func getCompressedOffsets(oi ObjectInfo, offset int64, decrypt func([]byte) ([]byte, error)) (compressedOffset int64, partSkip int64, firstPart int, decryptSkip int64, seqNum uint32) {
	var skipLength int64
	var cumulativeActualSize int64
	var firstPartIdx int
	for i, part := range oi.Parts {
		cumulativeActualSize += part.ActualSize
		if cumulativeActualSize <= offset {