Mage_Core_Model_Cache::processRequest()

public function processRequest()
{
    if (empty($this->_requestProcessors)) {
        return false;
    }

    $content = false;
    foreach ($this->_requestProcessors as $processor) {
        $processor = $this->_getProcessor($processor);
        if ($processor) {
            $content = $processor->extractContent($content);
        }
    }

    if ($content) {
        Mage::app()->getResponse()->appendBody($content);
        return true;
    }
    return false;
}