[#585] writecache: Fix DB counter

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

pkg/local_object_storage/writecache/writecachebbolt/delete.go

@@ -2,6 +2,7 @@ package writecachebbolt
 
 import (
 	"context"
+	"math"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
@@ -49,9 +50,12 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 
 	if dataSize > 0 {
 		storageType = writecache.StorageTypeDB
+		var recordDeleted bool
 		err := c.db.Update(func(tx *bbolt.Tx) error {
 			b := tx.Bucket(defaultBucket)
-			err := b.Delete([]byte(saddr))
+			key := []byte(saddr)
+			recordDeleted = b.Get(key) != nil
+			err := b.Delete(key)
 			return err
 		})
 		if err != nil {
@@ -62,6 +66,10 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 			storagelog.StorageTypeField(wcStorageType),
 			storagelog.OpField("db DELETE"),
 		)
+		if recordDeleted {
+			c.objCounters.cDB.Add(math.MaxUint64)
+			c.estimateCacheSize()
+		}
 		deleted = true
 		return nil
 	}
@@ -75,7 +83,7 @@ func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
 			storagelog.OpField("fstree DELETE"),
 		)
 		deleted = true
+		c.estimateCacheSize()
 	}
-
 	return metaerr.Wrap(err)
 }