Viewing file:  Instantiator.php (8.19 KB) -rw-r--r--
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<?php
/*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* and is licensed under the MIT license. For more information, see
* <http://www.doctrine-project.org>.
*/
namespace Doctrine\Instantiator;
use Closure;
use Doctrine\Instantiator\Exception\InvalidArgumentException;
use Doctrine\Instantiator\Exception\UnexpectedValueException;
use Exception;
use ReflectionClass;
/**
* {@inheritDoc}
*
* @author Marco Pivetta <ocramius@gmail.com>
*/
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.
*/
const SERIALIZATION_FORMAT_USE_UNSERIALIZER = 'C';
const SERIALIZATION_FORMAT_AVOID_UNSERIALIZER = 'O';
/**
* @var \Closure[] of {@see \Closure} instances used to instantiate specific classes
*/
private static $cachedInstantiators = array();
/**
* @var object[] of objects that can directly be cloned
*/
private static $cachedCloneables = array();
/**
* {@inheritDoc}
*/
public function instantiate($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
*
* @param string $className
*
* @return object
*/
private function buildAndCacheFromFactory($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 {@see \Closure} capable of instantiating the given $className without
* invoking its constructor.
*
* @param string $className
*
* @return Closure
*/
private function buildFactory($className)
{
$reflectionClass = $this->getReflectionClass($className);
if ($this->isInstantiableViaReflection($reflectionClass)) {
return function () use ($reflectionClass) {
return $reflectionClass->newInstanceWithoutConstructor();
};
}
$serializedString = sprintf(
'%s:%d:"%s":0:{}',
$this->getSerializationFormat($reflectionClass),
strlen($className),
$className
);
$this->checkIfUnSerializationIsSupported($reflectionClass, $serializedString);
return function () use ($serializedString) {
return unserialize($serializedString);
};
}
/**
* @param string $className
*
* @return ReflectionClass
*
* @throws InvalidArgumentException
*/
private function getReflectionClass($className)
{
if (! class_exists($className)) {
throw InvalidArgumentException::fromNonExistingClass($className);
}
$reflection = new ReflectionClass($className);
if ($reflection->isAbstract()) {
throw InvalidArgumentException::fromAbstractClass($reflection);
}
return $reflection;
}
/**
* @param ReflectionClass $reflectionClass
* @param string $serializedString
*
* @throws UnexpectedValueException
*
* @return void
*/
private function checkIfUnSerializationIsSupported(ReflectionClass $reflectionClass, $serializedString)
{
set_error_handler(function ($code, $message, $file, $line) use ($reflectionClass, & $error) {
$error = UnexpectedValueException::fromUncleanUnSerialization(
$reflectionClass,
$message,
$code,
$file,
$line
);
});
$this->attemptInstantiationViaUnSerialization($reflectionClass, $serializedString);
restore_error_handler();
if ($error) {
throw $error;
}
}
/**
* @param ReflectionClass $reflectionClass
* @param string $serializedString
*
* @throws UnexpectedValueException
*
* @return void
*/
private function attemptInstantiationViaUnSerialization(ReflectionClass $reflectionClass, $serializedString)
{
try {
unserialize($serializedString);
} catch (Exception $exception) {
restore_error_handler();
throw UnexpectedValueException::fromSerializationTriggeredException($reflectionClass, $exception);
}
}
/**
* @param ReflectionClass $reflectionClass
*
* @return bool
*/
private function isInstantiableViaReflection(ReflectionClass $reflectionClass)
{
if (\PHP_VERSION_ID >= 50600) {
return ! ($this->hasInternalAncestors($reflectionClass) && $reflectionClass->isFinal());
}
return \PHP_VERSION_ID >= 50400 && ! $this->hasInternalAncestors($reflectionClass);
}
/**
* Verifies whether the given class is to be considered internal
*
* @param ReflectionClass $reflectionClass
*
* @return bool
*/
private function hasInternalAncestors(ReflectionClass $reflectionClass)
{
do {
if ($reflectionClass->isInternal()) {
return true;
}
} while ($reflectionClass = $reflectionClass->getParentClass());
return false;
}
/**
* Verifies if the given PHP version implements the `Serializable` interface serialization
* with an incompatible serialization format. If that's the case, use serialization marker
* "C" instead of "O".
*
* @link http://news.php.net/php.internals/74654
*
* @param ReflectionClass $reflectionClass
*
* @return string the serialization format marker, either self::SERIALIZATION_FORMAT_USE_UNSERIALIZER
* or self::SERIALIZATION_FORMAT_AVOID_UNSERIALIZER
*/
private function getSerializationFormat(ReflectionClass $reflectionClass)
{
if ($this->isPhpVersionWithBrokenSerializationFormat()
&& $reflectionClass->implementsInterface('Serializable')
) {
return self::SERIALIZATION_FORMAT_USE_UNSERIALIZER;
}
return self::SERIALIZATION_FORMAT_AVOID_UNSERIALIZER;
}
/**
* Checks whether the current PHP runtime uses an incompatible serialization format
*
* @return bool
*/
private function isPhpVersionWithBrokenSerializationFormat()
{
return PHP_VERSION_ID === 50429 || PHP_VERSION_ID === 50513;
}
/**
* Checks if a class is cloneable
*
* @param ReflectionClass $reflection
*
* @return bool
*/
private function isSafeToClone(ReflectionClass $reflection)
{
if (method_exists($reflection, 'isCloneable') && ! $reflection->isCloneable()) {
return false;
}
// not cloneable if it implements `__clone`, as we want to avoid calling it
return ! $reflection->hasMethod('__clone');
}
}
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