batch.inc

<?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);
    }
}