// DataBySpec returns a ROI Data based on a string specification of the form
// "<roiname>,<uuid>". If the given string is not parsable, the "found" return value is false.
func DataBySpec(spec string) (d *Data, v dvid.VersionID, found bool, err error) {
roispec := strings.Split(spec, ",")
if len(roispec) != 2 {
err = fmt.Errorf("Expect ROI filters to have format %q, but got %q", "roi:<roiname>,<uuid>", spec)
return
}
roiName := dvid.InstanceName(roispec[0])
_, v, err = datastore.MatchingUUID(roispec[1])
if err != nil {
return
}
var data datastore.DataService
data, err = datastore.GetDataByVersionName(v, roiName)
if err != nil {
return
}
var ok bool
d, ok = data.(*Data)
if !ok {
err = fmt.Errorf("Data instance %q is not ROI instance", roiName)
return
}
found = true
return
}
func NewIterator(roiName dvid.InstanceName, versionID dvid.VersionID, b dvid.Bounder) (*Iterator, error) {
dataservice, err := datastore.GetDataByVersionName(versionID, roiName)
if err != nil {
return nil, fmt.Errorf("Can't get ROI with name %q: %v", roiName, err)
}
data, ok := dataservice.(*Data)
if !ok {
return nil, fmt.Errorf("Data name %q was not of roi data type\n", roiName)
}
// Convert voxel extents to block Z extents
minPt := b.StartPoint().(dvid.Chunkable)
maxPt := b.EndPoint().(dvid.Chunkable)
minBlockCoord := minPt.Chunk(data.BlockSize)
maxBlockCoord := maxPt.Chunk(data.BlockSize)
minIndex := minIndexByBlockZ(minBlockCoord.Value(2))
maxIndex := maxIndexByBlockZ(maxBlockCoord.Value(2))
ctx := datastore.NewVersionedCtx(data, versionID)
it := new(Iterator)
it.spans, err = getSpans(ctx, minIndex, maxIndex)
return it, err
}