Preferences caching

packages/pds/src/api/app/bsky/actor/getPreferences.ts

@@ -7,6 +7,16 @@ export default function (server: Server, ctx: AppContext) {
     auth: ctx.authVerifier.accessStandard(),
     handler: async ({ auth }) => {
       const requester = auth.credentials.did
+
+      const cachedPrefs = await ctx.preferencesCache?.get(requester)
+      if (cachedPrefs) {
+        const preferences = JSON.parse(cachedPrefs)
+        return {
+          encoding: 'application/json',
+          body: { preferences },
+        }
+      }
+
       const preferences = await ctx.actorStore.read(requester, (store) =>
         store.pref.getPreferences('app.bsky', auth.credentials.scope),
       )

packages/pds/src/api/app/bsky/actor/putPreferences.ts

@@ -18,13 +18,19 @@ export default function (server: Server, ctx: AppContext) {
           throw new InvalidRequestError('Preference is missing a $type')
         }
       }
+
       await ctx.actorStore.transact(requester, async (actorTxn) => {
         await actorTxn.pref.putPreferences(
           checkedPreferences,
           'app.bsky',
           auth.credentials.scope,
         )
       })
+
+      await ctx.preferencesCache?.set(
+        requester,
+        JSON.stringify(checkedPreferences),
+      )
     },
   })
 }

packages/pds/src/caching/redis-simple-store.ts

@@ -0,0 +1,51 @@
+import { SimpleStore } from '@atproto-labs/simple-store'
+import Redis from 'ioredis'
+
+import { redisLogger } from '../logger'
+
+export class RedisSimpleStore implements SimpleStore<string, string> {
+  /**
+   * @param redis - Redis client
+   * @param maxTTL - Maximum age of a cached revision in milliseconds
+   */
+  constructor(
+    protected readonly redis: Redis,
+    protected readonly maxTTL: number,
+    protected readonly storeName: string,
+  ) {
+    // Redis expects the expiration time in milliseconds
+    if (!Number.isFinite(this.maxTTL) || this.maxTTL <= 0) {
+      throw new TypeError('maxAge must be a positive number')
+    }
+  }
+
+  protected key(did: string): string {
+    return `${this.storeName}:${did}`
+  }
+
+  async get(did: string): Promise<string | undefined> {
+    try {
+      const value = await this.redis.get(this.key(did))
+      return value || undefined
+    } catch (err) {
+      redisLogger.error({ err, did }, `error getting ${this.storeName}`)
+      return undefined
+    }
+  }
+
+  async set(did: string, value: string): Promise<void> {
+    try {
+      await this.redis.set(this.key(did), value, 'PX', this.maxTTL)
+    } catch (err) {
+      redisLogger.error({ err, did, value }, `error setting ${this.storeName}`)
+    }
+  }
+
+  async del(did: string): Promise<void> {
+    try {
+      await this.redis.del(this.key(did))
+    } catch (err) {
+      redisLogger.error({ err, did }, `error deleting ${this.storeName}`)
+    }
+  }
+}

packages/pds/src/config/config.ts

@@ -235,10 +235,10 @@ export const envToCfg = (env: ServerEnvironment): ServerConfig => {
 
   const crawlersCfg: ServerConfig['crawlers'] = env.crawlers ?? []
 
-  const repoRevCacheCfg: ServerConfig['repoRevCache'] =
-    env.repoRevCacheMaxTTL != null && env.repoRevCacheMaxTTL > 0
-      ? { maxTTL: env.repoRevCacheMaxTTL }
-      : null
+  const cachingCfg: ServerConfig['caching'] = {
+    repoRevMaxTTL: env.repoRevCacheMaxTTL,
+    preferencesMaxTTL: env.preferencesCacheMaxTTL,
+  }
 
   const fetchCfg: ServerConfig['fetch'] = {
     disableSsrfProtection: env.fetchDisableSsrfProtection ?? false,
@@ -306,7 +306,7 @@ export const envToCfg = (env: ServerEnvironment): ServerConfig => {
     redis: redisCfg,
     rateLimits: rateLimitsCfg,
     crawlers: crawlersCfg,
-    repoRevCache: repoRevCacheCfg,
+    caching: cachingCfg,
     fetch: fetchCfg,
     oauth: oauthCfg,
   }
@@ -329,7 +329,7 @@ export type ServerConfig = {
   redis: RedisScratchConfig | null
   rateLimits: RateLimitsConfig
   crawlers: string[]
-  repoRevCache: RepoRevCacheConfig | null
+  caching: CachingConfig
   fetch: FetchConfig
   oauth: OAuthConfig
 }
@@ -398,8 +398,9 @@ export type EntrywayConfig = {
   plcRotationKey: string
 }
 
-export type RepoRevCacheConfig = {
-  maxTTL: number
+export type CachingConfig = {
+  repoRevMaxTTL?: number
+  preferencesMaxTTL?: number
 }
 
 export type FetchConfig = {

packages/pds/src/config/env.ts

@@ -120,8 +120,9 @@ export const readEnv = (): ServerEnvironment => {
     // fetch
     fetchDisableSsrfProtection: envBool('PDS_DISABLE_SSRF_PROTECTION'),
 
-    // Repo revision cache
+    // caching
     repoRevCacheMaxTTL: envInt('PDS_REPO_REV_CACHE_MAX_TTL'), // milliseconds (use 0 to disable)
+    preferencesCacheMaxTTL: envInt('PDS_REPO_REV_CACHE_MAX_TTL'), // milliseconds (use 0 to disable)
   }
 }
 
@@ -239,6 +240,7 @@ export type ServerEnvironment = {
   // fetch
   fetchDisableSsrfProtection?: boolean
 
-  // Repo revision cache
+  // Caching
   repoRevCacheMaxTTL?: number
+  preferencesCacheMaxTTL?: number
 }

packages/pds/src/context.ts

@@ -40,7 +40,7 @@ import { DiskBlobStore } from './disk-blobstore'
 import { getRedisClient } from './redis'
 import { ActorStore } from './actor-store'
 import { LocalViewer, LocalViewerCreator } from './read-after-write/viewer'
-import { RepoRevCacheRedis } from './account-manager/repo-rev-cache-redis'
+import { RedisSimpleStore } from './caching/redis-simple-store'
 
 export type AppContextOptions = {
   actorStore: ActorStore
@@ -56,6 +56,7 @@ export type AppContextOptions = {
   backgroundQueue: BackgroundQueue
   redisScratch?: Redis
   repoRevCache?: SimpleStore<string, string>
+  preferencesCache?: SimpleStore<string, string>
   ratelimitCreator?: RateLimiterCreator
   crawlers: Crawlers
   appViewAgent?: AtpAgent
@@ -83,6 +84,7 @@ export class AppContext {
   public backgroundQueue: BackgroundQueue
   public redisScratch?: Redis
   public repoRevCache?: SimpleStore<string, string>
+  public preferencesCache?: SimpleStore<string, string>
   public ratelimitCreator?: RateLimiterCreator
   public crawlers: Crawlers
   public appViewAgent: AtpAgent | undefined
@@ -109,6 +111,7 @@ export class AppContext {
     this.backgroundQueue = opts.backgroundQueue
     this.redisScratch = opts.redisScratch
     this.repoRevCache = opts.repoRevCache
+    this.preferencesCache = opts.preferencesCache
     this.ratelimitCreator = opts.ratelimitCreator
     this.crawlers = opts.crawlers
     this.appViewAgent = opts.appViewAgent
@@ -231,8 +234,22 @@ export class AppContext {
       : null
 
     const repoRevCache =
-      redisScratch && cfg.repoRevCache
-        ? new RepoRevCacheRedis(redisScratch, cfg.repoRevCache.maxTTL)
+      redisScratch && cfg.caching.repoRevMaxTTL
+        ? new RedisSimpleStore(
+            redisScratch,
+            cfg.caching.repoRevMaxTTL,
+            'latestRev',
+          )
+        : // Note: Single instance PDS that have no redis could use a memory cache
+          undefined
+
+    const preferencesCache =
+      redisScratch && cfg.caching.preferencesMaxTTL
+        ? new RedisSimpleStore(
+            redisScratch,
+            cfg.caching.preferencesMaxTTL,
+            'preferences',
+          )
         : // Note: Single instance PDS that have no redis could use a memory cache
           undefined
 
@@ -340,6 +357,7 @@ export class AppContext {
       backgroundQueue,
       redisScratch,
       repoRevCache,
+      preferencesCache,
       ratelimitCreator,
       crawlers,
       appViewAgent,