1 files changed, 34 insertions, 0 deletions
diff --git a/packages/backend/src/services/register-or-fetch-instance-doc.ts b/packages/backend/src/services/register-or-fetch-instance-doc.ts
new file mode 100644
index 0000000000..a548ab0497
--- /dev/null
+++ b/packages/backend/src/services/register-or-fetch-instance-doc.ts
@@ -0,0 +1,34 @@
+import { Instance } from '@/models/entities/instance';
+import { Instances } from '@/models/index';
+import { federationChart } from '@/services/chart/index';
+import { genId } from '@/misc/gen-id';
+import { toPuny } from '@/misc/convert-host';
+import { Cache } from '@/misc/cache';
+
+const cache = new Cache<Instance>(1000 * 60 * 60);
+
+export async function registerOrFetchInstanceDoc(host: string): Promise<Instance> {
+	host = toPuny(host);
+
+	const cached = cache.get(host);
+	if (cached) return cached;
+
+	const index = await Instances.findOne({ host });
+
+	if (index == null) {
+		const i = await Instances.save({
+			id: genId(),
+			host,
+			caughtAt: new Date(),
+			lastCommunicatedAt: new Date(),
+		});
+
+		federationChart.update(true);
+
+		cache.set(host, i);
+		return i;
+	} else {
+		cache.set(host, index);
+		return index;
+	}
+}