PHP:JSON解码限制

使用此代码:

$json = file_get_contents($this->url, true); 
$decode = json_decode($json, true); 

foreach ($decode as $key => $value) {
 ...
}

很简单，嗯?

传递带有最多500个数组元素的$ json ...可以正常使用！

Passing a $json with up to 500 array elements.... works right!

超过该限制...错误是:

Above that limit... the error is:

警告:为中的foreach()提供了无效的参数 /c/website/retriever/WsGlassRetriever.php，第19行

Warning: Invalid argument supplied for foreach() in /c/website/retriever/WsGlassRetriever.php on line 19

该函数的参数是否有内存限制?

Is there some memory limit for that function's argument?

我在文档中什么都没找到.我的版本是带有Suhosin-Patch 0.9.7(cli)的PHP 5.2.17-rnx1.1

I didn't found nothing about it in the docs. My version is PHP 5.2.17-rnx1.1 with Suhosin-Patch 0.9.7 (cli)