New database trait (#5549)

* Introduce trait

* The trait

* Generic

* Basic impls.

* Remove unneeded bounds

* Minor changes

* Switch over to the new DB trait

* Integrated parity-db and added CLI for db selection

* Default impl.

* Fix logs.

* Started integrating subdb

* Apply suggestions from code review

Co-Authored-By: Cecile Tonglet <cecile@parity.io>

* Apply suggestions from code review

Co-Authored-By: Nikolay Volf <nikvolf@gmail.com>

* Enable subdb

* Bump parity-db

* Fixed CLI macro

* Fixed browser build

* Fixed features

* Sort out features

* Use parity-db from crates.io

* Typo

Co-authored-by: arkpar <arkady.paronyan@gmail.com>
Co-authored-by: Cecile Tonglet <cecile@parity.io>
Co-authored-by: Nikolay Volf <nikvolf@gmail.com>

substrate/client/cli/src/params/shared_params.rs

@@ -17,9 +17,7 @@
 use sc_service::config::DatabaseConfig;
 use std::path::PathBuf;
 use structopt::StructOpt;
-
-/// default sub directory to store database
-const DEFAULT_DB_CONFIG_PATH: &'static str = "db";
+use crate::arg_enums::Database;
 
 /// Shared parameters used by all `CoreParams`.
 #[derive(Debug, StructOpt, Clone)]
@@ -79,10 +77,19 @@ impl SharedParams {
 		&self,
 		base_path: &PathBuf,
 		cache_size: usize,
+		database: Database,
 	) -> DatabaseConfig {
-		DatabaseConfig::Path {
-			path: base_path.join(DEFAULT_DB_CONFIG_PATH),
-			cache_size,
+		match database {
+			Database::RocksDb => DatabaseConfig::RocksDb {
+				path: base_path.join("db"),
+				cache_size,
+			},
+			Database::SubDb => DatabaseConfig::SubDb {
+				path: base_path.join("subdb"),
+			},
+			Database::ParityDb => DatabaseConfig::ParityDb {
+				path: base_path.join("paritydb"),
+			},
 		}
 	}