + REQUEST_TIME;
+    drupal_write_record('job_schedule', $job, array('name', 'type', 'id'));
+  }
+
+  /**
+   * Remove a job from the schedule, replace any existing job.
+   *
+   * A job is uniquely identified by $job = array(type, id).
+   */
+  public function remove($job) {
+    db_delete('job_schedule')
+      ->condition('name', $this->name)
+      ->condition('type', $job['type'])
+      ->condition('id', isset($job['id']) ? $job['id'] : 0)
+      ->execute();
+  }
+
+  /**
+   * Remove all jobs for a given type.
+   */
+  public function removeAll($type) {
+    db_delete('job_schedule')
+      ->condition('name', $this->name)
+      ->condition('type', $type)
+      ->execute();
+  }
+
+  /**
+   * Dispatches a job.
+   *
+   * Executes a worker callback or if schedule declares a queue name, queues a
+   * job for execution.
+   *
+   * @param $job
+   *   A $job array as passed into set() or read from job_schedule table.
+   *
+   * @throws Exception
+   *   Exceptions thrown by code called by this method are passed on.
+   */
+  public function dispatch($job) {
+    $info = $this->info();
+    if (!$job['periodic']) {
+      $this->remove($job);
+    }
+    if (!empty($info['queue name'])) {
+      if (DrupalQueue::get($info['queue name'])->createItem($job)) {
+        $this->reserve($job);
+      }
+    }
+    else {
+      $this->execute($job);
+    }
+  }
+
+  /**
+   * Executes a job that
+   *
+   * @param $job
+   *   A $job array as passed into set() or read from job_schedule table.
+   *
+   * @throws Exception
+   *   Exceptions thrown by code called by this method are passed on.
+   */
+  public function execute($job) {
+    $info = $this->info();
+    // If the job is periodic, re-schedule it before calling the worker, just in case
+    if ($job['periodic']) {
+      $job['last'] = REQUEST_TIME;
+      $this->reschedule($job);
+    }
+    if (function_exists($info['worker callback'])) {
+      call_user_func($info['worker callback'], $job);
+    }
+    else {
+      // @todo If worker doesn't exist anymore we should do something about it, remove and throw exception?
+      $this->remove($job);
+      throw new JobSchedulerException('Could not find worker callback function: ' . $info['worker callback']);
+    }
+  }
+
+  /**
+   * Re-schedule a job if intended to run again
+   *
+   * (If cannot determine the next time, drop the job)
+   */
+  public function reschedule($job) {
+    $job['scheduled'] = 0;
+    if (!empty($job['crontab'])) {
+      $crontab = new JobSchedulerCronTab($job['crontab']);
+      $job['next'] = $crontab->nextTime($job['last']);
+    }
+    else {
+      $job['next'] = $job['last'] + $job['period'];
+    }
+
+    if ($job['next']) {
+      drupal_write_record('job_schedule', $job, array('item_id'));
+    }
+    else {
+      // If no next time, it may mean it wont run again the next year (crontab)
+      $this->remove($job);
+    }
+  }
+
+  /**
+   * Check whether a job exists in the queue and update its parameters if so
+   */
+  public function check($job) {
+    $job += array('id' => 0, 'period' => 0, 'crontab' => '');
+    $existing = db_select('job_schedule')
+      ->fields('job_schedule')
+      ->condition('name', $this->name)
+      ->condition('type', $job['type'])
+      ->condition('id', $job['id'])
+      ->execute()
+      ->fetchAssoc();
+    // If existing, and changed period or crontab, we need to reschedule the job
+    if ($existing) {
+      if ($job['period'] != $existing['period'] || $job['crontab'] != $existing['crontab']) {
+        $existing['period'] = $job['period'];
+        $existing['crontab'] = $job['crontab'];
+        $this->reschedule($existing);
+      }
+      return $existing;
+    }
+  }
+}