remove deprecated LevelDBBackend

config/config.go

@@ -218,7 +218,7 @@ func DefaultBaseConfig() BaseConfig {
 		ProfListenAddress:  "",
 		FastSync:           true,
 		FilterPeers:        false,
-		DBBackend:          "leveldb",
+		DBBackend:          "goleveldb",
 		DBPath:             "data",
 	}
 }

libs/db/c_level_db.go

@@ -13,7 +13,6 @@ func init() {
 	dbCreator := func(name string, dir string) (DB, error) {
 		return NewCLevelDB(name, dir)
 	}
-	registerDBCreator(LevelDBBackend, dbCreator, true)
 	registerDBCreator(CLevelDBBackend, dbCreator, false)
 }
 

libs/db/c_level_db_test.go

@@ -92,7 +92,7 @@ func TestCLevelDBBackend(t *testing.T) {
 	// Can't use "" (current directory) or "./" here because levigo.Open returns:
 	// "Error initializing DB: IO error: test_XXX.db: Invalid argument"
 	dir := os.TempDir()
-	db := NewDB(name, LevelDBBackend, dir)
+	db := NewDB(name, CLevelDBBackend, dir)
 	defer cleanupDBDir(dir, name)
 
 	_, ok := db.(*CLevelDB)
@@ -102,7 +102,7 @@ func TestCLevelDBBackend(t *testing.T) {
 func TestCLevelDBStats(t *testing.T) {
 	name := fmt.Sprintf("test_%x", cmn.RandStr(12))
 	dir := os.TempDir()
-	db := NewDB(name, LevelDBBackend, dir)
+	db := NewDB(name, CLevelDBBackend, dir)
 	defer cleanupDBDir(dir, name)
 
 	assert.NotEmpty(t, db.Stats())

libs/db/db.go

@@ -5,18 +5,31 @@ import (
 	"strings"
 )
 
-//----------------------------------------
-// Main entry
-
 type DBBackendType string
 
+// These are valid db_backend values.
 const (
-	LevelDBBackend   DBBackendType = "leveldb" // legacy, defaults to goleveldb unless +gcc
-	CLevelDBBackend  DBBackendType = "cleveldb"
+	// GoLevelDBBackend represents goleveldb (github.com/syndtr/goleveldb - most
+	// popular implementation)
+	//   - pure go
+	//   - stable
 	GoLevelDBBackend DBBackendType = "goleveldb"
-	MemDBBackend     DBBackendType = "memdb"
-	FSDBBackend      DBBackendType = "fsdb" // using the filesystem naively
-	BoltDBBackend    DBBackendType = "boltdb"
+	// CLevelDBBackend represents cleveldb (uses levigo wrapper)
+	//   - fast
+	//   - requires gcc
+	CLevelDBBackend DBBackendType = "cleveldb"
+	// MemDBBackend represents in-memoty key value store, which is mostly used
+	// for testing.
+	MemDBBackend DBBackendType = "memdb"
+	// FSDBBackend represents filesystem database
+	//	 - EXPERIMENTAL
+	//   - slow
+	FSDBBackend DBBackendType = "fsdb"
+	// BoltDBBackend represents bolt (uses etcd's fork of bolt -
+	// github.com/etcd-io/bbolt)
+	//   - EXPERIMENTAL
+	//   - may be faster is some use-cases (random reads - indexer)
+	BoltDBBackend DBBackendType = "boltdb"
 )
 
 type dbCreator func(name string, dir string) (DB, error)

libs/db/go_level_db.go

@@ -15,7 +15,6 @@ func init() {
 	dbCreator := func(name string, dir string) (DB, error) {
 		return NewGoLevelDB(name, dir)
 	}
-	registerDBCreator(LevelDBBackend, dbCreator, false)
 	registerDBCreator(GoLevelDBBackend, dbCreator, false)
 }
 

lite/proxy/verifier.go

@@ -14,7 +14,7 @@ func NewVerifier(chainID, rootDir string, client lclient.SignStatusClient, logge
 	logger.Info("lite/proxy/NewVerifier()...", "chainID", chainID, "rootDir", rootDir, "client", client)
 
 	memProvider := lite.NewDBProvider("trusted.mem", dbm.NewMemDB()).SetLimit(cacheSize)
-	lvlProvider := lite.NewDBProvider("trusted.lvl", dbm.NewDB("trust-base", dbm.LevelDBBackend, rootDir))
+	lvlProvider := lite.NewDBProvider("trusted.lvl", dbm.NewDB("trust-base", dbm.GoLevelDBBackend, rootDir))
 	trust := lite.NewMultiProvider(
 		memProvider,
 		lvlProvider,