Revert "remove the setting, there are enough already"

This reverts commit 1f744f9.

custom/conf/app.example.ini

@@ -313,6 +313,7 @@ USER = root
 ;DB_TYPE = sqlite3
 ;PATH= ; defaults to data/gitea.db
 ;SQLITE_TIMEOUT = ; Query timeout defaults to: 500
+;SQLITE_JOURNAL_MODE = ; defaults to DELETE, can be used to enable WAL mode. https://www.sqlite.org/pragma.html#pragma_journal_mode
 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -382,6 +382,7 @@ The following configuration set `Content-Type: application/vnd.android.package-a
     - `verify-ca`: Enable TLS with verification of the database server certificate against its root certificate.
     - `verify-full`: Enable TLS and verify the database server name matches the given certificate in either the `Common Name` or `Subject Alternative Name` fields.
 - `SQLITE_TIMEOUT`: **500**: Query timeout for SQLite3 only.
+- `SQLITE_JOURNAL_MODE`: on windows & linux: **WAL**, otherwise **DELETE**: Change journal mode for SQlite3. See [SQlite3 docs](https://www.sqlite.org/pragma.html#pragma_journal_mode) for possible values.
 - `ITERATE_BUFFER_SIZE`: **50**: Internal buffer size for iterating.
 - `CHARSET`: **utf8mb4**: For MySQL only, either "utf8" or "utf8mb4". NOTICE: for "utf8mb4" you must use MySQL InnoDB > 5.6. Gitea is unable to check this.
 - `PATH`: **data/gitea.db**: For SQLite3 only, the database file path.

modules/setting/database.go

@@ -40,6 +40,7 @@ var (
 		LogSQL            bool
 		Charset           string
 		Timeout           int // seconds
+		SQliteJournalMode string
 		UseSQLite3        bool
 		UseMySQL          bool
 		UseMSSQL          bool
@@ -89,10 +90,24 @@ func InitDBConfig() {
 	if Database.UseMySQL && defaultCharset != "utf8mb4" {
 		log.Error("Deprecated database mysql charset utf8 support, please use utf8mb4 or convert utf8 to utf8mb4.")
 	}
+
 	if Database.UseSQLite3 {
 		Database.Path = sec.Key("PATH").MustString(filepath.Join(AppDataPath, "gitea.db"))
 		Database.Timeout = sec.Key("SQLITE_TIMEOUT").MustInt(500)
+
+		// WAL mode is preferred for better concurent write performance, but needs special VFS driver features,
+		// which are guaranteed to be available for unix & windows OSes
+		var defaultJournalMode string
+		switch runtime.GOOS {
+		// probably the BSDs are supported too, but i found no information on this - better safe than sorry.
+		case "windows", "linux": // "darwin", "freebsd", "openbsd", "netbsd":
+			defaultJournalMode = "WAL"
+		default:
+			defaultJournalMode = "DELETE"
+		}
+		Database.SQliteJournalMode = sec.Key("SQLITE_JOURNAL_MODE").MustString(defaultJournalMode)
 	}
+
 	Database.MaxIdleConns = sec.Key("MAX_IDLE_CONNS").MustInt(2)
 	if Database.UseMySQL {
 		Database.ConnMaxLifetime = sec.Key("CONN_MAX_LIFETIME").MustDuration(3 * time.Second)
@@ -138,17 +153,8 @@ func DBConnStr() (string, error) {
 		if err := os.MkdirAll(path.Dir(Database.Path), os.ModePerm); err != nil {
 			return "", fmt.Errorf("Failed to create directories: %v", err)
 		}
-
-		// WAL mode is preferred for better concurent write performance, but needs special VFS driver features,
-		// which are guaranteed to be available for unix & windows OSes: https://www.sqlite.org/wal.html
-		journalMode := "DELETE"
-		switch runtime.GOOS {
-		// probably the BSDs are supported too, but i found no information on this - better safe than sorry.
-		case "windows", "linux": // "darwin", "freebsd", "openbsd", "netbsd":
-			journalMode = "WAL"
-		}
 		connStr = fmt.Sprintf("file:%s?cache=shared&mode=rwc&_busy_timeout=%d&_txlock=immediate&_journal_mode=%s",
-			Database.Path, Database.Timeout, journalMode)
+			Database.Path, Database.Timeout, Database.SQliteJournalMode)
 	default:
 		return "", fmt.Errorf("Unknown database type: %s", Database.Type)
 	}