modules/ModuleDlstatsTag.php
public function dlstatsReplaceInsertTags($strTag)
	{
		$arrTag = trimsplit('::', $strTag);
		if ($arrTag[0] != 'dlstats')
		{
			if ($arrTag[0] != 'cache_dlstats')
			{
				return false; // not for us
			}
		}
		$this->loadLanguageFile('tl_dlstats');
		if (! isset($arrTag[2]))
		{
			$this->log($GLOBALS['TL_LANG']['tl_dlstats']['no_key'], 'ModuleDlstatsTag ReplaceInsertTags ', TL_ERROR);
			return false; // da fehlt was
		}
		// filename with article alias?
		if (strpos($arrTag[2], 'file=') !== false)
		{
			$arrTag[2] = substr($arrTag[2], strpos($arrTag[2], 'file=') + 5);
		}
		if ($arrTag[1] == 'totaldownloads')
		{
			$objDlstats = \Database::getInstance()->prepare("SELECT 
                                                                    `downloads`
                                                             FROM
                                                                    `tl_dlstats`
                                                             WHERE
                                                                    `filename` = ?")
                                    ->executeUncached(urldecode($arrTag[2]));
			if ($objDlstats->numRows < 1)
			{
				return 0;
			}
			$objDlstats->next();
			return $objDlstats->downloads;
		}
		// Tag is wrong 
		$this->log($GLOBALS['TL_LANG']['tl_dlstats']['wrong_key'], 'ModuleDlstatsTag ReplaceInsertTags ', TL_ERROR);
		return false; // wrong tag
	}
public function dlstatsReplaceInsertTags($strTag)
	{
		$arrTag = trimsplit('::', $strTag);
		if ($arrTag[0] != 'dlstats')
		{
			if ($arrTag[0] != 'cache_dlstats')
			{
				return false; // not for us
			}
		}
		$this->loadLanguageFile('tl_dlstats');
		if (! isset($arrTag[2]))
		{
			$this->log($GLOBALS['TL_LANG']['tl_dlstats']['no_key'], 'ModuleDlstatsTag ReplaceInsertTags ', TL_ERROR);
			return false; // da fehlt was
		}
		// filename with article alias?
		if (strpos($arrTag[2], 'file=') !== false)
		{
			$arrTag[2] = substr($arrTag[2], strpos($arrTag[2], 'file=') + 5);
		}
		if ($arrTag[1] == 'totaldownloads')
		{
			$objDlstats = \Database::getInstance()->prepare("SELECT 
                                                                    `downloads`
                                                             FROM
                                                                    `tl_dlstats`
                                                             WHERE
                                                                    `filename` = ?")
                                    ->executeUncached(urldecode($arrTag[2]));
			if ($objDlstats->numRows < 1)
			{
				return 0;
			}
			$objDlstats->next();
			return $objDlstats->downloads;
		}
		// Tag is wrong 
		$this->log($GLOBALS['TL_LANG']['tl_dlstats']['wrong_key'], 'ModuleDlstatsTag ReplaceInsertTags ', TL_ERROR);
		return false; // wrong tag
	}
replaceInsertTags

From TL 2.8 you can use prefix "cache_". Thus the InserTag will be not cached. (when "cache" is enabled)

dlstats::totaldownloads::filename - Total downloads for filename
cache_dlstats::totaldownloads::filename - Total downloads for filename (not cached)

<code>
{{cache_dlstats::totaldownloads::tl_files/cdc2010.pdf}}
{{cache_dlstats::totaldownloads::CDC_2010.html?file=tl_files/cdc2010.pdf}}
// in the ce_download template:
{{cache_dlstats::totaldownloads::<?php echo $this->href; ?>}}
// in the ce_downloads template:
{{cache_dlstats::totaldownloads::<?php echo $file['href']; ?>}}
</code>

@param string    $strTag Insert-Tag
@return mixed    integer on downloads, false on wrong Insert-Tag or wrong parameters
@access public