9.5/_memcached_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\Frontend\FrontendInterface;

use ‪TYPO3\CMS\Core\Core\Environment;


class ‪MemcachedBackend extends ‪AbstractBackend implements ‪TaggableBackendInterface, ‪TransientBackendInterface

{

    const ‪MAX_BUCKET_SIZE = 1048534;


    protected ‪$memcache;


    protected ‪$usedPeclModule = '';


    protected ‪$servers = [];


    protected ‪$flags;


    protected ‪$identifierPrefix;


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

    {

        if (!extension_loaded('memcache') && !extension_loaded('memcached')) {

            throw new ‪Exception('The PHP extension "memcache" or "memcached" must be installed and loaded in ' . 'order to use the Memcached backend.', 1213987706);

        }


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


        if ($this->usedPeclModule === '') {

            if (extension_loaded('memcache')) {

                $this->usedPeclModule = 'memcache';

            } elseif (extension_loaded('memcached')) {

                $this->usedPeclModule = 'memcached';

            }

        }

    }


    protected function ‪setServers(array ‪$servers)

    {

        $this->servers = ‪$servers;

    }


    protected function ‪setCompression($useCompression)

    {

        $compressionFlag = $this->usedPeclModule === 'memcache' ? MEMCACHE_COMPRESSED : \Memcached::OPT_COMPRESSION;

        if ($useCompression === true) {

            $this->flags ^= $compressionFlag;

        } else {

            $this->flags &= ~$compressionFlag;

        }

    }


    protected function ‪getCompression()

    {

        return $this->flags !== 0;

    }


    public function ‪initializeObject()

    {

        if (empty($this->servers)) {

            throw new Exception('No servers were given to Memcache', 1213115903);

        }

        $memcachedPlugin = '\\' . ucfirst($this->usedPeclModule);

        $this->memcache = new $memcachedPlugin;

        $defaultPort = $this->usedPeclModule === 'memcache' ? ini_get('memcache.default_port') : 11211;

        foreach ($this->servers as $server) {

            if (strpos($server, 'unix://') === 0) {

                $host = $server;

                $port = 0;

            } else {

                if (strpos($server, 'tcp://') === 0) {

                    $server = substr($server, 6);

                }

                if (strpos($server, ':') !== false) {

                    list($host, $port) = explode(':', $server, 2);

                } else {

                    $host = $server;

                    $port = $defaultPort;

                }

            }

            $this->memcache->addserver($host, $port);

        }

        if ($this->usedPeclModule === 'memcached') {

            $this->memcache->setOption(\Memcached::OPT_COMPRESSION, $this->‪getCompression());

        }

    }


    public function ‪setPeclModule($peclModule)

    {

        if ($peclModule !== 'memcache' && $peclModule !== 'memcached') {

            throw new Exception('PECL module must be either "memcache" or "memcached".', 1442239768);

        }


        $this->usedPeclModule = $peclModule;

    }


    public function ‪setCache(FrontendInterface ‪$cache)

    {

        parent::setCache(‪$cache);

        $identifierHash = substr(md5(‪Environment::getProjectPath() . $this->context . $this->cacheIdentifier), 0, 12);

        $this->identifierPrefix = 'TYPO3_' . $identifierHash . '_';

    }


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

    {

        if (strlen($this->identifierPrefix . $entryIdentifier) > 250) {

            throw new \InvalidArgumentException('Could not set value. Key more than 250 characters (' . $this->identifierPrefix . $entryIdentifier . ').', 1232969508);

        }

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

            throw new Exception('No cache frontend has been set yet via setCache().', 1207149215);

        }

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

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


        // Memcached consideres values over 2592000 sec (30 days) as UNIX timestamp

        // thus $expiration should be converted from lifetime to UNIX timestamp

        if ($expiration > 2592000) {

            $expiration += ‪$GLOBALS['EXEC_TIME'];

        }

        try {

            if (is_string($data) && strlen($data) > self::MAX_BUCKET_SIZE) {

                $data = str_split($data, 1024 * 1000);

                $success = true;

                $chunkNumber = 1;

                foreach ($data as $chunk) {

                    $success = $success && $this->‪setInternal($entryIdentifier . '_chunk_' . $chunkNumber, $chunk, $expiration);

                    $chunkNumber++;

                }

                $success = $success && $this->‪setInternal($entryIdentifier, 'TYPO3*chunked:' . $chunkNumber, $expiration);

            } else {

                $success = $this->‪setInternal($entryIdentifier, $data, $expiration);

            }

            if ($success === true) {

                $this->‪removeIdentifierFromAllTags($entryIdentifier);

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

            } else {

                throw new Exception('Could not set data to memcache server.', 1275830266);

            }

        } catch (\Exception $exception) {

            $this->logger->alert('Memcache: could not set value.', ['exception' => $exception]);

        }

    }


    protected function ‪setInternal($entryIdentifier, $data, $expiration)

    {

        if ($this->usedPeclModule === 'memcache') {

            return $this->memcache->set($this->identifierPrefix . $entryIdentifier, $data, $this->flags, $expiration);

        }

        return $this->memcache->set($this->identifierPrefix . $entryIdentifier, $data, $expiration);

    }


    public function get($entryIdentifier)

    {

        $value = $this->memcache->get($this->identifierPrefix . $entryIdentifier);

        if (is_string($value) && strpos($value, 'TYPO3*chunked:') === 0) {

            list(, $chunkCount) = explode(':', $value);

            $value = '';

            for ($chunkNumber = 1; $chunkNumber < $chunkCount; $chunkNumber++) {

                $value .= $this->memcache->get($this->identifierPrefix . $entryIdentifier . '_chunk_' . $chunkNumber);

            }

        }

        return $value;

    }


    public function ‪has($entryIdentifier)

    {

        if ($this->usedPeclModule === 'memcache') {

            return $this->memcache->get($this->identifierPrefix . $entryIdentifier) !== false;

        }


        // pecl-memcached supports storing literal FALSE

        $this->memcache->get($this->identifierPrefix . $entryIdentifier);

        return $this->memcache->getResultCode() !== \Memcached::RES_NOTFOUND;

    }


    public function remove($entryIdentifier)

    {

        $this->‪removeIdentifierFromAllTags($entryIdentifier);

        return $this->memcache->delete($this->identifierPrefix . $entryIdentifier, 0);

    }


    public function ‪findIdentifiersByTag($tag)

    {

        $identifiers = $this->memcache->get($this->identifierPrefix . 'tag_' . $tag);

        if ($identifiers !== false) {

            return (array)$identifiers;

        }

        return [];

    }


    public function ‪flush()

    {

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

            throw new Exception('No cache frontend has been set via setCache() yet.', 1204111376);

        }

        $this->‪flushByTag('%MEMCACHEBE%' . $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;

                $this->memcache->set($this->identifierPrefix . '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) {

            $this->memcache->set($this->identifierPrefix . '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)) {

                    $this->memcache->set($this->identifierPrefix . 'tag_' . $tag, $identifiers);

                } else {

                    $this->memcache->delete($this->identifierPrefix . 'tag_' . $tag, 0);

                }

            }

        }

        // Clear reverse tag index for this identifier

        $this->memcache->delete($this->identifierPrefix . 'ident_' . $entryIdentifier, 0);

    }


    protected function ‪findTagsByIdentifier($identifier)

    {

        $tags = $this->memcache->get($this->identifierPrefix . 'ident_' . $identifier);

        return $tags === false ? [] : (array)$tags;

    }


    public function ‪collectGarbage()

    {

    }

}