m

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/local_object_storage/engine/tree.go

@@ -468,3 +468,33 @@ func (e *StorageEngine) getTreeShard(ctx context.Context, cid cidSDK.ID, treeID
 
 	return 0, lst, pilorama.ErrTreeNotFound
 }
+
+func (e *StorageEngine) TreeListKeys(ctx context.Context, cid cidSDK.ID, treeID string, cursor pilorama.ListKeysCursor, count int) ([]pilorama.KeyInfo, pilorama.ListKeysCursor, error) {
+	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.TreeListKeys",
+		trace.WithAttributes(
+			attribute.String("container_id", cid.EncodeToString()),
+			attribute.String("tree_id", treeID),
+		),
+	)
+	defer span.End()
+
+	var err error
+	var res []pilorama.KeyInfo
+	for _, sh := range e.sortShards(cid) {
+		res, cursor, err = sh.TreeListKeys(ctx, cid, treeID, cursor, count)
+		if err != nil {
+			if err == shard.ErrPiloramaDisabled {
+				break
+			}
+			if !errors.Is(err, pilorama.ErrTreeNotFound) {
+				e.reportShardError(ctx, sh, "can't read tree synchronization height", err,
+					zap.Stringer("cid", cid),
+					zap.String("tree", treeID),
+					zap.String("trace_id", tracingPkg.GetTraceID(ctx)))
+			}
+			continue
+		}
+		return res, cursor, err
+	}
+	return res, cursor, err
+}

pkg/local_object_storage/pilorama/boltdb.go

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 	"slices"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -1166,6 +1167,206 @@ func (t *boltForest) TreeSortedByFilename(ctx context.Context, cid cidSDK.ID, tr
 	return res, last, metaerr.Wrap(err)
 }
 
+type ListKeysCursor struct {
+	prefix   []string
+	finished bool
+	stack    stack
+}
+
+func (c *ListKeysCursor) SetPrefix(prefix string) {
+	c.prefix = strings.Split(prefix, "/")
+}
+
+func (t *boltForest) TreeListKeys(_ context.Context, cid cidSDK.ID, treeID string, cursor ListKeysCursor, count int) ([]KeyInfo, ListKeysCursor, error) {
+	t.modeMtx.RLock()
+	defer t.modeMtx.RUnlock()
+
+	if t.mode.NoMetabase() {
+		return nil, cursor, ErrDegradedMode
+	}
+
+	if cursor.finished {
+		return nil, cursor, nil
+	}
+
+	var result []KeyInfo
+	err := t.db.View(func(tx *bbolt.Tx) error {
+		treeRoot := tx.Bucket(bucketName(cid, treeID))
+		if treeRoot == nil {
+			return ErrTreeNotFound
+		}
+
+		b := treeRoot.Bucket(dataBucket)
+		var err error
+		result, err = t.listKeys(b, &cursor, count, MultiNode{RootID})
+		return err
+	})
+
+	if cursor.stack.empty() {
+		cursor.finished = true
+	}
+	return result, cursor, metaerr.Wrap(err)
+}
+
+func (t *boltForest) listKeys(b *bbolt.Bucket, cursor *ListKeysCursor, count int, root MultiNode) ([]KeyInfo, error) {
+	var result []KeyInfo
+	if cursor.stack.empty() {
+		cursor.stack.push(treeLevel{
+			parentPrefix: "",
+			parent:       root,
+			children:     []heapInfo{{id: root, filename: "/"}},
+		})
+	} else {
+		cursor.stack.refillLastLevel(count, func(last string, p, c MultiNode, count int) []heapInfo {
+			return t.nextBatch(b, last, p, c, count)
+		})
+	}
+
+	// // If the node is a leaf, we could scan all filenames in the tree.
+	// // To prevent this we first count the number of children: if it is less than
+	// // the number of nodes we need to return, fallback to TreeGetChildren() implementation.
+	// if fewChildren = t.hasFewChildren(b, nodeIDs, count); fewChildren {
+	// 	var err error
+	// 	result, err = t.getChildren(b, nodeIDs)
+	// 	return err
+	// }
+
+	for !cursor.stack.empty() {
+		depth := len(cursor.stack.values)
+		node, _, prefix := cursor.stack.popSingle()
+		if strings.HasSuffix(node.filename, "/") {
+			h := newHeap(nil, count*5)
+			h.withSlash = true
+			if depth < len(cursor.prefix) {
+				t.fillSortedChildrenExact(b, node.id, h, cursor.prefix[depth-1])
+			} else if depth == len(cursor.prefix) {
+				t.fillSortedChildrenWithPrefix(b, node.id, h, cursor.prefix[depth-1])
+			} else {
+				t.fillSortedChildren(b, node.id, h)
+			}
+
+			var children []heapInfo
+			for hi, ok := h.pop(); ok; hi, ok = h.pop() {
+				children = append(children, hi)
+			}
+			if len(children) != 0 {
+				cursor.stack.push(treeLevel{
+					parentPrefix: prefix + node.filename,
+					parent:       node.id,
+					children:     children,
+				})
+			}
+			cursor.stack.trim()
+		} else if len(cursor.prefix) < depth {
+			treeKey := strings.TrimPrefix(prefix, "/") + node.filename
+			meta, err := t.getLatestMeta(b, node.id)
+			if err != nil {
+				return nil, err
+			}
+			result = append(result, KeyInfo{Key: treeKey, Meta: meta.Items})
+			if len(result) == count {
+				return result, nil
+			}
+		}
+	}
+	return result, nil
+}
+
+func (t *boltForest) getLatestMeta(b *bbolt.Bucket, ids MultiNode) (Meta, error) {
+	keySlice := make([]byte, 9)
+	var meta Meta
+	for _, id := range ids {
+		info, err := t.getChildInfo(b, keySlice, id)
+		if err != nil {
+			return Meta{}, err
+		}
+		if !isInternal(info.Meta.Items) && info.Meta.Time > meta.Time {
+			meta = info.Meta
+		}
+	}
+	return meta, nil
+}
+
+func (t *boltForest) fillSorted(b *bbolt.Bucket, full bool, filename string, parentIDs, nodeIDs MultiNode, h *fixedHeap) {
+	c := b.Cursor()
+
+	if full {
+		prefix := internalKeyPrefix(nil, AttributeFilename)
+
+		if filename != "" {
+			h.push(nodeIDs, filename+"/")
+		}
+		for i := 1; i < len(filename)-1; i++ {
+			l := i
+			prefix = append(prefix, byte(l), byte(l>>8))
+			prefix = append(prefix, filename[:i]...)
+
+			var children MultiNode
+			for k, _ := c.Seek(prefix); len(k) == len(prefix)+16 && k[0] == 'i' && bytes.HasPrefix(k[len(prefix)+2:], []byte(filename[:i])); k, _ = c.Next() {
+				parentID := binary.LittleEndian.Uint64(k[len(k)-16:])
+				if !slices.Contains(nodeIDs, parentID) {
+					continue
+				}
+
+				children = append(children, binary.LittleEndian.Uint64(k[len(k)-8:]))
+			}
+
+			h.push(children, filename[:i]+"/")
+		}
+	}
+	length := uint16(0)
+	count := 0
+
+	prefix := internalKeyPrefix(nil, AttributeFilename)
+	var nodes []uint64
+	var lastFilename *string
+	for k, _ := c.Seek(prefix); len(k) > 0 && k[0] == 'i'; k, _ = c.Next() {
+		if len(k) < len(prefix)+2+16 {
+			continue
+		}
+
+		parentID := binary.LittleEndian.Uint64(k[len(k)-16:])
+		if !slices.Contains(parentIDs, parentID) {
+			continue
+		}
+
+		actualLength := binary.LittleEndian.Uint16(k[len(prefix):])
+		childID := binary.LittleEndian.Uint64(k[len(k)-8:])
+		filename := string(k[len(prefix)+2 : len(k)-16])
+
+		if lastFilename == nil {
+			lastFilename = &filename
+			nodes = append(nodes, childID)
+		} else if *lastFilename == filename {
+			nodes = append(nodes, childID)
+		} else {
+			processed1 := h.push(nodes, *lastFilename)
+			processed2 := h.push(nodes, *lastFilename+"/")
+
+			nodes = MultiNode{childID}
+			lastFilename = &filename
+			if actualLength != length {
+				length = actualLength
+				count = 1
+			} else if processed1 || processed2 {
+				if count++; count > h.count {
+					lastFilename = nil
+					nodes = nil
+					length = actualLength + 1
+					count = 0
+					c.Seek(append(prefix, byte(length), byte(length>>8)))
+					c.Prev() // c.Next() will be performed by for loop
+				}
+			}
+		}
+	}
+
+	if len(nodes) != 0 && lastFilename != nil {
+		h.push(nodes, *lastFilename)
+		h.push(nodes, *lastFilename+"/")
+	}
+}
+
 func sortByFilename(nodes []NodeInfo) {
 	slices.SortFunc(nodes, func(a, b NodeInfo) int {
 		return bytes.Compare(a.Meta.GetAttr(AttributeFilename), b.Meta.GetAttr(AttributeFilename))
@@ -1199,6 +1400,102 @@ func (t *boltForest) getChildInfo(b *bbolt.Bucket, key []byte, childID Node) (No
 	return childInfo, nil
 }
 
+func (t *boltForest) fillSortedChildrenExact(b *bbolt.Bucket, nodeIDs MultiNode, h *fixedHeap, pp string) {
+	c := b.Cursor()
+
+	length := uint16(len(pp))
+	prefix := internalKeyPrefix(nil, AttributeFilename)
+	prefix = binary.LittleEndian.AppendUint16(prefix, length)
+	prefix = append(prefix, pp...)
+
+	var nodes []uint64
+	for k, _ := c.Seek(prefix); bytes.HasPrefix(k, prefix); k, _ = c.Next() {
+		parentID := binary.LittleEndian.Uint64(k[len(k)-16:])
+		if !slices.Contains(nodeIDs, parentID) {
+			continue
+		}
+
+		childID := binary.LittleEndian.Uint64(k[len(k)-8:])
+		nodes = append(nodes, childID)
+	}
+
+	if len(nodes) != 0 {
+		h.push(nodes, pp)
+	}
+}
+
+func (t *boltForest) fillSortedChildrenWithPrefix(b *bbolt.Bucket, nodeIDs MultiNode, h *fixedHeap, pp string) {
+	c := b.Cursor()
+
+	length := uint16(len(pp))
+	prefix := internalKeyPrefix(nil, AttributeFilename)
+
+	offset := len(prefix)
+	prefix = binary.LittleEndian.AppendUint16(prefix, length)
+	prefix = append(prefix, pp...)
+
+	count := 0
+
+	var nodes []uint64
+	var lastFilename *string
+	for k, _ := c.Seek(prefix); len(k) > 0 && k[0] == 'i'; k, _ = c.Next() {
+		if len(k) < len(prefix)+16 {
+			continue
+		}
+
+		actualLength := binary.LittleEndian.Uint16(k[offset:])
+		childID := binary.LittleEndian.Uint64(k[len(k)-8:])
+		filename := string(k[offset+2 : len(k)-16])
+		if !strings.HasPrefix(filename, pp) {
+			if lastFilename != nil {
+				h.push(nodes, *lastFilename)
+			}
+			lastFilename = nil
+			nodes = nil
+			length = actualLength + 1
+			count = 0
+			binary.LittleEndian.PutUint16(prefix[offset:], length)
+			c.Seek(prefix)
+			c.Prev() // c.Next() will be performed by for loop
+			continue
+		}
+
+		parentID := binary.LittleEndian.Uint64(k[len(k)-16:])
+		if !slices.Contains(nodeIDs, parentID) {
+			continue
+		}
+
+		if lastFilename == nil {
+			lastFilename = &filename
+			nodes = append(nodes, childID)
+		} else if *lastFilename == filename {
+			nodes = append(nodes, childID)
+		} else {
+			processed := h.push(nodes, *lastFilename)
+			nodes = MultiNode{childID}
+			lastFilename = &filename
+			if actualLength != length {
+				length = actualLength
+				count = 1
+			} else if processed {
+				if count++; count > h.count {
+					lastFilename = nil
+					nodes = nil
+					length = actualLength + 1
+					count = 0
+					binary.LittleEndian.PutUint16(prefix[offset:], length)
+					c.Seek(prefix)
+					c.Prev() // c.Next() will be performed by for loop
+				}
+			}
+		}
+	}
+
+	if len(nodes) != 0 && lastFilename != nil {
+		h.push(nodes, *lastFilename)
+	}
+}
+
 func (t *boltForest) fillSortedChildren(b *bbolt.Bucket, nodeIDs MultiNode, h *fixedHeap) {
 	c := b.Cursor()
 	prefix := internalKeyPrefix(nil, AttributeFilename)

pkg/local_object_storage/pilorama/boltdb_listing_test.go

@@ -0,0 +1,101 @@
+package pilorama
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"strings"
+	"testing"
+
+	cidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTreeListKeys(t *testing.T) {
+	for i := range providers {
+		if providers[i].name != "bbolt" {
+			continue
+		}
+		t.Run(providers[i].name, func(t *testing.T) {
+			testForestTreeListKeys(t, providers[i].construct(t).(*boltForest))
+		})
+	}
+}
+
+func testForestTreeListKeys(t *testing.T, s *boltForest) {
+	ctx := context.Background()
+	defer func() { require.NoError(t, s.Close(ctx)) }()
+
+	cid := cidtest.ID()
+	d := CIDDescriptor{cid, 0, 1}
+	treeID := "version"
+
+	keys := []KeyInfo{
+		{Key: "a"},
+		{Key: "a-"},
+		{Key: "a--"},
+		{Key: "ab"},
+		{Key: "a-/a"},
+		{Key: "a-/b"},
+		{Key: "a/b"},
+	}
+
+	for i := range keys {
+		path := strings.Split(keys[i].Key, "/")
+		keys[i].Meta = []KeyValue{
+			{Key: AttributeVersion, Value: []byte{byte(i)}}, // uuid.New().String())},
+			{Key: AttributeFilename, Value: []byte(path[len(path)-1])},
+		}
+		_, err := s.TreeAddByPath(ctx, d, treeID, AttributeFilename, path[:len(path)-1], keys[i].Meta)
+		require.NoError(t, err)
+	}
+
+	sortedKeys := slices.Clone(keys)
+	slices.SortFunc(sortedKeys, func(a, b KeyInfo) int {
+		return strings.Compare(a.Key, b.Key)
+	})
+
+	listKeys := func(t *testing.T, cursor ListKeysCursor, count int) ([]KeyInfo, ListKeysCursor) {
+		res, cursor, err := s.TreeListKeys(ctx, cid, treeID, cursor, count)
+		require.NoError(t, err)
+		return res, cursor
+	}
+
+	res, _ := listKeys(t, ListKeysCursor{}, 20)
+	require.Equal(t, sortedKeys, res)
+
+	t.Run("multiple invocations", func(t *testing.T) {
+		var cursor ListKeysCursor
+		var result []KeyInfo
+
+		res, cursor := listKeys(t, cursor, 2)
+		for len(res) != 0 {
+			result = append(result, res...)
+			res, cursor = listKeys(t, cursor, 2)
+		}
+		require.Equal(t, sortedKeys, result)
+	})
+	t.Run("with prefix", func(t *testing.T) {
+		for _, prefix := range []string{"a", "a-", "ab", "ab/", "a-/"} {
+			t.Run(fmt.Sprintf("prefix=%s", prefix), func(t *testing.T) {
+				expected := slices.Clone(sortedKeys)
+				for i := 0; i < len(expected); {
+					if strings.HasPrefix(expected[i].Key, prefix) {
+						i++
+					} else {
+						expected = slices.Delete(expected, i, i+1)
+					}
+				}
+
+				var cursor ListKeysCursor
+				cursor.SetPrefix(prefix)
+
+				res, _ := listKeys(t, cursor, 20)
+				require.Len(t, res, len(expected))
+				if len(expected) != 0 { // Ignore nil vs empty slice comparison.
+					require.Equal(t, expected, res)
+				}
+			})
+		}
+	})
+}

pkg/local_object_storage/pilorama/forest.go

@@ -120,6 +120,10 @@ func (f *memoryForest) TreeApplyBatch(ctx context.Context, cnr cid.ID, treeID st
 	return nil
 }
 
+func (f *memoryForest) TreeListKeys(_ context.Context, _ cid.ID, _ string, _ ListKeysCursor, _ int) ([]KeyInfo, ListKeysCursor, error) {
+	panic("unimplemented")
+}
+
 func (f *memoryForest) Init(context.Context) error {
 	return nil
 }

pkg/local_object_storage/pilorama/heap.go

@@ -34,6 +34,8 @@ type fixedHeap struct {
 	sorted bool
 	count  int
 	h      *filenameHeap
+
+	withSlash bool
 }
 
 func newHeap(start *string, count int) *fixedHeap {
@@ -50,6 +52,14 @@ func newHeap(start *string, count int) *fixedHeap {
 const amortizationMultiplier = 5
 
 func (h *fixedHeap) push(id MultiNode, filename string) bool {
+	res := h.pushAux(id, filename)
+	if h.withSlash {
+		return h.pushAux(id, filename+"/") || res
+	}
+	return res
+}
+
+func (h *fixedHeap) pushAux(id MultiNode, filename string) bool {
 	if h.start != nil && filename <= *h.start {
 		return false
 	}

pkg/local_object_storage/pilorama/interface.go

@@ -57,6 +57,12 @@ type Forest interface {
 	TreeLastSyncHeight(ctx context.Context, cid cidSDK.ID, treeID string) (uint64, error)
 	// TreeHeight returns current tree height.
 	TreeHeight(ctx context.Context, cid cidSDK.ID, treeID string) (uint64, error)
+	TreeListKeys(ctx context.Context, cid cidSDK.ID, treeID string, cursor ListKeysCursor, count int) ([]KeyInfo, ListKeysCursor, error)
+}
+
+type KeyInfo struct {
+	Key  string
+	Meta []KeyValue
 }
 
 type ForestStorage interface {

pkg/local_object_storage/pilorama/stack.go

@@ -0,0 +1,69 @@
+package pilorama
+
+import (
+	"go.etcd.io/bbolt"
+)
+
+type treeLevel struct {
+	parentPrefix string
+	parent       MultiNode
+	children     []heapInfo
+}
+
+type stack struct {
+	values []treeLevel
+}
+
+func (s *stack) empty() bool {
+	for i := range s.values {
+		if len(s.values[i].children) != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *stack) popSingle() (heapInfo, MultiNode, string) {
+	lastLevel := &s.values[len(s.values)-1]
+	prefix := lastLevel.parentPrefix
+	parents := lastLevel.parent
+	head, tail := lastLevel.children[0], lastLevel.children[1:]
+	lastLevel.children = tail
+
+	return head, parents, prefix
+}
+
+func (s *stack) trim() {
+	for len(s.values) > 0 && len(s.values[len(s.values)-1].children) == 0 {
+		s.values = s.values[:len(s.values)-1]
+	}
+}
+
+func (s *stack) push(level treeLevel) {
+	s.values = append(s.values, level)
+}
+
+func (s *stack) refillLastLevel(count int, nextBatch func(string, MultiNode, MultiNode, int) []heapInfo) {
+	lastLevel := &s.values[len(s.values)-1]
+	if len(lastLevel.children) > count {
+		return
+	}
+
+	parentIDs := lastLevel.parent
+	childrenIDs := lastLevel.children[len(lastLevel.children)-1].id
+	filename := lastLevel.children[len(lastLevel.children)-1].filename
+
+	batch := nextBatch(filename, parentIDs, childrenIDs, count)
+	lastLevel.children = append(lastLevel.children, batch...)
+}
+
+func (t *boltForest) nextBatch(b *bbolt.Bucket, last string, parentIDs, nodeIDs MultiNode, count int) []heapInfo {
+	h := newHeap(&last, count)
+	t.fillSorted(b, true, last, parentIDs, nodeIDs, h)
+
+	var result []heapInfo
+	for info, ok := h.pop(); ok; info, ok = h.pop() {
+		result = append(result, info)
+	}
+	return result
+}

pkg/local_object_storage/shard/tree.go

@@ -454,3 +454,22 @@ func (s *Shard) TreeApplyStream(ctx context.Context, cnr cidSDK.ID, treeID strin
 	}
 	return s.pilorama.TreeApplyStream(ctx, cnr, treeID, source)
 }
+
+func (s *Shard) TreeListKeys(ctx context.Context, cnr cidSDK.ID, treeID string, cursor pilorama.ListKeysCursor, count int) ([]pilorama.KeyInfo, pilorama.ListKeysCursor, error) {
+	ctx, span := tracing.StartSpanFromContext(ctx, "Shard.TreeListKeys",
+		trace.WithAttributes(attribute.String("shard_id", s.ID().String())),
+	)
+	defer span.End()
+
+	if s.pilorama == nil {
+		return nil, cursor, ErrPiloramaDisabled
+	}
+
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	if s.info.Mode.NoMetabase() {
+		return nil, cursor, ErrDegradedMode
+	}
+	return s.pilorama.TreeListKeys(ctx, cnr, treeID, cursor, count)
+}

pkg/services/tree/list_keys.go

@@ -0,0 +1,91 @@
+package tree
+
+import (
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/pilorama"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/acl"
+	cidSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+)
+
+func (s *Service) ListKeys(req *ListKeysRequest, srv TreeService_ListKeysServer) error {
+	b := req.GetBody()
+
+	var cnr cidSDK.ID
+	if err := cnr.Decode(b.GetContainerId()); err != nil {
+		return err
+	}
+
+	err := s.verifyClient(srv.Context(), req, cnr, nil, acl.OpObjectGet)
+	if err != nil {
+		return err
+	}
+
+	ns, pos, err := s.getContainerNodes(cnr)
+	if err != nil {
+		return err
+	}
+
+	if pos < 0 {
+		return relayStream(s, ns, req, srv, (TreeServiceClient).ListKeys)
+	}
+
+	const engineBatchSize = 1000
+
+	responseBatchSize := b.GetBatchSize()
+	if responseBatchSize > engineBatchSize {
+		responseBatchSize = engineBatchSize
+	}
+
+	batch := newListBatch(srv, int(responseBatchSize))
+	res, cursor, err := s.forest.TreeListKeys(srv.Context(), cnr, b.GetTreeId(), pilorama.ListKeysCursor{}, engineBatchSize)
+	for err == nil && len(res) != 0 {
+		for i := range res {
+			if err := batch.add(res[i]); err != nil {
+				return err
+			}
+		}
+		res, cursor, err = s.forest.TreeListKeys(srv.Context(), cnr, b.GetTreeId(), cursor, engineBatchSize)
+	}
+	return batch.commit()
+}
+
+type listBatch struct {
+	items []ListKeysResponse_Body_Info
+	srv   TreeService_ListKeysServer
+	limit int
+}
+
+func newListBatch(srv TreeService_ListKeysServer, count int) *listBatch {
+	return &listBatch{
+		srv:   srv,
+		limit: count,
+	}
+}
+
+func (b *listBatch) empty() bool {
+	return len(b.items) == 0
+}
+
+func (b *listBatch) add(info pilorama.KeyInfo) error {
+	b.items = append(b.items, ListKeysResponse_Body_Info{
+		Key:  info.Key,
+		Meta: metaToProto(info.Meta),
+	})
+	if len(b.items) < b.limit {
+		return nil
+	}
+	return b.commit()
+}
+
+func (b *listBatch) commit() error {
+	if len(b.items) == 0 {
+		return nil
+	}
+
+	items := b.items
+	b.items = b.items[:0]
+	return b.srv.Send(&ListKeysResponse{
+		Body: &ListKeysResponse_Body{
+			Keys: items,
+		},
+	})
+}

pkg/services/tree/redirect.go

@@ -30,6 +30,42 @@ func relayUnary[Req any, Resp any](ctx context.Context, s *Service, ns []netmapS
 	return resp, outErr
 }
 
+type treeServiceServer[Resp any] interface {
+	Context() context.Context
+	Send(*Resp) error
+}
+
+func relayStream[
+	Req any,
+	Resp any,
+	Server treeServiceServer[Resp],
+	Client interface{ Recv() (*Resp, error) },
+](
+	s *Service,
+	ns []netmapSDK.NodeInfo,
+	req *Req,
+	srv Server,
+	callback func(TreeServiceClient, context.Context, *Req, ...grpc.CallOption) (Client, error),
+) error {
+	var cli Client
+	var outErr error
+	err := s.forEachNode(srv.Context(), ns, func(c TreeServiceClient) bool {
+		cli, outErr = callback(c, srv.Context(), req)
+		return true
+	})
+	if err != nil {
+		return err
+	} else if outErr != nil {
+		return outErr
+	}
+	for resp, err := cli.Recv(); err == nil; resp, err = cli.Recv() {
+		if err := srv.Send(resp); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // forEachNode executes callback for each node in the container until true is returned.
 // Returns errNoSuitableNode if there was no successful attempt to dial any node.
 func (s *Service) forEachNode(ctx context.Context, cntNodes []netmapSDK.NodeInfo, f func(c TreeServiceClient) bool) error {

pkg/services/tree/service.go

@@ -381,23 +381,7 @@ func (s *Service) GetSubTree(req *GetSubTreeRequest, srv TreeService_GetSubTreeS
 		return err
 	}
 	if pos < 0 {
-		var cli TreeService_GetSubTreeClient
-		var outErr error
-		err = s.forEachNode(srv.Context(), ns, func(c TreeServiceClient) bool {
-			cli, outErr = c.GetSubTree(srv.Context(), req)
-			return true
-		})
-		if err != nil {
-			return err
-		} else if outErr != nil {
-			return outErr
-		}
-		for resp, err := cli.Recv(); err == nil; resp, err = cli.Recv() {
-			if err := srv.Send(resp); err != nil {
-				return err
-			}
-		}
-		return nil
+		return relayStream(s, ns, req, srv, (TreeServiceClient).GetSubTree)
 	}
 
 	return getSubTree(srv.Context(), srv, cid, b, s.forest)
@@ -449,10 +433,8 @@ func getSortedSubTree(ctx context.Context, srv TreeService_GetSubTreeServer, cid
 		parent: ps,
 	}}
 
-	for {
-		if len(stack) == 0 {
-			break
-		} else if item := &stack[len(stack)-1]; len(item.values) == 0 {
+	for len(stack) != 0 {
+		if item := &stack[len(stack)-1]; len(item.values) == 0 {
 			if len(stack) == 1 {
 				break
 			}
@@ -646,23 +628,7 @@ func (s *Service) GetOpLog(req *GetOpLogRequest, srv TreeService_GetOpLogServer)
 		return err
 	}
 	if pos < 0 {
-		var cli TreeService_GetOpLogClient
-		var outErr error
-		err := s.forEachNode(srv.Context(), ns, func(c TreeServiceClient) bool {
-			cli, outErr = c.GetOpLog(srv.Context(), req)
-			return true
-		})
-		if err != nil {
-			return err
-		} else if outErr != nil {
-			return outErr
-		}
-		for resp, err := cli.Recv(); err == nil; resp, err = cli.Recv() {
-			if err := srv.Send(resp); err != nil {
-				return err
-			}
-		}
-		return nil
+		return relayStream(s, ns, req, srv, (TreeServiceClient).GetOpLog)
 	}
 
 	h := b.GetHeight()

pkg/services/tree/service.proto

@@ -41,6 +41,9 @@ service TreeService {
   rpc GetSubTree(GetSubTreeRequest) returns (stream GetSubTreeResponse);
   // TreeList return list of the existing trees in the container.
   rpc TreeList(TreeListRequest) returns (TreeListResponse);
+  // ListKeys returns the list of all keys in the tree sorted by full
+  // filepath.
+  rpc ListKeys(ListKeysRequest) returns (stream ListKeysResponse);
 
   /* Synchronization API */
 
@@ -300,6 +303,30 @@ message TreeListResponse {
   Signature signature = 2;
 }
 
+message ListKeysRequest {
+  message Body {
+    bytes container_id = 1;
+    string tree_id = 2;
+    uint32 batch_size = 3;
+  }
+
+  Body body = 1;
+  Signature signature = 2;
+}
+
+message ListKeysResponse {
+  message Body {
+    message Info {
+      string key = 1;
+      repeated KeyValue meta = 2;
+    }
+    repeated Info keys = 1;
+  }
+
+  Body body = 1;
+  Signature signature = 2;
+}
+
 message ApplyRequest {
   message Body {
     // Container ID in V2 format.

pkg/services/tree/service_frostfs.pb.go

@@ -6746,6 +6746,973 @@ func (x *TreeListResponse) UnmarshalEasyJSON(in *jlexer.Lexer) {
 	}
 }
 
+type ListKeysRequest_Body struct {
+	ContainerId []byte `json:"containerId"`
+	TreeId      string `json:"treeId"`
+	BatchSize   uint32 `json:"batchSize"`
+}
+
+var (
+	_ encoding.ProtoMarshaler   = (*ListKeysRequest_Body)(nil)
+	_ encoding.ProtoUnmarshaler = (*ListKeysRequest_Body)(nil)
+	_ json.Marshaler            = (*ListKeysRequest_Body)(nil)
+	_ json.Unmarshaler          = (*ListKeysRequest_Body)(nil)
+)
+
+// StableSize returns the size of x in protobuf format.
+//
+// Structures with the same field values have the same binary size.
+func (x *ListKeysRequest_Body) StableSize() (size int) {
+	if x == nil {
+		return 0
+	}
+	size += proto.BytesSize(1, x.ContainerId)
+	size += proto.StringSize(2, x.TreeId)
+	size += proto.UInt32Size(3, x.BatchSize)
+	return size
+}
+
+// MarshalProtobuf implements the encoding.ProtoMarshaler interface.
+func (x *ListKeysRequest_Body) MarshalProtobuf(dst []byte) []byte {
+	m := pool.MarshalerPool.Get()
+	defer pool.MarshalerPool.Put(m)
+	x.EmitProtobuf(m.MessageMarshaler())
+	dst = m.Marshal(dst)
+	return dst
+}
+
+func (x *ListKeysRequest_Body) EmitProtobuf(mm *easyproto.MessageMarshaler) {
+	if x == nil {
+		return
+	}
+	if len(x.ContainerId) != 0 {
+		mm.AppendBytes(1, x.ContainerId)
+	}
+	if len(x.TreeId) != 0 {
+		mm.AppendString(2, x.TreeId)
+	}
+	if x.BatchSize != 0 {
+		mm.AppendUint32(3, x.BatchSize)
+	}
+}
+
+// UnmarshalProtobuf implements the encoding.ProtoUnmarshaler interface.
+func (x *ListKeysRequest_Body) UnmarshalProtobuf(src []byte) (err error) {
+	var fc easyproto.FieldContext
+	for len(src) > 0 {
+		src, err = fc.NextField(src)
+		if err != nil {
+			return fmt.Errorf("cannot read next field in %s", "ListKeysRequest_Body")
+		}
+		switch fc.FieldNum {
+		case 1: // ContainerId
+			data, ok := fc.Bytes()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "ContainerId")
+			}
+			x.ContainerId = data
+		case 2: // TreeId
+			data, ok := fc.String()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "TreeId")
+			}
+			x.TreeId = data
+		case 3: // BatchSize
+			data, ok := fc.Uint32()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "BatchSize")
+			}
+			x.BatchSize = data
+		}
+	}
+	return nil
+}
+func (x *ListKeysRequest_Body) GetContainerId() []byte {
+	if x != nil {
+		return x.ContainerId
+	}
+	return nil
+}
+func (x *ListKeysRequest_Body) SetContainerId(v []byte) {
+	x.ContainerId = v
+}
+func (x *ListKeysRequest_Body) GetTreeId() string {
+	if x != nil {
+		return x.TreeId
+	}
+	return ""
+}
+func (x *ListKeysRequest_Body) SetTreeId(v string) {
+	x.TreeId = v
+}
+func (x *ListKeysRequest_Body) GetBatchSize() uint32 {
+	if x != nil {
+		return x.BatchSize
+	}
+	return 0
+}
+func (x *ListKeysRequest_Body) SetBatchSize(v uint32) {
+	x.BatchSize = v
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *ListKeysRequest_Body) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	x.MarshalEasyJSON(&w)
+	return w.Buffer.BuildBytes(), w.Error
+}
+func (x *ListKeysRequest_Body) MarshalEasyJSON(out *jwriter.Writer) {
+	if x == nil {
+		out.RawString("null")
+		return
+	}
+	first := true
+	out.RawByte('{')
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"containerId\":"
+		out.RawString(prefix)
+		if x.ContainerId != nil {
+			out.Base64Bytes(x.ContainerId)
+		} else {
+			out.String("")
+		}
+	}
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"treeId\":"
+		out.RawString(prefix)
+		out.String(x.TreeId)
+	}
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"batchSize\":"
+		out.RawString(prefix)
+		out.Uint32(x.BatchSize)
+	}
+	out.RawByte('}')
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (x *ListKeysRequest_Body) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	x.UnmarshalEasyJSON(&r)
+	return r.Error()
+}
+func (x *ListKeysRequest_Body) UnmarshalEasyJSON(in *jlexer.Lexer) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "containerId":
+			{
+				var f []byte
+				{
+					tmp := in.Bytes()
+					if len(tmp) == 0 {
+						tmp = nil
+					}
+					f = tmp
+				}
+				x.ContainerId = f
+			}
+		case "treeId":
+			{
+				var f string
+				f = in.String()
+				x.TreeId = f
+			}
+		case "batchSize":
+			{
+				var f uint32
+				r := in.JsonNumber()
+				n := r.String()
+				v, err := strconv.ParseUint(n, 10, 32)
+				if err != nil {
+					in.AddError(err)
+					return
+				}
+				pv := uint32(v)
+				f = pv
+				x.BatchSize = f
+			}
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+
+type ListKeysRequest struct {
+	Body      *ListKeysRequest_Body `json:"body"`
+	Signature *Signature            `json:"signature"`
+}
+
+var (
+	_ encoding.ProtoMarshaler   = (*ListKeysRequest)(nil)
+	_ encoding.ProtoUnmarshaler = (*ListKeysRequest)(nil)
+	_ json.Marshaler            = (*ListKeysRequest)(nil)
+	_ json.Unmarshaler          = (*ListKeysRequest)(nil)
+)
+
+// StableSize returns the size of x in protobuf format.
+//
+// Structures with the same field values have the same binary size.
+func (x *ListKeysRequest) StableSize() (size int) {
+	if x == nil {
+		return 0
+	}
+	size += proto.NestedStructureSize(1, x.Body)
+	size += proto.NestedStructureSize(2, x.Signature)
+	return size
+}
+
+// ReadSignedData fills buf with signed data of x.
+// If buffer length is less than x.SignedDataSize(), new buffer is allocated.
+//
+// Returns any error encountered which did not allow writing the data completely.
+// Otherwise, returns the buffer in which the data is written.
+//
+// Structures with the same field values have the same signed data.
+func (x *ListKeysRequest) SignedDataSize() int {
+	return x.GetBody().StableSize()
+}
+
+// SignedDataSize returns size of the request signed data in bytes.
+//
+// Structures with the same field values have the same signed data size.
+func (x *ListKeysRequest) ReadSignedData(buf []byte) ([]byte, error) {
+	return x.GetBody().MarshalProtobuf(buf), nil
+}
+
+// MarshalProtobuf implements the encoding.ProtoMarshaler interface.
+func (x *ListKeysRequest) MarshalProtobuf(dst []byte) []byte {
+	m := pool.MarshalerPool.Get()
+	defer pool.MarshalerPool.Put(m)
+	x.EmitProtobuf(m.MessageMarshaler())
+	dst = m.Marshal(dst)
+	return dst
+}
+
+func (x *ListKeysRequest) EmitProtobuf(mm *easyproto.MessageMarshaler) {
+	if x == nil {
+		return
+	}
+	if x.Body != nil {
+		x.Body.EmitProtobuf(mm.AppendMessage(1))
+	}
+	if x.Signature != nil {
+		x.Signature.EmitProtobuf(mm.AppendMessage(2))
+	}
+}
+
+// UnmarshalProtobuf implements the encoding.ProtoUnmarshaler interface.
+func (x *ListKeysRequest) UnmarshalProtobuf(src []byte) (err error) {
+	var fc easyproto.FieldContext
+	for len(src) > 0 {
+		src, err = fc.NextField(src)
+		if err != nil {
+			return fmt.Errorf("cannot read next field in %s", "ListKeysRequest")
+		}
+		switch fc.FieldNum {
+		case 1: // Body
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Body")
+			}
+			x.Body = new(ListKeysRequest_Body)
+			if err := x.Body.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		case 2: // Signature
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Signature")
+			}
+			x.Signature = new(Signature)
+			if err := x.Signature.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		}
+	}
+	return nil
+}
+func (x *ListKeysRequest) GetBody() *ListKeysRequest_Body {
+	if x != nil {
+		return x.Body
+	}
+	return nil
+}
+func (x *ListKeysRequest) SetBody(v *ListKeysRequest_Body) {
+	x.Body = v
+}
+func (x *ListKeysRequest) GetSignature() *Signature {
+	if x != nil {
+		return x.Signature
+	}
+	return nil
+}
+func (x *ListKeysRequest) SetSignature(v *Signature) {
+	x.Signature = v
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *ListKeysRequest) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	x.MarshalEasyJSON(&w)
+	return w.Buffer.BuildBytes(), w.Error
+}
+func (x *ListKeysRequest) MarshalEasyJSON(out *jwriter.Writer) {
+	if x == nil {
+		out.RawString("null")
+		return
+	}
+	first := true
+	out.RawByte('{')
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"body\":"
+		out.RawString(prefix)
+		x.Body.MarshalEasyJSON(out)
+	}
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"signature\":"
+		out.RawString(prefix)
+		x.Signature.MarshalEasyJSON(out)
+	}
+	out.RawByte('}')
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (x *ListKeysRequest) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	x.UnmarshalEasyJSON(&r)
+	return r.Error()
+}
+func (x *ListKeysRequest) UnmarshalEasyJSON(in *jlexer.Lexer) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "body":
+			{
+				var f *ListKeysRequest_Body
+				f = new(ListKeysRequest_Body)
+				f.UnmarshalEasyJSON(in)
+				x.Body = f
+			}
+		case "signature":
+			{
+				var f *Signature
+				f = new(Signature)
+				f.UnmarshalEasyJSON(in)
+				x.Signature = f
+			}
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+
+type ListKeysResponse_Body_Info struct {
+	Key  string     `json:"key"`
+	Meta []KeyValue `json:"meta"`
+}
+
+var (
+	_ encoding.ProtoMarshaler   = (*ListKeysResponse_Body_Info)(nil)
+	_ encoding.ProtoUnmarshaler = (*ListKeysResponse_Body_Info)(nil)
+	_ json.Marshaler            = (*ListKeysResponse_Body_Info)(nil)
+	_ json.Unmarshaler          = (*ListKeysResponse_Body_Info)(nil)
+)
+
+// StableSize returns the size of x in protobuf format.
+//
+// Structures with the same field values have the same binary size.
+func (x *ListKeysResponse_Body_Info) StableSize() (size int) {
+	if x == nil {
+		return 0
+	}
+	size += proto.StringSize(1, x.Key)
+	for i := range x.Meta {
+		size += proto.NestedStructureSizeUnchecked(2, &x.Meta[i])
+	}
+	return size
+}
+
+// MarshalProtobuf implements the encoding.ProtoMarshaler interface.
+func (x *ListKeysResponse_Body_Info) MarshalProtobuf(dst []byte) []byte {
+	m := pool.MarshalerPool.Get()
+	defer pool.MarshalerPool.Put(m)
+	x.EmitProtobuf(m.MessageMarshaler())
+	dst = m.Marshal(dst)
+	return dst
+}
+
+func (x *ListKeysResponse_Body_Info) EmitProtobuf(mm *easyproto.MessageMarshaler) {
+	if x == nil {
+		return
+	}
+	if len(x.Key) != 0 {
+		mm.AppendString(1, x.Key)
+	}
+	for i := range x.Meta {
+		x.Meta[i].EmitProtobuf(mm.AppendMessage(2))
+	}
+}
+
+// UnmarshalProtobuf implements the encoding.ProtoUnmarshaler interface.
+func (x *ListKeysResponse_Body_Info) UnmarshalProtobuf(src []byte) (err error) {
+	var fc easyproto.FieldContext
+	for len(src) > 0 {
+		src, err = fc.NextField(src)
+		if err != nil {
+			return fmt.Errorf("cannot read next field in %s", "ListKeysResponse_Body_Info")
+		}
+		switch fc.FieldNum {
+		case 1: // Key
+			data, ok := fc.String()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Key")
+			}
+			x.Key = data
+		case 2: // Meta
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Meta")
+			}
+			x.Meta = append(x.Meta, KeyValue{})
+			ff := &x.Meta[len(x.Meta)-1]
+			if err := ff.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		}
+	}
+	return nil
+}
+func (x *ListKeysResponse_Body_Info) GetKey() string {
+	if x != nil {
+		return x.Key
+	}
+	return ""
+}
+func (x *ListKeysResponse_Body_Info) SetKey(v string) {
+	x.Key = v
+}
+func (x *ListKeysResponse_Body_Info) GetMeta() []KeyValue {
+	if x != nil {
+		return x.Meta
+	}
+	return nil
+}
+func (x *ListKeysResponse_Body_Info) SetMeta(v []KeyValue) {
+	x.Meta = v
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *ListKeysResponse_Body_Info) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	x.MarshalEasyJSON(&w)
+	return w.Buffer.BuildBytes(), w.Error
+}
+func (x *ListKeysResponse_Body_Info) MarshalEasyJSON(out *jwriter.Writer) {
+	if x == nil {
+		out.RawString("null")
+		return
+	}
+	first := true
+	out.RawByte('{')
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"key\":"
+		out.RawString(prefix)
+		out.String(x.Key)
+	}
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"meta\":"
+		out.RawString(prefix)
+		out.RawByte('[')
+		for i := range x.Meta {
+			if i != 0 {
+				out.RawByte(',')
+			}
+			x.Meta[i].MarshalEasyJSON(out)
+		}
+		out.RawByte(']')
+	}
+	out.RawByte('}')
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (x *ListKeysResponse_Body_Info) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	x.UnmarshalEasyJSON(&r)
+	return r.Error()
+}
+func (x *ListKeysResponse_Body_Info) UnmarshalEasyJSON(in *jlexer.Lexer) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "key":
+			{
+				var f string
+				f = in.String()
+				x.Key = f
+			}
+		case "meta":
+			{
+				var f KeyValue
+				var list []KeyValue
+				in.Delim('[')
+				for !in.IsDelim(']') {
+					f = KeyValue{}
+					f.UnmarshalEasyJSON(in)
+					list = append(list, f)
+					in.WantComma()
+				}
+				x.Meta = list
+				in.Delim(']')
+			}
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+
+type ListKeysResponse_Body struct {
+	Keys []ListKeysResponse_Body_Info `json:"keys"`
+}
+
+var (
+	_ encoding.ProtoMarshaler   = (*ListKeysResponse_Body)(nil)
+	_ encoding.ProtoUnmarshaler = (*ListKeysResponse_Body)(nil)
+	_ json.Marshaler            = (*ListKeysResponse_Body)(nil)
+	_ json.Unmarshaler          = (*ListKeysResponse_Body)(nil)
+)
+
+// StableSize returns the size of x in protobuf format.
+//
+// Structures with the same field values have the same binary size.
+func (x *ListKeysResponse_Body) StableSize() (size int) {
+	if x == nil {
+		return 0
+	}
+	for i := range x.Keys {
+		size += proto.NestedStructureSizeUnchecked(1, &x.Keys[i])
+	}
+	return size
+}
+
+// MarshalProtobuf implements the encoding.ProtoMarshaler interface.
+func (x *ListKeysResponse_Body) MarshalProtobuf(dst []byte) []byte {
+	m := pool.MarshalerPool.Get()
+	defer pool.MarshalerPool.Put(m)
+	x.EmitProtobuf(m.MessageMarshaler())
+	dst = m.Marshal(dst)
+	return dst
+}
+
+func (x *ListKeysResponse_Body) EmitProtobuf(mm *easyproto.MessageMarshaler) {
+	if x == nil {
+		return
+	}
+	for i := range x.Keys {
+		x.Keys[i].EmitProtobuf(mm.AppendMessage(1))
+	}
+}
+
+// UnmarshalProtobuf implements the encoding.ProtoUnmarshaler interface.
+func (x *ListKeysResponse_Body) UnmarshalProtobuf(src []byte) (err error) {
+	var fc easyproto.FieldContext
+	for len(src) > 0 {
+		src, err = fc.NextField(src)
+		if err != nil {
+			return fmt.Errorf("cannot read next field in %s", "ListKeysResponse_Body")
+		}
+		switch fc.FieldNum {
+		case 1: // Keys
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Keys")
+			}
+			x.Keys = append(x.Keys, ListKeysResponse_Body_Info{})
+			ff := &x.Keys[len(x.Keys)-1]
+			if err := ff.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		}
+	}
+	return nil
+}
+func (x *ListKeysResponse_Body) GetKeys() []ListKeysResponse_Body_Info {
+	if x != nil {
+		return x.Keys
+	}
+	return nil
+}
+func (x *ListKeysResponse_Body) SetKeys(v []ListKeysResponse_Body_Info) {
+	x.Keys = v
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *ListKeysResponse_Body) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	x.MarshalEasyJSON(&w)
+	return w.Buffer.BuildBytes(), w.Error
+}
+func (x *ListKeysResponse_Body) MarshalEasyJSON(out *jwriter.Writer) {
+	if x == nil {
+		out.RawString("null")
+		return
+	}
+	first := true
+	out.RawByte('{')
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"keys\":"
+		out.RawString(prefix)
+		out.RawByte('[')
+		for i := range x.Keys {
+			if i != 0 {
+				out.RawByte(',')
+			}
+			x.Keys[i].MarshalEasyJSON(out)
+		}
+		out.RawByte(']')
+	}
+	out.RawByte('}')
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (x *ListKeysResponse_Body) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	x.UnmarshalEasyJSON(&r)
+	return r.Error()
+}
+func (x *ListKeysResponse_Body) UnmarshalEasyJSON(in *jlexer.Lexer) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "keys":
+			{
+				var f ListKeysResponse_Body_Info
+				var list []ListKeysResponse_Body_Info
+				in.Delim('[')
+				for !in.IsDelim(']') {
+					f = ListKeysResponse_Body_Info{}
+					f.UnmarshalEasyJSON(in)
+					list = append(list, f)
+					in.WantComma()
+				}
+				x.Keys = list
+				in.Delim(']')
+			}
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+
+type ListKeysResponse struct {
+	Body      *ListKeysResponse_Body `json:"body"`
+	Signature *Signature             `json:"signature"`
+}
+
+var (
+	_ encoding.ProtoMarshaler   = (*ListKeysResponse)(nil)
+	_ encoding.ProtoUnmarshaler = (*ListKeysResponse)(nil)
+	_ json.Marshaler            = (*ListKeysResponse)(nil)
+	_ json.Unmarshaler          = (*ListKeysResponse)(nil)
+)
+
+// StableSize returns the size of x in protobuf format.
+//
+// Structures with the same field values have the same binary size.
+func (x *ListKeysResponse) StableSize() (size int) {
+	if x == nil {
+		return 0
+	}
+	size += proto.NestedStructureSize(1, x.Body)
+	size += proto.NestedStructureSize(2, x.Signature)
+	return size
+}
+
+// ReadSignedData fills buf with signed data of x.
+// If buffer length is less than x.SignedDataSize(), new buffer is allocated.
+//
+// Returns any error encountered which did not allow writing the data completely.
+// Otherwise, returns the buffer in which the data is written.
+//
+// Structures with the same field values have the same signed data.
+func (x *ListKeysResponse) SignedDataSize() int {
+	return x.GetBody().StableSize()
+}
+
+// SignedDataSize returns size of the request signed data in bytes.
+//
+// Structures with the same field values have the same signed data size.
+func (x *ListKeysResponse) ReadSignedData(buf []byte) ([]byte, error) {
+	return x.GetBody().MarshalProtobuf(buf), nil
+}
+
+// MarshalProtobuf implements the encoding.ProtoMarshaler interface.
+func (x *ListKeysResponse) MarshalProtobuf(dst []byte) []byte {
+	m := pool.MarshalerPool.Get()
+	defer pool.MarshalerPool.Put(m)
+	x.EmitProtobuf(m.MessageMarshaler())
+	dst = m.Marshal(dst)
+	return dst
+}
+
+func (x *ListKeysResponse) EmitProtobuf(mm *easyproto.MessageMarshaler) {
+	if x == nil {
+		return
+	}
+	if x.Body != nil {
+		x.Body.EmitProtobuf(mm.AppendMessage(1))
+	}
+	if x.Signature != nil {
+		x.Signature.EmitProtobuf(mm.AppendMessage(2))
+	}
+}
+
+// UnmarshalProtobuf implements the encoding.ProtoUnmarshaler interface.
+func (x *ListKeysResponse) UnmarshalProtobuf(src []byte) (err error) {
+	var fc easyproto.FieldContext
+	for len(src) > 0 {
+		src, err = fc.NextField(src)
+		if err != nil {
+			return fmt.Errorf("cannot read next field in %s", "ListKeysResponse")
+		}
+		switch fc.FieldNum {
+		case 1: // Body
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Body")
+			}
+			x.Body = new(ListKeysResponse_Body)
+			if err := x.Body.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		case 2: // Signature
+			data, ok := fc.MessageData()
+			if !ok {
+				return fmt.Errorf("cannot unmarshal field %s", "Signature")
+			}
+			x.Signature = new(Signature)
+			if err := x.Signature.UnmarshalProtobuf(data); err != nil {
+				return fmt.Errorf("unmarshal: %w", err)
+			}
+		}
+	}
+	return nil
+}
+func (x *ListKeysResponse) GetBody() *ListKeysResponse_Body {
+	if x != nil {
+		return x.Body
+	}
+	return nil
+}
+func (x *ListKeysResponse) SetBody(v *ListKeysResponse_Body) {
+	x.Body = v
+}
+func (x *ListKeysResponse) GetSignature() *Signature {
+	if x != nil {
+		return x.Signature
+	}
+	return nil
+}
+func (x *ListKeysResponse) SetSignature(v *Signature) {
+	x.Signature = v
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *ListKeysResponse) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	x.MarshalEasyJSON(&w)
+	return w.Buffer.BuildBytes(), w.Error
+}
+func (x *ListKeysResponse) MarshalEasyJSON(out *jwriter.Writer) {
+	if x == nil {
+		out.RawString("null")
+		return
+	}
+	first := true
+	out.RawByte('{')
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"body\":"
+		out.RawString(prefix)
+		x.Body.MarshalEasyJSON(out)
+	}
+	{
+		if !first {
+			out.RawByte(',')
+		} else {
+			first = false
+		}
+		const prefix string = "\"signature\":"
+		out.RawString(prefix)
+		x.Signature.MarshalEasyJSON(out)
+	}
+	out.RawByte('}')
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (x *ListKeysResponse) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	x.UnmarshalEasyJSON(&r)
+	return r.Error()
+}
+func (x *ListKeysResponse) UnmarshalEasyJSON(in *jlexer.Lexer) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "body":
+			{
+				var f *ListKeysResponse_Body
+				f = new(ListKeysResponse_Body)
+				f.UnmarshalEasyJSON(in)
+				x.Body = f
+			}
+		case "signature":
+			{
+				var f *Signature
+				f = new(Signature)
+				f.UnmarshalEasyJSON(in)
+				x.Signature = f
+			}
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+
 type ApplyRequest_Body struct {
 	ContainerId []byte   `json:"containerId"`
 	TreeId      string   `json:"treeId"`

pkg/services/tree/service_grpc.pb.go

@@ -29,6 +29,7 @@ const (
 	TreeService_GetNodeByPath_FullMethodName = "/tree.TreeService/GetNodeByPath"
 	TreeService_GetSubTree_FullMethodName    = "/tree.TreeService/GetSubTree"
 	TreeService_TreeList_FullMethodName      = "/tree.TreeService/TreeList"
+	TreeService_ListKeys_FullMethodName      = "/tree.TreeService/ListKeys"
 	TreeService_Apply_FullMethodName         = "/tree.TreeService/Apply"
 	TreeService_GetOpLog_FullMethodName      = "/tree.TreeService/GetOpLog"
 	TreeService_Healthcheck_FullMethodName   = "/tree.TreeService/Healthcheck"
@@ -52,6 +53,9 @@ type TreeServiceClient interface {
 	GetSubTree(ctx context.Context, in *GetSubTreeRequest, opts ...grpc.CallOption) (TreeService_GetSubTreeClient, error)
 	// TreeList return list of the existing trees in the container.
 	TreeList(ctx context.Context, in *TreeListRequest, opts ...grpc.CallOption) (*TreeListResponse, error)
+	// ListKeys returns the list of all keys in the tree sorted by full
+	// filepath.
+	ListKeys(ctx context.Context, in *ListKeysRequest, opts ...grpc.CallOption) (TreeService_ListKeysClient, error)
 	// Apply pushes log operation from another node to the current.
 	// The request must be signed by a container node.
 	Apply(ctx context.Context, in *ApplyRequest, opts ...grpc.CallOption) (*ApplyResponse, error)
@@ -155,6 +159,38 @@ func (c *treeServiceClient) TreeList(ctx context.Context, in *TreeListRequest, o
 	return out, nil
 }
 
+func (c *treeServiceClient) ListKeys(ctx context.Context, in *ListKeysRequest, opts ...grpc.CallOption) (TreeService_ListKeysClient, error) {
+	stream, err := c.cc.NewStream(ctx, &TreeService_ServiceDesc.Streams[1], TreeService_ListKeys_FullMethodName, opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &treeServiceListKeysClient{stream}
+	if err := x.ClientStream.SendMsg(in); err != nil {
+		return nil, err
+	}
+	if err := x.ClientStream.CloseSend(); err != nil {
+		return nil, err
+	}
+	return x, nil
+}
+
+type TreeService_ListKeysClient interface {
+	Recv() (*ListKeysResponse, error)
+	grpc.ClientStream
+}
+
+type treeServiceListKeysClient struct {
+	grpc.ClientStream
+}
+
+func (x *treeServiceListKeysClient) Recv() (*ListKeysResponse, error) {
+	m := new(ListKeysResponse)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
 func (c *treeServiceClient) Apply(ctx context.Context, in *ApplyRequest, opts ...grpc.CallOption) (*ApplyResponse, error) {
 	out := new(ApplyResponse)
 	err := c.cc.Invoke(ctx, TreeService_Apply_FullMethodName, in, out, opts...)
@@ -165,7 +201,7 @@ func (c *treeServiceClient) Apply(ctx context.Context, in *ApplyRequest, opts ..
 }
 
 func (c *treeServiceClient) GetOpLog(ctx context.Context, in *GetOpLogRequest, opts ...grpc.CallOption) (TreeService_GetOpLogClient, error) {
-	stream, err := c.cc.NewStream(ctx, &TreeService_ServiceDesc.Streams[1], TreeService_GetOpLog_FullMethodName, opts...)
+	stream, err := c.cc.NewStream(ctx, &TreeService_ServiceDesc.Streams[2], TreeService_GetOpLog_FullMethodName, opts...)
 	if err != nil {
 		return nil, err
 	}
@@ -223,6 +259,9 @@ type TreeServiceServer interface {
 	GetSubTree(*GetSubTreeRequest, TreeService_GetSubTreeServer) error
 	// TreeList return list of the existing trees in the container.
 	TreeList(context.Context, *TreeListRequest) (*TreeListResponse, error)
+	// ListKeys returns the list of all keys in the tree sorted by full
+	// filepath.
+	ListKeys(*ListKeysRequest, TreeService_ListKeysServer) error
 	// Apply pushes log operation from another node to the current.
 	// The request must be signed by a container node.
 	Apply(context.Context, *ApplyRequest) (*ApplyResponse, error)
@@ -257,6 +296,9 @@ func (UnimplementedTreeServiceServer) GetSubTree(*GetSubTreeRequest, TreeService
 func (UnimplementedTreeServiceServer) TreeList(context.Context, *TreeListRequest) (*TreeListResponse, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method TreeList not implemented")
 }
+func (UnimplementedTreeServiceServer) ListKeys(*ListKeysRequest, TreeService_ListKeysServer) error {
+	return status.Errorf(codes.Unimplemented, "method ListKeys not implemented")
+}
 func (UnimplementedTreeServiceServer) Apply(context.Context, *ApplyRequest) (*ApplyResponse, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method Apply not implemented")
 }
@@ -407,6 +449,27 @@ func _TreeService_TreeList_Handler(srv interface{}, ctx context.Context, dec fun
 	return interceptor(ctx, in, info, handler)
 }
 
+func _TreeService_ListKeys_Handler(srv interface{}, stream grpc.ServerStream) error {
+	m := new(ListKeysRequest)
+	if err := stream.RecvMsg(m); err != nil {
+		return err
+	}
+	return srv.(TreeServiceServer).ListKeys(m, &treeServiceListKeysServer{stream})
+}
+
+type TreeService_ListKeysServer interface {
+	Send(*ListKeysResponse) error
+	grpc.ServerStream
+}
+
+type treeServiceListKeysServer struct {
+	grpc.ServerStream
+}
+
+func (x *treeServiceListKeysServer) Send(m *ListKeysResponse) error {
+	return x.ServerStream.SendMsg(m)
+}
+
 func _TreeService_Apply_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
 	in := new(ApplyRequest)
 	if err := dec(in); err != nil {
@@ -510,6 +573,11 @@ var TreeService_ServiceDesc = grpc.ServiceDesc{
 			Handler:       _TreeService_GetSubTree_Handler,
 			ServerStreams: true,
 		},
+		{
+			StreamName:    "ListKeys",
+			Handler:       _TreeService_ListKeys_Handler,
+			ServerStreams: true,
+		},
 		{
 			StreamName:    "GetOpLog",
 			Handler:       _TreeService_GetOpLog_Handler,