resid pt 3: friendship checks & auth session reads

src/common/cache/cache-keys.ts

@@ -4,6 +4,8 @@ export const CACHE_NAMESPACE = {
   FRIENDS_LIST: 'friends-list',
   DOLLS_LIST: 'dolls-list',
   USERS_SEARCH: 'users-search',
+  FRIENDSHIP_CHECK: 'friendship-check',
+  AUTH_SESSION: 'auth-session',
 } as const;
 
 function normalizeKeyPart(value: string | undefined): string {
@@ -18,6 +20,8 @@ export const CACHE_TTL_SECONDS = {
   FRIENDS_LIST: 30,
   DOLLS_LIST: 30,
   USERS_SEARCH: 20,
+  FRIENDSHIP_CHECK: 120,
+  AUTH_SESSION: 30,
 } as const;
 
 export function friendsListCacheKey(userId: string): string {
@@ -56,6 +60,25 @@ export function usersSearchCacheKey(
 
 export const USERS_SEARCH_GLOBAL_TAG = 'global';
 
+export function friendshipCheckCacheKey(
+  userId: string,
+  friendId: string,
+): string {
+  return `${normalizeKeyPart(userId)}:${normalizeKeyPart(friendId)}`;
+}
+
+export function friendshipCheckUserTag(userId: string): string {
+  return `user:${normalizeKeyPart(userId)}`;
+}
+
+export function authSessionCacheKey(sessionId: string): string {
+  return normalizeKeyPart(sessionId);
+}
+
+export function authSessionUserTag(userId: string): string {
+  return `user:${normalizeKeyPart(userId)}`;
+}
+
 export function usersSearchUserTag(userId: string): string {
   return `user:${normalizeKeyPart(userId)}`;
 }

src/common/cache/cache-tags.service.ts

@@ -1,11 +1,24 @@
 import { Injectable } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
 import { CacheService } from './cache.service';
+import { parsePositiveInteger } from '../config/env.utils';
 
 const CACHE_TAG_SET_TTL_SECONDS = 86_400;
+const DEFAULT_CACHE_TAG_MAX_ENTRIES = 5_000;
 
 @Injectable()
 export class CacheTagsService {
-  constructor(private readonly cacheService: CacheService) {}
+  private readonly cacheTagMaxEntries: number;
+
+  constructor(
+    private readonly cacheService: CacheService,
+    private readonly configService: ConfigService,
+  ) {
+    this.cacheTagMaxEntries = parsePositiveInteger(
+      this.configService.get<string>('CACHE_TAG_MAX_ENTRIES'),
+      DEFAULT_CACHE_TAG_MAX_ENTRIES,
+    );
+  }
 
   async rememberKeyForTag(
     namespace: string,
@@ -28,6 +41,11 @@ export class CacheTagsService {
         redisClient.sadd(tagSetKey, keyWithNamespace),
         redisClient.expire(tagSetKey, CACHE_TAG_SET_TTL_SECONDS),
       ]);
+
+      const size = await redisClient.scard(tagSetKey);
+      if (size > this.cacheTagMaxEntries) {
+        await this.trimTagSet(tagSetKey, size - this.cacheTagMaxEntries);
+      }
     } catch (error) {
       this.cacheService.recordError('tag remember', tagSetKey, error);
     }
@@ -63,4 +81,26 @@ export class CacheTagsService {
       `${namespace}:${tag}`,
     );
   }
+
+  private async trimTagSet(
+    tagSetKey: string,
+    countToDrop: number,
+  ): Promise<void> {
+    const redisClient = this.cacheService.getRedisClient();
+    if (!redisClient || countToDrop <= 0) {
+      return;
+    }
+
+    try {
+      const sample = await redisClient.srandmember(tagSetKey, countToDrop);
+      const members = Array.isArray(sample) ? sample : [sample].filter(Boolean);
+      if (members.length === 0) {
+        return;
+      }
+
+      await redisClient.srem(tagSetKey, ...members);
+    } catch (error) {
+      this.cacheService.recordError('tag trim', tagSetKey, error);
+    }
+  }
 }

src/common/cache/index.ts

@@ -1,3 +1,4 @@
 export { CacheModule } from './cache.module';
 export { CacheService } from './cache.service';
+export { CacheTagsService } from './cache-tags.service';
 export { RedisThrottlerStorage } from './redis-throttler.storage';