core/rawdb, ethdb/pebble: avoid fsync db in tests (#27836)

Adds an option to disable fsync for database operations.
This is to make tests faster.

core/blockchain_repair_test.go

@@ -1767,6 +1767,7 @@ func testRepairWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme s
 	db, err := rawdb.Open(rawdb.OpenOptions{
 		Directory:         datadir,
 		AncientsDirectory: ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to create persistent database: %v", err)
@@ -1847,6 +1848,7 @@ func testRepairWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme s
 	db, err = rawdb.Open(rawdb.OpenOptions{
 		Directory:         datadir,
 		AncientsDirectory: ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to reopen persistent database: %v", err)
@@ -1968,6 +1970,7 @@ func testIssue23496(t *testing.T, scheme string) {
 	db, err = rawdb.Open(rawdb.OpenOptions{
 		Directory:         datadir,
 		AncientsDirectory: ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to reopen persistent database: %v", err)

core/blockchain_sethead_test.go

@@ -1971,6 +1971,7 @@ func testSetHeadWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme
 	db, err := rawdb.Open(rawdb.OpenOptions{
 		Directory:         datadir,
 		AncientsDirectory: ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to create persistent database: %v", err)

core/blockchain_snapshot_test.go

@@ -68,6 +68,7 @@ func (basic *snapshotTestBasic) prepare(t *testing.T) (*BlockChain, []*types.Blo
 	db, err := rawdb.Open(rawdb.OpenOptions{
 		Directory:         datadir,
 		AncientsDirectory: ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to create persistent database: %v", err)
@@ -258,6 +259,7 @@ func (snaptest *crashSnapshotTest) test(t *testing.T) {
 	newdb, err := rawdb.Open(rawdb.OpenOptions{
 		Directory:         snaptest.datadir,
 		AncientsDirectory: snaptest.ancient,
+		Ephemeral:         true,
 	})
 	if err != nil {
 		t.Fatalf("Failed to reopen persistent database: %v", err)

core/rawdb/database.go

@@ -352,6 +352,9 @@ type OpenOptions struct {
 	Cache             int    // the capacity(in megabytes) of the data caching
 	Handles           int    // number of files to be open simultaneously
 	ReadOnly          bool
+	// Ephemeral means that filesystem sync operations should be avoided: data integrity in the face of
+	// a crash is not important. This option should typically be used in tests.
+	Ephemeral bool
 }
 
 // openKeyValueDatabase opens a disk-based key-value database, e.g. leveldb or pebble.
@@ -374,7 +377,7 @@ func openKeyValueDatabase(o OpenOptions) (ethdb.Database, error) {
 	if o.Type == dbPebble || existingDb == dbPebble {
 		if PebbleEnabled {
 			log.Info("Using pebble as the backing database")
-			return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly)
+			return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
 		} else {
 			return nil, errors.New("db.engine 'pebble' not supported on this platform")
 		}
@@ -387,7 +390,7 @@ func openKeyValueDatabase(o OpenOptions) (ethdb.Database, error) {
 	// on supported platforms and LevelDB on anything else.
 	if PebbleEnabled {
 		log.Info("Defaulting to pebble as the backing database")
-		return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly)
+		return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
 	} else {
 		log.Info("Defaulting to leveldb as the backing database")
 		return NewLevelDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly)

core/rawdb/databases_64bit.go

@@ -28,8 +28,8 @@ const PebbleEnabled = true
 
 // NewPebbleDBDatabase creates a persistent key-value database without a freezer
 // moving immutable chain segments into cold storage.
-func NewPebbleDBDatabase(file string, cache int, handles int, namespace string, readonly bool) (ethdb.Database, error) {
-	db, err := pebble.New(file, cache, handles, namespace, readonly)
+func NewPebbleDBDatabase(file string, cache int, handles int, namespace string, readonly, ephemeral bool) (ethdb.Database, error) {
+	db, err := pebble.New(file, cache, handles, namespace, readonly, ephemeral)
 	if err != nil {
 		return nil, err
 	}