CFile::GetFromCache

static function GetFromCache($fileId, $realId = false)
{
	global $DB;

	$cache = MainApplication::getInstance()->getManagedCache();

	$bucketSize = (int)CACHED_b_file_bucket_size;
	if ($bucketSize <= 0)
	{
		$bucketSize = 10;
	}

	$bucket = (int)($fileId / $bucketSize);
	$https = (int)MainContext::getCurrent()->getRequest()->isHttps();
	$cacheId = self::CACHE_DIR . $https . (int)$realId . $bucket;

	if ($cache->read(CACHED_b_file, $cacheId, self::CACHE_DIR))
	{
		$files = $cache->get($cacheId);

		if (!isset($files[$fileId]))
		{
			// the trail of an incomplete bucket
			if (!is_array($files))
			{
				$files = [];
			}

			if ($file = static::GetFromDb($fileId, $realId)->Fetch())
			{
				$files[$fileId] = $file;
				static::CleanCache($fileId);
			}
		}
	}
	else
	{
		$files = [];

		$minId = $bucket * $bucketSize;
		$maxId = ($bucket + 1) * $bucketSize - 1;

		$sql = "
			SELECT f.*, 
				{$DB->DateToCharFunction("f.TIMESTAMP_X")} as TIMESTAMP_X, 
				NULL as VERSION_ORIGINAL_ID, '' as META
			FROM b_file f
			WHERE f.ID >= {$minId} 
				AND f.ID <= {$maxId} 
		";

		if ($realId !== true)
		{
			$sql .= "
				UNION
				SELECT f.*, 
					{$DB->DateToCharFunction("f.TIMESTAMP_X")} as TIMESTAMP_X, 
					fv.ORIGINAL_ID as VERSION_ORIGINAL_ID, fv.META as META
				FROM b_file f
					INNER JOIN b_file_version fv ON fv.VERSION_ID = f.ID 
				WHERE fv.ORIGINAL_ID >= {$minId} 
					AND fv.ORIGINAL_ID <= {$maxId}
				ORDER BY ID
			";
		}

		$rs = $DB->Query($sql);

		while ($file = $rs->fetch())
		{
			$originalId = ($file['VERSION_ORIGINAL_ID'] ?: $file["ID"]);
			$files[$originalId] = $file;
		}

		// store SRC in cache
		foreach ($files as $id => $file)
		{
			$files[$id]['SRC'] = static::GetFileSRC($file);
		}

		$cache->setImmediate($cacheId, $files);
	}
	return $files;
}