function entity_extract_ids($entity_type, $entity) {
  $info = entity_get_info($entity_type);
  // Objects being created might not have id/vid yet.
  $id = isset($entity->{$info['entity keys']['id']}) ? $entity->{$info['entity keys']['id']} : NULL;
  $vid = ($info['entity keys']['revision'] && isset($entity->{$info['entity keys']['revision']})) ? $entity->{$info['entity keys']['revision']} : NULL;

  if (!empty($info['entity keys']['bundle'])) {
    $bundle = $entity->{$info['entity keys']['bundle']};
    // Explicitly fail for malformed entites missing the bundle property.
    if (is_null($bundle)) {
      $funcs = array();
      $backtrace = debug_backtrace();
      $short_backtrace = array_slice($backtrace, 0, 10);
      foreach ($short_backtrace as $info) {
        $funcs[] = $info['function'];
      }
      if (count($backtrace) > 10) {
        $funcs[] = '[...]';
      }
      throw new Exception(t('Encountered an entity without a bundle property (entity type: @entity_type, callstack: @callstack).', array('@entity_type' => $entity_type, '@callstack' => implode(', ', $funcs))));
    }
  }
  else {
    // The entity type provides no bundle key: assume a single bundle, named
    // after the entity type.
    $bundle = $entity_type;
  }

  return array($id, $vid, $bundle);
}