Golang LabelMap Examples

Example #1

File: read.go Project: tartavull/dvid

// GetBlocks returns a slice of bytes corresponding to all the blocks along a span in X
func (d *Data) GetBlocks(v dvid.VersionID, start dvid.ChunkPoint3d, span int) ([]byte, error) {
	store, err := d.GetOrderedKeyValueDB()
	if err != nil {
		return nil, fmt.Errorf("Data type imageblk had error initializing store: %v\n", err)
	}

	indexBeg := dvid.IndexZYX(start)
	end := start
	end[0] += int32(span - 1)
	indexEnd := dvid.IndexZYX(end)
	begTKey := NewTKey(&indexBeg)
	endTKey := NewTKey(&indexEnd)

	ctx := datastore.NewVersionedCtx(d, v)

	iv := dvid.InstanceVersion{d.DataUUID(), v}
	mapping := labels.LabelMap(iv)

	keyvalues, err := store.GetRange(ctx, begTKey, endTKey)
	if err != nil {
		return nil, err
	}

	var buf bytes.Buffer

	// Save the # of keyvalues actually obtained.
	numkv := len(keyvalues)
	binary.Write(&buf, binary.LittleEndian, int32(numkv))

	// Write the block indices in XYZ little-endian format + the size of each block
	uncompress := true
	for _, kv := range keyvalues {
		block, _, err := dvid.DeserializeData(kv.V, uncompress)
		if err != nil {
			return nil, fmt.Errorf("Unable to deserialize block, %s (%v): %v", ctx, kv.K, err)
		}
		if mapping != nil {
			n := len(block) / 8
			for i := 0; i < n; i++ {
				orig := binary.LittleEndian.Uint64(block[i*8 : i*8+8])
				mapped, found := mapping.FinalLabel(orig)
				if !found {
					mapped = orig
				}
				binary.LittleEndian.PutUint64(block[i*8:i*8+8], mapped)
			}
		}

		_, err = buf.Write(block)
		if err != nil {
			return nil, err
		}
	}

	return buf.Bytes(), nil
}

Example #2

File: read.go Project: tartavull/dvid

// GetLabels copies labels from the storage engine to Labels, a requested subvolume or 2d image.
func (d *Data) GetLabels(v dvid.VersionID, vox *Labels, r *imageblk.ROI) error {
	store, err := d.GetOrderedKeyValueDB()
	if err != nil {
		return fmt.Errorf("Data type imageblk had error initializing store: %v\n", err)
	}

	// Only do one request at a time, although each request can start many goroutines.
	server.SpawnGoroutineMutex.Lock()
	defer server.SpawnGoroutineMutex.Unlock()

	ctx := datastore.NewVersionedCtx(d, v)

	iv := dvid.InstanceVersion{d.DataUUID(), v}
	mapping := labels.LabelMap(iv)

	wg := new(sync.WaitGroup)

	okv := store.(storage.BufferableOps)
	// extract buffer interface
	req, hasbuffer := okv.(storage.KeyValueRequester)
	if hasbuffer {
		okv = req.NewBuffer(ctx)
	}

	for it, err := vox.IndexIterator(d.BlockSize()); err == nil && it.Valid(); it.NextSpan() {
		indexBeg, indexEnd, err := it.IndexSpan()
		if err != nil {
			return err
		}
		begTKey := NewTKey(indexBeg)
		endTKey := NewTKey(indexEnd)

		// Get set of blocks in ROI if ROI provided
		var chunkOp *storage.ChunkOp
		if r != nil && r.Iter != nil {
			ptBeg := indexBeg.Duplicate().(dvid.ChunkIndexer)
			ptEnd := indexEnd.Duplicate().(dvid.ChunkIndexer)
			begX := ptBeg.Value(0)
			endX := ptEnd.Value(0)

			blocksInROI := make(map[string]bool, (endX - begX + 1))
			c := dvid.ChunkPoint3d{begX, ptBeg.Value(1), ptBeg.Value(2)}
			for x := begX; x <= endX; x++ {
				c[0] = x
				curIndex := dvid.IndexZYX(c)
				if r.Iter.InsideFast(curIndex) {
					indexString := string(curIndex.Bytes())
					blocksInROI[indexString] = true
				}
			}
			chunkOp = &storage.ChunkOp{&getOperation{vox, blocksInROI, mapping}, wg}
		} else {
			chunkOp = &storage.ChunkOp{&getOperation{vox, nil, mapping}, wg}
		}

		// Send the entire range of key-value pairs to chunk processor
		err = okv.ProcessRange(ctx, begTKey, endTKey, chunkOp, storage.ChunkFunc(d.ReadChunk))
		if err != nil {
			return fmt.Errorf("Unable to GET data %s: %v", ctx, err)
		}
	}

	if hasbuffer {
		// submit the entire buffer to the DB
		err = okv.(storage.RequestBuffer).Flush()

		if err != nil {
			return fmt.Errorf("Unable to GET data %s: %v", ctx, err)

		}
	}

	if err != nil {
		return err
	}
	wg.Wait()
	return nil
}