libs/db: remove deprecated `LevelDBBackend` const (#3632)

CHANGELOG_PENDING.md

@@ -9,6 +9,9 @@
 * Apps
 
 * Go API
+- [libs/db] Removed deprecated `LevelDBBackend` const
+  * If you have `db_backend` set to `leveldb` in your config file, please
+    change it to `goleveldb` or `cleveldb`.
 
 * Blockchain Protocol
 

UPGRADING.md

@@ -3,6 +3,14 @@
 This guide provides steps to be followed when you upgrade your applications to
 a newer version of Tendermint Core.
 
+
+## v0.32.0
+
+### Config Changes
+
+If you have `db_backend` set to `leveldb` in your config file, please change it
+to `goleveldb` or `cleveldb`.
+
 ## v0.31.6
 
 There are no breaking changes in this release except Go API of p2p and

libs/db/c_level_db.go

@@ -14,7 +14,6 @@ func init() {
 	dbCreator := func(name string, dir string) (DB, error) {
 		return NewCLevelDB(name, dir)
 	}
-	registerDBCreator(LevelDBBackend, dbCreator, true)
 	registerDBCreator(CLevelDBBackend, dbCreator, false)
 }
 

libs/db/db.go

@@ -9,10 +9,6 @@ type DBBackendType string
 
 // These are valid backend types.
 const (
-	// LevelDBBackend is a legacy type. Defaults to goleveldb unless cleveldb
-	// build tag was used, in which it becomes cleveldb.
-	// Deprecated: Use concrete types (golevedb, cleveldb, etc.)
-	LevelDBBackend DBBackendType = "leveldb"
 	// GoLevelDBBackend represents goleveldb (github.com/syndtr/goleveldb - most
 	// popular implementation)
 	//   - pure go

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)
 }