9.5/_apcu_backend_8php_source.html

<?php

namespace ‪TYPO3\CMS\Core\Cache\Backend;


/*

 * This file is part of the TYPO3 CMS project.

 *

 * It is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, either version 2

 * of the License, or any later version.

 *

 * For the full copyright and license information, please read the

 * LICENSE.txt file that was distributed with this source code.

 *

 * The TYPO3 project - inspiring people to share!

 */


use ‪TYPO3\CMS\Core\Cache\Exception;

use ‪TYPO3\CMS\Core\Cache\Exception\InvalidDataException;

use ‪TYPO3\CMS\Core\Cache\Frontend\FrontendInterface;

use ‪TYPO3\CMS\Core\Core\Environment;

use ‪TYPO3\CMS\Core\Utility\GeneralUtility;


class ‪ApcuBackend extends ‪AbstractBackend implements ‪TaggableBackendInterface

{

    protected ‪$identifierPrefix;


    protected function ‪setIdentifierPrefix(‪$identifierPrefix)

    {

        $this->identifierPrefix = ‪$identifierPrefix;

    }


    protected function ‪getIdentifierPrefix()

    {

        return ‪$this->identifierPrefix;

    }


    public function ‪__construct(‪$context, array $options = [])

    {

        if (!extension_loaded('apcu')) {

            throw new ‪Exception('The PHP extension "apcu" must be installed and loaded in order to use the APCu backend.', 1232985914);

        }

        if (PHP_SAPI === 'cli' && ini_get('apc.enable_cli') == 0) {

            throw new ‪Exception('The APCu backend cannot be used because apcu is disabled on CLI.', 1232985915);

        }

        parent::__construct(‪$context, $options);

    }


    public function ‪setCache(‪FrontendInterface ‪$cache)

    {

        parent::setCache(‪$cache);

        $processUser = $this->‪getCurrentUserData();

        $pathHash = GeneralUtility::shortMD5(‪Environment::getProjectPath() . $processUser['name'] . $this->context . ‪$cache->‪getIdentifier(), 12);

        $this->‪setIdentifierPrefix('TYPO3_' . $pathHash);

    }


    protected function ‪getCurrentUserData()

    {

        return extension_loaded('posix') ? posix_getpwuid(posix_geteuid()) : ['name' => 'default'];

    }


    public function set($entryIdentifier, $data, array $tags = [], $lifetime = null)

    {

        if (!$this->cache instanceof ‪FrontendInterface) {

            throw new ‪Exception('No cache frontend has been set yet via setCache().', 1232986118);

        }

        if (!is_string($data)) {

            throw new ‪InvalidDataException('The specified data is of type "' . gettype($data) . '" but a string is expected.', 1232986125);

        }

        $tags[] = '%APCBE%' . ‪$this->cacheIdentifier;

        $expiration = $lifetime ?? ‪$this->defaultLifetime;

        $success = apcu_store($this->‪getIdentifierPrefix() . $entryIdentifier, $data, $expiration);

        if ($success === true) {

            $this->‪removeIdentifierFromAllTags($entryIdentifier);

            $this->‪addIdentifierToTags($entryIdentifier, $tags);

        } else {

            $this->logger->alert('Error using APCu: Could not save data in the cache.');

        }

    }


    public function get($entryIdentifier)

    {

        $success = false;

        $value = apcu_fetch($this->‪getIdentifierPrefix() . $entryIdentifier, $success);

        return $success ? $value : $success;

    }


    public function ‪has($entryIdentifier)

    {

        $success = false;

        apcu_fetch($this->‪getIdentifierPrefix() . $entryIdentifier, $success);

        return $success;

    }


    public function remove($entryIdentifier)

    {

        $this->‪removeIdentifierFromAllTags($entryIdentifier);

        return apcu_delete($this->‪getIdentifierPrefix() . $entryIdentifier);

    }


    public function ‪findIdentifiersByTag($tag)

    {

        $success = false;

        $identifiers = apcu_fetch($this->‪getIdentifierPrefix() . 'tag_' . $tag, $success);

        if ($success === false) {

            return [];

        }

        return (array)$identifiers;

    }


    protected function ‪findTagsByIdentifier($identifier)

    {

        $success = false;

        $tags = apcu_fetch($this->‪getIdentifierPrefix() . 'ident_' . $identifier, $success);

        return $success ? (array)$tags : [];

    }


    public function ‪flush()

    {

        if (!$this->cache instanceof ‪FrontendInterface) {

            throw new ‪Exception('Yet no cache frontend has been set via setCache().', 1232986571);

        }

        $this->‪flushByTag('%APCBE%' . $this->cacheIdentifier);

    }


    public function ‪flushByTag($tag)

    {

        $identifiers = $this->‪findIdentifiersByTag($tag);

        foreach ($identifiers as $identifier) {

            $this->remove($identifier);

        }

    }


    protected function ‪addIdentifierToTags($entryIdentifier, array $tags)

    {

        // Get identifier-to-tag index to look for updates

        $existingTags = $this->‪findTagsByIdentifier($entryIdentifier);

        $existingTagsUpdated = false;


        foreach ($tags as $tag) {

            // Update tag-to-identifier index

            $identifiers = $this->‪findIdentifiersByTag($tag);

            if (!in_array($entryIdentifier, $identifiers, true)) {

                $identifiers[] = $entryIdentifier;

                apcu_store($this->‪getIdentifierPrefix() . 'tag_' . $tag, $identifiers);

            }

            // Test if identifier-to-tag index needs update

            if (!in_array($tag, $existingTags, true)) {

                $existingTags[] = $tag;

                $existingTagsUpdated = true;

            }

        }


        // Update identifier-to-tag index if needed

        if ($existingTagsUpdated) {

            apcu_store($this->‪getIdentifierPrefix() . 'ident_' . $entryIdentifier, $existingTags);

        }

    }


    protected function ‪removeIdentifierFromAllTags($entryIdentifier)

    {

        // Get tags for this identifier

        $tags = $this->‪findTagsByIdentifier($entryIdentifier);

        // De-associate tags with this identifier

        foreach ($tags as $tag) {

            $identifiers = $this->‪findIdentifiersByTag($tag);

            // Formally array_search() below should never return FALSE due to

            // the behavior of findTagsByIdentifier(). But if reverse index is

            // corrupted, we still can get 'FALSE' from array_search(). This is

            // not a problem because we are removing this identifier from

            // anywhere.

            if (($key = array_search($entryIdentifier, $identifiers)) !== false) {

                unset($identifiers[$key]);

                if (!empty($identifiers)) {

                    apcu_store($this->‪getIdentifierPrefix() . 'tag_' . $tag, $identifiers);

                } else {

                    apcu_delete($this->‪getIdentifierPrefix() . 'tag_' . $tag);

                }

            }

        }

        // Clear reverse tag index for this identifier

        apcu_delete($this->‪getIdentifierPrefix() . 'ident_' . $entryIdentifier);

    }


    public function ‪collectGarbage()

    {

    }

}