phpbb\install\module\update_filesystem\task\file_check::run PHP Method

    public function run()
    {
        if (!$this->installer_config->has_restart_point('check_update_files')) {
            $this->installer_config->create_progress_restart_point('check_update_files');
        }
        $old_path = $this->update_helper->get_path_to_old_update_files();
        $new_path = $this->update_helper->get_path_to_new_update_files();
        $update_info = $this->installer_config->get('update_info', array());
        $file_update_info = $this->installer_config->get('update_files', array());
        if (empty($update_info)) {
            $root_path = $this->phpbb_root_path;
            $update_info = $this->installer_config->get('update_info_unprocessed', array());
            $file_update_info = array();
            $file_update_info['update_without_diff'] = array_diff($update_info['binary'], $update_info['deleted']);
            // Filter out files that are already deleted
            $file_update_info['delete'] = array_filter($update_info['deleted'], function ($filename) use($root_path) {
                return file_exists($root_path . $filename);
            });
        }
        $progress_count = $this->installer_config->get('file_check_progress_count', 0);
        $task_count = count($update_info['files']);
        $this->iohandler->set_task_count($task_count);
        $this->iohandler->set_progress('UPDATE_CHECK_FILES', 0);
        // Create list of default extensions that should have been added prior
        // to this update
        $default_update_extensions = [];
        foreach (\phpbb\install\module\update_database\task\update_extensions::$default_extensions_update as $version => $extensions) {
            if ($this->update_helper->phpbb_version_compare($update_info['version']['from'], $version, '>')) {
                $default_update_extensions = array_merge($default_update_extensions, $extensions);
            }
        }
        foreach ($update_info['files'] as $key => $filename) {
            $old_file = $old_path . $filename;
            $new_file = $new_path . $filename;
            $file = $this->phpbb_root_path . $filename;
            if ($this->installer_config->get_time_remaining() <= 0 || $this->installer_config->get_memory_remaining() <= 0) {
                // Save progress
                $this->installer_config->set('update_info', $update_info);
                $this->installer_config->set('file_check_progress_count', $progress_count);
                $this->installer_config->set('update_files', $file_update_info);
                // Request refresh
                throw new resource_limit_reached_exception();
            }
            $progress_count++;
            $this->iohandler->set_progress('UPDATE_CHECK_FILES', $progress_count);
            // Do not copy default extension again if the previous version was
            // packaged with it but it does not exist (e.g. deleted by admin)
            if (strpos($file, $this->phpbb_root_path . 'ext/') !== false) {
                $skip_file = false;
                foreach ($default_update_extensions as $ext_name) {
                    if (strpos($file, $this->phpbb_root_path . 'ext/' . $ext_name) !== false && !$this->filesystem->exists($this->phpbb_root_path . 'ext/' . $ext_name . '/composer.json')) {
                        $skip_file = true;
                        break;
                    }
                }
                if ($skip_file) {
                    continue;
                }
            }
            if (!$this->filesystem->exists($file)) {
                $file_update_info['new'][] = $filename;
            } else {
                $file_checksum = md5_file($file);
                if ($file_checksum === md5_file($new_file)) {
                    // File already up to date
                    continue;
                } else {
                    if ($this->filesystem->exists($old_file) && $file_checksum === md5_file($old_file)) {
                        // No need to diff the file
                        $file_update_info['update_without_diff'][] = $filename;
                    } else {
                        $file_update_info['update_with_diff'][] = $filename;
                    }
                }
            }
            unset($update_info['files'][$key]);
        }
        $this->installer_config->set('update_files', $file_update_info);
        $this->installer_config->set('update_info', array());
    }