Question

I use NestedSetBehavior model extension in my project for using db table as a tree.

I wroute example:

    $model = SiteMap()->findAll();
    $log .= $this->debug_memory('used')."<br>";
    $ancestors = null;
    foreach ($model as $item) {
        $ancestors = $item->ancestors()->findAll();
    }
    $log .= $this->debug_memory('used')."<br>";
    echo $log;

(debug_memory source just return friendly memory_get_usage(), $model has 50 items)

The result is:

used: 10525440
used: 15892712

After simple calculation – memory usage increased on 5,24 Mb.

But i must use $item->ancestors()->findAll(); many times in cycle, so my memory increased on 138 Mb. And i get @out of memory error”.

I try use unset():

    $model = SiteMap()->findAll();
    $log .= $this->debug_memory('used')."<br>";
    $ancestors = null;
    foreach ($model as $item) {
       $ancestors= $item->ancestors()->findAll();
    }
    $ancestors = null;
    unset($ancestors);
    $log .= $this->debug_memory('used')."<br>";
    echo $log;

But i steel get result:

used: 10525984
used: 15893320

Behavior ancestors function source is:

public function ancestors($depth=null)
{
    $owner=$this->getOwner();
    $db=$owner->getDbConnection();
    $criteria=$owner->getDbCriteria();
    $alias=$db->quoteColumnName($owner->getTableAlias());

    $criteria->mergeWith(array(
        'condition'=>$alias.'.'.$db->quoteColumnName($this->leftAttribute).'<'.$owner->{$this->leftAttribute}.
            ' AND '.$alias.'.'.$db->quoteColumnName($this->rightAttribute).'>'.$owner->{$this->rightAttribute},
        'order'=>$alias.'.'.$db->quoteColumnName($this->leftAttribute),
    ));

    if($depth!==null)
        $criteria->addCondition($alias.'.'.$db->quoteColumnName($this->levelAttribute).'>='.($owner->{$this->levelAttribute}-$depth));

    if($this->hasManyRoots)
    {
        $criteria->addCondition($alias.'.'.$db->quoteColumnName($this->rootAttribute).'='.CDbCriteria::PARAM_PREFIX.CDbCriteria::$paramCount);
        $criteria->params[CDbCriteria::PARAM_PREFIX.CDbCriteria::$paramCount++]=$owner->{$this->rootAttribute};
    }

    return $owner;
}

So, my questions is, why this function use so many memory and why when i unset variable memory is not cleaning?

Answer 1

Comment out the logging in your protected/config/main.php file. (Or wherever you define your configuration settings.)

What you are seeing is likely a result of all the logs being written on each Active Record call, which would explain why unsetting the object doesn’t release memory: the memory used isn’t in the model, it’s in the log.

Try that and report results.