func DetectEmptyRanges()

in upload/detectEmptyRanges.go [26:64]
36 lines of code
8 McCabe index (conditional complexity)

func DetectEmptyRanges(diskStream *diskstream.DiskStream, uploadableRanges []*common.IndexRange) ([]*common.IndexRange, error) {
	if diskStream.GetDiskType() != footer.DiskTypeFixed {
		return uploadableRanges, nil
	}

	fmt.Println("\nDetecting empty ranges..")
	totalRangesCount := len(uploadableRanges)
	lastIndex := int32(-1)
	emptyRangesCount := int32(0)
	bits := make([]byte, int32(math.Ceil(float64(totalRangesCount)/float64(8))))
	bmap := bitmap.NewBitMapFromByteSliceCopy(bits)
	indexChan, errChan := LocateNonEmptyRangeIndices(diskStream, uploadableRanges)
L:
	for {
		select {
		case index, ok := <-indexChan:
			if !ok {
				break L
			}
			bmap.Set(index, true)
			emptyRangesCount += index - lastIndex - 1
			lastIndex = index
			fmt.Printf("\r Empty ranges : %d/%d", emptyRangesCount, totalRangesCount)
		case err := <-errChan:
			return nil, err
		}
	}

	// Remove empty ranges from the uploadable ranges slice.
	i := int32(0)
	for j := 0; j < totalRangesCount; j++ {
		if set, _ := bmap.Get(int32(j)); set {
			uploadableRanges[i] = uploadableRanges[j]
			i++
		}
	}
	uploadableRanges = uploadableRanges[:i]
	return uploadableRanges, nil
}