[#158] metabase: Construct DB using options

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

cmd/neofs-node/config.go

@@ -368,7 +368,9 @@ func initLocalStorage(c *cfg) {
 	)
 	fatalOnErr(err)
 
-	c.cfgObject.metastorage = meta.NewDB(boltDB)
+	c.cfgObject.metastorage = meta.NewDB(
+		meta.FromBoltDB(boltDB),
+	)
 }
 
 func initBucket(prefix string, c *cfg) (bucket bucket.Bucket, err error) {

pkg/local_object_storage/metabase/db.go

@@ -10,16 +10,33 @@ import (
 type DB struct {
 	path string
 
-	boltDB *bbolt.DB
+	*cfg
 
 	matchers map[object.SearchMatchType]func(string, string, string) bool
 }
 
+// Option is an option of DB constructor.
+type Option func(*cfg)
+
+type cfg struct {
+	boltDB *bbolt.DB
+}
+
+func defaultCfg() *cfg {
+	return &cfg{}
+}
+
 // NewDB creates, initializes and returns DB instance.
-func NewDB(boltDB *bbolt.DB) *DB {
+func NewDB(opts ...Option) *DB {
+	c := defaultCfg()
+
+	for i := range opts {
+		opts[i](c)
+	}
+
 	return &DB{
-		path:   boltDB.Path(),
+		path: c.boltDB.Path(),
-		boltDB: boltDB,
+		cfg:  c,
 		matchers: map[object.SearchMatchType]func(string, string, string) bool{
 			object.MatchStringEqual: stringEqualMatcher,
 		},
@@ -46,3 +63,10 @@ func stringEqualMatcher(key, objVal, filterVal string) bool {
 		return (filterVal == v2object.BooleanPropertyValueTrue) == (objVal == v2object.BooleanPropertyValueTrue)
 	}
 }
+
+// FromBoltDB returns option to construct DB from BoltDB instance.
+func FromBoltDB(db *bbolt.DB) Option {
+	return func(c *cfg) {
+		c.boltDB = db
+	}
+}

pkg/local_object_storage/metabase/db_test.go

@@ -220,7 +220,7 @@ func TestDB_Path(t *testing.T) {
 	bdb, err := bbolt.Open(path, 0600, nil)
 	require.NoError(t, err)
 
-	db := NewDB(bdb)
+	db := NewDB(FromBoltDB(bdb))
 
 	defer releaseDB(db)
 
@@ -233,7 +233,7 @@ func newDB(t testing.TB) *DB {
 	bdb, err := bbolt.Open(path, 0600, nil)
 	require.NoError(t, err)
 
-	return NewDB(bdb)
+	return NewDB(FromBoltDB(bdb))
 }
 
 func releaseDB(db *DB) {