我在每次迭代中首先取消设置循环中使用的每个变量,因此我真的不知道我还能做什么。我的猜测是,do/while会在每次迭代中收集一些数据,这就是消耗4kb内存的原因。我知道4kb听起来不像什么,但当你有数十万次迭代时,它很快就会累加。
有人能建议另一种遍历大量数据库行的方法或如何消除这种“内存泄漏”吗?
编辑:以下是更新后的循环代码。上面只有几个require_once()。
$URLs = new URLs_url(db());
$c = new Curl;
$c->headers = 1;
$c->timeout = 60;
$c->getinfo = true;
$c->follow = 0;
$c->save_cookies = false;
do {
// Get url that hasn't been checked for a week
$urls = null;
// Check week old
$urls = $URLs->all($where)->limit(10);
foreach($urls as $url) {
#echo date("d/m/Y h:i").' | Checking '.$url->url.' | db http_code: '.$url->http_code;
// Get http code
$c->url = $url->url;
$data = $c->get();
#echo ' - new http_code: '.$data['http_code'];
// Save info
$url->http_code = $data['http_code'];
$url->lastchecked = time();
$URLs->save($url);
$url = null;
#unset($c);
$data = null;
#echo "\n".memory_get_usage().' | ';
echo "\nInner loop memory usage: ".memory_get_usage();
}
echo "\nOuter loop memory usage: ".memory_get_usage();
} while($urls);
以下是两个循环中内存消耗情况的一些日志:
Inner loop memory usage: 611080
Inner loop memory usage: 612452
Inner loop memory usage: 613788
Inner loop memory usage: 615124
Inner loop memory usage: 616460
Inner loop memory usage: 617796
Inner loop memory usage: 619132
Inner loop memory usage: 620500
Inner loop memory usage: 621836
Inner loop memory usage: 623172
Outer loop memory usage: 545240
Inner loop memory usage: 630680
Inner loop memory usage: 632016
Inner loop memory usage: 633352
Inner loop memory usage: 634688
Inner loop memory usage: 636088
Inner loop memory usage: 637424
Inner loop memory usage: 638760
Inner loop memory usage: 640096
Inner loop memory usage: 641432
Inner loop memory usage: 642768
Outer loop memory usage: 556392
Inner loop memory usage: 640416
Inner loop memory usage: 641752
Inner loop memory usage: 643088
Inner loop memory usage: 644424
Inner loop memory usage: 645760
Inner loop memory usage: 647096
Inner loop memory usage: 648432
Inner loop memory usage: 649768
Inner loop memory usage: 651104
Inner loop memory usage: 652568
Outer loop memory usage: 567608
Inner loop memory usage: 645924
Inner loop memory usage: 647260
Inner loop memory usage: 648596
Inner loop memory usage: 649932
Inner loop memory usage: 651268
Inner loop memory usage: 652604
Inner loop memory usage: 653940
Inner loop memory usage: 655276
Inner loop memory usage: 656624
Inner loop memory usage: 657960
Outer loop memory usage: 578732