CDataProviderIterator

public function __construct(CDataProvider $dataProvider, $pageSize=null)
{
    $this->_dataProvider=$dataProvider;
    $this->_totalItemCount=$dataProvider->getTotalItemCount();

    if(($pagination=$this->_dataProvider->getPagination())===false)
        $this->_dataProvider->setPagination($pagination=new CPagination());

    if($pageSize!==null)
        $pagination->setPageSize($pageSize);
}

public function count()
{
    return $this->_totalItemCount;
}

public function current()
{
    return $this->_items[$this->_currentIndex];
}

public function getDataProvider()
{
    return $this->_dataProvider;
}

public function getTotalItemCount()
{
    return $this->_totalItemCount;
}

public function key()
{
    $pageSize=$this->_dataProvider->getPagination()->getPageSize();
    return $this->_currentPage*$pageSize+$this->_currentIndex;
}

protected function loadPage()
{
    $this->_dataProvider->getPagination()->setCurrentPage($this->_currentPage);
    return $this->_items=$this->dataProvider->getData(true);
}

public function next()
{
    $pageSize=$this->_dataProvider->getPagination()->getPageSize();
    $this->_currentIndex++;
    if($this->_currentIndex >= $pageSize)
    {
        $this->_currentPage++;
        $this->_currentIndex=0;
        $this->loadPage();
    }
}

public function rewind()
{
    $this->_currentIndex=0;
    $this->_currentPage=0;
    $this->loadPage();
}

public function valid()
{
    return $this->key() < $this->_totalItemCount;
}