<?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\Resource;
/**
* ClassExistenceResource represents a class existence.
* Freshness is only evaluated against resource existence.
*
* The resource must be a fully-qualified class name.
*
* @author Fabien Potencier <fabien@symfony.com>
*
* @final
*/
class ClassExistenceResource implements SelfCheckingResourceInterface
{
private string $resource;
private ?array $exists = null;
private static int $autoloadLevel = 0;
private static ?string $autoloadedClass = null;
private static array $existsCache = [];
/**
* @param string $resource The fully-qualified class name
* @param bool|null $exists Boolean when the existency check has already been done
*/
public function __construct(string $resource, bool $exists = null)
{
$this->resource = $resource;
if (null !== $exists) {
$this->exists = [$exists, null];
}
}
public function __toString(): string
{
return $this->resource;
}
public function getResource(): string
{
return $this->resource;
}
/**
* @throws \ReflectionException when a parent class/interface/trait is not found
*/
public function isFresh(int $timestamp): bool
{
$loaded = class_exists($this->resource, false) || interface_exists($this->resource, false) || trait_exists($this->resource, false);
if (null !== $exists = &self::$existsCache[$this->resource]) {
if ($loaded) {
$exists = [true, null];
} elseif (0 >= $timestamp && !$exists[0] && null !== $exists[1]) {
throw new \ReflectionException($exists[1]);
}
} elseif ([false, null] === $exists = [$loaded, null]) {
if (!self::$autoloadLevel++) {
spl_autoload_register(__CLASS__.'::throwOnRequiredClass');
}
$autoloadedClass = self::$autoloadedClass;
self::$autoloadedClass = ltrim($this->resource, '\\');
try {
$exists[0] = class_exists($this->resource) || interface_exists($this->resource, false) || trait_exists($this->resource, false);
} catch (\Exception $e) {
$exists[1] = $e->getMessage();
try {
self::throwOnRequiredClass($this->resource, $e);
} catch (\ReflectionException $e) {
if (0 >= $timestamp) {
throw $e;
}
}
} catch (\Throwable $e) {
$exists[1] = $e->getMessage();
throw $e;
} finally {
self::$autoloadedClass = $autoloadedClass;
if (!--self::$autoloadLevel) {
spl_autoload_unregister(__CLASS__.'::throwOnRequiredClass');
}
}
}
if (null === $this->exists) {
$this->exists = $exists;
}
return $this->exists[0] xor !$exists[0];
}
/**
* @internal
*/
public function __sleep(): array
{
if (null === $this->exists) {
$this->isFresh(0);
}
return ['resource', 'exists'];
}
/**
* @internal
*/
public function __wakeup()
{
if (\is_bool($this->exists)) {
$this->exists = [$this->exists, null];
}
}
/**
* Throws a reflection exception when the passed class does not exist but is required.
*
* A class is considered "not required" when it's loaded as part of a "class_exists" or similar check.
*
* This function can be used as an autoload function to throw a reflection
* exception if the class was not found by previous autoload functions.
*
* A previous exception can be passed. In this case, the class is considered as being
* required totally, so if it doesn't exist, a reflection exception is always thrown.
* If it exists, the previous exception is rethrown.
*
* @throws \ReflectionException
*
* @internal
*/
public static function throwOnRequiredClass(string $class, \Exception $previous = null)
{
// If the passed class is the resource being checked, we shouldn't throw.
if (null === $previous && self::$autoloadedClass === $class) {
return;
}
if (class_exists($class, false) || interface_exists($class, false) || trait_exists($class, false)) {
if (null !== $previous) {
throw $previous;
}
return;
}
if ($previous instanceof \ReflectionException) {
throw $previous;
}
$message = sprintf('Class "%s" not found.', $class);
if (self::$autoloadedClass !== $class) {
$message = substr_replace($message, sprintf(' while loading "%s"', self::$autoloadedClass), -1, 0);
}
if (null !== $previous) {
$message = $previous->getMessage();
}
$e = new \ReflectionException($message, 0, $previous);
if (null !== $previous) {
throw $e;
}
$trace = debug_backtrace();
$autoloadFrame = [
'function' => 'spl_autoload_call',
'args' => [$class],
];
if (isset($trace[1])) {
$callerFrame = $trace[1];
$i = 2;
} elseif (false !== $i = array_search($autoloadFrame, $trace, true)) {
$callerFrame = $trace[++$i];
} else {
throw $e;
}
if (isset($callerFrame['function']) && !isset($callerFrame['class'])) {
switch ($callerFrame['function']) {
case 'get_class_methods':
case 'get_class_vars':
case 'get_parent_class':
case 'is_a':
case 'is_subclass_of':
case 'class_exists':
case 'class_implements':
case 'class_parents':
case 'trait_exists':
case 'defined':
case 'interface_exists':
case 'method_exists':
case 'property_exists':
case 'is_callable':
return;
}
$props = [
'file' => $callerFrame['file'] ?? null,
'line' => $callerFrame['line'] ?? null,
'trace' => \array_slice($trace, 1 + $i),
];
foreach ($props as $p => $v) {
if (null !== $v) {
$r = new \ReflectionProperty(\Exception::class, $p);
$r->setValue($e, $v);
}
}
}
throw $e;
}
}