[#xx] Add error type for writecache misses

Signed-off-by: Alejandro Lopez <a.lopez@yadro.com>

pkg/local_object_storage/shard/get.go

@@ -2,6 +2,7 @@ package shard
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
@@ -138,10 +139,10 @@ func (s *Shard) fetchObjectData(ctx context.Context, addr oid.Address, skipMeta
 
 	if s.hasWriteCache() {
 		res, err := wc(s.writeCache)
-		if err == nil || IsErrOutOfRange(err) {
+		if err == nil || IsErrOutOfRange(err) || client.IsErrObjectNotFound(err) {
 			return res, false, err
 		}
-		if client.IsErrObjectNotFound(err) {
+		if errors.Is(err, writecache.ErrMiss) {
 			s.log.Debug(logs.ShardObjectIsMissingInWritecache,
 				zap.Stringer("addr", addr),
 				zap.Bool("skip_meta", skipMeta))

pkg/local_object_storage/writecache/writecache.go

@@ -63,4 +63,11 @@ var (
 	ErrBigObject = errors.New("too big object")
 	// ErrOutOfSpace is returned when there is no space left to put a new object.
 	ErrOutOfSpace = errors.New("no space left in the write cache")
+	// ErrMiss is returned when there is no information about the object in the cache.
+	// Note that the distinction between this error and ObjectNotFound is important. When
+	// the cache returns ObjectNotFound, it can be safely assumed that the object is not
+	// found in the cache or any underlying storage. When the cache returns ErrMiss, nothing
+	// is known about the object and thus the underlying storage must be consulted as well.
+	// This allows the cache to serve as a consistent view of the underlying storage.
+	ErrMiss = errors.New("write-cache miss")
 )

pkg/local_object_storage/writecache/writecachebadger/delete.go

@@ -6,10 +6,8 @@ import (
 
 	storagelog "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/log"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/metaerr"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
-	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"github.com/dgraph-io/badger/v4"
 	"go.opentelemetry.io/otel/attribute"
@@ -17,8 +15,6 @@ import (
 )
 
 // Delete removes object from write-cache.
-//
-// Returns an error of type apistatus.ObjectNotFound if object is missing in write-cache.
 func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 	_, span := tracing.StartSpanFromContext(ctx, "writecache.Delete",
 		trace.WithAttributes(
@@ -39,22 +35,22 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 		return writecache.ErrReadOnly
 	}
 
-	saddr := addr.EncodeToString()
+	key := addr2key(addr)
 
 	err := c.db.Update(func(tx *badger.Txn) error {
-		it, err := tx.Get([]byte(saddr))
+		it, err := tx.Get(key[:])
 		if err != nil {
 			if err == badger.ErrKeyNotFound {
-				return logicerr.Wrap(new(apistatus.ObjectNotFound))
+				return writecache.ErrMiss
 			}
 			return err
 		}
 		if it.ValueSize() > 0 {
 			storageType = writecache.StorageTypeDB
-			err := tx.Delete([]byte(saddr))
+			err := tx.Delete(key[:])
 			if err == nil {
 				storagelog.Write(c.log,
-					storagelog.AddressField(saddr),
+					storagelog.AddressField(addr.EncodeToString()),
 					storagelog.StorageTypeField(wcStorageType),
 					storagelog.OpField("db DELETE"),
 				)

pkg/local_object_storage/writecache/writecachebadger/generic_test.go

@@ -1,19 +0,0 @@
-package writecachebadger
-
-import (
-	"testing"
-	"time"
-
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/storagetest"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger/test"
-)
-
-func TestGeneric(t *testing.T) {
-	storagetest.TestAll(t, func(t *testing.T) storagetest.Component {
-		return New(
-			WithLogger(test.NewLogger(t, true)),
-			WithFlushWorkersCount(2),
-			WithPath(t.TempDir()),
-			WithGCInterval(1*time.Second))
-	})
-}

pkg/local_object_storage/writecache/writecachebadger/get.go

@@ -5,10 +5,8 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/metaerr"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
-	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"
 	"github.com/dgraph-io/badger/v4"
@@ -16,9 +14,6 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-// Get returns object from write-cache.
-//
-// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in write-cache.
 func (c *cache) Get(ctx context.Context, addr oid.Address) (*objectSDK.Object, error) {
 	_, span := tracing.StartSpanFromContext(ctx, "writecache.Get",
 		trace.WithAttributes(
@@ -47,12 +42,10 @@ func (c *cache) getInternal(addr oid.Address) (*objectSDK.Object, error) {
 		return obj, obj.Unmarshal(value)
 	}
 
-	return nil, logicerr.Wrap(new(apistatus.ObjectNotFound))
+	return nil, err
 }
 
 // Head returns object header from write-cache.
-//
-// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in write-cache.
 func (c *cache) Head(ctx context.Context, addr oid.Address) (*objectSDK.Object, error) {
 	_, span := tracing.StartSpanFromContext(ctx, "writecache.Head",
 		trace.WithAttributes(
@@ -70,8 +63,6 @@ func (c *cache) Head(ctx context.Context, addr oid.Address) (*objectSDK.Object,
 
 // Get fetches object from the underlying database.
 // Key should be a stringified address.
-//
-// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in db.
 func Get(db *badger.DB, key []byte) ([]byte, error) {
 	var value []byte
 
@@ -79,7 +70,7 @@ func Get(db *badger.DB, key []byte) ([]byte, error) {
 		it, err := tx.Get(key)
 		if err != nil {
 			if err == badger.ErrKeyNotFound {
-				return logicerr.Wrap(new(apistatus.ObjectNotFound))
+				return writecache.ErrMiss
 			}
 			return err
 		}
@@ -91,5 +82,5 @@ func Get(db *badger.DB, key []byte) ([]byte, error) {
 		return nil
 	})
 
-	return value, metaerr.Wrap(err)
+	return value, err
 }

pkg/local_object_storage/writecache/writecachebadger/writecachebadger_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 	"time"
 
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/storagetest"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/testutil"
 	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
@@ -16,7 +17,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestFlush(t *testing.T) {
+func TestGeneric(t *testing.T) {
 	createCacheFn := func(t *testing.T, smallSize uint64, mb *meta.DB, bs writecache.MainStorage, opts ...Option) writecache.Cache {
 		return New(
 			append([]Option{
@@ -59,5 +60,22 @@ func TestFlush(t *testing.T) {
 		},
 	}
 
-	writecachetest.TestFlush(t, createCacheFn, errCountOpt, failures...)
+	t.Run("api", func(t *testing.T) {
+		writecachetest.TestAPI(t, createCacheFn)
+	})
+
+	t.Run("flush", func(t *testing.T) {
+		writecachetest.TestFlush(t, createCacheFn, errCountOpt, failures...)
+	})
+
+	t.Run("storage", func(t *testing.T) {
+		storagetest.TestAll(t, func(t *testing.T) storagetest.Component {
+			return New(
+				WithLogger(test.NewLogger(t, true)),
+				WithFlushWorkersCount(2),
+				WithPath(t.TempDir()),
+				WithGCInterval(1*time.Second))
+		})
+	})
+
 }

pkg/local_object_storage/writecache/writecachebbolt/delete.go

@@ -10,6 +10,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/metaerr"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"go.etcd.io/bbolt"
 	"go.opentelemetry.io/otel/attribute"
@@ -17,8 +18,6 @@ import (
 )
 
 // Delete removes object from write-cache.
-//
-// Returns an error of type apistatus.ObjectNotFound if object is missing in write-cache.
 func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 	ctx, span := tracing.StartSpanFromContext(ctx, "writecache.Delete",
 		trace.WithAttributes(
@@ -61,6 +60,7 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 		if err != nil {
 			return err
 		}
+		deleted = true
 		storagelog.Write(c.log,
 			storagelog.AddressField(saddr),
 			storagelog.StorageTypeField(wcStorageType),
@@ -69,9 +69,9 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 		if recordDeleted {
 			c.objCounters.cDB.Add(math.MaxUint64)
 			c.estimateCacheSize()
+			return nil
 		}
-		deleted = true
-		return nil
+		return metaerr.Wrap(writecache.ErrMiss)
 	}
 
 	storageType = writecache.StorageTypeFSTree
@@ -85,5 +85,8 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 		deleted = true
 		c.estimateCacheSize()
 	}
+	if client.IsErrObjectNotFound(err) {
+		err = writecache.ErrMiss
+	}
 	return metaerr.Wrap(err)
 }

pkg/local_object_storage/writecache/writecachebbolt/generic_test.go

@@ -1,17 +0,0 @@
-package writecachebbolt
-
-import (
-	"testing"
-
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/storagetest"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger/test"
-)
-
-func TestGeneric(t *testing.T) {
-	storagetest.TestAll(t, func(t *testing.T) storagetest.Component {
-		return New(
-			WithLogger(test.NewLogger(t, true)),
-			WithFlushWorkersCount(2),
-			WithPath(t.TempDir()))
-	})
-}

pkg/local_object_storage/writecache/writecachebbolt/get.go

@@ -6,10 +6,8 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/metaerr"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
-	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"
 	"github.com/nspcc-dev/neo-go/pkg/util/slice"
@@ -52,7 +50,7 @@ func (c *cache) getInternal(ctx context.Context, saddr string, addr oid.Address)
 
 	res, err := c.fsTree.Get(ctx, common.GetPrm{Address: addr})
 	if err != nil {
-		return nil, logicerr.Wrap(new(apistatus.ObjectNotFound))
+		return nil, metaerr.Wrap(writecache.ErrMiss)
 	}
 
 	found = true
@@ -61,8 +59,6 @@ func (c *cache) getInternal(ctx context.Context, saddr string, addr oid.Address)
 }
 
 // Head returns object header from write-cache.
-//
-// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in write-cache.
 func (c *cache) Head(ctx context.Context, addr oid.Address) (*objectSDK.Object, error) {
 	saddr := addr.EncodeToString()
 
@@ -82,8 +78,6 @@ func (c *cache) Head(ctx context.Context, addr oid.Address) (*objectSDK.Object,
 
 // Get fetches object from the underlying database.
 // Key should be a stringified address.
-//
-// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in db.
 func Get(db *bbolt.DB, key []byte) ([]byte, error) {
 	var value []byte
 	err := db.View(func(tx *bbolt.Tx) error {
@@ -93,7 +87,7 @@ func Get(db *bbolt.DB, key []byte) ([]byte, error) {
 		}
 		value = b.Get(key)
 		if value == nil {
-			return logicerr.Wrap(new(apistatus.ObjectNotFound))
+			return metaerr.Wrap(writecache.ErrMiss)
 		}
 		value = slice.Copy(value)
 		return nil

pkg/local_object_storage/writecache/writecachebbolt/writecachebolt_test.go

@@ -9,6 +9,7 @@ import (
 
 	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/storagetest"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/testutil"
 	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
@@ -100,5 +101,20 @@ func TestFlush(t *testing.T) {
 		},
 	}
 
-	writecachetest.TestFlush(t, createCacheFn, errCountOpt, failures...)
+	t.Run("api", func(t *testing.T) {
+		writecachetest.TestAPI(t, createCacheFn)
+	})
+
+	t.Run("flush", func(t *testing.T) {
+		writecachetest.TestFlush(t, createCacheFn, errCountOpt, failures...)
+	})
+
+	t.Run("storage", func(t *testing.T) {
+		storagetest.TestAll(t, func(t *testing.T) storagetest.Component {
+			return New(
+				WithLogger(test.NewLogger(t, true)),
+				WithFlushWorkersCount(2),
+				WithPath(t.TempDir()))
+		})
+	})
 }

pkg/local_object_storage/writecache/writecachetest/api.go

@@ -0,0 +1,60 @@
+package writecachetest
+
+import (
+	"context"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/testutil"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
+	oidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAPI[Option any](t *testing.T, createCacheFn CreateCacheFunc[Option]) {
+	ctx := context.Background()
+	wc, _, _ := newCache(t, createCacheFn, smallSize)
+
+	obj := testutil.GenerateObject()
+	addr := testutil.AddressFromObject(t, obj)
+	data, err := obj.Marshal()
+	require.NoError(t, err)
+
+	// Get nonexistent object
+	{
+		_, gotErr := wc.Get(ctx, oidtest.Address())
+		require.ErrorIs(t, gotErr, writecache.ErrMiss)
+	}
+
+	// Put an object
+	{
+		_, err := wc.Put(ctx, common.PutPrm{
+			Address: addr,
+			Object:  obj,
+			RawData: data,
+		})
+
+		require.NoError(t, err)
+	}
+
+	// Get the object previously put
+	{
+		gotObj, err := wc.Get(ctx, addr)
+		require.NoError(t, err)
+		gotData, err := gotObj.Marshal()
+		require.NoError(t, err)
+		require.Equal(t, data, gotData)
+	}
+
+	// Delete the object previously put
+	{
+		require.NoError(t, wc.Delete(ctx, addr))
+		require.ErrorIs(t, wc.Delete(ctx, addr), writecache.ErrMiss)
+	}
+
+	// Get the object previously deleted
+	{
+		_, gotErr := wc.Get(ctx, addr)
+		require.Error(t, gotErr, writecache.ErrMiss)
+	}
+}

pkg/local_object_storage/writecache/writecachetest/flush.go

@@ -2,20 +2,10 @@ package writecachetest
 
 import (
 	"context"
-	"path/filepath"
 	"sync/atomic"
 	"testing"
 
-	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
-	"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/internal/testutil"
-	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard/mode"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
-	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
-	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"github.com/stretchr/testify/require"
 )
 
@@ -24,24 +14,6 @@ const (
 	smallSize = 256
 )
 
-type CreateCacheFunc[Option any] func(
-	t *testing.T,
-	smallSize uint64,
-	meta *meta.DB,
-	bs writecache.MainStorage,
-	opts ...Option,
-) writecache.Cache
-
-type TestFailureInjector[Option any] struct {
-	Desc     string
-	InjectFn func(*testing.T, writecache.Cache)
-}
-
-type objectPair struct {
-	addr oid.Address
-	obj  *objectSDK.Object
-}
-
 func TestFlush[Option any](
 	t *testing.T,
 	createCacheFn CreateCacheFunc[Option],
@@ -50,6 +22,11 @@ func TestFlush[Option any](
 ) {
 	t.Run("no errors", func(t *testing.T) {
 		wc, bs, mb := newCache(t, createCacheFn, smallSize)
+
+		// Set mode for metabase and blobstor to prevent background flushes.
+		require.NoError(t, mb.SetMode(mode.ReadOnly))
+		require.NoError(t, bs.SetMode(mode.ReadOnly))
+
 		objects := putObjects(t, wc)
 
 		require.NoError(t, bs.SetMode(mode.ReadWrite))
@@ -62,6 +39,11 @@ func TestFlush[Option any](
 
 	t.Run("flush on moving to degraded mode", func(t *testing.T) {
 		wc, bs, mb := newCache(t, createCacheFn, smallSize)
+
+		// Set mode for metabase and blobstor to prevent background flushes.
+		require.NoError(t, mb.SetMode(mode.ReadOnly))
+		require.NoError(t, bs.SetMode(mode.ReadOnly))
+
 		objects := putObjects(t, wc)
 
 		// Blobstor is read-only, so we expect en error from `flush` here.
@@ -82,6 +64,11 @@ func TestFlush[Option any](
 			t.Run(f.Desc, func(t *testing.T) {
 				errCountOpt, errCount := errCountOption()
 				wc, bs, mb := newCache(t, createCacheFn, smallSize, errCountOpt)
+
+				// Set mode for metabase and blobstor to prevent background flushes.
+				require.NoError(t, mb.SetMode(mode.ReadOnly))
+				require.NoError(t, bs.SetMode(mode.ReadOnly))
+
 				objects := putObjects(t, wc)
 				f.InjectFn(t, wc)
 
@@ -99,87 +86,3 @@ func TestFlush[Option any](
 		}
 	})
 }
-
-func newCache[Option any](
-	t *testing.T,
-	createCacheFn CreateCacheFunc[Option],
-	smallSize uint64,
-	opts ...Option,
-) (writecache.Cache, *blobstor.BlobStor, *meta.DB) {
-	dir := t.TempDir()
-	mb := meta.New(
-		meta.WithPath(filepath.Join(dir, "meta")),
-		meta.WithEpochState(dummyEpoch{}))
-	require.NoError(t, mb.Open(false))
-	require.NoError(t, mb.Init())
-
-	bs := blobstor.New(blobstor.WithStorages([]blobstor.SubStorage{
-		{
-			Storage: fstree.New(
-				fstree.WithPath(filepath.Join(dir, "blob")),
-				fstree.WithDepth(0),
-				fstree.WithDirNameLen(1)),
-		},
-	}))
-	require.NoError(t, bs.Open(false))
-	require.NoError(t, bs.Init())
-
-	wc := createCacheFn(t, smallSize, mb, bs, opts...)
-	t.Cleanup(func() { require.NoError(t, wc.Close()) })
-	require.NoError(t, wc.Open(false))
-	require.NoError(t, wc.Init())
-
-	// First set mode for metabase and blobstor to prevent background flushes.
-	require.NoError(t, mb.SetMode(mode.ReadOnly))
-	require.NoError(t, bs.SetMode(mode.ReadOnly))
-
-	return wc, bs, mb
-}
-
-func putObject(t *testing.T, c writecache.Cache, size int) objectPair {
-	obj := testutil.GenerateObjectWithSize(size)
-	data, err := obj.Marshal()
-	require.NoError(t, err)
-
-	var prm common.PutPrm
-	prm.Address = objectCore.AddressOf(obj)
-	prm.Object = obj
-	prm.RawData = data
-
-	_, err = c.Put(context.Background(), prm)
-	require.NoError(t, err)
-
-	return objectPair{prm.Address, prm.Object}
-}
-
-func putObjects(t *testing.T, c writecache.Cache) []objectPair {
-	objects := make([]objectPair, objCount)
-	for i := range objects {
-		objects[i] = putObject(t, c, 1+(i%2)*smallSize)
-	}
-	return objects
-}
-
-func check(t *testing.T, mb *meta.DB, bs *blobstor.BlobStor, objects []objectPair) {
-	for i := range objects {
-		var mPrm meta.StorageIDPrm
-		mPrm.SetAddress(objects[i].addr)
-
-		mRes, err := mb.StorageID(context.Background(), mPrm)
-		require.NoError(t, err)
-
-		var prm common.GetPrm
-		prm.Address = objects[i].addr
-		prm.StorageID = mRes.StorageID()
-
-		res, err := bs.Get(context.Background(), prm)
-		require.NoError(t, err)
-		require.Equal(t, objects[i].obj, res.Object)
-	}
-}
-
-type dummyEpoch struct{}
-
-func (dummyEpoch) CurrentEpoch() uint64 {
-	return 0
-}

pkg/local_object_storage/writecache/writecachetest/writecachetest.go

@@ -0,0 +1,116 @@
+package writecachetest
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
+	"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/internal/testutil"
+	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"github.com/stretchr/testify/require"
+)
+
+type CreateCacheFunc[Option any] func(
+	t *testing.T,
+	smallSize uint64,
+	meta *meta.DB,
+	bs writecache.MainStorage,
+	opts ...Option,
+) writecache.Cache
+
+type TestFailureInjector[Option any] struct {
+	Desc     string
+	InjectFn func(*testing.T, writecache.Cache)
+}
+
+type objectPair struct {
+	addr oid.Address
+	obj  *objectSDK.Object
+}
+
+func newCache[Option any](
+	t *testing.T,
+	createCacheFn CreateCacheFunc[Option],
+	smallSize uint64,
+	opts ...Option,
+) (writecache.Cache, *blobstor.BlobStor, *meta.DB) {
+	dir := t.TempDir()
+	mb := meta.New(
+		meta.WithPath(filepath.Join(dir, "meta")),
+		meta.WithEpochState(dummyEpoch{}))
+	require.NoError(t, mb.Open(false))
+	require.NoError(t, mb.Init())
+
+	bs := blobstor.New(blobstor.WithStorages([]blobstor.SubStorage{
+		{
+			Storage: fstree.New(
+				fstree.WithPath(filepath.Join(dir, "blob")),
+				fstree.WithDepth(0),
+				fstree.WithDirNameLen(1)),
+		},
+	}))
+	require.NoError(t, bs.Open(false))
+	require.NoError(t, bs.Init())
+
+	wc := createCacheFn(t, smallSize, mb, bs, opts...)
+	t.Cleanup(func() { require.NoError(t, wc.Close()) })
+	require.NoError(t, wc.Open(false))
+	require.NoError(t, wc.Init())
+
+	return wc, bs, mb
+}
+
+func putObject(t *testing.T, c writecache.Cache, size int) objectPair {
+	obj := testutil.GenerateObjectWithSize(size)
+	data, err := obj.Marshal()
+	require.NoError(t, err)
+
+	var prm common.PutPrm
+	prm.Address = objectCore.AddressOf(obj)
+	prm.Object = obj
+	prm.RawData = data
+
+	_, err = c.Put(context.Background(), prm)
+	require.NoError(t, err)
+
+	return objectPair{prm.Address, prm.Object}
+}
+
+func putObjects(t *testing.T, c writecache.Cache) []objectPair {
+	objects := make([]objectPair, objCount)
+	for i := range objects {
+		objects[i] = putObject(t, c, 1+(i%2)*smallSize)
+	}
+	return objects
+}
+
+func check(t *testing.T, mb *meta.DB, bs *blobstor.BlobStor, objects []objectPair) {
+	for i := range objects {
+		var mPrm meta.StorageIDPrm
+		mPrm.SetAddress(objects[i].addr)
+
+		mRes, err := mb.StorageID(context.Background(), mPrm)
+		require.NoError(t, err)
+
+		var prm common.GetPrm
+		prm.Address = objects[i].addr
+		prm.StorageID = mRes.StorageID()
+
+		res, err := bs.Get(context.Background(), prm)
+		require.NoError(t, err)
+		require.Equal(t, objects[i].obj, res.Object)
+	}
+}
+
+type dummyEpoch struct{}
+
+func (dummyEpoch) CurrentEpoch() uint64 {
+	return 0
+}