function tracker_cron

Implements hook_cron().

Updates tracking information for any items still to be tracked. The variable 'tracker_index_nid' is set to ((the last node ID that was indexed) - 1) and used to select the nodes to be processed. If there are no remaining nodes to process, 'tracker_index_nid' will be 0.

File

modules/tracker/tracker.module, line 79

Code

function tracker_cron() {
    $max_nid = variable_get('tracker_index_nid', 0);
    $batch_size = variable_get('tracker_batch_size', 1000);
    if ($max_nid > 0) {
        $last_nid = FALSE;
        $result = db_query_range('SELECT nid, uid, status FROM {node} WHERE nid <= :max_nid ORDER BY nid DESC', 0, $batch_size, array(
            ':max_nid' => $max_nid,
        ), array(
            'target' => 'slave',
        ));
        $count = 0;
        foreach ($result as $row) {
            // Calculate the changed timestamp for this node.
            $changed = _tracker_calculate_changed($row->nid);
            // Remove existing data for this node.
            db_delete('tracker_node')->condition('nid', $row->nid)
                ->execute();
            db_delete('tracker_user')->condition('nid', $row->nid)
                ->execute();
            // Insert the node-level data.
            db_insert('tracker_node')->fields(array(
                'nid' => $row->nid,
                'published' => $row->status,
                'changed' => $changed,
            ))
                ->execute();
            // Insert the user-level data for the node's author.
            db_insert('tracker_user')->fields(array(
                'nid' => $row->nid,
                'published' => $row->status,
                'changed' => $changed,
                'uid' => $row->uid,
            ))
                ->execute();
            $query = db_select('comment', 'c', array(
                'target' => 'slave',
            ));
            // Force PostgreSQL to do an implicit cast by adding 0.
            $query->addExpression('0 + :changed', 'changed', array(
                ':changed' => $changed,
            ));
            $query->addField('c', 'status', 'published');
            $query->distinct()
                ->fields('c', array(
                'uid',
                'nid',
            ))
                ->condition('c.nid', $row->nid)
                ->condition('c.uid', $row->uid, '<>')
                ->condition('c.status', COMMENT_PUBLISHED);
            // Insert the user-level data for the commenters (except if a commenter
            // is the node's author).
            db_insert('tracker_user')->from($query)
                ->execute();
            // Note that we have indexed at least one node.
            $last_nid = $row->nid;
            $count++;
        }
        if ($last_nid !== FALSE) {
            // Prepare a starting point for the next run.
            variable_set('tracker_index_nid', $last_nid - 1);
            watchdog('tracker', 'Indexed %count content items for tracking.', array(
                '%count' => $count,
            ));
        }
        else {
            // If all nodes have been indexed, set to zero to skip future cron runs.
            variable_set('tracker_index_nid', 0);
        }
    }
}