minor #28295 [VarExporter] optimize dumped code in time and space (nicolas-grekas)

This PR was merged into the 4.2-dev branch. Discussion ---------- [VarExporter] optimize dumped code in time and space | Q | A | ------------- | --- | Branch? | master | Bug fix? | no | New feature? | no | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | - | License | MIT | Doc PR | - Let's squeeze some more µs when running exported code. On a simple case run 100k times with a few objects, I go from 1.8s to 1.5s. The generated exports are also a bit smaller if it matters. This works by: - using local variables instead of manually dealing with a stack - creating more optimized object hydrators for internal classes This PR also fixes handling of hard references that are bound to external variables. Commits ------- 07e90d71d8 [VarExporter] optimize dumped code in time and space
2018-09-04 08:34:59 +02:00 · 2018-09-04 08:34:59 +02:00 · cabbf51af4
commit cabbf51af4
parent a82b2a78c6 07e90d71d8
20 changed files with 317 additions and 228 deletions
--- a/src/Symfony/Component/VarExporter/Internal/Exporter.php
+++ b/src/Symfony/Component/VarExporter/Internal/Exporter.php
@ -48,10 +48,11 @@ class Exporter
                $refs[$k] = $value = $values[$k];
                if ($value instanceof Reference && 0 > $value->id) {
                    $valuesAreStatic = false;
+                    ++$value->count;
                    continue;
                }
                $refsPool[] = array(&$refs[$k], $value, &$value);
-                $refs[$k] = $values[$k] = new Reference(-\count($refsPool));
+                $refs[$k] = $values[$k] = new Reference(-\count($refsPool), $value);
            }

            if (\is_array($value)) {
@ -80,12 +81,13 @@ class Exporter
                Registry::getClassReflector($class);
                serialize(Registry::$prototypes[$class]);
            }
+            $reflector = Registry::$reflectors[$class];
            $proto = Registry::$prototypes[$class];

            if ($value instanceof \ArrayIterator || $value instanceof \ArrayObject) {
                // ArrayIterator and ArrayObject need special care because their "flags"
                // option changes the behavior of the (array) casting operator.
-                $proto = Registry::$cloneable[$class] ? clone Registry::$prototypes[$class] : Registry::$reflectors[$class]->newInstanceWithoutConstructor();
+                $proto = Registry::$cloneable[$class] ? clone Registry::$prototypes[$class] : $reflector->newInstanceWithoutConstructor();
                $properties = self::getArrayObjectProperties($value, $arrayValue, $proto);
            } elseif ($value instanceof \SplObjectStorage) {
                // By implementing Serializable, SplObjectStorage breaks internal references,
@ -116,20 +118,29 @@ class Exporter
            foreach ($arrayValue as $name => $v) {
                $n = (string) $name;
                if ('' === $n || "\0" !== $n[0]) {
-                    $c = $class;
+                    $c = '*';
+                    $properties[$c][$n] = $v;
+                    unset($sleep[$n]);
                } elseif ('*' === $n[1]) {
-                    $c = $class;
                    $n = substr($n, 3);
+                    $c = $reflector->getProperty($n)->class;
+                    if ('Error' === $c) {
+                        $c = 'TypeError';
+                    } elseif ('Exception' === $c) {
+                        $c = 'ErrorException';
+                    }
+                    $properties[$c][$n] = $v;
+                    unset($sleep[$n]);
                } else {
                    $i = strpos($n, "\0", 2);
                    $c = substr($n, 1, $i - 1);
                    $n = substr($n, 1 + $i);
-                }
-                if (null === $sleep) {
-                    $properties[$c][$n] = $v;
-                } elseif (isset($sleep[$n]) && $c === $class) {
-                    $properties[$c][$n] = $v;
-                    unset($sleep[$n]);
+                    if (null === $sleep) {
+                        $properties[$c][$n] = $v;
+                    } elseif (isset($sleep[$n]) && $c === $class) {
+                        $properties[$c][$n] = $v;
+                        unset($sleep[$n]);
+                    }
                }
                if (\array_key_exists($name, $proto) && $proto[$name] === $v) {
                    unset($properties[$c][$n]);
@ -173,11 +184,14 @@ class Exporter

        if ($value instanceof Reference) {
            if (0 <= $value->id) {
-                return '\\'.Registry::class.'::$objects['.$value->id.']';
+                return '$o['.$value->id.']';
+            }
+            if (!$value->count) {
+                return self::export($value->value, $indent);
            }
            $value = -$value->id;

-            return '&\\'.Registry::class.'::$references['.$value.']';
+            return '&$r['.$value.']';
        }
        $subIndent = $indent.'    ';

@ -213,9 +227,11 @@ class Exporter
            $code = '';
            foreach ($value as $k => $v) {
                $code .= $subIndent;
-                if ($k !== ++$j) {
+                if (!\is_int($k) || 1 !== $k - $j) {
                    $code .= self::export($k, $subIndent).' => ';
-                    $j = INF;
+                }
+                if (\is_int($k)) {
+                    $j = $k;
                }
                $code .= self::export($v, $subIndent).",\n";
            }
@ -224,82 +240,110 @@ class Exporter
        }

        if ($value instanceof Values) {
-            $code = '';
+            $code = $subIndent."\$r = [],\n";
            foreach ($value->values as $k => $v) {
-                $code .= $subIndent.'\\'.Registry::class.'::$references['.$k.'] = '.self::export($v, $subIndent).",\n";
+                $code .= $subIndent.'$r['.$k.'] = '.self::export($v, $subIndent).",\n";
            }

            return "[\n".$code.$indent.']';
        }

        if ($value instanceof Registry) {
-            $code = '';
-            $reflectors = array();
-            $serializables = array();
-
-            foreach ($value as $k => $class) {
-                if (':' === ($class[1] ?? null)) {
-                    $serializables[$k] = $class;
-                    continue;
-                }
-                $c = '\\'.$class.'::class';
-                $reflectors[$class] = '\\'.Registry::class.'::$reflectors['.$c.'] ?? \\'.Registry::class.'::getClassReflector('.$c.', '
-                    .self::export(Registry::$instantiableWithoutConstructor[$class]).', '
-                    .self::export(Registry::$cloneable[$class])
-                .')';
-
-                if (Registry::$cloneable[$class]) {
-                    $code .= $subIndent.'clone \\'.Registry::class.'::$prototypes['.$c."],\n";
-                } elseif (Registry::$instantiableWithoutConstructor[$class]) {
-                    $code .= $subIndent.'\\'.Registry::class.'::$reflectors['.$c."]->newInstanceWithoutConstructor(),\n";
-                } else {
-                    $code .= $subIndent.'\\'.Registry::class.'::$reflectors['.$c."]->newInstance(),\n";
-                }
-            }
-
-            if ($reflectors) {
-                $code = "[\n".$subIndent.implode(",\n".$subIndent, $reflectors).",\n".$indent."], [\n".$code.$indent.'], ';
-                $code .= !$serializables ? "[\n".$indent.']' : self::export($serializables, $indent);
-            } else {
-                $code = '[], []';
-                $code .= ', '.self::export($serializables, $indent);
-            }
-
-            return '\\'.Registry::class.'::push('.$code.')';
+            return self::exportRegistry($value, $indent, $subIndent);
        }

-        if ($value instanceof Configurator) {
-            $code = '';
-            foreach ($value->properties as $class => $properties) {
-                $code .= $subIndent.'    \\'.$class.'::class => '.self::export($properties, $subIndent.'    ').",\n";
-            }
-
-            $code = array(
-                self::export($value->registry, $subIndent),
-                self::export($value->values, $subIndent),
-                '' !== $code ? "[\n".$code.$subIndent.']' : '[]',
-                self::export($value->value, $subIndent),
-                self::export($value->wakeups, $subIndent),
-            );
-
-            return '\\'.\get_class($value)."::pop(\n".$subIndent.implode(",\n".$subIndent, $code)."\n".$indent.')';
+        if ($value instanceof Hydrator) {
+            return self::exportHydrator($value, $indent, $subIndent);
        }

        throw new \UnexpectedValueException(sprintf('Cannot export value of type "%s".', \is_object($value) ? \get_class($value) : \gettype($value)));
    }

+    private static function exportRegistry(Registry $value, string $indent, string $subIndent): string
+    {
+        $code = '';
+        $reflectors = array();
+        $serializables = array();
+        $seen = array();
+        $prototypesAccess = 0;
+        $factoriesAccess = 0;
+        $r = '\\'.Registry::class;
+        $j = -1;
+
+        foreach ($value as $k => $class) {
+            if (':' === ($class[1] ?? null)) {
+                $serializables[$k] = $class;
+                continue;
+            }
+            $code .= $subIndent.(1 !== $k - $j ? $k.' => ' : '');
+            $j = $k;
+            $eol = ",\n";
+            $c = '[\\'.$class.'::class]';
+
+            if ($seen[$class] ?? false) {
+                if (Registry::$cloneable[$class]) {
+                    ++$prototypesAccess;
+                    $code .= 'clone $p'.$c;
+                } else {
+                    ++$factoriesAccess;
+                    $code .= '$f'.$c.'()';
+                }
+            } else {
+                $seen[$class] = true;
+                if (Registry::$cloneable[$class]) {
+                    $code .= 'clone ('.($prototypesAccess++ ? '$p' : '($p =& '.$r.'::$prototypes)').$c.' ?? '.$r.'::p';
+                } else {
+                    $code .= '('.($factoriesAccess++ ? '$f' : '($f =& '.$r.'::$factories)').$c.' ?? '.$r.'::f';
+                    $eol = '()'.$eol;
+                }
+                $code .= '('.substr($c, 1, -1).', '.self::export(Registry::$instantiableWithoutConstructor[$class]).'))';
+            }
+            $code .= $eol;
+        }
+
+        if (1 === $prototypesAccess) {
+            $code = str_replace('($p =& '.$r.'::$prototypes)', $r.'::$prototypes', $code);
+        }
+        if (1 === $factoriesAccess) {
+            $code = str_replace('($f =& '.$r.'::$factories)', $r.'::$factories', $code);
+        }
+        if ('' !== $code) {
+            $code = "\n".$code.$indent;
+        }
+
+        if ($serializables) {
+            $code = $r.'::unserialize(['.$code.'], '.self::export($serializables, $indent).')';
+        } else {
+            $code = '['.$code.']';
+        }
+
+        return '$o = '.$code;
+    }
+
+    private static function exportHydrator(Hydrator $value, string $indent, string $subIndent): string
+    {
+        $code = '';
+        foreach ($value->properties as $class => $properties) {
+            $c = '*' !== $class ? '\\'.$class.'::class' : "'*'";
+            $code .= $subIndent.'    '.$c.' => '.self::export($properties, $subIndent.'    ').",\n";
+        }
+
+        $code = array(
+            self::export($value->registry, $subIndent),
+            self::export($value->values, $subIndent),
+            '' !== $code ? "[\n".$code.$subIndent.']' : '[]',
+            self::export($value->value, $subIndent),
+            self::export($value->wakeups, $subIndent),
+        );
+
+        return '\\'.\get_class($value)."::hydrate(\n".$subIndent.implode(",\n".$subIndent, $code)."\n".$indent.')';
+    }
+
    /**
-     * Extracts the state of an ArrayIterator or ArrayObject instance.
-     *
-     * For performance this method is public and has no type-hints.
-     *
     * @param \ArrayIterator|\ArrayObject $value
-     * @param array                       &$arrayValue
-     * @param object                      $proto
-     *
-     * @return array
+     * @param \ArrayIterator|\ArrayObject $proto
     */
-    public static function getArrayObjectProperties($value, &$arrayValue, $proto)
+    private static function getArrayObjectProperties($value, array &$arrayValue, $proto): array
    {
        $reflector = $value instanceof \ArrayIterator ? 'ArrayIterator' : 'ArrayObject';
        $reflector = Registry::$reflectors[$reflector] ?? Registry::getClassReflector($reflector);
--- a/src/Symfony/Component/VarExporter/Internal/Configurator.php
+++ b/src/Symfony/Component/VarExporter/Internal/Configurator.php
@ -16,9 +16,9 @@ namespace Symfony\Component\VarExporter\Internal;
 *
 * @internal
 */
-class Configurator
+class Hydrator
 {
-    public static $configurators = array();
+    public static $hydrators = array();

    public $registry;
    public $values;
@ -35,12 +35,10 @@ class Configurator
        $this->wakeups = $wakeups;
    }

-    public static function pop($objects, $values, $properties, $value, $wakeups)
+    public static function hydrate($objects, $values, $properties, $value, $wakeups)
    {
-        list(Registry::$objects, Registry::$references) = \array_pop(Registry::$stack);
-
        foreach ($properties as $class => $vars) {
-            (self::$configurators[$class] ?? self::getConfigurator($class))($vars, $objects);
+            (self::$hydrators[$class] ?? self::getHydrator($class))($vars, $objects);
        }
        foreach ($wakeups as $i) {
            $objects[$i]->__wakeup();
@ -49,18 +47,22 @@ class Configurator
        return $value;
    }

-    public static function getConfigurator($class)
+    public static function getHydrator($class)
    {
-        $classReflector = Registry::$reflectors[$class] ?? Registry::getClassReflector($class);
-
-        if (!$classReflector->isInternal()) {
-            return self::$configurators[$class] = \Closure::bind(function ($properties, $objects) {
+        if ('*' === $class) {
+            return self::$hydrators[$class] = static function ($properties, $objects) {
                foreach ($properties as $name => $values) {
                    foreach ($values as $i => $v) {
                        $objects[$i]->$name = $v;
                    }
                }
-            }, null, $class);
+            };
+        }
+
+        $classReflector = Registry::$reflectors[$class] ?? Registry::getClassReflector($class);
+
+        if (!$classReflector->isInternal()) {
+            return self::$hydrators[$class] = (self::$hydrators['*'] ?? self::getHydrator('*'))->bindTo(null, $class);
        }

        switch ($class) {
@ -68,7 +70,7 @@ class Configurator
            case 'ArrayObject':
                $constructor = $classReflector->getConstructor();

-                return self::$configurators[$class] = static function ($properties, $objects) use ($constructor) {
+                return self::$hydrators[$class] = static function ($properties, $objects) use ($constructor) {
                    foreach ($properties as $name => $values) {
                        if ("\0" !== $name) {
                            foreach ($values as $i => $v) {
@ -81,8 +83,16 @@ class Configurator
                    }
                };

+            case 'ErrorException':
+                return self::$hydrators[$class] = (self::$hydrators['*'] ?? self::getHydrator('*'))->bindTo(null, new class() extends \ErrorException {
+                });
+
+            case 'TypeError':
+                return self::$hydrators[$class] = (self::$hydrators['*'] ?? self::getHydrator('*'))->bindTo(null, new class() extends \Error {
+                });
+
            case 'SplObjectStorage':
-                return self::$configurators[$class] = static function ($properties, $objects) {
+                return self::$hydrators[$class] = static function ($properties, $objects) {
                    foreach ($properties as $name => $values) {
                        if ("\0" === $name) {
                            foreach ($values as $i => $v) {
@ -100,23 +110,18 @@ class Configurator
        }

        $propertyReflectors = array();
-        foreach ($classReflector->getProperties(\ReflectionProperty::IS_PROTECTED | \ReflectionProperty::IS_PRIVATE) as $propertyReflector) {
+        foreach ($classReflector->getProperties() as $propertyReflector) {
            if (!$propertyReflector->isStatic()) {
                $propertyReflector->setAccessible(true);
                $propertyReflectors[$propertyReflector->name] = $propertyReflector;
            }
        }

-        return self::$configurators[$class] = static function ($properties, $objects) use ($propertyReflectors) {
+        return self::$hydrators[$class] = static function ($properties, $objects) use ($propertyReflectors) {
            foreach ($properties as $name => $values) {
-                if (isset($propertyReflectors[$name])) {
-                    foreach ($values as $i => $v) {
-                        $propertyReflectors[$name]->setValue($objects[$i], $v);
-                    }
-                } else {
-                    foreach ($values as $i => $v) {
-                        $objects[$i]->$name = $v;
-                    }
+                $p = $propertyReflectors[$name];
+                foreach ($values as $i => $v) {
+                    $p->setValue($objects[$i], $v);
                }
            }
        };
--- a/src/Symfony/Component/VarExporter/Internal/Reference.php
+++ b/src/Symfony/Component/VarExporter/Internal/Reference.php
@ -19,9 +19,12 @@ namespace Symfony\Component\VarExporter\Internal;
 class Reference
 {
    public $id;
+    public $value;
+    public $count = 0;

-    public function __construct(int $id)
+    public function __construct(int $id, $value = null)
    {
        $this->id = $id;
+        $this->value = $value;
    }
 }
--- a/src/Symfony/Component/VarExporter/Internal/Registry.php
+++ b/src/Symfony/Component/VarExporter/Internal/Registry.php
@ -18,11 +18,9 @@ namespace Symfony\Component\VarExporter\Internal;
 */
 class Registry
 {
-    public static $stack = array();
-    public static $objects = array();
-    public static $references = array();
    public static $reflectors = array();
    public static $prototypes = array();
+    public static $factories = array();
    public static $cloneable = array();
    public static $instantiableWithoutConstructor = array();

@ -33,28 +31,33 @@ class Registry
        }
    }

-    public static function push($reflectors, $objects, $serializables)
+    public static function unserialize($objects, $serializables)
    {
-        self::$stack[] = array(self::$objects, self::$references);
-        self::$references = array();
-
-        if (!$serializables) {
-            return self::$objects = $objects;
-        }
        $unserializeCallback = ini_set('unserialize_callback_func', __CLASS__.'::getClassReflector');

        try {
            foreach ($serializables as $k => $v) {
                $objects[$k] = unserialize($v);
            }
-        } catch (\Throwable $e) {
-            list(self::$objects, self::$references) = array_pop(self::$stack);
-            throw $e;
        } finally {
            ini_set('unserialize_callback_func', $unserializeCallback);
        }

-        return self::$objects = $objects;
+        return $objects;
+    }
+
+    public static function p($class, $instantiableWithoutConstructor)
+    {
+        self::getClassReflector($class, $instantiableWithoutConstructor, true);
+
+        return self::$prototypes[$class];
+    }
+
+    public static function f($class, $instantiableWithoutConstructor)
+    {
+        $reflector = self::$reflectors[$class] ?? self::getClassReflector($class, $instantiableWithoutConstructor, false);
+
+        return self::$factories[$class] = \Closure::fromCallable(array($reflector, $instantiableWithoutConstructor ? 'newInstanceWithoutConstructor' : 'newInstance'));
    }

    public static function getClassReflector($class, $instantiableWithoutConstructor = null, $cloneable = null)
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/array-iterator.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/array-iterator.php
@ -1,12 +1,9 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\ArrayIterator::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\ArrayIterator::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\ArrayIterator::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (\Symfony\Component\VarExporter\Internal\Registry::$prototypes[\ArrayIterator::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\ArrayIterator::class, true)),
+    ],
    null,
    [
        \ArrayIterator::class => [
@ -20,6 +17,6 @@ return \Symfony\Component\VarExporter\Internal\Configurator::pop(
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/array-object-custom.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/array-object-custom.php
@ -1,12 +1,9 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyArrayObject::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyArrayObject::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyArrayObject::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (\Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyArrayObject::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\Symfony\Component\VarExporter\Tests\MyArrayObject::class, true)),
+    ],
    null,
    [
        \ArrayObject::class => [
@ -20,6 +17,6 @@ return \Symfony\Component\VarExporter\Internal\Configurator::pop(
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/array-object.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/array-object.php
@ -1,13 +1,10 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\ArrayObject::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\ArrayObject::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\ArrayObject::class],
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\ArrayObject::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (($p =& \Symfony\Component\VarExporter\Internal\Registry::$prototypes)[\ArrayObject::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\ArrayObject::class, true)),
+        clone $p[\ArrayObject::class],
+    ],
    null,
    [
        \ArrayObject::class => [
@ -15,16 +12,18 @@ return \Symfony\Component\VarExporter\Internal\Configurator::pop(
                [
                    [
                        1,
-                        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+                        $o[0],
                    ],
                    0,
                ],
            ],
+        ],
+        '*' => [
            'foo' => [
-                \Symfony\Component\VarExporter\Internal\Registry::$objects[1],
+                $o[1],
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/clone.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/clone.php
@ -1,19 +1,15 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyCloneable::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyCloneable::class, true, false),
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyNotCloneable::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyNotCloneable::class, true, false),
-    ], [
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyCloneable::class]->newInstanceWithoutConstructor(),
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyNotCloneable::class]->newInstanceWithoutConstructor(),
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        (($f =& \Symfony\Component\VarExporter\Internal\Registry::$factories)[\Symfony\Component\VarExporter\Tests\MyCloneable::class] ?? \Symfony\Component\VarExporter\Internal\Registry::f(\Symfony\Component\VarExporter\Tests\MyCloneable::class, true))(),
+        ($f[\Symfony\Component\VarExporter\Tests\MyNotCloneable::class] ?? \Symfony\Component\VarExporter\Internal\Registry::f(\Symfony\Component\VarExporter\Tests\MyNotCloneable::class, true))(),
+    ],
    null,
    [],
    [
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[1],
+        $o[0],
+        $o[1],
    ],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/datetime.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/datetime.php
@ -1,15 +1,12 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\DateTime::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\DateTime::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\DateTime::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (\Symfony\Component\VarExporter\Internal\Registry::$prototypes[\DateTime::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\DateTime::class, true)),
+    ],
    null,
    [
-        \DateTime::class => [
+        '*' => [
            'date' => [
                '1970-01-01 00:00:00.000000',
            ],
@ -21,7 +18,7 @@ return \Symfony\Component\VarExporter\Internal\Configurator::pop(
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    [
        1 => 0,
    ]
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/error.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/error.php
@ -0,0 +1,30 @@
+<?php
+
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        (\Symfony\Component\VarExporter\Internal\Registry::$factories[\Error::class] ?? \Symfony\Component\VarExporter\Internal\Registry::f(\Error::class, true))(),
+    ],
+    null,
+    [
+        \TypeError::class => [
+            'file' => [
+                \dirname(__DIR__).\DIRECTORY_SEPARATOR.'VarExporterTest.php',
+            ],
+            'line' => [
+                234,
+            ],
+        ],
+        \Error::class => [
+            'trace' => [
+                [
+                    'file' => \dirname(__DIR__).\DIRECTORY_SEPARATOR.'VarExporterTest.php',
+                    'line' => 123,
+                ],
+            ],
+        ],
+    ],
+    $o[0],
+    [
+        1 => 0,
+    ]
+);
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/external-references.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/external-references.php
@ -0,0 +1,7 @@
+<?php
+
+return [
+    [
+        123,
+    ],
+];
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/hard-references-recursive.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/hard-references-recursive.php
@ -1,15 +1,16 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([], [], []),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [],
    [
-        \Symfony\Component\VarExporter\Internal\Registry::$references[1] = [
-            &\Symfony\Component\VarExporter\Internal\Registry::$references[1],
+        $r = [],
+        $r[1] = [
+            &$r[1],
        ],
    ],
    [],
    [
-        &\Symfony\Component\VarExporter\Internal\Registry::$references[1],
+        &$r[1],
    ],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/hard-references.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/hard-references.php
@ -1,20 +1,18 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\stdClass::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\stdClass::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\stdClass::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (\Symfony\Component\VarExporter\Internal\Registry::$prototypes[\stdClass::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\stdClass::class, true)),
+    ],
    [
-        \Symfony\Component\VarExporter\Internal\Registry::$references[1] = \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+        $r = [],
+        $r[1] = $o[0],
    ],
    [],
    [
-        &\Symfony\Component\VarExporter\Internal\Registry::$references[1],
-        &\Symfony\Component\VarExporter\Internal\Registry::$references[1],
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+        &$r[1],
+        &$r[1],
+        $o[0],
    ],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/incomplete-class.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/incomplete-class.php
@ -1,11 +1,11 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([], [], [
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = \Symfony\Component\VarExporter\Internal\Registry::unserialize([], [
        'O:20:"SomeNotExistingClass":0:{}',
    ]),
    null,
    [],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/private.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/private.php
@ -1,34 +1,26 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyPrivateValue::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyPrivateValue::class, true, true),
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyPrivateValue::class],
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (($p =& \Symfony\Component\VarExporter\Internal\Registry::$prototypes)[\Symfony\Component\VarExporter\Tests\MyPrivateValue::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\Symfony\Component\VarExporter\Tests\MyPrivateValue::class, true)),
+        clone ($p[\Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class, true)),
+    ],
    null,
    [
        \Symfony\Component\VarExporter\Tests\MyPrivateValue::class => [
            'prot' => [
                123,
+                123,
            ],
            'priv' => [
                234,
                234,
            ],
        ],
-        \Symfony\Component\VarExporter\Tests\MyPrivateChildValue::class => [
-            'prot' => [
-                1 => 123,
-            ],
-        ],
    ],
    [
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[1],
+        $o[0],
+        $o[1],
    ],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/serializable.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/serializable.php
@ -1,14 +1,14 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([], [], [
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = \Symfony\Component\VarExporter\Internal\Registry::unserialize([], [
        'C:50:"Symfony\\Component\\VarExporter\\Tests\\MySerializable":3:{123}',
    ]),
    null,
    [],
    [
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
-        \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+        $o[0],
+        $o[0],
    ],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/spl-object-storage.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/spl-object-storage.php
@ -1,25 +1,21 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\SplObjectStorage::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\SplObjectStorage::class, true, true),
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\stdClass::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\stdClass::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\SplObjectStorage::class],
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\stdClass::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (($p =& \Symfony\Component\VarExporter\Internal\Registry::$prototypes)[\SplObjectStorage::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\SplObjectStorage::class, true)),
+        clone ($p[\stdClass::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\stdClass::class, true)),
+    ],
    null,
    [
        \SplObjectStorage::class => [
            "\0" => [
                [
-                    \Symfony\Component\VarExporter\Internal\Registry::$objects[1],
+                    $o[1],
                    345,
                ],
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    []
 );
--- a/src/Symfony/Component/VarExporter/Tests/Fixtures/wakeup.php
+++ b/src/Symfony/Component/VarExporter/Tests/Fixtures/wakeup.php
@ -1,28 +1,28 @@
 <?php

-return \Symfony\Component\VarExporter\Internal\Configurator::pop(
-    \Symfony\Component\VarExporter\Internal\Registry::push([
-        \Symfony\Component\VarExporter\Internal\Registry::$reflectors[\Symfony\Component\VarExporter\Tests\MyWakeup::class] ?? \Symfony\Component\VarExporter\Internal\Registry::getClassReflector(\Symfony\Component\VarExporter\Tests\MyWakeup::class, true, true),
-    ], [
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyWakeup::class],
-        clone \Symfony\Component\VarExporter\Internal\Registry::$prototypes[\Symfony\Component\VarExporter\Tests\MyWakeup::class],
-    ], [
-    ]),
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (($p =& \Symfony\Component\VarExporter\Internal\Registry::$prototypes)[\Symfony\Component\VarExporter\Tests\MyWakeup::class] ?? \Symfony\Component\VarExporter\Internal\Registry::p(\Symfony\Component\VarExporter\Tests\MyWakeup::class, true)),
+        clone $p[\Symfony\Component\VarExporter\Tests\MyWakeup::class],
+    ],
    null,
    [
-        \Symfony\Component\VarExporter\Tests\MyWakeup::class => [
+        '*' => [
            'sub' => [
-                \Symfony\Component\VarExporter\Internal\Registry::$objects[1],
+                $o[1],
                123,
            ],
+            'bis' => [
+                1 => 123,
+            ],
            'baz' => [
                1 => 123,
            ],
        ],
    ],
-    \Symfony\Component\VarExporter\Internal\Registry::$objects[0],
+    $o[0],
    [
        1 => 1,
-        2 => 0,
+        0,
    ]
 );
--- a/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php
+++ b/src/Symfony/Component/VarExporter/Tests/VarExporterTest.php
@ -12,9 +12,9 @@
 namespace Symfony\Component\VarExporter\Tests;

 use PHPUnit\Framework\TestCase;
+use Symfony\Component\VarDumper\Test\VarDumperTestTrait;
 use Symfony\Component\VarExporter\Internal\Registry;
 use Symfony\Component\VarExporter\VarExporter;
-use Symfony\Component\VarDumper\Test\VarDumperTestTrait;

 class VarExporterTest extends TestCase
 {
@ -28,7 +28,7 @@ class VarExporterTest extends TestCase
    {
        $unserializeCallback = ini_set('unserialize_callback_func', 'var_dump');
        try {
-            Registry::push(array(), array(), array('O:20:"SomeNotExistingClass":0:{}'));
+            Registry::unserialize(array(), array('O:20:"SomeNotExistingClass":0:{}'));
        } finally {
            $this->assertSame('var_dump', ini_set('unserialize_callback_func', $unserializeCallback));
        }
@ -80,10 +80,11 @@ class VarExporterTest extends TestCase
        $this->assertSame($serializedValue, serialize($value));

        $dump = "<?php\n\nreturn ".$marshalledValue.";\n";
+        $dump = str_replace(var_export(__FILE__, true), "\\dirname(__DIR__).\\DIRECTORY_SEPARATOR.'VarExporterTest.php'", $dump);
        $fixtureFile = __DIR__.'/Fixtures/'.$testName.'.php';
        $this->assertStringEqualsFile($fixtureFile, $dump);

-        if ('incomplete-class' === $testName) {
+        if ('incomplete-class' === $testName || 'external-references' === $testName) {
            return;
        }
        $marshalledValue = include $fixtureFile;
@ -146,6 +147,24 @@ class VarExporterTest extends TestCase
        $value[0] = &$value;

        yield array('hard-references-recursive', $value);
+
+        static $value = array(123);
+
+        yield array('external-references', array(&$value), true);
+
+        unset($value);
+
+        $value = new \Error();
+
+        $r = new \ReflectionProperty('Error', 'trace');
+        $r->setAccessible(true);
+        $r->setValue($value, array('file' => __FILE__, 'line' => 123));
+
+        $r = new \ReflectionProperty('Error', 'line');
+        $r->setAccessible(true);
+        $r->setValue($value, 234);
+
+        yield array('error', $value);
    }
 }

--- a/src/Symfony/Component/VarExporter/VarExporter.php
+++ b/src/Symfony/Component/VarExporter/VarExporter.php
@ -11,9 +11,8 @@

 namespace Symfony\Component\VarExporter;

-use Symfony\Component\VarExporter\Internal\Configurator;
 use Symfony\Component\VarExporter\Internal\Exporter;
-use Symfony\Component\VarExporter\Internal\Reference;
+use Symfony\Component\VarExporter\Internal\Hydrator;
 use Symfony\Component\VarExporter\Internal\Registry;
 use Symfony\Component\VarExporter\Internal\Values;

@ -56,8 +55,10 @@ final class VarExporter
        } finally {
            $references = array();
            foreach ($refsPool as $i => $v) {
+                if ($v[0]->count) {
+                    $references[1 + $i] = $v[2];
+                }
                $v[0] = $v[1];
-                $references[1 + $i] = $v[2];
            }
        }

@ -85,7 +86,11 @@ final class VarExporter
            }
        }

-        $value = new Configurator(new Registry($classes), $references ? new Values($references) : null, $properties, $value, $wakeups);
+        if ($classes || $references) {
+            $value = new Hydrator(new Registry($classes), $references ? new Values($references) : null, $properties, $value, $wakeups);
+        } else {
+            $isStaticValue = true;
+        }

        return Exporter::export($value);
    }