[#645] blobstor: Add simple blobtree impl

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/blobstor/blobtree/blobtree.go

@@ -0,0 +1,80 @@
+package blobtree
+
+import (
+	"errors"
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+	"syscall"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/compression"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
+	utilSync "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/sync"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+var _ common.Storage = &BlobTree{}
+
+type BlobTree struct {
+	cfg        cfg
+	dirLock    *utilSync.KeyLocker[string]
+	fileLock   *utilSync.KeyLocker[string]
+	compressor *compression.Config
+	dispatcher *rootDispatcher
+	suffix     atomic.Uint64
+}
+
+func New(opts ...Option) *BlobTree {
+	b := &BlobTree{
+		cfg: cfg{
+			targetFileSizeBytes: 4 * 1024 * 1024,
+			rootPath:            "./",
+			depth:               3,
+			permissions:         0700,
+			initWorkersCount:    1000,
+		},
+		dirLock:  utilSync.NewKeyLocker[string](),
+		fileLock: utilSync.NewKeyLocker[string](),
+	}
+
+	for _, opt := range opts {
+		opt(&b.cfg)
+	}
+
+	b.dispatcher = newRootDispatcher()
+
+	return b
+}
+
+func (b *BlobTree) getDirectoryPath(addr oid.Address) string {
+	sAddr := addr.Object().EncodeToString() + "." + addr.Container().EncodeToString()
+	var sb strings.Builder
+	size := int(1+b.cfg.depth*(directoryLength+1)) + len(b.cfg.rootPath) // /path + slash + (character + slash for every level)
+	sb.Grow(size)
+	sb.WriteString(b.cfg.rootPath)
+
+	for i := uint64(0); i < b.cfg.depth; i++ {
+		sb.WriteRune(filepath.Separator)
+		sb.WriteString(sAddr[:directoryLength])
+		sAddr = sAddr[directoryLength:]
+	}
+
+	sb.WriteRune(filepath.Separator)
+	return sb.String()
+}
+
+func (b *BlobTree) createDir(dir string) error {
+	b.dirLock.Lock(dir)
+	defer b.dirLock.Unlock(dir)
+
+	if err := util.MkdirAllX(dir, b.cfg.permissions); err != nil {
+		if errors.Is(err, syscall.ENOSPC) {
+			err = common.ErrNoSpace
+			return err
+		}
+		return err
+	}
+
+	return nil
+}

pkg/local_object_storage/blobstor/blobtree/config.go

@@ -0,0 +1,14 @@
+package blobtree
+
+import "io/fs"
+
+var directoryLength uint64 = 1
+
+type cfg struct {
+	rootPath            string
+	depth               uint64
+	targetFileSizeBytes uint64
+	permissions         fs.FileMode
+	readOnly            bool
+	initWorkersCount    int
+}

pkg/local_object_storage/blobstor/blobtree/content.go

@@ -0,0 +1,191 @@
+package blobtree
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+
+	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+const (
+	defaultVersion = 0
+
+	sizeOfVersion     = 1
+	sizeOfCount       = 8
+	sizeOfDataLength  = 8
+	sizeOfContainerID = sha256.Size
+	sizeOfObjectID    = sha256.Size
+)
+
+var (
+	errFileToSmall                   = errors.New("invalid file content: not enough bytes to read count of records")
+	errInvalidFileContentVersion     = errors.New("invalid file content: not enough bytes to read record version")
+	errInvalidFileContentContainerID = errors.New("invalid file content: not enough bytes to read container ID")
+	errInvalidFileContentObjectID    = errors.New("invalid file content: not enough bytes to read object ID")
+	errInvalidFileContentLength      = errors.New("invalid file content: not enough bytes to read data length")
+	errInvalidFileContentData        = errors.New("invalid file content: not enough bytes to read data")
+)
+
+type objectData struct {
+	Version byte
+	Address oid.Address
+	Data    []byte
+}
+
+func (b *BlobTree) readFileContent(path string) ([]objectData, error) {
+	rawData, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return []objectData{}, nil
+		}
+		return nil, err
+	}
+	return b.unmarshalSlice(rawData)
+}
+
+func (b *BlobTree) unmarshalSlice(data []byte) ([]objectData, error) {
+	if len(data) < sizeOfCount {
+		return nil, errFileToSmall
+	}
+	count := binary.LittleEndian.Uint64(data[:8])
+	result := make([]objectData, 0, count)
+
+	data = data[sizeOfCount:]
+	var idx uint64
+	for idx = 0; idx < count; idx++ {
+		record, read, err := b.unmarshalRecord(data)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, record)
+		data = data[read:]
+	}
+
+	return result, nil
+}
+
+func (b *BlobTree) unmarshalRecord(data []byte) (objectData, uint64, error) {
+	if len(data) < sizeOfVersion {
+		return objectData{}, 0, errInvalidFileContentVersion
+	}
+	var result objectData
+	var read uint64
+	result.Version = data[0]
+	if result.Version != defaultVersion {
+		return objectData{}, 0, fmt.Errorf("invalid file content: unknown version %d", result.Version)
+	}
+	read += sizeOfVersion
+
+	if len(data[read:]) < sizeOfContainerID {
+		return objectData{}, 0, errInvalidFileContentContainerID
+	}
+	var contID cid.ID
+	if err := contID.Decode(data[read : read+sizeOfContainerID]); err != nil {
+		return objectData{}, 0, fmt.Errorf("invalid file content: failed to read container ID: %w", err)
+	}
+	read += sizeOfContainerID
+
+	if len(data[read:]) < sizeOfObjectID {
+		return objectData{}, 0, errInvalidFileContentObjectID
+	}
+	var objID oid.ID
+	if err := objID.Decode(data[read : read+sizeOfObjectID]); err != nil {
+		return objectData{}, 0, fmt.Errorf("invalid file content: failed to read object ID: %w", err)
+	}
+	read += sizeOfObjectID
+
+	result.Address.SetContainer(contID)
+	result.Address.SetObject(objID)
+
+	if len(data[read:]) < sizeOfDataLength {
+		return objectData{}, 0, errInvalidFileContentLength
+	}
+	dataLength := binary.LittleEndian.Uint64(data[read : read+sizeOfDataLength])
+	read += sizeOfDataLength
+
+	if uint64(len(data[read:])) < dataLength {
+		return objectData{}, 0, errInvalidFileContentData
+	}
+	result.Data = make([]byte, dataLength)
+	copy(result.Data, data[read:read+dataLength])
+	read += dataLength
+
+	return result, read, nil
+}
+
+func (b *BlobTree) saveContentToFile(records []objectData, path string) (uint64, error) {
+	data, err := b.marshalSlice(records)
+	if err != nil {
+		return 0, err
+	}
+	return uint64(len(data)), b.writeFile(path, data)
+}
+
+func (b *BlobTree) writeFile(p string, data []byte) error {
+	f, err := os.OpenFile(p, os.O_WRONLY|os.O_CREATE|os.O_TRUNC|os.O_EXCL|os.O_SYNC, b.cfg.permissions)
+	if err != nil {
+		return err
+	}
+	_, err = f.Write(data)
+	if err1 := f.Close(); err1 != nil && err == nil {
+		err = err1
+	}
+	return err
+}
+
+func (b *BlobTree) marshalSlice(records []objectData) ([]byte, error) {
+	buf := make([]byte, b.estimateSize(records))
+	result := buf
+	binary.LittleEndian.PutUint64(buf, uint64(len(records)))
+	buf = buf[sizeOfCount:]
+	for _, record := range records {
+		written := b.marshalRecord(record, buf)
+		buf = buf[written:]
+	}
+	return result, nil
+}
+
+func (b *BlobTree) marshalRecord(record objectData, dst []byte) uint64 {
+	var written uint64
+
+	dst[0] = record.Version
+	dst = dst[sizeOfVersion:]
+	written += sizeOfVersion
+
+	record.Address.Container().Encode(dst)
+	dst = dst[sizeOfContainerID:]
+	written += sizeOfContainerID
+
+	record.Address.Object().Encode(dst)
+	dst = dst[sizeOfObjectID:]
+	written += sizeOfObjectID
+
+	binary.LittleEndian.PutUint64(dst, uint64(len(record.Data)))
+	dst = dst[sizeOfDataLength:]
+	written += sizeOfDataLength
+
+	copy(dst, record.Data)
+	written += uint64(len(record.Data))
+
+	return written
+}
+
+func (b *BlobTree) estimateSize(records []objectData) uint64 {
+	var result uint64
+	result += sizeOfCount
+	for _, record := range records {
+		result += (sizeOfVersion + sizeOfContainerID + sizeOfObjectID + sizeOfDataLength)
+		result += uint64(len(record.Data))
+	}
+	return result
+}
+
+func (b *BlobTree) getFilePath(dir string, idx uint64) string {
+	return filepath.Join(dir, strconv.FormatUint(idx, 16))
+}

pkg/local_object_storage/blobstor/blobtree/control.go

@@ -0,0 +1,98 @@
+package blobtree
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/compression"
+	"golang.org/x/sync/errgroup"
+)
+
+var Type = "blobtree"
+
+func (b *BlobTree) Open(readOnly bool) error {
+	b.cfg.readOnly = readOnly
+	return nil
+}
+
+func (b *BlobTree) Init() error {
+	if err := b.createDir(b.cfg.rootPath); err != nil {
+		return err
+	}
+
+	var eg errgroup.Group
+	eg.SetLimit(b.cfg.initWorkersCount)
+	eg.Go(func() error {
+		return b.initDir(&eg, b.cfg.rootPath, 0)
+	})
+	return eg.Wait()
+}
+
+func (b *BlobTree) initDir(eg *errgroup.Group, dir string, depth uint64) error {
+	entities, err := os.ReadDir(dir)
+	if err != nil {
+		return err
+	}
+	for _, entity := range entities {
+		if depth < b.cfg.depth && entity.IsDir() {
+			eg.Go(func() error {
+				return b.initDir(eg, filepath.Join(dir, entity.Name()), depth+1)
+			})
+			continue
+		}
+
+		if depth != b.cfg.depth {
+			continue
+		}
+
+		if b.isTempFile(entity.Name()) {
+			if err = os.Remove(filepath.Join(dir, entity.Name())); err != nil {
+				return err
+			}
+			continue
+		}
+
+		idx, err := b.parseIdx(entity.Name())
+		if err != nil {
+			continue
+		}
+		b.dispatcher.Init(dir, idx)
+
+		stat, err := os.Stat(filepath.Join(dir, entity.Name()))
+		if err != nil {
+			return err
+		}
+		if stat.Size() < int64(b.cfg.targetFileSizeBytes) {
+			b.dispatcher.ReturnIdx(dir, idx)
+		}
+	}
+	return nil
+}
+
+func (b *BlobTree) isTempFile(name string) bool {
+	return strings.Contains(name, tempFileSymbols)
+}
+
+func (b *BlobTree) parseIdx(name string) (uint64, error) {
+	return strconv.ParseUint(name, 16, 64)
+}
+
+func (b *BlobTree) Close() error {
+	return nil
+}
+
+func (b *BlobTree) Type() string { return Type }
+func (b *BlobTree) Path() string { return b.cfg.rootPath }
+
+func (b *BlobTree) SetCompressor(cc *compression.Config) {
+	b.compressor = cc
+}
+
+func (b *BlobTree) Compressor() *compression.Config {
+	return b.compressor
+}
+
+func (b *BlobTree) SetReportErrorFunc(_ func(string, error)) {}
+func (b *BlobTree) SetParentID(_ string)                     {}

pkg/local_object_storage/blobstor/blobtree/delete.go

@@ -0,0 +1,124 @@
+package blobtree
+
+import (
+	"context"
+	"encoding/binary"
+	"os"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+func (b *BlobTree) Delete(_ context.Context, prm common.DeletePrm) (common.DeleteRes, error) {
+	if b.cfg.readOnly {
+		return common.DeleteRes{}, common.ErrReadOnly
+	}
+
+	if len(prm.StorageID) == storageIDLength {
+		return b.deleteFromIdx(prm.Address, binary.LittleEndian.Uint64(prm.StorageID))
+	}
+	return b.findAndDelete(prm.Address)
+}
+
+func (b *BlobTree) deleteFromIdx(addr oid.Address, idx uint64) (common.DeleteRes, error) {
+	dir := b.getDirectoryPath(addr)
+	path := b.getFilePath(dir, idx)
+
+	b.fileLock.Lock(path)
+	defer b.fileLock.Unlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		return common.DeleteRes{}, err
+	}
+
+	deleteIdx := -1
+	for i := range records {
+		if records[i].Address.Equals(addr) {
+			deleteIdx = i
+			break
+		}
+	}
+
+	if deleteIdx == -1 {
+		return common.DeleteRes{}, logicerr.Wrap(new(apistatus.ObjectNotFound))
+	}
+
+	if len(records) == 1 {
+		err = os.Remove(path)
+		if err == nil {
+			b.dispatcher.ReturnIdx(dir, idx)
+			// decrease files metric
+		}
+		return common.DeleteRes{}, err
+	}
+
+	records = append(records[:idx], records[idx+1:]...)
+	size, err := b.writeToTmpAndRename(records, path)
+	if err != nil {
+		return common.DeleteRes{}, err
+	}
+	if size < b.cfg.targetFileSizeBytes {
+		b.dispatcher.ReturnIdx(dir, idx)
+	}
+	return common.DeleteRes{}, nil
+}
+
+func (b *BlobTree) findAndDelete(addr oid.Address) (common.DeleteRes, error) {
+	dir := b.getDirectoryPath(addr)
+	idx, err := b.findFileIdx(dir, addr)
+	if err != nil {
+		return common.DeleteRes{}, err
+	}
+	return b.deleteFromIdx(addr, idx)
+}
+
+func (b *BlobTree) findFileIdx(dir string, addr oid.Address) (uint64, error) {
+	entities, err := os.ReadDir(dir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return 0, logicerr.Wrap(new(apistatus.ObjectNotFound))
+		}
+		return 0, err
+	}
+	for _, entity := range entities {
+		if entity.IsDir() {
+			continue
+		}
+		if b.isTempFile(entity.Name()) {
+			continue
+		}
+		idx, err := b.parseIdx(entity.Name())
+		if err != nil {
+			continue
+		}
+		path := b.getFilePath(dir, idx)
+		contains, err := b.fileContainsObject(path, addr)
+		if err != nil {
+			return 0, err
+		}
+		if contains {
+			return idx, nil
+		}
+	}
+	return 0, logicerr.Wrap(new(apistatus.ObjectNotFound))
+}
+
+func (b *BlobTree) fileContainsObject(path string, addr oid.Address) (bool, error) {
+	b.fileLock.RLock(path)
+	defer b.fileLock.RUnlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		return false, err
+	}
+
+	for i := range records {
+		if records[i].Address.Equals(addr) {
+			return true, nil
+		}
+	}
+	return false, nil
+}

pkg/local_object_storage/blobstor/blobtree/dispatcher.go

@@ -0,0 +1,94 @@
+package blobtree
+
+import (
+	"sync"
+)
+
+type rootDispatcher struct {
+	dispatchers map[string]*dirDispatcher
+	guard       sync.Mutex
+}
+
+func newRootDispatcher() *rootDispatcher {
+	return &rootDispatcher{
+		dispatchers: make(map[string]*dirDispatcher),
+	}
+}
+
+func (d *rootDispatcher) GetIdxForWrite(dir string) uint64 {
+	return d.getDirDispatcher(dir).GetIdxForWrite()
+}
+
+func (d *rootDispatcher) ReturnIdx(dir string, idx uint64) {
+	d.getDirDispatcher(dir).ReturnIdx(idx)
+}
+
+func (d *rootDispatcher) Init(dir string, idx uint64) {
+	d.getDirDispatcher(dir).Init(idx)
+}
+
+func (d *rootDispatcher) getDirDispatcher(dir string) *dirDispatcher {
+	d.guard.Lock()
+	defer d.guard.Unlock()
+
+	if result, ok := d.dispatchers[dir]; ok {
+		return result
+	}
+
+	result := newDirDispatcher(dir)
+	d.dispatchers[dir] = result
+	return result
+}
+
+type dirDispatcher struct {
+	dir       string
+	guard     sync.Mutex
+	indicies  map[uint64]struct{}
+	nextIndex uint64
+}
+
+func newDirDispatcher(dir string) *dirDispatcher {
+	return &dirDispatcher{
+		dir:      dir,
+		indicies: make(map[uint64]struct{}),
+	}
+}
+
+func (d *dirDispatcher) GetIdxForWrite() uint64 {
+	d.guard.Lock()
+	defer d.guard.Unlock()
+
+	var result uint64
+	var found bool
+
+	for idx := range d.indicies {
+		result = idx
+		found = true
+		break
+	}
+
+	if found {
+		delete(d.indicies, result)
+		return result
+	}
+
+	result = d.nextIndex
+	d.nextIndex++
+	return result
+}
+
+func (d *dirDispatcher) ReturnIdx(idx uint64) {
+	d.guard.Lock()
+	defer d.guard.Unlock()
+
+	d.indicies[idx] = struct{}{}
+}
+
+func (d *dirDispatcher) Init(idx uint64) {
+	d.guard.Lock()
+	defer d.guard.Unlock()
+
+	if d.nextIndex <= idx {
+		d.nextIndex = idx + 1
+	}
+}

pkg/local_object_storage/blobstor/blobtree/dispatcher_test.go

@@ -0,0 +1,29 @@
+package blobtree
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDispatcher(t *testing.T) {
+	t.Parallel()
+
+	d := newRootDispatcher()
+	idx := d.GetIdxForWrite("/dir1")
+	require.Equal(t, uint64(0), idx)
+	d.ReturnIdx("/dir1", idx)
+
+	idx = d.GetIdxForWrite("/dir1")
+	require.Equal(t, uint64(0), idx)
+
+	idx = d.GetIdxForWrite("/dir1")
+	require.Equal(t, uint64(1), idx)
+
+	d.Init("/dir2", 5)
+	idx = d.GetIdxForWrite("/dir2")
+	require.Equal(t, uint64(6), idx)
+
+	idx = d.GetIdxForWrite("/dir2")
+	require.Equal(t, uint64(7), idx)
+}

pkg/local_object_storage/blobstor/blobtree/exists.go

@@ -0,0 +1,54 @@
+package blobtree
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+func (b *BlobTree) Exists(_ context.Context, prm common.ExistsPrm) (common.ExistsRes, error) {
+	if len(prm.StorageID) == storageIDLength {
+		return b.existsFromIdx(prm.Address, binary.LittleEndian.Uint64(prm.StorageID))
+	}
+	return b.findAndCheck(prm.Address)
+}
+
+func (b *BlobTree) existsFromIdx(addr oid.Address, idx uint64) (common.ExistsRes, error) {
+	dir := b.getDirectoryPath(addr)
+	path := b.getFilePath(dir, idx)
+
+	b.fileLock.RLock(path)
+	defer b.fileLock.RUnlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		return common.ExistsRes{}, err
+	}
+
+	for i := range records {
+		if records[i].Address.Equals(addr) {
+			return common.ExistsRes{
+				Exists: true,
+			}, nil
+		}
+	}
+
+	return common.ExistsRes{}, nil
+}
+
+func (b *BlobTree) findAndCheck(addr oid.Address) (common.ExistsRes, error) {
+	dir := b.getDirectoryPath(addr)
+	_, err := b.findFileIdx(dir, addr)
+	if err != nil {
+		var notFound *apistatus.ObjectNotFound
+		if errors.As(err, &notFound) {
+			return common.ExistsRes{}, nil
+		}
+		return common.ExistsRes{}, err
+	}
+	return common.ExistsRes{Exists: true}, nil
+}

pkg/local_object_storage/blobstor/blobtree/generic_test.go

@@ -0,0 +1,39 @@
+package blobtree
+
+import (
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/internal/blobstortest"
+)
+
+func TestGeneric(t *testing.T) {
+	newTreeFromPath := func(path string) common.Storage {
+		return New(
+			WithPath(path),
+			WithDepth(2))
+	}
+
+	newTree := func(t *testing.T) common.Storage {
+		return newTreeFromPath(t.TempDir())
+	}
+
+	blobstortest.TestAll(t, newTree, 2048, 16*1024)
+
+	t.Run("info", func(t *testing.T) {
+		path := t.TempDir()
+		blobstortest.TestInfo(t, func(*testing.T) common.Storage {
+			return newTreeFromPath(path)
+		}, Type, path)
+	})
+}
+
+func TestControl(t *testing.T) {
+	newTree := func(t *testing.T) common.Storage {
+		return New(
+			WithPath(t.TempDir()),
+			WithDepth(2))
+	}
+
+	blobstortest.TestControl(t, newTree, 2048, 2048)
+}

pkg/local_object_storage/blobstor/blobtree/get.go

@@ -0,0 +1,107 @@
+package blobtree
+
+import (
+	"context"
+	"encoding/binary"
+	"os"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+func (b *BlobTree) Get(_ context.Context, prm common.GetPrm) (common.GetRes, error) {
+	if len(prm.StorageID) == storageIDLength {
+		return b.getFromIdx(prm.Address, binary.LittleEndian.Uint64(prm.StorageID))
+	}
+	return b.findAndGet(prm.Address)
+}
+
+func (b *BlobTree) getFromIdx(addr oid.Address, idx uint64) (common.GetRes, error) {
+	dir := b.getDirectoryPath(addr)
+	path := b.getFilePath(dir, idx)
+
+	b.fileLock.RLock(path)
+	defer b.fileLock.RUnlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		return common.GetRes{}, err
+	}
+
+	for _, record := range records {
+		if record.Address.Equals(addr) {
+			return b.unmarshalGetRes(record)
+		}
+	}
+
+	return common.GetRes{}, logicerr.Wrap(new(apistatus.ObjectNotFound))
+}
+
+func (b *BlobTree) unmarshalGetRes(record objectData) (common.GetRes, error) {
+	data, err := b.compressor.Decompress(record.Data)
+	if err != nil {
+		return common.GetRes{}, err
+	}
+
+	obj := objectSDK.New()
+	if err := obj.Unmarshal(data); err != nil {
+		return common.GetRes{}, err
+	}
+	return common.GetRes{Object: obj, RawData: data}, nil
+}
+
+func (b *BlobTree) findAndGet(addr oid.Address) (common.GetRes, error) {
+	dir := b.getDirectoryPath(addr)
+	entities, err := os.ReadDir(dir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return common.GetRes{}, logicerr.Wrap(new(apistatus.ObjectNotFound))
+		}
+		return common.GetRes{}, err
+	}
+	for _, entity := range entities {
+		if entity.IsDir() {
+			continue
+		}
+		if b.isTempFile(entity.Name()) {
+			continue
+		}
+		idx, err := b.parseIdx(entity.Name())
+		if err != nil {
+			continue
+		}
+		path := b.getFilePath(dir, idx)
+		res, err := b.tryReadObject(path, addr)
+		if err != nil {
+			return common.GetRes{}, err
+		}
+		if res.Object != nil {
+			return res, nil
+		}
+	}
+	return common.GetRes{}, logicerr.Wrap(new(apistatus.ObjectNotFound))
+}
+
+func (b *BlobTree) tryReadObject(path string, addr oid.Address) (common.GetRes, error) {
+	b.fileLock.RLock(path)
+	defer b.fileLock.RUnlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		return common.GetRes{}, err
+	}
+
+	for _, record := range records {
+		if record.Address.Equals(addr) {
+			res, err := b.unmarshalGetRes(record)
+			if err != nil {
+				return common.GetRes{}, err
+			}
+			return res, nil
+		}
+	}
+	return common.GetRes{}, nil
+}

pkg/local_object_storage/blobstor/blobtree/get_range.go

@@ -0,0 +1,28 @@
+package blobtree
+
+import (
+	"context"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+)
+
+func (b *BlobTree) GetRange(ctx context.Context, prm common.GetRangePrm) (common.GetRangeRes, error) {
+	res, err := b.Get(ctx, common.GetPrm{Address: prm.Address, StorageID: prm.StorageID})
+	if err != nil {
+		return common.GetRangeRes{}, err
+	}
+
+	payload := res.Object.Payload()
+	from := prm.Range.GetOffset()
+	to := from + prm.Range.GetLength()
+
+	if pLen := uint64(len(payload)); to < from || pLen < from || pLen < to {
+		return common.GetRangeRes{}, logicerr.Wrap(new(apistatus.ObjectOutOfRange))
+	}
+
+	return common.GetRangeRes{
+		Data: payload[from:to],
+	}, nil
+}

pkg/local_object_storage/blobstor/blobtree/iterate.go

@@ -0,0 +1,96 @@
+package blobtree
+
+import (
+	"context"
+	"encoding/binary"
+	"os"
+	"path/filepath"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+)
+
+func (b *BlobTree) Iterate(_ context.Context, prm common.IteratePrm) (common.IterateRes, error) {
+	return common.IterateRes{}, b.iterateDir(b.cfg.rootPath, 0, prm)
+}
+
+func (b *BlobTree) iterateDir(dir string, depth uint64, prm common.IteratePrm) error {
+	entities, err := os.ReadDir(dir)
+	if err != nil {
+		if prm.IgnoreErrors {
+			return nil
+		}
+		return err
+	}
+
+	for _, entity := range entities {
+		if depth < b.cfg.depth && entity.IsDir() {
+			err := b.iterateDir(filepath.Join(dir, entity.Name()), depth+1, prm)
+			if err != nil {
+				return err
+			}
+		}
+		if depth != b.cfg.depth {
+			continue
+		}
+		if b.isTempFile(entity.Name()) {
+			continue
+		}
+		idx, err := b.parseIdx(entity.Name())
+		if err != nil {
+			continue
+		}
+		path := b.getFilePath(dir, idx)
+		err = b.iterateRecords(idx, path, prm)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (b *BlobTree) iterateRecords(idx uint64, path string, prm common.IteratePrm) error {
+	b.fileLock.RLock(path)
+	defer b.fileLock.RUnlock(path)
+
+	records, err := b.readFileContent(path)
+	if err != nil {
+		if prm.IgnoreErrors {
+			return nil
+		}
+		return err
+	}
+
+	for _, record := range records {
+		if prm.LazyHandler != nil {
+			if err = prm.LazyHandler(record.Address, func() ([]byte, error) {
+				return record.Data, nil
+			}); err != nil {
+				return err
+			}
+			continue
+		}
+
+		record.Data, err = b.compressor.Decompress(record.Data)
+		if err != nil {
+			if prm.IgnoreErrors {
+				if prm.ErrorHandler != nil {
+					return prm.ErrorHandler(record.Address, err)
+				}
+				continue
+			}
+			return err
+		}
+
+		storageID := make([]byte, storageIDLength)
+		binary.LittleEndian.PutUint64(storageID, idx)
+		err = prm.Handler(common.IterationElement{
+			Address:    record.Address,
+			ObjectData: record.Data,
+			StorageID:  storageID,
+		})
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

pkg/local_object_storage/blobstor/blobtree/option.go

@@ -0,0 +1,29 @@
+package blobtree
+
+import "io/fs"
+
+type Option func(*cfg)
+
+func WithPath(path string) Option {
+	return func(c *cfg) {
+		c.rootPath = path
+	}
+}
+
+func WithDepth(depth uint64) Option {
+	return func(c *cfg) {
+		c.depth = depth
+	}
+}
+
+func WithPerm(p fs.FileMode) Option {
+	return func(c *cfg) {
+		c.permissions = p
+	}
+}
+
+func WithTargetSize(size uint64) Option {
+	return func(c *cfg) {
+		c.targetFileSizeBytes = size
+	}
+}

pkg/local_object_storage/blobstor/blobtree/put.go

@@ -0,0 +1,88 @@
+package blobtree
+
+import (
+	"context"
+	"encoding/binary"
+	"os"
+	"strconv"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+)
+
+const (
+	tempFileSymbols = "###"
+	storageIDLength = 8
+)
+
+func (b *BlobTree) Put(_ context.Context, prm common.PutPrm) (common.PutRes, error) {
+	if b.cfg.readOnly {
+		return common.PutRes{}, common.ErrReadOnly
+	}
+
+	dir := b.getDirectoryPath(prm.Address)
+
+	if err := b.createDir(dir); err != nil {
+		return common.PutRes{}, err
+	}
+
+	if !prm.DontCompress {
+		prm.RawData = b.compressor.Compress(prm.RawData)
+	}
+
+	idx, err := b.saveToFile(prm, dir)
+	if err != nil {
+		return common.PutRes{}, err
+	}
+
+	storageID := make([]byte, storageIDLength)
+	binary.LittleEndian.PutUint64(storageID, idx)
+	return common.PutRes{StorageID: storageID}, nil
+}
+
+func (b *BlobTree) saveToFile(prm common.PutPrm, dir string) (uint64, error) {
+	returnIdx := true
+	idx := b.dispatcher.GetIdxForWrite(dir)
+	path := b.getFilePath(dir, idx)
+
+	b.fileLock.Lock(path)
+	defer b.fileLock.Unlock(path)
+
+	defer func() {
+		if returnIdx {
+			b.dispatcher.ReturnIdx(dir, idx)
+		}
+	}()
+
+	currentContent, err := b.readFileContent(path)
+	if err != nil {
+		return 0, err
+	}
+	var newRecord objectData
+	newRecord.Address = prm.Address
+	newRecord.Data = prm.RawData
+
+	size, err := b.writeToTmpAndRename(append(currentContent, newRecord), path)
+	if err != nil {
+		return 0, err
+	}
+	returnIdx = size < b.cfg.targetFileSizeBytes
+
+	return idx, nil
+}
+
+func (b *BlobTree) writeToTmpAndRename(records []objectData, path string) (uint64, error) {
+	tmpFile := path + tempFileSymbols + strconv.FormatUint(b.suffix.Add(1), 16)
+
+	size, err := b.saveContentToFile(records, tmpFile)
+	if err != nil {
+		_ = os.Remove(tmpFile)
+		return 0, err
+	}
+
+	if err := os.Rename(tmpFile, path); err != nil {
+		_ = os.Remove(tmpFile)
+		return 0, err
+	}
+
+	return size, nil
+}

pkg/local_object_storage/blobstor/perf_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/blobovniczatree"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/blobtree"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/fstree"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/memstore"
@@ -81,6 +82,15 @@ var storages = []storage{
 			)
 		},
 	},
+	{
+		desc: "blobtree",
+		create: func(dir string) common.Storage {
+			return blobtree.New(
+				blobtree.WithDepth(2),
+				blobtree.WithPath(dir),
+			)
+		},
+	},
 }
 
 func BenchmarkSubstorageReadPerf(b *testing.B) {

pkg/util/sync/key_locker.go

@@ -3,8 +3,8 @@ package sync
 import "sync"
 
 type locker struct {
-	mtx     sync.Mutex
-	waiters int // not protected by mtx, must used outer mutex to update concurrently
+	mtx       sync.RWMutex
+	userCount int // not protected by mtx, must used outer mutex to update concurrently
 }
 
 type KeyLocker[K comparable] struct {
@@ -19,26 +19,50 @@ func NewKeyLocker[K comparable]() *KeyLocker[K] {
 }
 
 func (l *KeyLocker[K]) Lock(key K) {
+	l.lock(key, false)
+}
+
+func (l *KeyLocker[K]) RLock(key K) {
+	l.lock(key, true)
+}
+
+func (l *KeyLocker[K]) lock(key K, read bool) {
 	l.lockersMtx.Lock()
 
 	if locker, found := l.lockers[key]; found {
-		locker.waiters++
+		locker.userCount++
 		l.lockersMtx.Unlock()
 
-		locker.mtx.Lock()
+		if read {
+			locker.mtx.RLock()
+		} else {
+			locker.mtx.Lock()
+		}
 		return
 	}
 
 	locker := &locker{
-		waiters: 1,
+		userCount: 1,
+	}
+	if read {
+		locker.mtx.RLock()
+	} else {
+		locker.mtx.Lock()
 	}
-	locker.mtx.Lock()
 
 	l.lockers[key] = locker
 	l.lockersMtx.Unlock()
 }
 
 func (l *KeyLocker[K]) Unlock(key K) {
+	l.unlock(key, false)
+}
+
+func (l *KeyLocker[K]) RUnlock(key K) {
+	l.unlock(key, true)
+}
+
+func (l *KeyLocker[K]) unlock(key K, read bool) {
 	l.lockersMtx.Lock()
 	defer l.lockersMtx.Unlock()
 
@@ -47,10 +71,14 @@ func (l *KeyLocker[K]) Unlock(key K) {
 		return
 	}
 
-	if locker.waiters == 1 {
+	if locker.userCount == 1 {
 		delete(l.lockers, key)
 	}
-	locker.waiters--
+	locker.userCount--
 
-	locker.mtx.Unlock()
+	if read {
+		locker.mtx.RUnlock()
+	} else {
+		locker.mtx.Unlock()
+	}
 }

pkg/util/sync/key_locker_test.go

@@ -9,7 +9,7 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-func TestKeyLocker(t *testing.T) {
+func TestKeyLockerWrite(t *testing.T) {
 	taken := false
 	eg, _ := errgroup.WithContext(context.Background())
 	keyLocker := NewKeyLocker[int]()
@@ -30,3 +30,17 @@ func TestKeyLocker(t *testing.T) {
 	}
 	require.NoError(t, eg.Wait())
 }
+
+func TestKeyLockerRead(t *testing.T) {
+	eg, _ := errgroup.WithContext(context.Background())
+	keyLocker := NewKeyLocker[int]()
+	for i := 0; i < 100; i++ {
+		eg.Go(func() error {
+			keyLocker.RLock(0)
+			defer keyLocker.RUnlock(0)
+
+			return nil
+		})
+	}
+	require.NoError(t, eg.Wait())
+}