cms/drupal/includes/batch.inc
changeset 541 e756a8c72c3d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/includes/batch.inc	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,539 @@
+<?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()
+ */
+
+/**
+ * Loads a batch from the database.
+ *
+ * @param $id
+ *   The ID of the batch to load. When a progressive batch is being processed,
+ *   the relevant ID is found in $_REQUEST['id'].
+ *
+ * @return
+ *   An array representing the batch, or FALSE if no batch was found.
+ */
+function batch_load($id) {
+  $batch = db_query("SELECT batch FROM {batch} WHERE bid = :bid AND token = :token", array(
+    ':bid' => $id,
+    ':token' => drupal_get_token($id),
+  ))->fetchField();
+  if ($batch) {
+    return unserialize($batch);
+  }
+  return FALSE;
+}
+
+/**
+ * Renders the batch processing page based on the current state of the batch.
+ *
+ * @see _batch_shutdown()
+ */
+function _batch_page() {
+  $batch = &batch_get();
+
+  if (!isset($_REQUEST['id'])) {
+    return FALSE;
+  }
+
+  // Retrieve the current state of the batch.
+  if (!$batch) {
+    $batch = batch_load($_REQUEST['id']);
+    if (!$batch) {
+      drupal_set_message(t('No active batch.'), 'error');
+      drupal_goto();
+    }
+  }
+
+  // Register database update for the end of processing.
+  drupal_register_shutdown_function('_batch_shutdown');
+
+  // Add batch-specific CSS.
+  foreach ($batch['sets'] as $batch_set) {
+    if (isset($batch_set['css'])) {
+      foreach ($batch_set['css'] as $css) {
+        drupal_add_css($css);
+      }
+    }
+  }
+
+  $op = isset($_REQUEST['op']) ? $_REQUEST['op'] : '';
+  $output = NULL;
+  switch ($op) {
+    case 'start':
+      $output = _batch_start();
+      break;
+
+    case 'do':
+      // JavaScript-based progress page callback.
+      _batch_do();
+      break;
+
+    case 'do_nojs':
+      // Non-JavaScript-based progress page.
+      $output = _batch_progress_page_nojs();
+      break;
+
+    case 'finished':
+      $output = _batch_finished();
+      break;
+  }
+
+  return $output;
+}
+
+/**
+ * Initializes the batch processing.
+ *
+ * JavaScript-enabled clients are identified by the 'has_js' cookie set in
+ * drupal.js. If no JavaScript-enabled page has been visited during the current
+ * user's browser session, the non-JavaScript version is returned.
+ */
+function _batch_start() {
+  if (isset($_COOKIE['has_js']) && $_COOKIE['has_js']) {
+    return _batch_progress_page_js();
+  }
+  else {
+    return _batch_progress_page_nojs();
+  }
+}
+
+/**
+ * Outputs a batch processing page with JavaScript support.
+ *
+ * This initializes the batch and error messages. Note that in JavaScript-based
+ * processing, the batch processing page is displayed only once and updated via
+ * AHAH requests, so only the first batch set gets to define the page title.
+ * Titles specified by subsequent batch sets are not displayed.
+ *
+ * @see batch_set()
+ * @see _batch_do()
+ */
+function _batch_progress_page_js() {
+  $batch = batch_get();
+
+  $current_set = _batch_current_set();
+  drupal_set_title($current_set['title'], PASS_THROUGH);
+
+  // Merge required query parameters for batch processing into those provided by
+  // batch_set() or hook_batch_alter().
+  $batch['url_options']['query']['id'] = $batch['id'];
+
+  $js_setting = array(
+    'batch' => array(
+      'errorMessage' => $current_set['error_message'] . '<br />' . $batch['error_message'],
+      'initMessage' => $current_set['init_message'],
+      'uri' => url($batch['url'], $batch['url_options']),
+    ),
+  );
+  drupal_add_js($js_setting, 'setting');
+  drupal_add_library('system', 'drupal.batch');
+
+  return '<div id="progress"></div>';
+}
+
+/**
+ * Does one execution pass with JavaScript and returns progress to the browser.
+ *
+ * @see _batch_progress_page_js()
+ * @see _batch_process()
+ */
+function _batch_do() {
+  // HTTP POST required.
+  if ($_SERVER['REQUEST_METHOD'] != 'POST') {
+    drupal_set_message(t('HTTP POST is required.'), 'error');
+    drupal_set_title(t('Error'));
+    return '';
+  }
+
+  // Perform actual processing.
+  list($percentage, $message) = _batch_process();
+
+  drupal_json_output(array('status' => TRUE, 'percentage' => $percentage, 'message' => $message));
+}
+
+/**
+ * Outputs a batch processing page without JavaScript support.
+ *
+ * @see _batch_process()
+ */
+function _batch_progress_page_nojs() {
+  $batch = &batch_get();
+
+  $current_set = _batch_current_set();
+  drupal_set_title($current_set['title'], PASS_THROUGH);
+
+  $new_op = 'do_nojs';
+
+  if (!isset($batch['running'])) {
+    // This is the first page so we return some output immediately.
+    $percentage       = 0;
+    $message          = $current_set['init_message'];
+    $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'];
+    $fallback = theme('maintenance_page', array('content' => $fallback, 'show_messages' => FALSE));
+
+    // We strip the end of the page using a marker in the template, so any
+    // additional HTML output by PHP shows up inside the page rather than below
+    // it. While this causes invalid HTML, the same would be true if we didn't,
+    // as content is not allowed to appear after </html> anyway.
+    list($fallback) = explode('<!--partial-->', $fallback);
+    print $fallback;
+
+    // Perform actual processing.
+    list($percentage, $message) = _batch_process($batch);
+    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().
+  $batch['url_options']['query']['id'] = $batch['id'];
+  $batch['url_options']['query']['op'] = $new_op;
+
+  $url = url($batch['url'], $batch['url_options']);
+  $element = array(
+    '#tag' => 'meta',
+    '#attributes' => array(
+      'http-equiv' => 'Refresh',
+      'content' => '0; URL=' . $url,
+    ),
+  );
+  drupal_add_html_head($element, 'batch_progress_meta_refresh');
+
+  return theme('progress_bar', array('percent' => $percentage, 'message' => $message));
+}
+
+/**
+ * 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
+ *   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.
+  $set_changed = TRUE;
+
+  // If this batch was marked for progressive execution (e.g. forms submitted by
+  // drupal_form_submit()), initialize a timer to determine whether we need to
+  // proceed with the same batch phase when a processing time of 1 second has
+  // been exceeded.
+  if ($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 = $queue->claimItem()) {
+      list($function, $args) = $item->data;
+
+      // Build the 'context' array and execute the function call.
+      $batch_context = array(
+        'sandbox'  => &$current_set['sandbox'],
+        'results'  => &$current_set['results'],
+        'finished' => &$finished,
+        'message'  => &$task_message,
+      );
+      call_user_func_array($function, array_merge($args, array(&$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'] = array();
+      }
+    }
+
+    // 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 form_execute_handlers()), 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'];
+      $total            = $old_set['total'];
+      $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;
+    $percentage = _batch_api_percentage($total, $current);
+    $elapsed    = isset($current_set['elapsed']) ? $current_set['elapsed'] : 0;
+    $values     = array(
+      '@remaining'  => $remaining,
+      '@total'      => $total,
+      '@current'    => floor($current),
+      '@percentage' => $percentage,
+      '@elapsed'    => format_interval($elapsed / 1000),
+      // If possible, estimate remaining processing time.
+      '@estimate'   => ($current > 0) ? format_interval(($elapsed * ($total - $current) / $current) / 1000) : '-',
+    );
+    $message = strtr($progress_message, $values);
+    if (!empty($message)) {
+      $message .= '<br />';
+    }
+    if (!empty($task_message)) {
+      $message .= $task_message;
+    }
+
+    return array($percentage, $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 $total
+ *   The total number of operations.
+ * @param $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 $current represents the
+ *   fraction of the operation that has been completed.
+ *
+ * @return
+ *   The properly formatted percentage, as a string. We output percentages
+ *   using the correct number of decimal places so that we never print "100%"
+ *   until we are finished, but we also never print more decimal places than
+ *   are meaningful.
+ *
+ * @see _batch_process()
+ */
+function _batch_api_percentage($total, $current) {
+  if (!$total || $total == $current) {
+    // If $total doesn't evaluate as true or is equal to the current set, then
+    // we're finished, and we can return "100".
+    $percentage = "100";
+  }
+  else {
+    // We add a new digit at 200, 2000, etc. (since, for example, 199/200
+    // would round up to 100% if we didn't).
+    $decimal_places = max(0, floor(log10($total / 2.0)) - 1);
+    do {
+      // Calculate the percentage to the specified number of decimal places.
+      $percentage = sprintf('%01.' . $decimal_places . 'f', round($current / $total * 100, $decimal_places));
+      // When $current is an integer, the above calculation will always be
+      // correct. However, if $current is a floating point number (in the case
+      // of a multi-step batch operation that is not yet complete), $percentage
+      // may be erroneously rounded up to 100%. To prevent that, we add one
+      // more decimal place and try again.
+      $decimal_places++;
+    } while ($percentage == '100');
+  }
+  return $percentage;
+}
+
+/**
+ * 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 if a subsequent set was found in the batch.
+ */
+function _batch_next_set() {
+  $batch = &batch_get();
+  if (isset($batch['sets'][$batch['current_set'] + 1])) {
+    $batch['current_set']++;
+    $current_set = &_batch_current_set();
+    if (isset($current_set['form_submit']) && ($function = $current_set['form_submit']) && function_exists($function)) {
+      // We use our stored copies of $form and $form_state to account for
+      // possible alterations by previous form submit handlers.
+      $function($batch['form_state']['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() {
+  $batch = &batch_get();
+
+  // Execute the 'finished' callbacks for each batch set, if defined.
+  foreach ($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 = $queue->getAllItems();
+        call_user_func($batch_set['finished'], $batch_set['success'], $batch_set['results'], $operations, format_interval($batch_set['elapsed'] / 1000));
+      }
+    }
+  }
+
+  // Clean up the batch table and unset the static $batch variable.
+  if ($batch['progressive']) {
+    db_delete('batch')
+      ->condition('bid', $batch['id'])
+      ->execute();
+    foreach ($batch['sets'] as $batch_set) {
+      if ($queue = _batch_queue($batch_set)) {
+        $queue->deleteQueue();
+      }
+    }
+  }
+  $_batch = $batch;
+  $batch = NULL;
+
+  // Clean-up the session. Not needed for CLI updates.
+  if (isset($_SESSION)) {
+    unset($_SESSION['batches'][$batch['id']]);
+    if (empty($_SESSION['batches'])) {
+      unset($_SESSION['batches']);
+    }
+  }
+
+  // Redirect if needed.
+  if ($_batch['progressive']) {
+    // Revert the 'destination' that was saved in batch_process().
+    if (isset($_batch['destination'])) {
+      $_GET['destination'] = $_batch['destination'];
+    }
+
+    // Determine the target path to redirect to.
+    if (!isset($_batch['form_state']['redirect'])) {
+      if (isset($_batch['redirect'])) {
+        $_batch['form_state']['redirect'] = $_batch['redirect'];
+      }
+      else {
+        $_batch['form_state']['redirect'] = $_batch['source_url'];
+      }
+    }
+
+    // Use drupal_redirect_form() to handle the redirection logic.
+    drupal_redirect_form($_batch['form_state']);
+
+    // If no redirection happened, redirect to the originating page. In case the
+    // form needs to be rebuilt, save the final $form_state for
+    // drupal_build_form().
+    if (!empty($_batch['form_state']['rebuild'])) {
+      $_SESSION['batch_form_state'] = $_batch['form_state'];
+    }
+    $function = $_batch['redirect_callback'];
+    if (function_exists($function)) {
+      $function($_batch['source_url'], array('query' => array('op' => 'finish', 'id' => $_batch['id'])));
+    }
+  }
+}
+
+/**
+ * Shutdown function: Stores the current batch data for the next request.
+ *
+ * @see _batch_page()
+ * @see drupal_register_shutdown_function()
+ */
+function _batch_shutdown() {
+  if ($batch = batch_get()) {
+    db_update('batch')
+      ->fields(array('batch' => serialize($batch)))
+      ->condition('bid', $batch['id'])
+      ->execute();
+  }
+}