refactor progress

packages/date_utils/src/DateFormatterCache.tsx

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2026 Fluxer Contributors
+ *
+ * This file is part of Fluxer.
+ *
+ * Fluxer is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Fluxer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const formatterCache = new Map<string, Intl.DateTimeFormat>();
+
+function buildCacheKey(locale: string, options: Intl.DateTimeFormatOptions): string {
+	return `${locale}:${JSON.stringify(options)}`;
+}
+
+export function getDateFormatter(locale: string, options: Intl.DateTimeFormatOptions = {}): Intl.DateTimeFormat {
+	const key = buildCacheKey(locale, options);
+	const cached = formatterCache.get(key);
+	if (cached !== undefined) {
+		return cached;
+	}
+	const formatter = new Intl.DateTimeFormat(locale, options);
+	formatterCache.set(key, formatter);
+	return formatter;
+}