为什么Doctrine\ORM\Configuration的“DoctrineProxies”对象包含宇宙？ [英] Why does Doctrine\ORM\Configuration's "DoctrineProxies" Object contain the Universe?
问题描述
//实体类的一部分项目：
/ ** @Column（name =product_id，type =integer）* /
private $ productId;
然后我执行了这个代码：
// 3行〜直接从Doctrine配置获取EntityManager
include'config / doctrine-config.php';
$ config = Setup :: createAnnotationMetadataConfiguration（$ paths，$ isDevMode）;
$ em = EntityManager :: create（$ dbParams，$ config）;
//我自己的代码来检索一个实体实例：
$ instance = $ em-> find（Item :: class，2）;
print_r（$ instance）;
这是我得到的输出（跳过几个其他类似的属性）：
Application\Entity\Item对象
（
[id：Application\Entity\Item：private] => ; 2
[description：Application\Entity\Item：private] => Product Kit
[productId：Application\Entity\Item：private] => -1
）
请注意，从出来的上面有6（6）行， print_r（）函数。
一切都很好，直到
接下来，我将 $ productId 列更改为 ManyToOne 关系在我的项目实体类，如下所示：
/ **
* @ManyToOne targetEntity =Product，inversedBy =id）
* @JoinColumn（name =product_id，referencedColumnName =id）
* /
private $ productId;
我运行的代码相同。
两百万，三百九十万六千行 em>行 print_r 输出。
查看打印输出我看到 DoctrineProxies\__CG__\Application\Entity\Product Object包含 2,392,564 由 print_r
问题：
这个对象是什么，为什么在打印出来时，占用近300Mb的磁盘空间是如此之大吗？
我不禁想知道这种复杂性是否会导致每天的性能问题码。例如，我没有在我的日常代码中打印出 $ instance 变量的内容，但是我肯定会返回方法调用。这是否意味着它是一个300Mb的变量，从 $ em-> find（Item :: class，2）; 调用以上？
（非常）部分列表
应用程序\Entity \Item对象
（
[id：Application\Entity\Item：private] => 2
[description：Application\Entity\Item：private] =>产品套件
[ProductId：Application\Entity\Item：private] => DoctrineProxies\__CG__\Application\Entity\Product对象
（
[__initializer__] => ; Closure Object
（
[静态] =>数组
（
[entityPersister] => Doctrine\ORM\Persisters\Entity\BasicEntityPersister Object
（
[class：protected] => Doctrine\ORM\Mapping\ClassMetadata Object
（
[name] => Application\Entity\Product
[namespace] =>应用ation\Entity
[rootEntityName] => Application\Entity\Product
[inheritanceType] => 1
[generatorType] => 5
[fieldMappings] => Array
（
[id] => Array
（
[fieldName] => id
[type] => integer
[scale ] => 0
[length] =>
[unique] =>
[nullable] =>
[precision] => 0
[columnName] => id
[id] => 1
）
[fieldNames] =>数组
（
[id] =&
[description] => description
）
[columnNames] => Array
（
[id] => id
[description] => description
）
[idGenerator] => Doctrine\ORM\Id\AssignedGenerator对象
[reflClass] => ReflectionClass对象
（
[name] => Application\Entity\产品
）
[namingStrategy：protected] => Doctrine\ORM\Mapping\DefaultNamingStrategy Object
[instantiator：Doctrine\ORM\Mapping\ClassMetadataInfo：private] => Doctrine\Instantiator\Instantiator Object
）
[conn：protected] => Doctrine\DBAL\Connection Object
（
[_conn：protected] => Doctrine\DBAL\Driver\PDOConnection Object
（
）
[_config：protected] => Doctrine\ORM\Configuration对象
（
[_attributes：protected] => Array
（
[metadataCacheImpl] => Doctrine\Common\Cache\ArrayCache Object
（
[data：Doctrine\Common\Cache\ArrayCache：private] => Array
（
[dc2_b1e855bc8c5c80316087e39e6c34bc26_ [Application\Entity\Item $ CLASSMETADATA] [1]] => Array
（
[0] => Doctrine\ORM\Mapping\ClassMetadata Object
（
[name] => Application\Entity\Item
[namespace] => Application\Entity
[rootEntityName] => Application\Entity\Item
[customGeneratorDefinition] =>
[customRepositoryClassName] =>
[isMappedSuperclass] =>
[isEmbeddedClass] =>
[parentClasses] =>数组
[BAZILLION LINES为了简洁而修改]
不能使用XDebug或类似工具（限制转储对象大小）转储代理对象。
问题真的很简单：
代理 - >引用EntityManager - >引用UnitOfWork - >包含代理
这显然导致递归数据结构转储，这反过来又会导致一个混乱，任何时候你尝试转储没有明确的限制。
In my ORM code I have an Entity with a field fined like so:
//part of entity class Item:
/** @Column(name="product_id", type="integer") */
private $productId;
I then executed this code:
//3 lines ~straight out of Doctrine configuration to get EntityManager
include 'config/doctrine-config.php';
$config = Setup::createAnnotationMetadataConfiguration($paths, $isDevMode);
$em = EntityManager::create($dbParams, $config);
//my own code to retrieve an entity instance:
$instance = $em->find(Item::class, 2);
print_r($instance);
And this is the output I get (skipping few other similar properties):
Application\Entity\Item Object
(
[id:Application\Entity\Item:private] => 2
[description:Application\Entity\Item:private] => Product Kit
[productId:Application\Entity\Item:private] => -1
)
Note how there are 6 (six) lines above that came out of print_r() function.
And everything was fine, Until
Next, I have changed the $productId column to ManyToOne Relationship on my Item Entity class, like so:
/**
* @ManyToOne(targetEntity="Product", inversedBy="id")
* @JoinColumn(name="product_id", referencedColumnName="id")
*/
private $productId;
I ran the same code.
OUT CAME THE UNIVERSE OF 2,392,600 LINES, WHAT?
Two million, three hundred and ninety two thousand, six hundred lines lines of print_r output.
looking at the print-out I see that DoctrineProxies\__CG__\Application\Entity\Product Object contains 2,392,564 lines printed by print_r
Question:
What is exactly in this object and why is it so big as to take up nearly 300Mb of disk space when printed out?
I cannot help but wonder if such complexity is apt to cause performance issues in every-day code. For example, I am not printing out the contents of the $instance variable in my every-day code, but I surely return the humongousness from a method call. Does that mean it is a 300Mb variable that gets passed from i.e. the $em->find(Item::class, 2); call above?
(Very) Partial Listing
Application\Entity\Item Object
(
[id:Application\Entity\Item:private] => 2
[description:Application\Entity\Item:private] => Product Kit
[ProductId:Application\Entity\Item:private] => DoctrineProxies\__CG__\Application\Entity\Product Object
(
[__initializer__] => Closure Object
(
[static] => Array
(
[entityPersister] => Doctrine\ORM\Persisters\Entity\BasicEntityPersister Object
(
[class:protected] => Doctrine\ORM\Mapping\ClassMetadata Object
(
[name] => Application\Entity\Product
[namespace] => Application\Entity
[rootEntityName] => Application\Entity\Product
[inheritanceType] => 1
[generatorType] => 5
[fieldMappings] => Array
(
[id] => Array
(
[fieldName] => id
[type] => integer
[scale] => 0
[length] =>
[unique] =>
[nullable] =>
[precision] => 0
[columnName] => id
[id] => 1
)
[fieldNames] => Array
(
[id] => id
[description] => description
)
[columnNames] => Array
(
[id] => id
[description] => description
)
[idGenerator] => Doctrine\ORM\Id\AssignedGenerator Object
[reflClass] => ReflectionClass Object
(
[name] => Application\Entity\Product
)
[namingStrategy:protected] => Doctrine\ORM\Mapping\DefaultNamingStrategy Object
[instantiator:Doctrine\ORM\Mapping\ClassMetadataInfo:private] => Doctrine\Instantiator\Instantiator Object
)
[conn:protected] => Doctrine\DBAL\Connection Object
(
[_conn:protected] => Doctrine\DBAL\Driver\PDOConnection Object
(
)
[_config:protected] => Doctrine\ORM\Configuration Object
(
[_attributes:protected] => Array
(
[metadataCacheImpl] => Doctrine\Common\Cache\ArrayCache Object
(
[data:Doctrine\Common\Cache\ArrayCache:private] => Array
(
[dc2_b1e855bc8c5c80316087e39e6c34bc26_[Application\Entity\Item$CLASSMETADATA][1]] => Array
(
[0] => Doctrine\ORM\Mapping\ClassMetadata Object
(
[name] => Application\Entity\Item
[namespace] => Application\Entity
[rootEntityName] => Application\Entity\Item
[customGeneratorDefinition] =>
[customRepositoryClassName] =>
[isMappedSuperclass] =>
[isEmbeddedClass] =>
[parentClasses] => Array
[BAZILLION LINES redacted for brevity]
You can't dump a proxy object without XDebug or similar tools (which limit the dumped object size).
The problem is really, really simple:
Proxy -> references EntityManager -> references UnitOfWork -> contains Proxy
This obviously leads to a recursive data-structure dump, which in turn leads to a mess any time you try to dump it without sensible limits.
这篇关于为什么Doctrine\ORM\Configuration的“DoctrineProxies”对象包含宇宙？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
