FileBackend.php

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<?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\Service\OpcodeCacheService;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Core\Utility\StringUtility;

class FileBackend extends \TYPO3\CMS\Core\Cache\Backend\SimpleFileBackend implements \TYPO3\CMS\Core\Cache\Backend\PhpCapableBackendInterface, \TYPO3\CMS\Core\Cache\Backend\FreezableBackendInterface, \TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface
{
    const SEPARATOR = '^';
    const EXPIRYTIME_FORMAT = 'YmdHis';
    const EXPIRYTIME_LENGTH = 14;
    const DATASIZE_DIGITS = 10;
    protected $cacheEntryFileExtension = '';

    protected $cacheEntryIdentifiers = [];

    protected $frozen = false;

    public function freeze()
    {
        if ($this->frozen === true) {
            throw new \RuntimeException(sprintf('The cache "%s" is already frozen.', $this->cacheIdentifier), 1323353176);
        }
        $cacheEntryFileExtensionLength = strlen($this->cacheEntryFileExtension);
        for ($directoryIterator = new \DirectoryIterator($this->cacheDirectory); $directoryIterator->valid(); $directoryIterator->next()) {
            if ($directoryIterator->isDot()) {
                continue;
            }
            if ($cacheEntryFileExtensionLength > 0) {
                $entryIdentifier = substr($directoryIterator->getFilename(), 0, -$cacheEntryFileExtensionLength);
            } else {
                $entryIdentifier = $directoryIterator->getFilename();
            }
            $this->cacheEntryIdentifiers[$entryIdentifier] = true;
            file_put_contents($this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension, $this->get($entryIdentifier));
        }
        file_put_contents($this->cacheDirectory . 'FrozenCache.data', serialize($this->cacheEntryIdentifiers));
        $this->frozen = true;
    }

    public function isFrozen()
    {
        return $this->frozen;
    }

    public function setCache(\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache)
    {
        parent::setCache($cache);
        if (file_exists($this->cacheDirectory . 'FrozenCache.data')) {
            $this->frozen = true;
            $this->cacheEntryIdentifiers = unserialize(file_get_contents($this->cacheDirectory . 'FrozenCache.data'));
        }
    }

    public function set($entryIdentifier, $data, array $tags = [], $lifetime = null)
    {
        if (!is_string($data)) {
            throw new \TYPO3\CMS\Core\Cache\Exception\InvalidDataException('The specified data is of type "' . gettype($data) . '" but a string is expected.', 1204481674);
        }
        if ($entryIdentifier !== basename($entryIdentifier)) {
            throw new \InvalidArgumentException('The specified entry identifier must not contain a path segment.', 1282073032);
        }
        if ($entryIdentifier === '') {
            throw new \InvalidArgumentException('The specified entry identifier must not be empty.', 1298114280);
        }
        if ($this->frozen === true) {
            throw new \RuntimeException(sprintf('Cannot add or modify cache entry because the backend of cache "%s" is frozen.', $this->cacheIdentifier), 1323344192);
        }
        $this->remove($entryIdentifier);
        $temporaryCacheEntryPathAndFilename = $this->cacheDirectory . StringUtility::getUniqueId() . '.temp';
        $lifetime = $lifetime === null ? $this->defaultLifetime : $lifetime;
        $expiryTime = $lifetime === 0 ? 0 : $GLOBALS['EXEC_TIME'] + $lifetime;
        $metaData = str_pad($expiryTime, self::EXPIRYTIME_LENGTH) . implode(' ', $tags) . str_pad(strlen($data), self::DATASIZE_DIGITS);
        $result = file_put_contents($temporaryCacheEntryPathAndFilename, $data . $metaData);
        \TYPO3\CMS\Core\Utility\GeneralUtility::fixPermissions($temporaryCacheEntryPathAndFilename);
        if ($result === false) {
            throw new \TYPO3\CMS\Core\Cache\Exception('The temporary cache file "' . $temporaryCacheEntryPathAndFilename . '" could not be written.', 1204026251);
        }
        $i = 0;
        $cacheEntryPathAndFilename = $this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension;
        while (($result = rename($temporaryCacheEntryPathAndFilename, $cacheEntryPathAndFilename)) === false && $i < 5) {
            $i++;
        }
        if ($result === false) {
            throw new \TYPO3\CMS\Core\Cache\Exception('The cache file "' . $cacheEntryPathAndFilename . '" could not be written.', 1222361632);
        }
        if ($this->cacheEntryFileExtension === '.php') {
            GeneralUtility::makeInstance(OpcodeCacheService::class)->clearAllActive($cacheEntryPathAndFilename);
        }
    }

    public function get($entryIdentifier)
    {
        if ($this->frozen === true) {
            return isset($this->cacheEntryIdentifiers[$entryIdentifier]) ? file_get_contents($this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension) : false;
        }
        if ($entryIdentifier !== basename($entryIdentifier)) {
            throw new \InvalidArgumentException('The specified entry identifier must not contain a path segment.', 1282073033);
        }
        $pathAndFilename = $this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension;
        if ($this->isCacheFileExpired($pathAndFilename)) {
            return false;
        }
        $dataSize = (int)file_get_contents($pathAndFilename, null, null, (filesize($pathAndFilename) - self::DATASIZE_DIGITS), self::DATASIZE_DIGITS);
        return file_get_contents($pathAndFilename, null, null, 0, $dataSize);
    }

    public function has($entryIdentifier)
    {
        if ($this->frozen === true) {
            return isset($this->cacheEntryIdentifiers[$entryIdentifier]);
        }
        if ($entryIdentifier !== basename($entryIdentifier)) {
            throw new \InvalidArgumentException('The specified entry identifier must not contain a path segment.', 1282073034);
        }
        return !$this->isCacheFileExpired(($this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension));
    }

    public function remove($entryIdentifier)
    {
        if ($entryIdentifier !== basename($entryIdentifier)) {
            throw new \InvalidArgumentException('The specified entry identifier must not contain a path segment.', 1282073035);
        }
        if ($entryIdentifier === '') {
            throw new \InvalidArgumentException('The specified entry identifier must not be empty.', 1298114279);
        }
        if ($this->frozen === true) {
            throw new \RuntimeException(sprintf('Cannot remove cache entry because the backend of cache "%s" is frozen.', $this->cacheIdentifier), 1323344193);
        }
        $pathAndFilename = $this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension;
        if (file_exists($pathAndFilename) === false) {
            return false;
        }
        if (@unlink($pathAndFilename) === false) {
            return false;
        }
        return true;
    }

    public function findIdentifiersByTag($searchedTag)
    {
        $entryIdentifiers = [];
        $now = $GLOBALS['EXEC_TIME'];
        $cacheEntryFileExtensionLength = strlen($this->cacheEntryFileExtension);
        for ($directoryIterator = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\DirectoryIterator::class, $this->cacheDirectory); $directoryIterator->valid(); $directoryIterator->next()) {
            if ($directoryIterator->isDot()) {
                continue;
            }
            $cacheEntryPathAndFilename = $directoryIterator->getPathname();
            $index = (int)file_get_contents($cacheEntryPathAndFilename, null, null, (filesize($cacheEntryPathAndFilename) - self::DATASIZE_DIGITS), self::DATASIZE_DIGITS);
            $metaData = file_get_contents($cacheEntryPathAndFilename, null, null, $index);
            $expiryTime = (int)substr($metaData, 0, self::EXPIRYTIME_LENGTH);
            if ($expiryTime !== 0 && $expiryTime < $now) {
                continue;
            }
            if (in_array($searchedTag, explode(' ', substr($metaData, self::EXPIRYTIME_LENGTH, -self::DATASIZE_DIGITS)))) {
                if ($cacheEntryFileExtensionLength > 0) {
                    $entryIdentifiers[] = substr($directoryIterator->getFilename(), 0, -$cacheEntryFileExtensionLength);
                } else {
                    $entryIdentifiers[] = $directoryIterator->getFilename();
                }
            }
        }
        return $entryIdentifiers;
    }

    public function flush()
    {
        parent::flush();
        if ($this->frozen === true) {
            $this->frozen = false;
        }
    }

    public function flushByTag($tag)
    {
        $identifiers = $this->findIdentifiersByTag($tag);
        if (empty($identifiers)) {
            return;
        }
        foreach ($identifiers as $entryIdentifier) {
            $this->remove($entryIdentifier);
        }
    }

    protected function isCacheFileExpired($cacheEntryPathAndFilename)
    {
        if (file_exists($cacheEntryPathAndFilename) === false) {
            return true;
        }
        $index = (int)file_get_contents($cacheEntryPathAndFilename, null, null, (filesize($cacheEntryPathAndFilename) - self::DATASIZE_DIGITS), self::DATASIZE_DIGITS);
        $expiryTime = (int)file_get_contents($cacheEntryPathAndFilename, null, null, $index, self::EXPIRYTIME_LENGTH);
        return $expiryTime !== 0 && $expiryTime < $GLOBALS['EXEC_TIME'];
    }

    public function collectGarbage()
    {
        if ($this->frozen === true) {
            return;
        }
        for ($directoryIterator = new \DirectoryIterator($this->cacheDirectory); $directoryIterator->valid(); $directoryIterator->next()) {
            if ($directoryIterator->isDot()) {
                continue;
            }
            if ($this->isCacheFileExpired($directoryIterator->getPathname())) {
                $cacheEntryFileExtensionLength = strlen($this->cacheEntryFileExtension);
                if ($cacheEntryFileExtensionLength > 0) {
                    $this->remove(substr($directoryIterator->getFilename(), 0, -$cacheEntryFileExtensionLength));
                } else {
                    $this->remove($directoryIterator->getFilename());
                }
            }
        }
    }

    protected function findCacheFilesByIdentifier($entryIdentifier)
    {
        $pattern = $this->cacheDirectory . $entryIdentifier;
        $filesFound = glob($pattern);
        if ($filesFound === false || empty($filesFound)) {
            return false;
        }
        return $filesFound;
    }

    public function requireOnce($entryIdentifier)
    {
        if ($this->frozen === true) {
            if (isset($this->cacheEntryIdentifiers[$entryIdentifier])) {
                return require_once $this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension;
            }
            return false;
        }
        if ($entryIdentifier !== basename($entryIdentifier)) {
            throw new \InvalidArgumentException('The specified entry identifier must not contain a path segment.', 1282073036);
        }
        $pathAndFilename = $this->cacheDirectory . $entryIdentifier . $this->cacheEntryFileExtension;
        return $this->isCacheFileExpired($pathAndFilename) ? false : require_once $pathAndFilename;
    }
}