/**
* Freezes an object.
*
* If the object has not been frozen before, the attribute
* __php_object_freezer_uuid will be added to it.
*
* In the example below, we freeze an object of class A. As this object
* aggregates an object of class B, the object freezer has to freeze two
* objects in total.
*
* <code>
* <?php
* require_once 'Object/Freezer.php';
*
* class A
* {
* protected $b;
*
* public function __construct()
* {
* $this->b = new B;
* }
* }
*
* class B
* {
* protected $foo = 'bar';
* }
*
* $freezer = new Object_Freezer;
* var_dump($freezer->freeze(new A));
* ?>
* </code>
*
* Below is the output of the code example above.
*
* <code>
* array(2) {
* ["root"]=>
* string(36) "32246c35-f47b-4fbc-a2ad-ed14e520865e"
* ["objects"]=>
* array(2) {
* ["32246c35-f47b-4fbc-a2ad-ed14e520865e"]=>
* array(3) {
* ["className"]=>
* string(1) "A"
* ["isDirty"]=>
* bool(true)
* ["state"]=>
* array(2) {
* ["b"]=>
* string(57)
* "__php_object_freezer_3cd682bf-8eba-4fec-90e2-ebe98aa07ab7"
* ["__php_object_freezer_hash"]=>
* string(40) "8b80da9c38c0c41c829cbbefbca9b18aa67ff607"
* }
* }
* ["3cd682bf-8eba-4fec-90e2-ebe98aa07ab7"]=>
* array(3) {
* ["className"]=>
* string(1) "B"
* ["isDirty"]=>
* bool(true)
* ["state"]=>
* array(2) {
* ["foo"]=>
* string(3) "bar"
* ["__php_object_freezer_hash"]=>
* string(40) "e04e935f09f2d526258d8a16613c5bce31e84e87"
* }
* }
* }
* }
* </code>
*
* The reference to the object of class B that the object of class A had
* before it was frozen has been replaced with the UUID of the frozen
* object of class B
* (__php_object_freezer_3cd682bf-8eba-4fec-90e2-ebe98aa07ab7).
*
* The result array's "root" element contains the UUID for the now frozen
* object of class A (32246c35-f47b-4fbc-a2ad-ed14e520865e).
*
* @param object $object The object that is to be frozen.
* @param array $objects Only used internally.
*
* @return array The frozen object(s).
*
* @throws InvalidArgumentException
*/
public function freeze($object, array &$objects = [])
{
// Bail out if a non-object was passed.
if (!is_object($object)) {
throw Object_Freezer_Util::getInvalidArgumentException(1, 'object');
}
// The object has not been frozen before, generate a new UUID and
// store it in the "special" __php_object_freezer_uuid attribute.
if (!isset($object->__php_object_freezer_uuid)) {
$object->__php_object_freezer_uuid = $this->idGenerator->getId();
}
$isDirty = $this->isDirty($object, true);
$uuid = $object->__php_object_freezer_uuid;
if (!isset($objects[$uuid])) {
$objects[$uuid] = ['className' => get_class($object), 'isDirty' => $isDirty, 'state' => []];
// Iterate over the attributes of the object.
foreach (Object_Freezer_Util::readAttributes($object) as $k => $v) {
if ($k !== '__php_object_freezer_uuid') {
if (is_array($v)) {
$this->freezeArray($v, $objects);
} elseif (is_object($v) && !in_array(get_class($v), $this->blacklist)) {
// Freeze the aggregated object.
$this->freeze($v, $objects);
// Replace $v with the aggregated object's UUID.
$v = '__php_object_freezer_' . $v->__php_object_freezer_uuid;
} elseif (is_resource($v)) {
$v = null;
}
// Store the attribute in the object's state array.
$objects[$uuid]['state'][$k] = $v;
}
}
}
return ['root' => $uuid, 'objects' => $objects];
}
/**
* Implementation of Object_Freezer_HashGenerator that uses the SHA1
* hashing function on the attribute values of an object without recursing
* into aggregated arrays or objects.
*
* @param object $object The object that is to be hashed.
*
* @return string
*
* @throws InvalidArgumentException
*/
public function getHash($object)
{
// Bail out if a non-object was passed.
if (!is_object($object)) {
throw Object_Freezer_Util::getInvalidArgumentException(1, 'object');
}
$attributes = Object_Freezer_Util::readAttributes($object);
ksort($attributes);
if (isset($attributes['__php_object_freezer_hash'])) {
unset($attributes['__php_object_freezer_hash']);
}
foreach ($attributes as $key => $value) {
if (is_array($value)) {
$attributes[$key] = '<array>';
} elseif (is_object($value)) {
if (!isset($value->__php_object_freezer_uuid)) {
$value->__php_object_freezer_uuid = $this->idGenerator->getId();
}
$attributes[$key] = $value->__php_object_freezer_uuid;
} elseif (is_resource($value)) {
$attributes[$key] = null;
}
}
return sha1(get_class($object) . implode(':', $attributes));
}
