nextcloud-server/apps/settings/lib/SetupChecks/PhpOpcacheSetup.php

<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */
namespace OCA\Settings\SetupChecks;

use bantu\IniGetWrapper\IniGetWrapper;
use OCP\IL10N;
use OCP\IURLGenerator;
use OCP\SetupCheck\ISetupCheck;
use OCP\SetupCheck\SetupResult;

class PhpOpcacheSetup implements ISetupCheck {
	public function __construct(
		private IL10N $l10n,
		private IURLGenerator $urlGenerator,
		private IniGetWrapper $iniGetWrapper,
	) {
	}

	public function getName(): string {
		return $this->l10n->t('PHP opcache');
	}

	public function getCategory(): string {
		return 'php';
	}

	/**
	 * Checks whether a PHP OPcache is properly set up
	 * @return array{'warning'|'error',list<string>} The level and the list of OPcache setup recommendations
	 */
	protected function getOpcacheSetupRecommendations(): array {
		$level = 'warning';

		// If the module is not loaded, return directly to skip inapplicable checks
		if (!extension_loaded('Zend OPcache')) {
			return ['error',[$this->l10n->t('The PHP OPcache module is not loaded. For better performance it is recommended to load it into your PHP installation.')]];
		}

		$recommendations = [];

		// Check whether Nextcloud is allowed to use the OPcache API
		$isPermitted = true;
		$permittedPath = (string)$this->iniGetWrapper->getString('opcache.restrict_api');
		if ($permittedPath !== '' && !str_starts_with(\OC::$SERVERROOT, rtrim($permittedPath, '/'))) {
			$isPermitted = false;
		}

		if (!$this->iniGetWrapper->getBool('opcache.enable')) {
			$recommendations[] = $this->l10n->t('OPcache is disabled. For better performance, it is recommended to apply "opcache.enable=1" to your PHP configuration.');
			$level = 'error';
		} elseif ($this->iniGetWrapper->getBool('opcache.file_cache_only')) {
			$recommendations[] = $this->l10n->t('The shared memory based OPcache is disabled. For better performance, it is recommended to apply "opcache.file_cache_only=0" to your PHP configuration and use the file cache as second level cache only.');
		} else {
			// Check whether opcache_get_status has been explicitly disabled and in case skip usage based checks
			$disabledFunctions = $this->iniGetWrapper->getString('disable_functions');
			if (isset($disabledFunctions) && str_contains($disabledFunctions, 'opcache_get_status')) {
				return [$level, $recommendations];
			}

			$status = opcache_get_status(false);

			if ($status === false) {
				$recommendations[] = $this->l10n->t('OPcache is not working as it should, opcache_get_status() returns false, please check configuration.');
				$level = 'error';
			}

			// Check whether OPcache is full, which can be either the overall OPcache size or limit of cached keys reached.
			// If the limit of cached keys has been reached, num_cached_keys equals max_cached_keys. The recommendation contains this value instead of opcache.max_accelerated_files, since the effective limit is a next higher prime number: https://www.php.net/manual/en/opcache.configuration.php#ini.opcache.max-accelerated-files
			// Else, the remaining $status['memory_usage']['free_memory'] was too low to store another script. Aside of used_memory, this can be also due to wasted_memory, remaining cache keys from scripts changed on disk.
			// Wasted memory is cleared only via opcache_reset(), or if $status['memory_usage']['current_wasted_percentage'] reached opcache.max_wasted_percentage, which triggers an engine restart and hence OPcache reset. Due to this complexity, we check for $status['cache_full'] only.
			if ($status['cache_full'] === true) {
				if ($status['opcache_statistics']['num_cached_keys'] === $status['opcache_statistics']['max_cached_keys']) {
					$recommendations[] = $this->l10n->t('The maximum number of OPcache keys is nearly exceeded. To assure that all scripts can be kept in the cache, it is recommended to apply "opcache.max_accelerated_files" to your PHP configuration with a value higher than "%s".', [($status['opcache_statistics']['max_cached_keys'] ?: 'currently')]);
				} else {
					$recommendations[] = $this->l10n->t('The OPcache buffer is nearly full. To assure that all scripts can be hold in cache, it is recommended to apply "opcache.memory_consumption" to your PHP configuration with a value higher than "%s".', [($this->iniGetWrapper->getNumeric('opcache.memory_consumption') ?: 'currently')]);
				}
			}

			// Interned strings buffer: recommend to raise size if more than 90% is used
			$interned_strings_buffer = $this->iniGetWrapper->getNumeric('opcache.interned_strings_buffer') ?? 0;
			$memory_consumption = $this->iniGetWrapper->getNumeric('opcache.memory_consumption') ?? 0;
			if (
				// Do not recommend to raise the interned strings buffer size above a quarter of the total OPcache size
				($interned_strings_buffer < ($memory_consumption / 4))
				&& (
					empty($status['interned_strings_usage']['free_memory'])
					|| ($status['interned_strings_usage']['used_memory'] / $status['interned_strings_usage']['free_memory'] > 9)
				)
			) {
				$recommendations[] = $this->l10n->t('The OPcache interned strings buffer is nearly full. To assure that repeating strings can be effectively cached, it is recommended to apply "opcache.interned_strings_buffer" to your PHP configuration with a value higher than "%s".', [($this->iniGetWrapper->getNumeric('opcache.interned_strings_buffer') ?: 'currently')]);
			}
		}

		// Check for saved comments only when OPcache is currently disabled. If it was enabled, opcache.save_comments=0 would break Nextcloud in the first place.
		if (!$this->iniGetWrapper->getBool('opcache.save_comments')) {
			$recommendations[] = $this->l10n->t('OPcache is configured to remove code comments. With OPcache enabled, "opcache.save_comments=1" must be set for Nextcloud to function.');
			$level = 'error';
		}

		if (!$isPermitted) {
			$recommendations[] = $this->l10n->t('Nextcloud is not allowed to use the OPcache API. With OPcache enabled, it is highly recommended to include all Nextcloud directories with "opcache.restrict_api" or unset this setting to disable OPcache API restrictions, to prevent errors during Nextcloud core or app upgrades.');
			$level = 'error';
		}

		return [$level, $recommendations];
	}

	public function run(): SetupResult {
		// Skip OPcache checks if running from CLI
		if (\OC::$CLI && !$this->iniGetWrapper->getBool('opcache.enable_cli')) {
			return SetupResult::success($this->l10n->t('Checking from CLI, OPcache checks have been skipped.'));
		}

		[$level,$recommendations] = $this->getOpcacheSetupRecommendations();
		if (!empty($recommendations)) {
			return match($level) {
				'error' => SetupResult::error(
					$this->l10n->t('The PHP OPcache module is not properly configured. %s.', implode("\n", $recommendations)),
					$this->urlGenerator->linkToDocs('admin-php-opcache')
				),
				default => SetupResult::warning(
					$this->l10n->t('The PHP OPcache module is not properly configured. %s.', implode("\n", $recommendations)),
					$this->urlGenerator->linkToDocs('admin-php-opcache')
				),
			};
		} else {
			return SetupResult::success($this->l10n->t('Correctly configured'));
		}
	}
}