shard: pass meta problem as error, drop HasMeta() from *Res

If we have no error and got a result -- no one cares about HasMeta(). If
we've got an error then currently some codes cares about meta status, but it
can be passed as an additional error as well. Related to #3024, in reality
meta should be internal to the shard, but this change at least avoids
excessive booleans.

Signed-off-by: Roman Khimov <[email protected]>

pkg/local_object_storage/engine/get.go

@@ -40,19 +40,19 @@ func (e *StorageEngine) Get(addr oid.Address) (*objectSDK.Object, error) {
 	)
 	sp.SetAddress(addr)
 
-	err = e.get(addr, func(s *shard.Shard, ignoreMetadata bool) (bool, error) {
+	err = e.get(addr, func(s *shard.Shard, ignoreMetadata bool) error {
 		sp.SetIgnoreMeta(ignoreMetadata)
 		sr, err := s.Get(sp)
 		if err != nil {
-			return sr.HasMeta(), err
+			return err
 		}
 		obj = sr.Object()
-		return sr.HasMeta(), nil
+		return nil
 	})
 	return obj, err
 }
 
-func (e *StorageEngine) get(addr oid.Address, shardFunc func(s *shard.Shard, ignoreMetadata bool) (hasMetadata bool, err error)) error {
+func (e *StorageEngine) get(addr oid.Address, shardFunc func(s *shard.Shard, ignoreMetadata bool) error) error {
 	var (
 		hasDegraded   bool
 		shardWithMeta shardWrapper
@@ -64,11 +64,11 @@ func (e *StorageEngine) get(addr oid.Address, shardFunc func(s *shard.Shard, ign
 		noMeta := sh.GetMode().NoMetabase()
 		hasDegraded = hasDegraded || noMeta
 
-		hasMetadata, err := shardFunc(sh.Shard, noMeta)
+		err := shardFunc(sh.Shard, noMeta)
 		if err != nil {
 			var siErr *objectSDK.SplitInfoError
 
-			if hasMetadata {
+			if errors.Is(err, shard.ErrMetaWithNoObject) {
 				shardWithMeta = sh
 				metaError = err
 			}
@@ -121,7 +121,7 @@ func (e *StorageEngine) get(addr oid.Address, shardFunc func(s *shard.Shard, ign
 			continue
 		}
 
-		_, err := shardFunc(sh.Shard, true)
+		err := shardFunc(sh.Shard, true)
 		if shard.IsErrOutOfRange(err) {
 			return apistatus.ObjectOutOfRange{}
 		}
@@ -151,13 +151,13 @@ func (e *StorageEngine) GetBytes(addr oid.Address) ([]byte, error) {
 		b   []byte
 		err error
 	)
-	err = e.get(addr, func(s *shard.Shard, ignoreMetadata bool) (hasMetadata bool, err error) {
+	err = e.get(addr, func(s *shard.Shard, ignoreMetadata bool) error {
 		if ignoreMetadata {
 			b, err = s.GetBytes(addr)
 		} else {
-			b, hasMetadata, err = s.GetBytesWithMetadataLookup(addr)
+			b, err = s.GetBytesWithMetadataLookup(addr)
 		}
-		return
+		return err
 	})
 	return b, err
 }

pkg/local_object_storage/engine/range.go

@@ -48,13 +48,13 @@ func (e *StorageEngine) GetRange(addr oid.Address, offset uint64, length uint64)
 	shPrm.SetAddress(addr)
 	shPrm.SetRange(offset, length)
 
-	err = e.get(addr, func(sh *shard.Shard, ignoreMetadata bool) (bool, error) {
+	err = e.get(addr, func(sh *shard.Shard, ignoreMetadata bool) error {
 		shPrm.SetIgnoreMeta(ignoreMetadata)
 		res, err := sh.GetRange(shPrm)
 		if err == nil {
 			data = res.Object().Payload()
 		}
-		return res.HasMeta(), err
+		return err
 	})
 	return data, err
 }

pkg/local_object_storage/shard/get.go

@@ -1,6 +1,7 @@
 package shard
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor"
@@ -13,6 +14,9 @@ import (
 	"go.uber.org/zap"
 )
 
+// ErrMetaWithNoObject is returned when shard has metadata, but no object.
+var ErrMetaWithNoObject = errors.New("got meta, but no object")
+
 // GetPrm groups the parameters of Get operation.
 type GetPrm struct {
 	addr     oid.Address
@@ -21,8 +25,7 @@ type GetPrm struct {
 
 // GetRes groups the resulting values of Get operation.
 type GetRes struct {
-	obj     *objectSDK.Object
-	hasMeta bool
+	obj *objectSDK.Object
 }
 
 // SetAddress is a Get option to set the address of the requested object.
@@ -43,11 +46,6 @@ func (r GetRes) Object() *objectSDK.Object {
 	return r.obj
 }
 
-// HasMeta returns true if info about the object was found in the metabase.
-func (r GetRes) HasMeta() bool {
-	return r.hasMeta
-}
-
 // Get reads an object from shard.
 //
 // Returns any error encountered that
@@ -85,8 +83,10 @@ func (s *Shard) Get(prm GetPrm) (GetRes, error) {
 	}
 
 	skipMeta := prm.skipMeta || s.info.Mode.NoMetabase()
-	var err error
-	res.hasMeta, err = s.fetchObjectData(prm.addr, skipMeta, cb, wc)
+	gotMeta, err := s.fetchObjectData(prm.addr, skipMeta, cb, wc)
+	if err != nil && gotMeta {
+		err = fmt.Errorf("%w, %w", err, ErrMetaWithNoObject)
+	}
 
 	return res, err
 }
@@ -160,18 +160,17 @@ func (s *Shard) fetchObjectData(addr oid.Address, skipMeta bool,
 // canonical NeoFS binary format. Returns [apistatus.ObjectNotFound] if object
 // is missing.
 func (s *Shard) GetBytes(addr oid.Address) ([]byte, error) {
-	b, _, err := s.getBytesWithMetadataLookup(addr, true)
-	return b, err
+	return s.getBytesWithMetadataLookup(addr, true)
 }
 
 // GetBytesWithMetadataLookup works similar to [shard.GetBytes], but pre-checks
 // object presence in the underlying metabase: if object cannot be accessed from
 // the metabase, GetBytesWithMetadataLookup returns an error.
-func (s *Shard) GetBytesWithMetadataLookup(addr oid.Address) ([]byte, bool, error) {
+func (s *Shard) GetBytesWithMetadataLookup(addr oid.Address) ([]byte, error) {
 	return s.getBytesWithMetadataLookup(addr, false)
 }
 
-func (s *Shard) getBytesWithMetadataLookup(addr oid.Address, skipMeta bool) ([]byte, bool, error) {
+func (s *Shard) getBytesWithMetadataLookup(addr oid.Address, skipMeta bool) ([]byte, error) {
 	s.m.RLock()
 	defer s.m.RUnlock()
 
@@ -185,5 +184,8 @@ func (s *Shard) getBytesWithMetadataLookup(addr oid.Address, skipMeta bool) ([]b
 		b, err = w.GetBytes(addr)
 		return err
 	})
-	return b, hasMeta, err
+	if err != nil && hasMeta {
+		err = fmt.Errorf("%w, %w", err, ErrMetaWithNoObject)
+	}
+	return b, err
 }

pkg/local_object_storage/shard/get_test.go

@@ -48,7 +48,6 @@ func testShardGet(t *testing.T, hasWriteCache bool) {
 		res, err := testGet(t, sh, getPrm, hasWriteCache)
 		require.NoError(t, err)
 		require.Equal(t, obj, res.Object())
-		require.True(t, res.HasMeta())
 
 		testGetBytes(t, sh, addr, obj.Marshal())
 	})
@@ -70,7 +69,6 @@ func testShardGet(t *testing.T, hasWriteCache bool) {
 		res, err := testGet(t, sh, getPrm, hasWriteCache)
 		require.NoError(t, err)
 		require.Equal(t, obj, res.Object())
-		require.True(t, res.HasMeta())
 
 		testGetBytes(t, sh, addr, obj.Marshal())
 	})
@@ -136,10 +134,9 @@ func testGetBytes(t testing.TB, sh *shard.Shard, addr oid.Address, objBin []byte
 	require.NoError(t, err)
 	require.Equal(t, objBin, b)
 
-	b, hasMeta, err := sh.GetBytesWithMetadataLookup(addr)
+	b, err = sh.GetBytesWithMetadataLookup(addr)
 	require.NoError(t, err)
 	require.Equal(t, objBin, b)
-	require.True(t, hasMeta)
 }
 
 // binary equal is used when object contains empty lists in the structure and

pkg/local_object_storage/shard/range.go

@@ -1,6 +1,8 @@
 package shard
 
 import (
+	"fmt"
+
 	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor"
 	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/common"
 	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/util/logicerr"
@@ -23,8 +25,7 @@ type RngPrm struct {
 
 // RngRes groups the resulting values of GetRange operation.
 type RngRes struct {
-	obj     *object.Object
-	hasMeta bool
+	obj *object.Object
 }
 
 // SetAddress is a Rng option to set the address of the requested object.
@@ -52,11 +53,6 @@ func (r RngRes) Object() *object.Object {
 	return r.obj
 }
 
-// HasMeta returns true if info about the object was found in the metabase.
-func (r RngRes) HasMeta() bool {
-	return r.hasMeta
-}
-
 // GetRange reads part of an object from shard.
 //
 // Returns any error encountered that
@@ -109,8 +105,10 @@ func (s *Shard) GetRange(prm RngPrm) (RngRes, error) {
 	}
 
 	skipMeta := prm.skipMeta || s.info.Mode.NoMetabase()
-	var err error
-	res.hasMeta, err = s.fetchObjectData(prm.addr, skipMeta, cb, wc)
+	gotMeta, err := s.fetchObjectData(prm.addr, skipMeta, cb, wc)
+	if err != nil && gotMeta {
+		err = fmt.Errorf("%w, %w", err, ErrMetaWithNoObject)
+	}
 
 	return res, err
 }