[#1268] blobstor: Cleanup zstd encoders/decoders

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/local_object_storage/blobstor/blobovnicza.go

@@ -78,6 +78,8 @@ type blobovniczas struct {
 	// list of active (opened, non-filled) blobovniczas
 	activeMtx sync.RWMutex
 	active    map[string]blobovniczaWithIndex
+
+	onClose []func()
 }
 
 type blobovniczaWithIndex struct {
@@ -800,14 +802,21 @@ func (b *blobovniczas) updateAndGet(p string, old *uint64) (blobovniczaWithIndex
 func (b *blobovniczas) init() error {
 	b.log.Debug("initializing Blobovnicza's")
 
-	zstdC, err := zstdCompressor()
+	enc, zstdC, err := zstdCompressor()
 	if err != nil {
 		return fmt.Errorf("could not create zstd compressor: %v", err)
 	}
-	zstdD, err := zstdDecompressor()
+	b.onClose = append(b.onClose, func() {
+		if err := enc.Close(); err != nil {
+			b.log.Debug("can't close zstd compressor", zap.String("err", err.Error()))
+		}
+	})
+
+	dec, zstdD, err := zstdDecompressor()
 	if err != nil {
 		return fmt.Errorf("could not create zstd decompressor: %v", err)
 	}
+	b.onClose = append(b.onClose, dec.Close)
 
 	// Compression is always done based on config settings.
 	if b.compressionEnabled {
@@ -875,6 +884,10 @@ func (b *blobovniczas) close() error {
 
 	b.activeMtx.Unlock()
 
+	for i := range b.onClose {
+		b.onClose[i]()
+	}
+
 	return nil
 }
 

pkg/local_object_storage/blobstor/compress.go

@@ -16,24 +16,24 @@ func noOpDecompressor(data []byte) ([]byte, error) {
 	return data, nil
 }
 
-func zstdCompressor() (func([]byte) []byte, error) {
+func zstdCompressor() (*zstd.Encoder, func([]byte) []byte, error) {
 	enc, err := zstd.NewWriter(nil)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	return func(data []byte) []byte {
+	return enc, func(data []byte) []byte {
 		return enc.EncodeAll(data, make([]byte, 0, len(data)))
 	}, nil
 }
 
-func zstdDecompressor() (func([]byte) ([]byte, error), error) {
+func zstdDecompressor() (*zstd.Decoder, func([]byte) ([]byte, error), error) {
 	dec, err := zstd.NewReader(nil)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	return func(data []byte) ([]byte, error) {
+	return dec, func(data []byte) ([]byte, error) {
 		return dec.DecodeAll(data, nil)
 	}, nil
 }

pkg/local_object_storage/blobstor/iterate_test.go

@@ -161,6 +161,10 @@ func TestIterate_IgnoreErrors(t *testing.T) {
 	require.NotEqual(t, "", p, "expected to not have at least 1 blobovnicza in cache")
 	require.NoError(t, os.Chmod(p, 0))
 
+	require.NoError(t, b.Close())
+	require.NoError(t, bs.Open())
+	require.NoError(t, bs.Init())
+
 	var prm IteratePrm
 	prm.SetIterationHandler(func(e IterationElement) error {
 		return nil