redis pt 2: read cache wiring & event based invalidations

src/auth/auth.service.ts

@@ -13,6 +13,7 @@ import {
   verify,
 } from 'jsonwebtoken';
 import { PrismaService } from '../database/prisma.service';
+import { EventEmitter2 } from '@nestjs/event-emitter';
 import type { SocialAuthProfile } from './types/social-auth-profile';
 import type {
   AuthTokens,
@@ -35,6 +36,7 @@ import {
   usernameFromEmail,
 } from './auth.utils';
 import type { SsoProvider } from './dto/sso-provider';
+import { UserEvents } from '../users/events/user.events';
 
 interface SsoStateClaims {
   provider: SsoProvider;
@@ -56,6 +58,7 @@ export class AuthService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly configService: ConfigService,
+    private readonly eventEmitter: EventEmitter2,
   ) {
     this.jwtSecret = this.configService.get<string>('JWT_SECRET') || '';
     this.jwtIssuer =
@@ -254,6 +257,10 @@ export class AuthService {
         },
       });
 
+      this.eventEmitter.emit(UserEvents.SEARCH_INDEX_INVALIDATED, {
+        userId: user.id,
+      });
+
       return user;
     }
 
@@ -273,7 +280,7 @@ export class AuthService {
       );
     }
 
-    return this.prisma.$transaction(async (tx) => {
+    const user = await this.prisma.$transaction(async (tx) => {
       let user = await tx.user.findUnique({
         where: { email },
       });
@@ -311,6 +318,12 @@ export class AuthService {
 
       return user;
     });
+
+    this.eventEmitter.emit(UserEvents.SEARCH_INDEX_INVALIDATED, {
+      userId: user.id,
+    });
+
+    return user;
   }
 
   private async resolveUsername(

src/common/cache/cache-keys.ts

@@ -0,0 +1,61 @@
+const EMPTY_VALUE_TOKEN = '_';
+
+export const CACHE_NAMESPACE = {
+  FRIENDS_LIST: 'friends-list',
+  DOLLS_LIST: 'dolls-list',
+  USERS_SEARCH: 'users-search',
+} as const;
+
+function normalizeKeyPart(value: string | undefined): string {
+  if (!value) {
+    return EMPTY_VALUE_TOKEN;
+  }
+
+  return encodeURIComponent(value);
+}
+
+export const CACHE_TTL_SECONDS = {
+  FRIENDS_LIST: 30,
+  DOLLS_LIST: 30,
+  USERS_SEARCH: 20,
+} as const;
+
+export function friendsListCacheKey(userId: string): string {
+  return normalizeKeyPart(userId);
+}
+
+export function friendsListOwnerTag(userId: string): string {
+  return `owner:${normalizeKeyPart(userId)}`;
+}
+
+export function friendsListDependsOnUserTag(userId: string): string {
+  return `depends-on:${normalizeKeyPart(userId)}`;
+}
+
+export function dollsListCacheKey(
+  ownerId: string,
+  requesterId: string,
+): string {
+  return `${normalizeKeyPart(ownerId)}:${normalizeKeyPart(requesterId)}`;
+}
+
+export function dollsListOwnerTag(ownerId: string): string {
+  return `owner:${normalizeKeyPart(ownerId)}`;
+}
+
+export function dollsListViewerTag(viewerId: string): string {
+  return `viewer:${normalizeKeyPart(viewerId)}`;
+}
+
+export function usersSearchCacheKey(
+  username: string | undefined,
+  excludeUserId: string | undefined,
+): string {
+  return `${normalizeKeyPart(username?.trim().toLowerCase())}:${normalizeKeyPart(excludeUserId)}`;
+}
+
+export const USERS_SEARCH_GLOBAL_TAG = 'global';
+
+export function usersSearchUserTag(userId: string): string {
+  return `user:${normalizeKeyPart(userId)}`;
+}

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

@@ -0,0 +1,66 @@
+import { Injectable } from '@nestjs/common';
+import { CacheService } from './cache.service';
+
+const CACHE_TAG_SET_TTL_SECONDS = 86_400;
+
+@Injectable()
+export class CacheTagsService {
+  constructor(private readonly cacheService: CacheService) {}
+
+  async rememberKeyForTag(
+    namespace: string,
+    tag: string,
+    cacheKey: string,
+  ): Promise<void> {
+    const redisClient = this.cacheService.getRedisClient();
+    if (!redisClient) {
+      return;
+    }
+
+    const tagSetKey = this.getTagSetKey(namespace, tag);
+    const keyWithNamespace = this.cacheService.getNamespacedKey(
+      namespace,
+      cacheKey,
+    );
+
+    try {
+      await Promise.all([
+        redisClient.sadd(tagSetKey, keyWithNamespace),
+        redisClient.expire(tagSetKey, CACHE_TAG_SET_TTL_SECONDS),
+      ]);
+    } catch (error) {
+      this.cacheService.recordError('tag remember', tagSetKey, error);
+    }
+  }
+
+  async invalidateTag(namespace: string, tag: string): Promise<void> {
+    const redisClient = this.cacheService.getRedisClient();
+    if (!redisClient) {
+      return;
+    }
+
+    const tagSetKey = this.getTagSetKey(namespace, tag);
+
+    try {
+      const keys = await redisClient.smembers(tagSetKey);
+      if (keys.length === 0) {
+        await redisClient.del(tagSetKey);
+        return;
+      }
+
+      const pipeline = redisClient.pipeline();
+      keys.forEach((key) => pipeline.del(key));
+      pipeline.del(tagSetKey);
+      await pipeline.exec();
+    } catch (error) {
+      this.cacheService.recordError('tag invalidate', tagSetKey, error);
+    }
+  }
+
+  private getTagSetKey(namespace: string, tag: string): string {
+    return this.cacheService.getNamespacedKey(
+      'cache-tag',
+      `${namespace}:${tag}`,
+    );
+  }
+}

src/common/cache/cache.module.ts

@@ -1,12 +1,13 @@
 import { Global, Module } from '@nestjs/common';
 import { RedisModule } from '../../database/redis.module';
+import { CacheTagsService } from './cache-tags.service';
 import { CacheService } from './cache.service';
 import { RedisThrottlerStorage } from './redis-throttler.storage';
 
 @Global()
 @Module({
   imports: [RedisModule],
-  providers: [CacheService, RedisThrottlerStorage],
-  exports: [CacheService, RedisThrottlerStorage],
+  providers: [CacheService, CacheTagsService, RedisThrottlerStorage],
+  exports: [CacheService, CacheTagsService, RedisThrottlerStorage],
 })
 export class CacheModule {}

src/dolls/dolls-cache-invalidation.service.ts

@@ -0,0 +1,37 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import { CACHE_NAMESPACE, dollsListOwnerTag } from '../common/cache/cache-keys';
+import { DollEvents } from './events/doll.events';
+import {
+  type DollCreatedEvent,
+  type DollDeletedEvent,
+  type DollUpdatedEvent,
+} from './events/doll.events';
+
+@Injectable()
+export class DollsCacheInvalidationService {
+  constructor(private readonly cacheTagsService: CacheTagsService) {}
+
+  @OnEvent(DollEvents.DOLL_CREATED)
+  async handleDollCreated(payload: DollCreatedEvent): Promise<void> {
+    await this.invalidateOwnerLists(payload.userId);
+  }
+
+  @OnEvent(DollEvents.DOLL_UPDATED)
+  async handleDollUpdated(payload: DollUpdatedEvent): Promise<void> {
+    await this.invalidateOwnerLists(payload.userId);
+  }
+
+  @OnEvent(DollEvents.DOLL_DELETED)
+  async handleDollDeleted(payload: DollDeletedEvent): Promise<void> {
+    await this.invalidateOwnerLists(payload.userId);
+  }
+
+  private async invalidateOwnerLists(ownerId: string): Promise<void> {
+    await this.cacheTagsService.invalidateTag(
+      CACHE_NAMESPACE.DOLLS_LIST,
+      dollsListOwnerTag(ownerId),
+    );
+  }
+}

src/dolls/dolls.module.ts

@@ -1,6 +1,7 @@
 import { Module, forwardRef } from '@nestjs/common';
 import { DollsService } from './dolls.service';
 import { DollsController } from './dolls.controller';
+import { DollsCacheInvalidationService } from './dolls-cache-invalidation.service';
 import { DollsNotificationService } from './dolls-notification.service';
 import { DatabaseModule } from '../database/database.module';
 import { AuthModule } from '../auth/auth.module';
@@ -9,7 +10,11 @@ import { WsModule } from '../ws/ws.module';
 @Module({
   imports: [DatabaseModule, AuthModule, forwardRef(() => WsModule)],
   controllers: [DollsController],
-  providers: [DollsService, DollsNotificationService],
+  providers: [
+    DollsService,
+    DollsNotificationService,
+    DollsCacheInvalidationService,
+  ],
   exports: [DollsService],
 })
 export class DollsModule {}

src/dolls/dolls.service.ts

@@ -15,6 +15,15 @@ import {
   DollUpdatedEvent,
   DollDeletedEvent,
 } from './events/doll.events';
+import { CacheService } from '../common/cache/cache.service';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import {
+  CACHE_NAMESPACE,
+  CACHE_TTL_SECONDS,
+  dollsListCacheKey,
+  dollsListOwnerTag,
+  dollsListViewerTag,
+} from '../common/cache/cache-keys';
 
 @Injectable()
 export class DollsService {
@@ -23,6 +32,8 @@ export class DollsService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly eventEmitter: EventEmitter2,
+    private readonly cacheService: CacheService,
+    private readonly cacheTagsService: CacheTagsService,
   ) {}
 
   async getFriendIds(userId: string): Promise<string[]> {
@@ -76,6 +87,48 @@ export class DollsService {
   async listByOwner(
     ownerId: string,
     requestingUserId: string,
+  ): Promise<Doll[]> {
+    const cacheKey = dollsListCacheKey(ownerId, requestingUserId);
+    const namespacedKey = this.cacheService.getNamespacedKey(
+      CACHE_NAMESPACE.DOLLS_LIST,
+      cacheKey,
+    );
+    const cached = await this.cacheService.get(namespacedKey);
+
+    if (cached) {
+      try {
+        return JSON.parse(cached) as Doll[];
+      } catch (error) {
+        this.cacheService.recordError('dolls list parse', namespacedKey, error);
+      }
+    }
+
+    const dolls = await this.listByOwnerFromDatabase(ownerId, requestingUserId);
+
+    await this.cacheService.set(
+      namespacedKey,
+      JSON.stringify(dolls),
+      CACHE_TTL_SECONDS.DOLLS_LIST,
+    );
+    await Promise.all([
+      this.cacheTagsService.rememberKeyForTag(
+        CACHE_NAMESPACE.DOLLS_LIST,
+        dollsListOwnerTag(ownerId),
+        cacheKey,
+      ),
+      this.cacheTagsService.rememberKeyForTag(
+        CACHE_NAMESPACE.DOLLS_LIST,
+        dollsListViewerTag(requestingUserId),
+        cacheKey,
+      ),
+    ]);
+
+    return dolls;
+  }
+
+  private async listByOwnerFromDatabase(
+    ownerId: string,
+    requestingUserId: string,
   ): Promise<Doll[]> {
     // If requesting own dolls, no need to check friendship
     if (ownerId === requestingUserId) {

src/friends/friends-cache-invalidation.service.ts

@@ -0,0 +1,65 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import {
+  CACHE_NAMESPACE,
+  dollsListViewerTag,
+  friendsListDependsOnUserTag,
+  friendsListOwnerTag,
+} from '../common/cache/cache-keys';
+import { FriendEvents } from './events/friend.events';
+import type {
+  FriendRequestAcceptedEvent,
+  UnfriendedEvent,
+} from './events/friend.events';
+
+@Injectable()
+export class FriendsCacheInvalidationService {
+  constructor(private readonly cacheTagsService: CacheTagsService) {}
+
+  @OnEvent(FriendEvents.REQUEST_ACCEPTED)
+  async handleFriendAccepted(
+    payload: FriendRequestAcceptedEvent,
+  ): Promise<void> {
+    const senderId = payload.friendRequest.senderId;
+    const receiverId = payload.friendRequest.receiverId;
+    await this.invalidateFriendAndDollViews(senderId, receiverId);
+  }
+
+  @OnEvent(FriendEvents.UNFRIENDED)
+  async handleUnfriended(payload: UnfriendedEvent): Promise<void> {
+    await this.invalidateFriendAndDollViews(payload.userId, payload.friendId);
+  }
+
+  private async invalidateFriendAndDollViews(
+    firstUserId: string,
+    secondUserId: string,
+  ): Promise<void> {
+    await Promise.all([
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.FRIENDS_LIST,
+        friendsListOwnerTag(firstUserId),
+      ),
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.FRIENDS_LIST,
+        friendsListOwnerTag(secondUserId),
+      ),
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.FRIENDS_LIST,
+        friendsListDependsOnUserTag(firstUserId),
+      ),
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.FRIENDS_LIST,
+        friendsListDependsOnUserTag(secondUserId),
+      ),
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.DOLLS_LIST,
+        dollsListViewerTag(firstUserId),
+      ),
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.DOLLS_LIST,
+        dollsListViewerTag(secondUserId),
+      ),
+    ]);
+  }
+}

src/friends/friends.module.ts

@@ -1,5 +1,6 @@
 import { Module, forwardRef } from '@nestjs/common';
 import { FriendsController } from './friends.controller';
+import { FriendsCacheInvalidationService } from './friends-cache-invalidation.service';
 import { FriendsService } from './friends.service';
 import { FriendsNotificationService } from './friends-notification.service';
 import { DatabaseModule } from '../database/database.module';
@@ -15,7 +16,11 @@ import { WsModule } from '../ws/ws.module';
     forwardRef(() => WsModule),
   ],
   controllers: [FriendsController],
-  providers: [FriendsService, FriendsNotificationService],
+  providers: [
+    FriendsService,
+    FriendsNotificationService,
+    FriendsCacheInvalidationService,
+  ],
   exports: [FriendsService],
 })
 export class FriendsModule {}

src/friends/friends.service.ts

@@ -15,6 +15,15 @@ import {
   FriendRequestDeniedEvent,
   UnfriendedEvent,
 } from './events/friend.events';
+import { CacheService } from '../common/cache/cache.service';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import {
+  CACHE_NAMESPACE,
+  CACHE_TTL_SECONDS,
+  friendsListCacheKey,
+  friendsListDependsOnUserTag,
+  friendsListOwnerTag,
+} from '../common/cache/cache-keys';
 
 export type FriendRequestWithRelations = FriendRequest & {
   sender: User;
@@ -28,6 +37,8 @@ export class FriendsService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly eventEmitter: EventEmitter2,
+    private readonly cacheService: CacheService,
+    private readonly cacheTagsService: CacheTagsService,
   ) {}
 
   async sendFriendRequest(
@@ -272,7 +283,28 @@ export class FriendsService {
   }
 
   async getFriends(userId: string) {
-    return this.prisma.friendship.findMany({
+    const cacheKey = friendsListCacheKey(userId);
+    const namespacedKey = this.cacheService.getNamespacedKey(
+      CACHE_NAMESPACE.FRIENDS_LIST,
+      cacheKey,
+    );
+    const cached = await this.cacheService.get(namespacedKey);
+
+    if (cached) {
+      try {
+        return JSON.parse(cached) as Awaited<
+          ReturnType<PrismaService['friendship']['findMany']>
+        >;
+      } catch (error) {
+        this.cacheService.recordError(
+          'friends list parse',
+          namespacedKey,
+          error,
+        );
+      }
+    }
+
+    const friendships = await this.prisma.friendship.findMany({
       where: { userId },
       include: {
         friend: {
@@ -285,6 +317,29 @@ export class FriendsService {
         createdAt: 'desc',
       },
     });
+
+    await this.cacheService.set(
+      namespacedKey,
+      JSON.stringify(friendships),
+      CACHE_TTL_SECONDS.FRIENDS_LIST,
+    );
+
+    const dependentFriendTags = friendships.map((friendship) =>
+      friendsListDependsOnUserTag(friendship.friendId),
+    );
+    const tags = [friendsListOwnerTag(userId), ...dependentFriendTags];
+
+    await Promise.all(
+      tags.map((tag) =>
+        this.cacheTagsService.rememberKeyForTag(
+          CACHE_NAMESPACE.FRIENDS_LIST,
+          tag,
+          cacheKey,
+        ),
+      ),
+    );
+
+    return friendships;
   }
 
   async unfriend(userId: string, friendId: string): Promise<void> {

src/users/events/user.events.ts

@@ -2,6 +2,7 @@ import { Doll } from '@prisma/client';
 
 export const UserEvents = {
   ACTIVE_DOLL_CHANGED: 'user.active-doll.changed',
+  SEARCH_INDEX_INVALIDATED: 'user.search-index.invalidated',
 } as const;
 
 export interface UserActiveDollChangedEvent {
@@ -9,3 +10,7 @@ export interface UserActiveDollChangedEvent {
   dollId: string | null;
   doll: Doll | null;
 }
+
+export interface UserSearchIndexInvalidatedEvent {
+  userId?: string;
+}

src/users/users-cache-invalidation.service.ts

@@ -0,0 +1,38 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import {
+  CACHE_NAMESPACE,
+  USERS_SEARCH_GLOBAL_TAG,
+  usersSearchUserTag,
+} from '../common/cache/cache-keys';
+import { UserEvents } from './events/user.events';
+import type { UserSearchIndexInvalidatedEvent } from './events/user.events';
+
+@Injectable()
+export class UsersCacheInvalidationService {
+  constructor(private readonly cacheTagsService: CacheTagsService) {}
+
+  @OnEvent(UserEvents.SEARCH_INDEX_INVALIDATED)
+  async handleSearchIndexInvalidation(
+    payload: UserSearchIndexInvalidatedEvent,
+  ): Promise<void> {
+    const tasks: Promise<void>[] = [
+      this.cacheTagsService.invalidateTag(
+        CACHE_NAMESPACE.USERS_SEARCH,
+        USERS_SEARCH_GLOBAL_TAG,
+      ),
+    ];
+
+    if (payload.userId) {
+      tasks.push(
+        this.cacheTagsService.invalidateTag(
+          CACHE_NAMESPACE.USERS_SEARCH,
+          usersSearchUserTag(payload.userId),
+        ),
+      );
+    }
+
+    await Promise.all(tasks);
+  }
+}

src/users/users.module.ts

@@ -1,5 +1,6 @@
 import { Module, forwardRef } from '@nestjs/common';
 import { UsersService } from './users.service';
+import { UsersCacheInvalidationService } from './users-cache-invalidation.service';
 import { UsersController } from './users.controller';
 import { UsersNotificationService } from './users-notification.service';
 import { AuthModule } from '../auth/auth.module';
@@ -16,7 +17,11 @@ import { WsModule } from '../ws/ws.module';
  */
 @Module({
   imports: [forwardRef(() => AuthModule), forwardRef(() => WsModule)],
-  providers: [UsersService, UsersNotificationService],
+  providers: [
+    UsersService,
+    UsersNotificationService,
+    UsersCacheInvalidationService,
+  ],
   controllers: [UsersController],
   exports: [UsersService],
 })

src/users/users.service.ts

@@ -10,6 +10,15 @@ import { User, Prisma } from '@prisma/client';
 import type { UpdateUserDto } from './dto/update-user.dto';
 import { UserEvents } from './events/user.events';
 import { normalizeEmail } from '../auth/auth.utils';
+import { CacheService } from '../common/cache/cache.service';
+import { CacheTagsService } from '../common/cache/cache-tags.service';
+import {
+  CACHE_NAMESPACE,
+  CACHE_TTL_SECONDS,
+  usersSearchUserTag,
+  usersSearchCacheKey,
+  USERS_SEARCH_GLOBAL_TAG,
+} from '../common/cache/cache-keys';
 
 export interface CreateLocalUserDto {
   email: string;
@@ -30,6 +39,8 @@ export class UsersService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly eventEmitter: EventEmitter2,
+    private readonly cacheService: CacheService,
+    private readonly cacheTagsService: CacheTagsService,
   ) {}
 
   // Legacy Keycloak user creation removed in favor of local auth.
@@ -92,6 +103,8 @@ export class UsersService {
       data: updateData,
     });
 
+    this.eventEmitter.emit(UserEvents.SEARCH_INDEX_INVALIDATED, { userId: id });
+
     this.logger.log(`User ${id} profile update requested`);
 
     return updatedUser;
@@ -121,6 +134,8 @@ export class UsersService {
       where: { id },
     });
 
+    this.eventEmitter.emit(UserEvents.SEARCH_INDEX_INVALIDATED, { userId: id });
+
     this.logger.log(`User ${id} deleted their account`);
   }
 
@@ -128,6 +143,25 @@ export class UsersService {
     username?: string,
     excludeUserId?: string,
   ): Promise<User[]> {
+    const cacheKey = usersSearchCacheKey(username, excludeUserId);
+    const namespacedKey = this.cacheService.getNamespacedKey(
+      CACHE_NAMESPACE.USERS_SEARCH,
+      cacheKey,
+    );
+    const cached = await this.cacheService.get(namespacedKey);
+
+    if (cached) {
+      try {
+        return JSON.parse(cached) as User[];
+      } catch (error) {
+        this.cacheService.recordError(
+          'users search parse',
+          namespacedKey,
+          error,
+        );
+      }
+    }
+
     const where: Prisma.UserWhereInput = {};
 
     if (username) {
@@ -151,6 +185,24 @@ export class UsersService {
       },
     });
 
+    await this.cacheService.set(
+      namespacedKey,
+      JSON.stringify(users),
+      CACHE_TTL_SECONDS.USERS_SEARCH,
+    );
+    await this.cacheTagsService.rememberKeyForTag(
+      CACHE_NAMESPACE.USERS_SEARCH,
+      USERS_SEARCH_GLOBAL_TAG,
+      cacheKey,
+    );
+    if (excludeUserId) {
+      await this.cacheTagsService.rememberKeyForTag(
+        CACHE_NAMESPACE.USERS_SEARCH,
+        usersSearchUserTag(excludeUserId),
+        cacheKey,
+      );
+    }
+
     return users;
   }
 
@@ -251,7 +303,7 @@ export class UsersService {
     const now = new Date();
     const roles: string[] = [];
 
-    return this.prisma.user.create({
+    const user = await this.prisma.user.create({
       data: {
         email: normalizeEmail(createDto.email),
         name: createDto.name,
@@ -262,6 +314,12 @@ export class UsersService {
         keycloakSub: null,
       } as unknown as Prisma.UserUncheckedCreateInput,
     });
+
+    this.eventEmitter.emit(UserEvents.SEARCH_INDEX_INVALIDATED, {
+      userId: user.id,
+    });
+
+    return user;
   }
 
   async updatePasswordHash(