/** * @param mapper IGFS blocks mapper. * @param fileId IGFS file ID. * @param blockId File block ID. * @param partCnt Total partitions count. * @return Partition index. */ private int partition(IgfsGroupDataBlocksKeyMapper mapper, IgniteUuid fileId, long blockId, int partCnt) { return U.safeAbs((Integer) mapper.affinityKey(new IgfsBlockKey(fileId, null, false, blockId)) % partCnt); }