게임 토큰 회수를 Redis에 유지하고 재시작과 알림 누락을 방어한다

app/game-api/src/auth/flushStore.ts

@@ -1,3 +1,10 @@
+import {
+    buildSessionRevocationBaselineKey,
+    buildUserSessionRevocationKey,
+    parseSessionRevocationWatermark,
+    SessionRevocationCommandBudget,
+} from '@sammo-ts/common/auth/sessionRevocation';
+
 export interface GatewayUserFlushEvent {
     userId: string;
     flushedAt: string;
@@ -8,7 +15,7 @@ export interface GatewayUserFlushEvent {
 }
 
 export interface FlushStore {
-    getFlushedAt(userId: string): Date | null;
+    getFlushedAt(userId: string): Date | null | Promise<Date | null>;
     applyFlush(event: GatewayUserFlushEvent): void;
 }
 
@@ -31,6 +38,63 @@ export class InMemoryFlushStore implements FlushStore {
     }
 }
 
+interface RevocationRedisClient {
+    readonly isReady?: boolean;
+    mGet(keys: string[]): Promise<(string | null)[]>;
+    withAbortSignal?(signal: AbortSignal): RevocationRedisClient;
+}
+
+/** Pub/sub accelerates closure; Redis is checked again at every authorization boundary. */
+export class RedisFlushStore implements FlushStore {
+    private readonly local = new Map<string, Date>();
+    private readonly commands = new SessionRevocationCommandBudget(64);
+    constructor(
+        private readonly client: RevocationRedisClient,
+        private readonly channel: string
+    ) {}
+
+    private commandClient(): RevocationRedisClient {
+        if (this.client.isReady === false) throw new Error('Session revocation storage is unavailable.');
+        return this.client.withAbortSignal?.(AbortSignal.timeout(2000)) ?? this.client;
+    }
+
+    async assertInitialized(): Promise<void> {
+        const values = await this.commands.run(() =>
+            this.commandClient().mGet([buildSessionRevocationBaselineKey(this.channel)])
+        );
+        if (values.length !== 1 || !parseSessionRevocationWatermark(values[0]!))
+            throw new Error('Gateway session revocation must be initialized before game API startup.');
+    }
+
+    async getFlushedAt(userId: string): Promise<Date | null> {
+        const values = await this.commands.run(() =>
+            this.commandClient().mGet([
+                buildSessionRevocationBaselineKey(this.channel),
+                buildUserSessionRevocationKey(this.channel, userId),
+            ])
+        );
+        if (values.length !== 2) throw new Error('Session revocation storage is unavailable.');
+        const baseline = parseSessionRevocationWatermark(values[0]!);
+        if (!baseline) throw new Error('Session revocation storage is unavailable.');
+        const persisted = parseSessionRevocationWatermark(values[1]!);
+        return new Date(
+            Math.max(baseline.getTime(), persisted?.getTime() ?? 0, this.local.get(userId)?.getTime() ?? 0)
+        );
+    }
+
+    applyFlush(event: GatewayUserFlushEvent): void {
+        const parsed = new Date(event.flushedAt);
+        if (Number.isNaN(parsed.getTime())) return;
+        const prior = this.local.get(event.userId);
+        if (!prior || parsed > prior) {
+            this.local.delete(event.userId);
+            this.local.set(event.userId, parsed);
+        }
+        // 이 캐시는 재시작/eviction 뒤에도 Redis watermark를 확인하므로 권한 근거가 아니다.
+        if (this.local.size > 4096) this.local.delete(this.local.keys().next().value!);
+    }
+}
+
 export class RedisGatewayFlushSubscriber {
     private readonly client: {
         subscribe: (channel: string, listener: (message: string) => void) => Promise<void>;