Driver_Database_Driver_Mongo_Result::fetch_assoc

protected function fetch_assoc()
{
    if ($this->_result instanceof ArrayIterator)
    {
        $data = $this->_result->current();
        $this->_result->next();

        return $data;
    }

    // 当有缓存数据
    if (isset($this->_data[$this->_current_row]))
    {
        return $this->_data[$this->_current_row];
    }

    $data = $this->_result->getNext();
    if (isset($data['_id']) && is_object($data['_id']) && $data['_id'] instanceof MongoId)
    {
        $data['_id'] = (string)$data['_id'];
    }

    if ( isset($this->_query['select_as']) )foreach ($this->_query['select_as'] as $key=>$value)
    {
        // 对查询出的数据做select as转换
        if (isset($data[$key]))
        {
            $data[$value] = $data[$key];
            unset($data[$key]);
        }
    }

    if (count($this->_data[$this->_current_row])>1000)
    {
        // 释放内存
        $this->_data[$this->_current_row] = array();
    }

    // 记录
    $this->_data[$this->_current_row] = $data;

    return $data;
}