Viewing file:  Instantiator.php (6.7 KB) -rwxrwxr-x
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<?php
namespace Doctrine\Instantiator;
use ArrayIterator;
use Doctrine\Instantiator\Exception\InvalidArgumentException;
use Doctrine\Instantiator\Exception\UnexpectedValueException;
use Exception;
use ReflectionClass;
use ReflectionException;
use Serializable;
use function class_exists;
use function is_subclass_of;
use function restore_error_handler;
use function set_error_handler;
use function sprintf;
use function strlen;
use function unserialize;
final class Instantiator implements InstantiatorInterface
{
/**
* Markers used internally by PHP to define whether {@see \unserialize} should invoke
* the method {@see \Serializable::unserialize()} when dealing with classes implementing
* the {@see \Serializable} interface.
*/
public const SERIALIZATION_FORMAT_USE_UNSERIALIZER = 'C';
public const SERIALIZATION_FORMAT_AVOID_UNSERIALIZER = 'O';
/**
* Used to instantiate specific classes, indexed by class name.
*
* @var callable[]
*/
private static $cachedInstantiators = [];
/**
* Array of objects that can directly be cloned, indexed by class name.
*
* @var object[]
*/
private static $cachedCloneables = [];
/**
* {@inheritDoc}
*/
public function instantiate($className)
{
if (isset(self::$cachedCloneables[$className])) {
return clone self::$cachedCloneables[$className];
}
if (isset(self::$cachedInstantiators[$className])) {
$factory = self::$cachedInstantiators[$className];
return $factory();
}
return $this->buildAndCacheFromFactory($className);
}
/**
* Builds the requested object and caches it in static properties for performance
*
* @return object
*
* @template T of object
* @phpstan-param class-string<T> $className
*
* @phpstan-return T
*/
private function buildAndCacheFromFactory(string $className)
{
$factory = self::$cachedInstantiators[$className] = $this->buildFactory($className);
$instance = $factory();
if ($this->isSafeToClone(new ReflectionClass($instance))) {
self::$cachedCloneables[$className] = clone $instance;
}
return $instance;
}
/**
* Builds a callable capable of instantiating the given $className without
* invoking its constructor.
*
* @throws InvalidArgumentException
* @throws UnexpectedValueException
* @throws ReflectionException
*
* @template T of object
* @phpstan-param class-string<T> $className
*
* @phpstan-return callable(): T
*/
private function buildFactory(string $className): callable
{
$reflectionClass = $this->getReflectionClass($className);
if ($this->isInstantiableViaReflection($reflectionClass)) {
return [$reflectionClass, 'newInstanceWithoutConstructor'];
}
$serializedString = sprintf(
'%s:%d:"%s":0:{}',
is_subclass_of($className, Serializable::class) ? self::SERIALIZATION_FORMAT_USE_UNSERIALIZER : self::SERIALIZATION_FORMAT_AVOID_UNSERIALIZER,
strlen($className),
$className
);
$this->checkIfUnSerializationIsSupported($reflectionClass, $serializedString);
return static function () use ($serializedString) {
return unserialize($serializedString);
};
}
/**
* @throws InvalidArgumentException
* @throws ReflectionException
*
* @template T of object
* @phpstan-param class-string<T> $className
*
* @phpstan-return ReflectionClass<T>
*/
private function getReflectionClass(string $className): ReflectionClass
{
if (! class_exists($className)) {
throw InvalidArgumentException::fromNonExistingClass($className);
}
$reflection = new ReflectionClass($className);
if ($reflection->isAbstract()) {
throw InvalidArgumentException::fromAbstractClass($reflection);
}
return $reflection;
}
/**
* @throws UnexpectedValueException
*
* @template T of object
* @phpstan-param ReflectionClass<T> $reflectionClass
*/
private function checkIfUnSerializationIsSupported(ReflectionClass $reflectionClass, string $serializedString): void
{
set_error_handler(static function (int $code, string $message, string $file, int $line) use ($reflectionClass, &$error): bool {
$error = UnexpectedValueException::fromUncleanUnSerialization(
$reflectionClass,
$message,
$code,
$file,
$line
);
return true;
});
try {
$this->attemptInstantiationViaUnSerialization($reflectionClass, $serializedString);
} finally {
restore_error_handler();
}
if ($error) {
throw $error;
}
}
/**
* @throws UnexpectedValueException
*
* @template T of object
* @phpstan-param ReflectionClass<T> $reflectionClass
*/
private function attemptInstantiationViaUnSerialization(ReflectionClass $reflectionClass, string $serializedString): void
{
try {
unserialize($serializedString);
} catch (Exception $exception) {
throw UnexpectedValueException::fromSerializationTriggeredException($reflectionClass, $exception);
}
}
/**
* @template T of object
* @phpstan-param ReflectionClass<T> $reflectionClass
*/
private function isInstantiableViaReflection(ReflectionClass $reflectionClass): bool
{
return ! ($this->hasInternalAncestors($reflectionClass) && $reflectionClass->isFinal());
}
/**
* Verifies whether the given class is to be considered internal
*
* @template T of object
* @phpstan-param ReflectionClass<T> $reflectionClass
*/
private function hasInternalAncestors(ReflectionClass $reflectionClass): bool
{
do {
if ($reflectionClass->isInternal()) {
return true;
}
$reflectionClass = $reflectionClass->getParentClass();
} while ($reflectionClass);
return false;
}
/**
* Checks if a class is cloneable
*
* Classes implementing `__clone` cannot be safely cloned, as that may cause side-effects.
*
* @template T of object
* @phpstan-param ReflectionClass<T> $reflectionClass
*/
private function isSafeToClone(ReflectionClass $reflectionClass): bool
{
return $reflectionClass->isCloneable()
&& ! $reflectionClass->hasMethod('__clone')
&& ! $reflectionClass->isSubclassOf(ArrayIterator::class);
}
}
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