Golang dvid.NewTimeLog函数代码示例

// call KVAutobus key_range API
func (db *KVAutobus) getKeyRange(kStart, kEnd storage.Key) (Ks, error) {
	b64key1 := encodeKey(kStart)
	b64key2 := encodeKey(kEnd)
	url := fmt.Sprintf("%s/kvautobus/api/key_range/%s/%s/%s/", db.host, db.collection, b64key1, b64key2)

	timedLog := dvid.NewTimeLog()
	resp, err := db.client.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil // Handle no keys found.
	}

	r := msgp.NewReader(bufio.NewReader(resp.Body))
	var mks Ks
	if err := mks.DecodeMsg(r); err != nil {
		return nil, err
	}
	for _, mk := range mks {
		storage.StoreKeyBytesRead <- len(mk)
	}
	timedLog.Infof("PROXY key_range to %s returned %d (%d keys)\n", db.host, resp.StatusCode, len(mks))
	return mks, nil
}

// check if any metadata has been written into this store.
func (db *KVAutobus) metadataExists() (bool, error) {
	var ctx storage.MetadataContext
	kStart, kEnd := ctx.KeyRange()
	b64key1 := encodeKey(kStart)
	b64key2 := encodeKey(kEnd)
	url := fmt.Sprintf("%s/kvautobus/api/key_range/%s/%s/%s/", db.host, db.collection, b64key1, b64key2)
	dvid.Infof("metdataExists: doing GET on %s\n", url)

	timedLog := dvid.NewTimeLog()
	resp, err := db.client.Get(url)
	if err != nil {
		return false, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return true, nil // Handle no keys found.
	}

	r := msgp.NewReader(bufio.NewReader(resp.Body))
	var mks Ks
	if err := mks.DecodeMsg(r); err != nil {
		return false, err
	}
	timedLog.Infof("PROXY key_range metadata to %s returned %d (%d keys)\n", db.host, resp.StatusCode, len(mks))
	if len(mks) == 0 {
		return false, nil
	}
	return true, nil
}

// call KVAutobus keyvalue_range API
func (db *KVAutobus) getKVRange(kStart, kEnd storage.Key) (KVs, error) {
	b64key1 := encodeKey(kStart)
	b64key2 := encodeKey(kEnd)
	url := fmt.Sprintf("%s/kvautobus/api/keyvalue_range/%s/%s/", db.host, b64key1, b64key2)

	timedLog := dvid.NewTimeLog()
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil // Handle no keys found.
	}

	r := msgp.NewReader(bufio.NewReader(resp.Body))
	var mkvs KVs
	if err := mkvs.DecodeMsg(r); err != nil {
		dvid.Errorf("Couldn't decode getKVRange return\n")
		return nil, err
	}

	timedLog.Infof("PROXY keyvalue_range to %s returned %d (%d kv pairs)\n", db.host, resp.StatusCode, len(mkvs))
	return mkvs, nil
}

// GetVoxels copies voxels from the storage engine to Voxels, a requested subvolume or 2d image.
func (d *Data) GetVoxels(v dvid.VersionID, vox *Voxels, r *ROI) error {
	timedLog := dvid.NewTimeLog()
	defer timedLog.Infof("GetVoxels %s", vox)

	store, err := storage.MutableStore()
	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)

	wg := new(sync.WaitGroup)
	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, r.attenuation}, wg}
		} else {
			chunkOp = &storage.ChunkOp{&getOperation{vox, nil, 0}, wg}
		}

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

// 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()

	action := strings.ToLower(r.Method)
	switch action {
	case "get":
		// Acceptable
	default:
		server.BadRequest(w, r, "googlevoxels can only handle GET HTTP verbs at this time")
		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]
	}
	if len(parts) < 4 {
		server.BadRequest(w, r, "incomplete API request")
		return
	}

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

	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 "tile":
		if err := d.ServeTile(w, r, parts); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		timedLog.Infof("HTTP %s: tile (%s)", r.Method, r.URL)

	case "raw":
		if err := d.ServeImage(w, r, parts); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		timedLog.Infof("HTTP %s: image (%s)", r.Method, r.URL)
	default:
		server.BadRequest(w, r, "Illegal request for googlevoxels data.  See 'help' for REST API")
	}
}

func (d *Data) processSplit(v dvid.VersionID, delta labels.DeltaSplit) {
	timedLog := dvid.NewTimeLog()

	mutID := d.NewMutationID()
	splitOpStart := labels.DeltaSplitStart{delta.OldLabel, delta.NewLabel}
	splitOpEnd := labels.DeltaSplitEnd{delta.OldLabel, delta.NewLabel}
	iv := dvid.InstanceVersion{d.DataUUID(), v}
	labels.SplitStart(iv, splitOpStart)

	d.StartUpdate()
	if delta.Split == nil {
		// Coarse Split
		for _, izyxStr := range delta.SortedBlocks {
			n := izyxStr.Hash(numBlockHandlers)
			d.MutAdd(mutID)
			op := splitOp{
				mutID:    mutID,
				oldLabel: delta.OldLabel,
				newLabel: delta.NewLabel,
				block:    izyxStr,
			}
			d.procCh[n] <- procMsg{op: op, v: v}
		}
	} else {
		// Fine Split
		for izyxStr, blockRLEs := range delta.Split {
			n := izyxStr.Hash(numBlockHandlers)
			d.MutAdd(mutID)
			op := splitOp{
				mutID:    mutID,
				oldLabel: delta.OldLabel,
				newLabel: delta.NewLabel,
				rles:     blockRLEs,
				block:    izyxStr,
			}
			d.procCh[n] <- procMsg{op: op, v: v}
		}
	}
	// Wait for all blocks to be split then mark end of split op.
	go func() {
		d.MutWait(mutID)
		d.MutDelete(mutID)
		labels.SplitStop(iv, splitOpEnd)
		timedLog.Debugf("labelblk sync complete for split of %d -> %d", delta.OldLabel, delta.NewLabel)
		d.StopUpdate()
		d.publishDownresCommit(v, mutID)
	}()
}

func (db *KVAutobus) deleteRange(kStart, kEnd storage.Key) error {
	b64key1 := encodeKey(kStart)
	b64key2 := encodeKey(kEnd)
	url := fmt.Sprintf("%s/kvautobus/api/keyvalue_range/%s/%s/%s/", db.host, db.collection, b64key1, b64key2)

	timedLog := dvid.NewTimeLog()
	req, err := http.NewRequest("DELETE", url, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	resp, err := db.client.Do(req)
	if err != nil {
		return err
	}
	timedLog.Infof("PROXY delete keyvalue_range to %s returned %d\n", db.host, resp.StatusCode)
	return nil
}

// LoadImages bulk loads images using different techniques if it is a multidimensional
// file like HDF5 or a sequence of PNG/JPG/TIF images.
func (d *Data) LoadImages(v dvid.VersionID, offset dvid.Point, filenames []string) error {
	if len(filenames) == 0 {
		return nil
	}
	timedLog := dvid.NewTimeLog()

	// We only want one PUT on given version for given data to prevent interleaved
	// chunk PUTs that could potentially overwrite slice modifications.
	ctx := storage.NewDataContext(d, v)
	loadMutex := ctx.Mutex()
	loadMutex.Lock()

	// Handle cleanup given multiple goroutines still writing data.
	load := &bulkLoadInfo{filenames: filenames, versionID: v, offset: offset}
	defer func() {
		loadMutex.Unlock()

		if load.extentChanged.Value() {
			err := datastore.SaveDataByVersion(v, d)
			if err != nil {
				dvid.Errorf("Error in trying to save repo for voxel extent change: %v\n", err)
			}
		}
	}()

	// Use different loading techniques if we have a potentially multidimensional HDF5 file
	// or many 2d images.
	var err error
	if dvid.Filename(filenames[0]).HasExtensionPrefix("hdf", "h5") {
		err = d.loadHDF(load)
	} else {
		err = d.loadXYImages(load)
	}

	if err != nil {
		timedLog.Infof("RPC load of %d files had error: %v\n", err)
	} else {
		timedLog.Infof("RPC load of %d files completed.\n", len(filenames))
	}
	return err
}

func (d *Data) processMerge(v dvid.VersionID, delta labels.DeltaMerge) {
	timedLog := dvid.NewTimeLog()
	d.StartUpdate()

	mutID := d.NewMutationID()
	for izyxStr := range delta.Blocks {
		n := izyxStr.Hash(numBlockHandlers)
		d.MutAdd(mutID)
		op := mergeOp{mutID: mutID, MergeOp: delta.MergeOp, block: izyxStr}
		d.procCh[n] <- procMsg{op: op, v: v}
	}
	// When we've processed all the delta blocks, we can remove this merge op
	// from the merge cache since all labels will have completed.
	go func() {
		d.MutWait(mutID)
		d.MutDelete(mutID)
		timedLog.Debugf("labelblk sync complete for merge (%d blocks) of %s -> %d", len(delta.Blocks), delta.MergeOp.Merged, delta.MergeOp.Target)
		d.StopUpdate()
		d.publishDownresCommit(v, mutID)
	}()
}

// call KVAutobus keyvalue_range API
func (db *KVAutobus) getKVRange(ctx storage.Context, kStart, kEnd storage.Key) (KVs, error) {
	// Get any request context and pass to kvautobus for tracking.
	reqctx, ok := ctx.(storage.RequestCtx)
	var reqID string
	if ok {
		parts := strings.Split(reqctx.GetRequestID(), "/")
		if len(parts) > 0 {
			reqID = parts[len(parts)-1]
		}
	}

	// Construct the KVAutobus URL
	b64key1 := encodeKey(kStart)
	b64key2 := encodeKey(kEnd)
	url := fmt.Sprintf("%s/kvautobus/api/keyvalue_range/%s/%s/%s/?=%s", db.host, db.collection, b64key1, b64key2, reqID)

	timedLog := dvid.NewTimeLog()
	resp, err := db.client.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil // Handle no keys found.
	}

	r := msgp.NewReader(bufio.NewReader(resp.Body))
	var mkvs KVs
	if err := mkvs.DecodeMsg(r); err != nil {
		dvid.Errorf("Couldn't decode getKVRange return\n")
		return nil, err
	}
	for _, mkv := range mkvs {
		storage.StoreKeyBytesRead <- len(mkv[0])
		storage.StoreValueBytesRead <- len(mkv[1])
	}

	timedLog.Infof("[%s] PROXY keyvalue_range to %s returned %d (%d kv pairs)\n", reqID, db.host, resp.StatusCode, len(mkvs))
	return mkvs, nil
}

func (db *KVAutobus) RawGet(key storage.Key) ([]byte, error) {
	b64key := encodeKey(key)
	url := fmt.Sprintf("%s/kvautobus/api/value/%s/", db.host, b64key)

	timedLog := dvid.NewTimeLog()
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	timedLog.Infof("PROXY get to %s returned %d\n", db.host, resp.StatusCode)
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil // Handle no key found.
	}

	r := msgp.NewReader(bufio.NewReader(resp.Body))
	var bin Binary
	if err := bin.DecodeMsg(r); err != nil {
		return nil, err
	}
	return []byte(bin), nil
}

func (d *Data) serveVolume(w http.ResponseWriter, r *http.Request, geom *GoogleSubvolGeom, noblanks bool) error {
	// If it's outside, write blank tile unless user wants no blanks.
	if geom.outside {
		if noblanks {
			http.NotFound(w, r)
			return fmt.Errorf("Requested subvolume is outside of available volume.")
		}
		return nil
	}

	// If we are within volume, get data from Google.
	url, err := geom.GetURL(d.VolumeID, "")
	if err != nil {
		return err
	}

	timedLog := dvid.NewTimeLog()
	client, err := d.GetClient()
	if err != nil {
		dvid.Errorf("Can't get OAuth2 connection to Google: %v\n", err)
		return err
	}
	resp, err := client.Get(url)
	if err != nil {
		return err
	}
	timedLog.Infof("PROXY HTTP to Google: %s, returned response %d", url, resp.StatusCode)
	defer resp.Body.Close()

	// If it's on edge, we need to pad the subvolume to the requested size.
	if geom.edge {
		return fmt.Errorf("Googlevoxels subvolume GET does not pad data on edge at this time")
	}

	// If we aren't on edge or outside, our return status should be OK.
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("Unexpected status code %d on volume request (%q, volume id %q)", resp.StatusCode, d.DataName(), d.VolumeID)
	}

	w.Header().Set("Content-type", "application/octet-stream")

	queryStrings := r.URL.Query()
	compression := queryStrings.Get("compression")

	switch compression {
	case "lz4":
		// Decompress snappy
		sdata, err := ioutil.ReadAll(resp.Body)
		timedLog.Infof("Got snappy-encoded subvolume from Google, %d bytes\n", len(sdata))
		if err != nil {
			return err
		}
		data, err := snappy.Decode(nil, sdata)
		if err != nil {
			return err
		}
		// Recompress and transmit as lz4
		lz4data := make([]byte, lz4.CompressBound(data))
		outSize, err := lz4.Compress(data, lz4data)
		if err != nil {
			return err
		}
		if _, err := w.Write(lz4data[:outSize]); err != nil {
			return err
		}
		timedLog.Infof("Sent lz4-encoded subvolume from DVID, %d bytes\n", outSize)

	default: // "snappy"
		// Just stream data from Google
		respBytes := 0
		const BufferSize = 32 * 1024
		buf := make([]byte, BufferSize)
		for {
			n, err := resp.Body.Read(buf)
			respBytes += n
			eof := (err == io.EOF)
			if err != nil && !eof {
				return err
			}
			if _, err = w.Write(buf[:n]); err != nil {
				return err
			}
			if f, ok := w.(http.Flusher); ok {
				f.Flush()
			}
			if eof {
				break
			}
		}
		timedLog.Infof("Proxied snappy-encoded subvolume from Google, %d bytes\n", respBytes)
	}

	return nil
}

// 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()

	action := strings.ToLower(r.Method)
	switch action {
	case "get", "post":
		// Acceptable
	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]
	}
	if len(parts) < 4 {
		server.BadRequest(w, r, "incomplete API request")
		return
	}

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

	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 "tile":
		if action == "post" {
			server.BadRequest(w, r, "DVID does not yet support POST of imagetile")
			return
		}
		if err := d.ServeTile(uuid, ctx, w, r, parts); err != nil {
			server.BadRequest(w, r, err)
			return
		}
		timedLog.Infof("HTTP %s: tile (%s)", r.Method, r.URL)

	case "raw", "isotropic":
		if action == "post" {
			server.BadRequest(w, r, "imagetile '%s' can only PUT tiles not images", d.DataName())
			return
		}
		if len(parts) < 7 {
			server.BadRequest(w, r, "%q 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
		}
		if plane.ShapeDimensions() != 2 {
			server.BadRequest(w, r, "Quadtrees can only return 2d images not %s", plane)
			return
		}
		slice, err := dvid.NewSliceFromStrings(planeStr, offsetStr, sizeStr, "_")
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		source, err := datastore.GetDataByUUID(uuid, d.Source)
		if err != nil {
			server.BadRequest(w, r, err)
			return
		}
		src, ok := source.(*imageblk.Data)
		if !ok {
			server.BadRequest(w, r, "Cannot construct imagetile for non-voxels data: %s", d.Source)
			return
		}
		img, err := d.GetImage(ctx, src, slice, parts[3] == "isotropic")
		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: tile-accelerated %s %s (%s)", r.Method, planeStr, parts[3], r.URL)
	default:
//.........这里部分代码省略.........

func (d *Data) ConstructTiles(uuidStr string, tileSpec TileSpec, request datastore.Request) error {
	config := request.Settings()
	uuid, versionID, err := datastore.MatchingUUID(uuidStr)
	if err != nil {
		return err
	}
	if err = datastore.AddToNodeLog(uuid, []string{request.Command.String()}); err != nil {
		return err
	}

	source, err := datastore.GetDataByUUID(uuid, d.Source)
	if err != nil {
		return err
	}
	src, ok := source.(*imageblk.Data)
	if !ok {
		return fmt.Errorf("Cannot construct imagetile for non-voxels data: %s", d.Source)
	}

	// Save the current tile specification
	d.Levels = tileSpec
	if err := datastore.SaveDataByUUID(uuid, d); err != nil {
		return err
	}

	// Get size of tile at lowest resolution.
	lastLevel := Scaling(len(tileSpec) - 1)
	loresSpec, found := tileSpec[lastLevel]
	if !found {
		return fmt.Errorf("Illegal tile spec.  Should have levels 0 to absent %d.", lastLevel)
	}
	var loresSize [3]float64
	for i := 0; i < 3; i++ {
		loresSize[i] = float64(loresSpec.Resolution[i]) * float64(DefaultTileSize[i])
	}
	loresMag := dvid.Point3d{1, 1, 1}
	for i := Scaling(0); i < lastLevel; i++ {
		levelMag := tileSpec[i].levelMag
		loresMag[0] *= levelMag[0]
		loresMag[1] *= levelMag[1]
		loresMag[2] *= levelMag[2]
	}

	// Get min and max points in terms of distance.
	var minPtDist, maxPtDist [3]float64
	for i := uint8(0); i < 3; i++ {
		minPtDist[i] = float64(src.MinPoint.Value(i)) * float64(src.VoxelSize[i])
		maxPtDist[i] = float64(src.MaxPoint.Value(i)) * float64(src.VoxelSize[i])
	}

	// Adjust min and max points for the tileable surface at lowest resolution.
	var minTiledPt, maxTiledPt dvid.Point3d
	for i := 0; i < 3; i++ {
		minInt, _ := math.Modf(minPtDist[i] / loresSize[i])
		maxInt, _ := math.Modf(maxPtDist[i] / loresSize[i])
		minTileCoord := int32(minInt)
		maxTileCoord := int32(maxInt)
		minTiledPt[i] = minTileCoord * DefaultTileSize[i] * loresMag[i]
		maxTiledPt[i] = (maxTileCoord+1)*DefaultTileSize[i]*loresMag[i] - 1
	}
	sizeVolume := maxTiledPt.Sub(minTiledPt).AddScalar(1)

	// Setup swappable ExtData buffers (the stitched slices) so we can be generating tiles
	// at same time we are reading and stitching them.
	var bufferLock [2]sync.Mutex
	var sliceBuffers [2]*imageblk.Voxels
	var bufferNum int

	// Get the planes we should tile.
	planes, err := config.GetShapes("planes", ";")
	if planes == nil {
		// If no planes are specified, construct imagetile for 3 orthogonal planes.
		planes = []dvid.DataShape{dvid.XY, dvid.XZ, dvid.YZ}
	}

	outF, err := d.putTileFunc(versionID)

	// sort the tile spec keys to iterate from highest to lowest resolution
	var sortedKeys []int
	for scaling, _ := range tileSpec {
		sortedKeys = append(sortedKeys, int(scaling))
	}
	sort.Ints(sortedKeys)

	for _, plane := range planes {
		timedLog := dvid.NewTimeLog()
		offset := minTiledPt.Duplicate()

		switch {

		case plane.Equals(dvid.XY):
			width, height, err := plane.GetSize2D(sizeVolume)
			if err != nil {
				return err
			}
			dvid.Debugf("Tiling XY image %d x %d pixels\n", width, height)
			for z := src.MinPoint.Value(2); z <= src.MaxPoint.Value(2); z++ {
				server.BlockOnInteractiveRequests("imagetile.ConstructTiles [xy]")

				sliceLog := dvid.NewTimeLog()
//.........这里部分代码省略.........

// 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 int32) ([]byte, error) {
	timedLog := dvid.NewTimeLog()
	defer timedLog.Infof("GetBlocks %s, span %d", start, span)

	store, err := storage.MutableStore()
	if err != nil {
		return nil, fmt.Errorf("Data type imageblk had error initializing store: %v\n", err)
	}

	indexBeg := dvid.IndexZYX(start)
	sx, sy, sz := indexBeg.Unpack()

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

	// Allocate one uncompressed-sized slice with background values.
	blockBytes := int32(d.BlockSize().Prod()) * d.Values.BytesPerElement()
	numBytes := blockBytes * span

	buf := make([]byte, numBytes, numBytes)
	if d.Background != 0 {
		for i := range buf {
			buf[i] = byte(d.Background)
		}
	}

	// Write the blocks that we can get concurrently on this byte slice.
	ctx := datastore.NewVersionedCtx(d, v)

	var wg sync.WaitGroup
	err = store.ProcessRange(ctx, keyBeg, keyEnd, &storage.ChunkOp{}, func(c *storage.Chunk) error {
		if c == nil || c.TKeyValue == nil {
			return nil
		}
		kv := c.TKeyValue
		if kv.V == nil {
			return nil
		}

		// Determine which block this is.
		indexZYX, err := DecodeTKey(kv.K)
		if err != nil {
			return err
		}
		x, y, z := indexZYX.Unpack()
		if z != sz || y != sy || x < sx || x >= sx+int32(span) {
			return fmt.Errorf("Received key-value for %s, not supposed to be within span range %s, length %d", *indexZYX, start, span)
		}
		n := x - sx
		i := n * blockBytes
		j := i + blockBytes

		// Spawn goroutine to transfer data
		wg.Add(1)
		go xferBlock(buf[i:j], c, &wg)
		return nil
	})
	if err != nil {
		return nil, err
	}
	wg.Wait()
	return buf, nil
}