Example #1
0
// ServeHTTP handles all incoming HTTP requests for this data.
func (d *Data) ServeHTTP(uuid dvid.UUID, ctx *datastore.VersionedCtx, w http.ResponseWriter, r *http.Request) {
	// TODO -- Refactor this method to break it up and make it simpler.  Use the web routing for the endpoints.

	timedLog := dvid.NewTimeLog()

	// Get the action (GET, POST)
	action := strings.ToLower(r.Method)
	switch action {
	case "get":
	case "post":
	case "delete":
	default:
		server.BadRequest(w, r, "labelblk only handles GET, POST, and DELETE HTTP verbs")
		return
	}

	// Break URL request into arguments
	url := r.URL.Path[len(server.WebAPIPath):]
	parts := strings.Split(url, "/")
	if len(parts[len(parts)-1]) == 0 {
		parts = parts[:len(parts)-1]
	}

	// Get query strings and possible roi
	var roiptr *imageblk.ROI
	queryValues := r.URL.Query()
	roiname := dvid.InstanceName(queryValues.Get("roi"))
	if len(roiname) != 0 {
		roiptr = new(imageblk.ROI)
	}

	// Handle POST on data -> setting of configuration
	if len(parts) == 3 && action == "post" {
		config, err := server.DecodeJSON(r)
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if err := d.ModifyConfig(config); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if err := datastore.SaveDataByUUID(uuid, d); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		fmt.Fprintf(w, "Changed '%s' based on received configuration:\n%s\n", d.DataName(), config)
		return
	}

	if len(parts) < 4 {
		server.BadRequest(w, r, "Incomplete API request")
		return
	}

	// Process help and info.
	switch parts[3] {
	case "help":
		w.Header().Set("Content-Type", "text/plain")
		fmt.Fprintln(w, dtype.Help())

	case "metadata":
		jsonStr, err := d.NdDataMetadata()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		w.Header().Set("Content-Type", "application/vnd.dvid-nd-data+json")
		fmt.Fprintln(w, jsonStr)

	case "info":
		jsonBytes, err := d.MarshalJSON()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, string(jsonBytes))

	case "label":
		// GET <api URL>/node/<UUID>/<data name>/label/<coord>
		if len(parts) < 5 {
			server.BadRequest(w, r, "DVID requires coord to follow 'label' command")
			return
		}
		coord, err := dvid.StringToPoint(parts[4], "_")
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		label, err := d.GetLabelAtPoint(ctx.VersionID(), coord)
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		w.Header().Set("Content-type", "application/json")
		jsonStr := fmt.Sprintf(`{"Label": %d}`, label)
		fmt.Fprintf(w, jsonStr)
		timedLog.Infof("HTTP %s: label at %s (%s)", r.Method, coord, r.URL)

	case "labels":
		// POST <api URL>/node/<UUID>/<data name>/labels
		if action != "post" {
			server.BadRequest(w, r, "Batch labels query must be a POST request")
			return
		}
		data, err := ioutil.ReadAll(r.Body)
		if err != nil {
			server.BadRequest(w, r, "Bad POSTed data for batch reverse query.  Should be JSON.")
			return
		}
		var coords []dvid.Point3d
		if err := json.Unmarshal(data, &coords); err != nil {
			server.BadRequest(w, r, fmt.Sprintf("Bad labels request JSON: %v", err))
			return
		}
		w.Header().Set("Content-type", "application/json")
		fmt.Fprintf(w, "[")
		sep := false
		for _, coord := range coords {
			label, err := d.GetLabelAtPoint(ctx.VersionID(), coord)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if sep {
				fmt.Fprintf(w, ",")
			}
			fmt.Fprintf(w, "%d", label)
			sep = true
		}
		fmt.Fprintf(w, "]")
		timedLog.Infof("HTTP batch label-at-point query (%d coordinates)", len(coords))

	case "blocks":
		// DELETE <api URL>/node/<UUID>/<data name>/blocks/<block coord>/<spanX>
		if len(parts) < 6 {
			server.BadRequest(w, r, "DVID requires starting block coord and # of blocks along X to follow 'blocks' endpoint.")
			return
		}
		blockCoord, err := dvid.StringToChunkPoint3d(parts[4], "_")
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		span, err := strconv.Atoi(parts[5])
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if action != "delete" {
			server.BadRequest(w, r, "DVID currently accepts only DELETE on the 'blocks' endpoint")
			return
		}
		if err := d.DeleteBlocks(ctx, blockCoord, span); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		timedLog.Infof("HTTP %s: delete %d blocks from %s (%s)", r.Method, span, blockCoord, r.URL)

	case "pseudocolor":
		if len(parts) < 7 {
			server.BadRequest(w, r, "'%s' must be followed by shape/size/offset", parts[3])
			return
		}
		shapeStr, sizeStr, offsetStr := parts[4], parts[5], parts[6]
		planeStr := dvid.DataShapeString(shapeStr)
		plane, err := planeStr.DataShape()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		switch plane.ShapeDimensions() {
		case 2:
			slice, err := dvid.NewSliceFromStrings(planeStr, offsetStr, sizeStr, "_")
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if action != "get" {
				server.BadRequest(w, r, "DVID does not permit 2d mutations, only 3d block-aligned stores")
				return
			}
			lbl, err := d.NewLabels(slice, nil)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if roiptr != nil {
				roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), lbl)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			img, err := d.GetImage(ctx.VersionID(), lbl, roiptr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}

			// Convert to pseudocolor
			pseudoColor, err := colorImage(img)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}

			//dvid.ElapsedTime(dvid.Normal, startTime, "%s %s upto image formatting", op, slice)
			var formatStr string
			if len(parts) >= 8 {
				formatStr = parts[7]
			}
			err = dvid.WriteImageHttp(w, pseudoColor, formatStr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			timedLog.Infof("HTTP %s: %s (%s)", r.Method, plane, r.URL)
		default:
			server.BadRequest(w, r, "DVID currently supports only 2d pseudocolor image requests")
			return
		}

	case "raw", "isotropic":
		if len(parts) < 7 {
			server.BadRequest(w, r, "'%s' must be followed by shape/size/offset", parts[3])
			return
		}
		var isotropic bool = (parts[3] == "isotropic")
		shapeStr, sizeStr, offsetStr := parts[4], parts[5], parts[6]
		planeStr := dvid.DataShapeString(shapeStr)
		plane, err := planeStr.DataShape()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		switch plane.ShapeDimensions() {
		case 2:
			slice, err := dvid.NewSliceFromStrings(planeStr, offsetStr, sizeStr, "_")
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if action != "get" {
				server.BadRequest(w, r, "DVID does not permit 2d mutations, only 3d block-aligned stores")
				return
			}
			rawSlice, err := dvid.Isotropy2D(d.Properties.VoxelSize, slice, isotropic)
			lbl, err := d.NewLabels(rawSlice, nil)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if roiptr != nil {
				roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), lbl)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			img, err := d.GetImage(ctx.VersionID(), lbl, roiptr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if isotropic {
				dstW := int(slice.Size().Value(0))
				dstH := int(slice.Size().Value(1))
				img, err = img.ScaleImage(dstW, dstH)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			var formatStr string
			if len(parts) >= 8 {
				formatStr = parts[7]
			}
			//dvid.ElapsedTime(dvid.Normal, startTime, "%s %s upto image formatting", op, slice)
			err = dvid.WriteImageHttp(w, img.Get(), formatStr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			timedLog.Infof("HTTP %s: %s (%s)", r.Method, plane, r.URL)
		case 3:
			queryStrings := r.URL.Query()
			throttle := queryStrings.Get("throttle")
			if throttle == "true" || throttle == "on" {
				select {
				case <-server.Throttle:
					// Proceed with operation, returning throttle token to server at end.
					defer func() {
						server.Throttle <- 1
					}()
				default:
					throttleMsg := fmt.Sprintf("Server already running maximum of %d throttled operations",
						server.MaxThrottledOps)
					http.Error(w, throttleMsg, http.StatusServiceUnavailable)
					return
				}
			}
			compression := queryValues.Get("compression")
			subvol, err := dvid.NewSubvolumeFromStrings(offsetStr, sizeStr, "_")
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if action == "get" {
				lbl, err := d.NewLabels(subvol, nil)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				if roiptr != nil {
					roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), lbl)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
				}
				data, err := d.GetVolume(ctx.VersionID(), lbl, roiptr)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				w.Header().Set("Content-type", "application/octet-stream")
				switch compression {
				case "":
					_, err = w.Write(data)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
				case "lz4":
					compressed := make([]byte, lz4.CompressBound(data))
					var n, outSize int
					if outSize, err = lz4.Compress(data, compressed); err != nil {
						server.BadRequest(w, r, err)
						return
					}
					compressed = compressed[:outSize]
					if n, err = w.Write(compressed); err != nil {
						server.BadRequest(w, r, err)
						return
					}
					if n != outSize {
						errmsg := fmt.Sprintf("Only able to write %d of %d lz4 compressed bytes\n", n, outSize)
						dvid.Errorf(errmsg)
						server.BadRequest(w, r, errmsg)
						return
					}
				case "gzip":
					gw := gzip.NewWriter(w)
					if _, err = gw.Write(data); err != nil {
						server.BadRequest(w, r, err)
						return
					}
					if err = gw.Close(); err != nil {
						server.BadRequest(w, r, err)
						return
					}
				default:
					server.BadRequest(w, r, "unknown compression type %q", compression)
					return
				}
			} else {
				if isotropic {
					server.BadRequest(w, r, "can only POST 'raw' not 'isotropic' images")
					return
				}
				// Make sure vox is block-aligned
				if !dvid.BlockAligned(subvol, d.BlockSize()) {
					server.BadRequest(w, r, "cannot store labels in non-block aligned geometry %s -> %s", subvol.StartPoint(), subvol.EndPoint())
					return
				}

				var data []byte
				switch compression {
				case "":
					tlog := dvid.NewTimeLog()
					data, err = ioutil.ReadAll(r.Body)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
					tlog.Debugf("read 3d uncompressed POST")
				case "lz4":
					tlog := dvid.NewTimeLog()
					data, err = ioutil.ReadAll(r.Body)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
					if len(data) == 0 {
						server.BadRequest(w, r, "received 0 LZ4 compressed bytes")
						return
					}
					tlog.Debugf("read 3d lz4 POST")
					tlog = dvid.NewTimeLog()
					uncompressed := make([]byte, subvol.NumVoxels()*8)
					err = lz4.Uncompress(data, uncompressed)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
					data = uncompressed
					tlog.Debugf("uncompressed 3d lz4 POST")
				case "gzip":
					tlog := dvid.NewTimeLog()
					gr, err := gzip.NewReader(r.Body)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
					data, err = ioutil.ReadAll(gr)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
					if err = gr.Close(); err != nil {
						server.BadRequest(w, r, err)
						return
					}
					tlog.Debugf("read and uncompress 3d gzip POST")
				default:
					server.BadRequest(w, r, "unknown compression type %q", compression)
					return
				}
				lbl, err := d.NewLabels(subvol, data)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				if roiptr != nil {
					roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), lbl)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
				}
				if err = d.PutVoxels(ctx.VersionID(), lbl.Voxels, roiptr); err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			timedLog.Infof("HTTP %s: %s (%s)", r.Method, subvol, r.URL)
		default:
			server.BadRequest(w, r, "DVID currently supports shapes of only 2 and 3 dimensions")
			return
		}

	default:
		server.BadRequest(w, r, "Unrecognized API call %q for labelblk data %q.  See API help.",
			parts[3], d.DataName())
	}
}
Example #2
0
// PutVoxels persists voxels from a subvolume into the storage engine.
// The subvolume must be aligned to blocks of the data instance, which simplifies
// the routine if the PUT is a mutation (signals MutateBlockEvent) instead of ingestion.
func (d *Data) PutVoxels(v dvid.VersionID, mutID uint64, vox *Voxels, roiname dvid.InstanceName, mutate bool) error {
	r, err := GetROI(v, roiname, vox)
	if err != nil {
		return err
	}

	// Make sure vox is block-aligned
	if !dvid.BlockAligned(vox, d.BlockSize()) {
		return fmt.Errorf("cannot store voxels in non-block aligned geometry %s -> %s", vox.StartPoint(), vox.EndPoint())
	}

	wg := new(sync.WaitGroup)

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

	// Keep track of changing extents and mark repo as dirty if changed.
	var extentChanged bool
	defer func() {
		if extentChanged {
			err := datastore.SaveDataByVersion(v, d)
			if err != nil {
				dvid.Infof("Error in trying to save repo on change: %v\n", err)
			}
		}
	}()

	// Track point extents
	extents := d.Extents()
	if extents.AdjustPoints(vox.StartPoint(), vox.EndPoint()) {
		extentChanged = true
	}

	// extract buffer interface if it exists
	var putbuffer storage.RequestBuffer
	store, err := d.GetOrderedKeyValueDB()
	if err != nil {
		return fmt.Errorf("Data type imageblk had error initializing store: %v\n", err)
	}
	if req, ok := store.(storage.KeyValueRequester); ok {
		ctx := datastore.NewVersionedCtx(d, v)
		putbuffer = req.NewBuffer(ctx)
	}

	// Iterate through index space for this data.
	for it, err := vox.IndexIterator(d.BlockSize()); err == nil && it.Valid(); it.NextSpan() {
		i0, i1, err := it.IndexSpan()
		if err != nil {
			return err
		}
		ptBeg := i0.Duplicate().(dvid.ChunkIndexer)
		ptEnd := i1.Duplicate().(dvid.ChunkIndexer)

		begX := ptBeg.Value(0)
		endX := ptEnd.Value(0)

		if extents.AdjustIndices(ptBeg, ptEnd) {
			extentChanged = true
		}

		wg.Add(int(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)

			// Don't PUT if this index is outside a specified ROI
			if r != nil && r.Iter != nil && !r.Iter.InsideFast(curIndex) {
				wg.Done()
				continue
			}

			kv := &storage.TKeyValue{K: NewTKey(&curIndex)}
			putOp := &putOperation{vox, curIndex, v, mutate, mutID}
			op := &storage.ChunkOp{putOp, wg}
			d.PutChunk(&storage.Chunk{op, kv}, putbuffer)
		}
	}

	wg.Wait()

	// if a bufferable op, flush
	if putbuffer != nil {
		putbuffer.Flush()
	}

	return nil
}
Example #3
0
// PutVoxels persists voxels from a subvolume into the storage engine.
// The subvolume must be aligned to blocks of the data instance.
//
// This requirement simplifies the coding quite a bit.  Earlier versions
// of DVID allowed 2d writes, which required reading blocks, writing subsets of data
// into those blocks, and then writing the result all within a transaction. It is
// difficult to scale without requiring GETs within transactions and more complicated
// coordination when moving to distributed front-end DVIDs.
func (d *Data) PutVoxels(v dvid.VersionID, vox *Voxels, roi *ROI) error {

	// Make sure vox is block-aligned
	if !dvid.BlockAligned(vox, d.BlockSize()) {
		return fmt.Errorf("cannot store voxels in non-block aligned geometry %s -> %s", vox.StartPoint(), vox.EndPoint())
	}

	wg := new(sync.WaitGroup)

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

	// Keep track of changing extents and mark repo as dirty if changed.
	var extentChanged bool
	defer func() {
		if extentChanged {
			err := datastore.SaveDataByVersion(v, d)
			if err != nil {
				dvid.Infof("Error in trying to save repo on change: %v\n", err)
			}
		}
	}()

	// Track point extents
	extents := d.Extents()
	if extents.AdjustPoints(vox.StartPoint(), vox.EndPoint()) {
		extentChanged = true
	}

	// Iterate through index space for this data.
	for it, err := vox.IndexIterator(d.BlockSize()); err == nil && it.Valid(); it.NextSpan() {
		i0, i1, err := it.IndexSpan()
		if err != nil {
			return err
		}
		ptBeg := i0.Duplicate().(dvid.ChunkIndexer)
		ptEnd := i1.Duplicate().(dvid.ChunkIndexer)

		begX := ptBeg.Value(0)
		endX := ptEnd.Value(0)

		if extents.AdjustIndices(ptBeg, ptEnd) {
			extentChanged = true
		}

		wg.Add(int(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)

			// Don't PUT if this index is outside a specified ROI
			if roi != nil && roi.Iter != nil && !roi.Iter.InsideFast(curIndex) {
				wg.Done()
				continue
			}

			kv := &storage.TKeyValue{K: NewTKey(&curIndex)}
			putOp := &putOperation{vox, curIndex, v}
			op := &storage.ChunkOp{putOp, wg}
			d.PutChunk(&storage.Chunk{op, kv})
		}
	}

	wg.Wait()
	return nil
}
Example #4
0
// ServeHTTP handles all incoming HTTP requests for this data.
func (d *Data) ServeHTTP(uuid dvid.UUID, ctx *datastore.VersionedCtx, w http.ResponseWriter, r *http.Request) {
	timedLog := dvid.NewTimeLog()

	// Get the action (GET, POST)
	action := strings.ToLower(r.Method)
	switch action {
	case "get":
	case "post":
	default:
		server.BadRequest(w, r, "Can only handle GET or POST HTTP verbs")
		return
	}

	// Break URL request into arguments
	url := r.URL.Path[len(server.WebAPIPath):]
	parts := strings.Split(url, "/")
	if len(parts[len(parts)-1]) == 0 {
		parts = parts[:len(parts)-1]
	}

	// Get query strings and possible roi
	var roiptr *ROI
	queryValues := r.URL.Query()
	roiname := dvid.InstanceName(queryValues.Get("roi"))
	if len(roiname) != 0 {
		roiptr = new(ROI)
		attenuationStr := queryValues.Get("attenuation")
		if len(attenuationStr) != 0 {
			attenuation, err := strconv.Atoi(attenuationStr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if attenuation < 1 || attenuation > 7 {
				server.BadRequest(w, r, "Attenuation should be from 1 to 7 (divides by 2^n)")
				return
			}
			roiptr.attenuation = uint8(attenuation)
		}
	}

	// Handle POST on data -> setting of configuration
	if len(parts) == 3 && action == "put" {
		fmt.Printf("Setting configuration of data '%s'\n", d.DataName())
		config, err := server.DecodeJSON(r)
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if err := d.ModifyConfig(config); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if err := datastore.SaveDataByUUID(uuid, d); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		fmt.Fprintf(w, "Changed '%s' based on received configuration:\n%s\n", d.DataName(), config)
		return
	}

	if len(parts) < 4 {
		server.BadRequest(w, r, "Incomplete API request")
		return
	}

	// Process help and info.
	switch parts[3] {
	case "help":
		w.Header().Set("Content-Type", "text/plain")
		fmt.Fprintln(w, d.Help())
		return

	case "metadata":
		jsonStr, err := d.NdDataMetadata()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		w.Header().Set("Content-Type", "application/vnd.dvid-nd-data+json")
		fmt.Fprintln(w, jsonStr)
		return

	case "info":
		jsonBytes, err := d.MarshalJSON()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, string(jsonBytes))
		return

	case "rawkey":
		// GET <api URL>/node/<UUID>/<data name>/rawkey?x=<block x>&y=<block y>&z=<block z>
		if len(parts) != 4 {
			server.BadRequest(w, r, "rawkey endpoint should be followed by query strings (x, y, and z) giving block coord")
			return
		}

	case "blocks":
		// GET  <api URL>/node/<UUID>/<data name>/blocks/<block coord>/<spanX>
		// POST <api URL>/node/<UUID>/<data name>/blocks/<block coord>/<spanX>
		if len(parts) < 6 {
			server.BadRequest(w, r, "%q must be followed by block-coord/span-x", parts[3])
			return
		}
		blockCoord, err := dvid.StringToChunkPoint3d(parts[4], "_")
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		span, err := strconv.Atoi(parts[5])
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		if action == "get" {
			data, err := d.GetBlocks(ctx.VersionID(), blockCoord, int32(span))
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			w.Header().Set("Content-type", "application/octet-stream")
			_, err = w.Write(data)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
		} else {
			if err := d.PutBlocks(ctx.VersionID(), blockCoord, span, r.Body); err != nil {
				server.BadRequest(w, r, err)
				return
			}
		}
		timedLog.Infof("HTTP %s: Blocks (%s)", r.Method, r.URL)

	case "arb":
		// GET  <api URL>/node/<UUID>/<data name>/arb/<top left>/<top right>/<bottom left>/<res>[/<format>]
		if len(parts) < 8 {
			server.BadRequest(w, r, "%q must be followed by top-left/top-right/bottom-left/res", parts[3])
			return
		}
		queryStrings := r.URL.Query()
		throttle := queryStrings.Get("throttle")
		if throttle == "true" || throttle == "on" {
			select {
			case <-server.Throttle:
				// Proceed with operation, returning throttle token to server at end.
				defer func() {
					server.Throttle <- 1
				}()
			default:
				throttleMsg := fmt.Sprintf("Server already running maximum of %d throttled operations",
					server.MaxThrottledOps)
				http.Error(w, throttleMsg, http.StatusServiceUnavailable)
				return
			}
		}
		img, err := d.GetArbitraryImage(ctx, parts[4], parts[5], parts[6], parts[7])
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		var formatStr string
		if len(parts) >= 9 {
			formatStr = parts[8]
		}
		err = dvid.WriteImageHttp(w, img.Get(), formatStr)
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		timedLog.Infof("HTTP %s: Arbitrary image (%s)", r.Method, r.URL)

	case "raw", "isotropic":
		// GET  <api URL>/node/<UUID>/<data name>/isotropic/<dims>/<size>/<offset>[/<format>]
		if len(parts) < 7 {
			server.BadRequest(w, r, "%q must be followed by shape/size/offset", parts[3])
			return
		}
		var isotropic bool = (parts[3] == "isotropic")
		shapeStr, sizeStr, offsetStr := parts[4], parts[5], parts[6]
		planeStr := dvid.DataShapeString(shapeStr)
		plane, err := planeStr.DataShape()
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		switch plane.ShapeDimensions() {
		case 2:
			slice, err := dvid.NewSliceFromStrings(planeStr, offsetStr, sizeStr, "_")
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if action != "get" {
				server.BadRequest(w, r, "DVID does not permit 2d mutations, only 3d block-aligned stores")
				return
			}
			rawSlice, err := dvid.Isotropy2D(d.Properties.VoxelSize, slice, isotropic)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			vox, err := d.NewVoxels(rawSlice, nil)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if roiptr != nil {
				roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), vox)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			img, err := d.GetImage(ctx.VersionID(), vox, roiptr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if isotropic {
				dstW := int(slice.Size().Value(0))
				dstH := int(slice.Size().Value(1))
				img, err = img.ScaleImage(dstW, dstH)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			var formatStr string
			if len(parts) >= 8 {
				formatStr = parts[7]
			}
			err = dvid.WriteImageHttp(w, img.Get(), formatStr)
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			timedLog.Infof("HTTP %s: %s (%s)", r.Method, plane, r.URL)
		case 3:
			queryStrings := r.URL.Query()
			if queryStrings.Get("throttle") == "on" {
				select {
				case <-server.Throttle:
					// Proceed with operation, returning throttle token to server at end.
					defer func() {
						server.Throttle <- 1
					}()
				default:
					throttleMsg := fmt.Sprintf("Server already running maximum of %d throttled operations",
						server.MaxThrottledOps)
					http.Error(w, throttleMsg, http.StatusServiceUnavailable)
					return
				}
			}
			subvol, err := dvid.NewSubvolumeFromStrings(offsetStr, sizeStr, "_")
			if err != nil {
				server.BadRequest(w, r, err)
				return
			}
			if action == "get" {
				vox, err := d.NewVoxels(subvol, nil)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				if roiptr != nil {
					roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), vox)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
				}
				data, err := d.GetVolume(ctx.VersionID(), vox, roiptr)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				w.Header().Set("Content-type", "application/octet-stream")
				_, err = w.Write(data)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
			} else {
				if isotropic {
					err := fmt.Errorf("can only PUT 'raw' not 'isotropic' images")
					server.BadRequest(w, r, err)
					return
				}
				// Make sure vox is block-aligned
				if !dvid.BlockAligned(subvol, d.BlockSize()) {
					server.BadRequest(w, r, "cannot store voxels in non-block aligned geometry %s -> %s", subvol.StartPoint(), subvol.EndPoint())
					return
				}

				data, err := ioutil.ReadAll(r.Body)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				vox, err := d.NewVoxels(subvol, data)
				if err != nil {
					server.BadRequest(w, r, err)
					return
				}
				if roiptr != nil {
					roiptr.Iter, err = roi.NewIterator(roiname, ctx.VersionID(), vox)
					if err != nil {
						server.BadRequest(w, r, err)
						return
					}
				}
				if err = d.PutVoxels(ctx.VersionID(), vox, roiptr); err != nil {
					server.BadRequest(w, r, err)
					return
				}
			}
			timedLog.Infof("HTTP %s: %s (%s)", r.Method, subvol, r.URL)
		default:
			server.BadRequest(w, r, "DVID currently supports shapes of only 2 and 3 dimensions")
		}
	default:
		server.BadRequest(w, r, "Unrecognized API call for voxels %q.  See API help.", d.DataName())
	}
}