<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Config;
use Symfony\Component\Config\Resource\ResourceInterface;
use Symfony\Component\Filesystem\Exception\IOException;
use Symfony\Component\Filesystem\Filesystem;
/**
* ResourceCheckerConfigCache uses instances of ResourceCheckerInterface
* to check whether cached data is still fresh.
*
* @author Matthias Pigulla <mp@webfactory.de>
*/
class ResourceCheckerConfigCache implements ConfigCacheInterface
{
/**
* @var string
*/
private $file;
/**
* @var iterable|ResourceCheckerInterface[]
*/
private $resourceCheckers;
/**
* @param string $file The absolute cache path
* @param iterable|ResourceCheckerInterface[] $resourceCheckers The ResourceCheckers to use for the freshness check
*/
public function __construct($file, $resourceCheckers = [])
{
$this->file = $file;
$this->resourceCheckers = $resourceCheckers;
}
/**
* {@inheritdoc}
*/
public function getPath()
{
return $this->file;
}
/**
* Checks if the cache is still fresh.
*
* This implementation will make a decision solely based on the ResourceCheckers
* passed in the constructor.
*
* The first ResourceChecker that supports a given resource is considered authoritative.
* Resources with no matching ResourceChecker will silently be ignored and considered fresh.
*
* @return bool true if the cache is fresh, false otherwise
*/
public function isFresh()
{
if (!is_file($this->file)) {
return false;
}
if ($this->resourceCheckers instanceof \Traversable && !$this->resourceCheckers instanceof \Countable) {
$this->resourceCheckers = iterator_to_array($this->resourceCheckers);
}
if (!\count($this->resourceCheckers)) {
return true; // shortcut - if we don't have any checkers we don't need to bother with the meta file at all
}
$metadata = $this->getMetaFile();
if (!is_file($metadata)) {
return false;
}
$meta = $this->safelyUnserialize($metadata);
if (false === $meta) {
return false;
}
$time = filemtime($this->file);
foreach ($meta as $resource) {
/* @var ResourceInterface $resource */
foreach ($this->resourceCheckers as $checker) {
if (!$checker->supports($resource)) {
continue; // next checker
}
if ($checker->isFresh($resource, $time)) {
break; // no need to further check this resource
}
return false; // cache is stale
}
// no suitable checker found, ignore this resource
}
return true;
}
/**
* Writes cache.
*
* @param string $content The content to write in the cache
* @param ResourceInterface[] $metadata An array of metadata
*
* @throws \RuntimeException When cache file can't be written
*/
public function write($content, array $metadata = null)
{
$mode = 0666;
$umask = umask();
$filesystem = new Filesystem();
$filesystem->dumpFile($this->file, $content);
try {
$filesystem->chmod($this->file, $mode, $umask);
} catch (IOException $e) {
// discard chmod failure (some filesystem may not support it)
}
if (null !== $metadata) {
$filesystem->dumpFile($this->getMetaFile(), serialize($metadata));
try {
$filesystem->chmod($this->getMetaFile(), $mode, $umask);
} catch (IOException $e) {
// discard chmod failure (some filesystem may not support it)
}
}
if (\function_exists('opcache_invalidate') && filter_var(ini_get('opcache.enable'), \FILTER_VALIDATE_BOOLEAN)) {
@opcache_invalidate($this->file, true);
}
}
/**
* Gets the meta file path.
*
* @return string The meta file path
*/
private function getMetaFile()
{
return $this->file.'.meta';
}
private function safelyUnserialize($file)
{
$e = null;
$meta = false;
$content = file_get_contents($file);
$signalingException = new \UnexpectedValueException();
$prevUnserializeHandler = ini_set('unserialize_callback_func', '');
$prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) use (&$prevErrorHandler, $signalingException) {
if (__FILE__ === $file) {
throw $signalingException;
}
return $prevErrorHandler ? $prevErrorHandler($type, $msg, $file, $line, $context) : false;
});
try {
$meta = unserialize($content);
} catch (\Error $e) {
} catch (\Exception $e) {
}
restore_error_handler();
ini_set('unserialize_callback_func', $prevUnserializeHandler);
if (null !== $e && $e !== $signalingException) {
throw $e;
}
return $meta;
}
}