Same filename and directory in other branches
  1. 8.9.x core/includes/batch.inc
  2. 9 core/includes/batch.inc

Batch processing API for processes to run in multiple HTTP requests.

Note that batches are usually invoked by form submissions, which is why the core interaction functions of the batch processing API live in form.inc.

See also

form.inc

batch_set()

batch_process()

batch_get()

File

core/includes/batch.inc
View source
<?php

/**
 * @file
 * Batch processing API for processes to run in multiple HTTP requests.
 *
 * Note that batches are usually invoked by form submissions, which is
 * why the core interaction functions of the batch processing API live in
 * form.inc.
 *
 * @see form.inc
 * @see batch_set()
 * @see batch_process()
 * @see batch_get()
 */
use Drupal\Component\Utility\Timer;
use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Batch\Percentage;
use Drupal\Core\Form\FormState;
use Drupal\Core\Url;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RedirectResponse;

/**
 * Renders the batch processing page based on the current state of the batch.
 *
 * @param \Symfony\Component\HttpFoundation\Request $request
 *   The current request object.
 *
 * @see _batch_shutdown()
 */
function _batch_page(Request $request) {
  $batch =& batch_get();
  if (!($request_id = $request->query
    ->get('id'))) {
    return FALSE;
  }

  // Retrieve the current state of the batch.
  if (!$batch) {
    $batch = \Drupal::service('batch.storage')
      ->load($request_id);
    if (!$batch) {
      \Drupal::messenger()
        ->addError(t('No active batch.'));
      return new RedirectResponse(Url::fromRoute('<front>', [], [
        'absolute' => TRUE,
      ])
        ->toString());
    }
  }

  // We need to store the updated batch information in the batch storage after
  // processing the batch. In order for the error page to work correctly this
  // needs to be done even in case of a PHP fatal error in which case the end of
  // this function is never reached. Therefore we register a shutdown function
  // to handle this case. Because with FastCGI and fastcgi_finish_request()
  // shutdown functions are called after the HTTP connection is closed, updating
  // the batch information in a shutdown function would lead to race conditions
  // between consecutive requests if the batch processing continues. In case of
  // a fatal error the processing stops anyway, so it works even with FastCGI.
  // However, we must ensure to only update in the shutdown phase in this
  // particular case we track whether the batch information still needs to be
  // updated.
  // @see _batch_shutdown()
  // @see \Symfony\Component\HttpFoundation\Response::send()
  drupal_register_shutdown_function('_batch_shutdown');
  _batch_needs_update(TRUE);
  $build = [];

  // Add batch-specific libraries.
  foreach ($batch['sets'] as $batch_set) {
    if (isset($batch_set['library'])) {
      foreach ($batch_set['library'] as $library) {
        $build['#attached']['library'][] = $library;
      }
    }
  }
  $response = FALSE;
  $op = $request->query
    ->get('op', '');
  switch ($op) {
    case 'start':
    case 'do_nojs':

      // Display the full progress page on startup and on each additional
      // non-JavaScript iteration.
      $current_set = _batch_current_set();
      $build['#title'] = $current_set['title'];
      $build['content'] = _batch_progress_page();
      $response = $build;
      break;
    case 'do':

      // JavaScript-based progress page callback.
      $response = _batch_do();
      break;
    case 'finished':

      // _batch_finished() returns a RedirectResponse.
      $response = _batch_finished();
      break;
  }
  if ($batch) {
    \Drupal::service('batch.storage')
      ->update($batch);
  }
  _batch_needs_update(FALSE);
  return $response;
}

/**
 * Checks whether the batch information needs to be updated in the storage.
 *
 * @param bool $new_value
 *   (optional) A new value to set.
 *
 * @return bool
 *   TRUE if the batch information needs to be updated; FALSE otherwise.
 */
function _batch_needs_update($new_value = NULL) {
  $needs_update =& drupal_static(__FUNCTION__, FALSE);
  if (isset($new_value)) {
    $needs_update = $new_value;
  }
  return $needs_update;
}

/**
 * Does one execution pass with JavaScript and returns progress to the browser.
 *
 * @see _batch_progress_page_js()
 * @see _batch_process()
 */
function _batch_do() {

  // Perform actual processing.
  [
    $percentage,
    $message,
    $label,
  ] = _batch_process();
  return new JsonResponse([
    'status' => TRUE,
    'percentage' => $percentage,
    'message' => $message,
    'label' => $label,
  ]);
}

/**
 * Outputs a batch processing page.
 *
 * @see _batch_process()
 */
function _batch_progress_page() {
  $batch =& batch_get();
  $current_set = _batch_current_set();
  $new_op = 'do_nojs';
  if (!isset($batch['running'])) {

    // This is the first page so we return some output immediately.
    $percentage = 0;
    $message = $current_set['init_message'];
    $label = '';
    $batch['running'] = TRUE;
  }
  else {

    // This is one of the later requests; do some processing first.
    // Error handling: if PHP dies due to a fatal error (e.g. a nonexistent
    // function), it will output whatever is in the output buffer, followed by
    // the error message.
    ob_start();
    $fallback = $current_set['error_message'] . '<br />' . $batch['error_message'];

    // We strip the end of the page using a marker in the template, so any
    // additional HTML output by PHP shows up inside the page rather than below
    // it. While this causes invalid HTML, the same would be true if we didn't,
    // as content is not allowed to appear after </html> anyway.
    $bare_html_page_renderer = \Drupal::service('bare_html_page_renderer');
    $response = $bare_html_page_renderer
      ->renderBarePage([
      '#markup' => $fallback,
    ], $current_set['title'], 'maintenance_page', [
      '#show_messages' => FALSE,
    ]);

    // Just use the content of the response.
    $fallback = $response
      ->getContent();
    [
      $fallback,
    ] = explode('<!--partial-->', $fallback);
    print $fallback;

    // Perform actual processing.
    [
      $percentage,
      $message,
      $label,
    ] = _batch_process();
    if ($percentage == 100) {
      $new_op = 'finished';
    }

    // PHP did not die; remove the fallback output.
    ob_end_clean();
  }

  // Merge required query parameters for batch processing into those provided by
  // batch_set() or hook_batch_alter().
  $query_options = $batch['url']
    ->getOption('query');
  $query_options['id'] = $batch['id'];
  $query_options['op'] = $new_op;
  $batch['url']
    ->setOption('query', $query_options);
  $url = $batch['url']
    ->toString(TRUE)
    ->getGeneratedUrl();
  $build = [
    '#theme' => 'progress_bar',
    '#percent' => $percentage,
    '#message' => [
      '#markup' => $message,
    ],
    '#label' => $label,
    '#attached' => [
      'html_head' => [
        [
          [
            // Redirect through a 'Refresh' meta tag if JavaScript is disabled.
            '#tag' => 'meta',
            '#noscript' => TRUE,
            '#attributes' => [
              'http-equiv' => 'Refresh',
              'content' => '0; URL=' . $url,
            ],
          ],
          'batch_progress_meta_refresh',
        ],
      ],
      // Adds JavaScript code and settings for clients where JavaScript is enabled.
      'drupalSettings' => [
        'batch' => [
          'errorMessage' => $current_set['error_message'] . '<br />' . $batch['error_message'],
          'initMessage' => $current_set['init_message'],
          'uri' => $url,
        ],
      ],
      'library' => [
        'core/drupal.batch',
      ],
    ],
  ];
  return $build;
}

/**
 * Processes sets in a batch.
 *
 * If the batch was marked for progressive execution (default), this executes as
 * many operations in batch sets until an execution time of 1 second has been
 * exceeded. It will continue with the next operation of the same batch set in
 * the next request.
 *
 * @return array
 *   An array containing a completion value (in percent) and a status message.
 */
function _batch_process() {
  $batch =& batch_get();
  $current_set =& _batch_current_set();

  // Indicate that this batch set needs to be initialized.
  $set_changed = TRUE;
  $task_message = '';

  // If this batch was marked for progressive execution (e.g. forms submitted by
  // \Drupal::formBuilder()->submitForm(), initialize a timer to determine
  // whether we need to proceed with the same batch phase when a processing time
  // of 1 second has been exceeded.
  if ($batch['progressive']) {
    Timer::start('batch_processing');
  }
  if (empty($current_set['start'])) {
    $current_set['start'] = microtime(TRUE);
  }
  $queue = _batch_queue($current_set);
  while (!$current_set['success']) {

    // If this is the first time we iterate this batch set in the current
    // request, we check if it requires an additional file for functions
    // definitions.
    if ($set_changed && isset($current_set['file']) && is_file($current_set['file'])) {
      include_once \Drupal::root() . '/' . $current_set['file'];
    }
    $task_message = '';

    // Assume a single pass operation and set the completion level to 1 by
    // default.
    $finished = 1;
    if ($item = $queue
      ->claimItem()) {
      [
        $callback,
        $args,
      ] = $item->data;

      // Build the 'context' array and execute the function call.
      $batch_context = [
        'sandbox' => &$current_set['sandbox'],
        'results' => &$current_set['results'],
        'finished' => &$finished,
        'message' => &$task_message,
      ];
      call_user_func_array($callback, array_merge($args, [
        &$batch_context,
      ]));
      if ($finished >= 1) {

        // Make sure this step is not counted twice when computing $current.
        $finished = 0;

        // Remove the processed operation and clear the sandbox.
        $queue
          ->deleteItem($item);
        $current_set['count']--;
        $current_set['sandbox'] = [];
      }
    }

    // When all operations in the current batch set are completed, browse
    // through the remaining sets, marking them 'successfully processed'
    // along the way, until we find a set that contains operations.
    // _batch_next_set() executes form submit handlers stored in 'control'
    // sets (see \Drupal::service('form_submitter')), which can in turn add new
    // sets to the batch.
    $set_changed = FALSE;
    $old_set = $current_set;
    while (empty($current_set['count']) && ($current_set['success'] = TRUE) && _batch_next_set()) {
      $current_set =& _batch_current_set();
      $current_set['start'] = microtime(TRUE);
      $set_changed = TRUE;
    }

    // At this point, either $current_set contains operations that need to be
    // processed or all sets have been completed.
    $queue = _batch_queue($current_set);

    // If we are in progressive mode, break processing after 1 second.
    if ($batch['progressive'] && Timer::read('batch_processing') > 1000) {

      // Record elapsed wall clock time.
      $current_set['elapsed'] = round((microtime(TRUE) - $current_set['start']) * 1000, 2);
      break;
    }
  }
  if ($batch['progressive']) {

    // Gather progress information.
    // Reporting 100% progress will cause the whole batch to be considered
    // processed. If processing was paused right after moving to a new set,
    // we have to use the info from the new (unprocessed) set.
    if ($set_changed && isset($current_set['queue'])) {

      // Processing will continue with a fresh batch set.
      $remaining = $current_set['count'];
      $total = $current_set['total'];
      $progress_message = $current_set['init_message'];
      $task_message = '';
    }
    else {

      // Processing will continue with the current batch set.
      $remaining = $old_set['count'] ?? 0;
      $total = $old_set['total'] ?? 0;
      $progress_message = $old_set['progress_message'] ?? '';
    }

    // Total progress is the number of operations that have fully run plus the
    // completion level of the current operation.
    $current = $total - $remaining + ($finished ?? 0);
    $percentage = _batch_api_percentage($total, $current);
    $elapsed = $current_set['elapsed'] ?? 0;
    $values = [
      '@remaining' => $remaining,
      '@total' => $total,
      '@current' => floor($current),
      '@percentage' => $percentage,
      '@elapsed' => \Drupal::service('date.formatter')
        ->formatInterval((int) ($elapsed / 1000)),
      // If possible, estimate remaining processing time.
      '@estimate' => $current > 0 ? \Drupal::service('date.formatter')
        ->formatInterval((int) ($elapsed * ($total - $current) / $current / 1000)) : '-',
    ];
    $message = strtr($progress_message, $values);
    return [
      $percentage,
      $message,
      $task_message,
    ];
  }
  else {

    // If we are not in progressive mode, the entire batch has been processed.
    return _batch_finished();
  }
}

/**
 * Formats the percent completion for a batch set.
 *
 * @param int $total
 *   The total number of operations.
 * @param int|float $current
 *   The number of the current operation. This may be a floating point number
 *   rather than an integer in the case of a multi-step operation that is not
 *   yet complete; in that case, the fractional part of $current represents the
 *   fraction of the operation that has been completed.
 *
 * @return string
 *   The properly formatted percentage, as a string. We output percentages
 *   using the correct number of decimal places so that we never print "100%"
 *   until we are finished, but we also never print more decimal places than
 *   are meaningful.
 *
 * @see _batch_process()
 */
function _batch_api_percentage($total, $current) {
  return Percentage::format($total, $current);
}

/**
 * Returns the batch set being currently processed.
 */
function &_batch_current_set() {
  $batch =& batch_get();
  return $batch['sets'][$batch['current_set']];
}

/**
 * Retrieves the next set in a batch.
 *
 * If there is a subsequent set in this batch, assign it as the new set to
 * process and execute its form submit handler (if defined), which may add
 * further sets to this batch.
 *
 * @return true|null
 *   TRUE if a subsequent set was found in the batch; no value will be returned
 *   if no subsequent set was found.
 */
function _batch_next_set() {
  $batch =& batch_get();
  $set_indexes = array_keys($batch['sets']);
  $current_set_index_key = array_search($batch['current_set'], $set_indexes);
  if (isset($set_indexes[$current_set_index_key + 1])) {
    $batch['current_set'] = $set_indexes[$current_set_index_key + 1];
    $current_set =& _batch_current_set();
    if (isset($current_set['form_submit']) && ($callback = $current_set['form_submit']) && is_callable($callback)) {

      // We use our stored copies of $form and $form_state to account for
      // possible alterations by previous form submit handlers.
      $complete_form =& $batch['form_state']
        ->getCompleteForm();
      call_user_func_array($callback, [
        &$complete_form,
        &$batch['form_state'],
      ]);
    }
    return TRUE;
  }
}

/**
 * Ends the batch processing.
 *
 * Call the 'finished' callback of each batch set to allow custom handling of
 * the results and resolve page redirection.
 */
function _batch_finished() {
  $batch =& batch_get();
  $batch_finished_redirect = NULL;

  // Execute the 'finished' callbacks for each batch set, if defined.
  foreach ($batch['sets'] as $batch_set) {
    if (isset($batch_set['finished'])) {

      // Check if the set requires an additional file for function definitions.
      if (isset($batch_set['file']) && is_file($batch_set['file'])) {
        include_once \Drupal::root() . '/' . $batch_set['file'];
      }
      if (is_callable($batch_set['finished'])) {
        $queue = _batch_queue($batch_set);
        $operations = $queue
          ->getAllItems();
        $batch_set_result = call_user_func_array($batch_set['finished'], [
          $batch_set['success'],
          $batch_set['results'],
          $operations,
          \Drupal::service('date.formatter')
            ->formatInterval((int) ($batch_set['elapsed'] / 1000)),
        ]);

        // If a batch 'finished' callback requested a redirect after the batch
        // is complete, save that for later use. If more than one batch set
        // returned a redirect, the last one is used.
        if ($batch_set_result instanceof RedirectResponse) {
          $batch_finished_redirect = $batch_set_result;
        }
      }
    }
  }

  // Clean up the batch table and unset the static $batch variable.
  if ($batch['progressive']) {
    \Drupal::service('batch.storage')
      ->delete($batch['id']);
    foreach ($batch['sets'] as $batch_set) {
      if ($queue = _batch_queue($batch_set)) {
        $queue
          ->deleteQueue();
      }
    }

    // Clean-up the session. Not needed for CLI updates.
    $session = \Drupal::request()
      ->getSession();
    $batches = $session
      ->get('batches', []);
    unset($batches[$batch['id']]);
    if (empty($batches)) {
      $session
        ->remove('batches');
    }
    else {
      $session
        ->set('batches', $batches);
    }
  }
  $_batch = $batch;
  $batch = NULL;

  // Redirect if needed.
  if ($_batch['progressive']) {

    // Revert the 'destination' that was saved in batch_process().
    if (isset($_batch['destination'])) {
      \Drupal::request()->query
        ->set('destination', $_batch['destination']);
    }

    // Determine the target path to redirect to. If a batch 'finished' callback
    // returned a redirect response object, use that. Otherwise, fall back on
    // the form redirection.
    if (isset($batch_finished_redirect)) {
      return $batch_finished_redirect;
    }
    elseif (!isset($_batch['form_state'])) {
      $_batch['form_state'] = new FormState();
    }
    if ($_batch['form_state']
      ->getRedirect() === NULL) {
      $redirect = $_batch['batch_redirect'] ?: $_batch['source_url'];

      // Any path with a scheme does not correspond to a route.
      if (!$redirect instanceof Url) {
        $options = UrlHelper::parse($redirect);
        if (parse_url($options['path'], PHP_URL_SCHEME)) {
          $redirect = Url::fromUri($options['path'], $options);
        }
        else {
          $redirect = \Drupal::pathValidator()
            ->getUrlIfValid($options['path']);
          if (!$redirect) {

            // Stay on the same page if the redirect was invalid.
            $redirect = Url::fromRoute('<current>');
          }
          $redirect
            ->setOptions($options);
        }
      }
      $_batch['form_state']
        ->setRedirectUrl($redirect);
    }

    // Use \Drupal\Core\Form\FormSubmitterInterface::redirectForm() to handle
    // the redirection logic.
    $redirect = \Drupal::service('form_submitter')
      ->redirectForm($_batch['form_state']);
    if (is_object($redirect)) {
      return $redirect;
    }

    // If no redirection happened, redirect to the originating page. In case the
    // form needs to be rebuilt, save the final $form_state for
    // \Drupal\Core\Form\FormBuilderInterface::buildForm().
    if ($_batch['form_state']
      ->isRebuilding()) {
      $session = \Drupal::request()
        ->getSession();
      $session
        ->set('batch_form_state', $_batch['form_state']);
    }
    $callback = $_batch['redirect_callback'];
    $_batch['source_url']
      ->mergeOptions([
      'query' => [
        'op' => 'finish',
        'id' => $_batch['id'],
      ],
    ]);
    if (is_callable($callback)) {
      $callback($_batch['source_url'], $_batch['source_url']
        ->getOption('query'));
    }
    elseif ($callback === NULL) {

      // Default to RedirectResponse objects when nothing specified.
      return new RedirectResponse($_batch['source_url']
        ->setAbsolute()
        ->toString());
    }
  }
}

/**
 * Shutdown function: Stores the current batch data for the next request.
 *
 * @see _batch_page()
 * @see drupal_register_shutdown_function()
 */
function _batch_shutdown() {
  if (($batch = batch_get()) && _batch_needs_update()) {
    \Drupal::service('batch.storage')
      ->update($batch);
  }
}

Functions

Namesort descending Description
_batch_api_percentage Formats the percent completion for a batch set.
_batch_current_set Returns the batch set being currently processed.
_batch_do Does one execution pass with JavaScript and returns progress to the browser.
_batch_finished Ends the batch processing.
_batch_needs_update Checks whether the batch information needs to be updated in the storage.
_batch_next_set Retrieves the next set in a batch.
_batch_page Renders the batch processing page based on the current state of the batch.
_batch_process Processes sets in a batch.
_batch_progress_page Outputs a batch processing page.
_batch_shutdown Shutdown function: Stores the current batch data for the next request.