feat(builtins): search with background refresh

.env.sample

@@ -102,6 +102,11 @@ BUILTIN_GET_TORRENT_TIMEOUT=5000
 # How many of the get torrent tasks should be running at the same time
 # Higher values will increase search times but use more system resources.
 BUILTIN_GET_TORRENT_CONCURRENCY=100
+# The minimum interval between background refreshes for built-in addon search caches. Triggered during normal searches.
+# e.g. Searches remain cached for the addon-specific TTLs but once this interval has passed, a background refresh can be triggered to ensure fresh results 
+# without making the user wait.
+# Default: 1 day
+BUILTIN_MINIMUM_BACKGROUND_REFRESH_INTERVAL=86400
 
 
 # ---- Bitmagnet ----

packages/core/src/builtins/base/nab/api.ts

@@ -10,6 +10,7 @@ import {
 } from '../../../utils/index.js';
 import { Parser } from 'xml2js';
 import { Logger } from 'winston';
+import { searchWithBackgroundRefresh } from '../../utils/general.js';
 
 // --- Generic Custom Error ---
 export class NabApiError extends Error {
@@ -333,12 +334,21 @@ export class BaseNabApi<N extends 'torznab' | 'newznab'> {
     params: Record<string, string | number | boolean> = {}
   ): Promise<SearchResponse<N>> {
     const cacheKey = `${this.baseUrl}${this.apiPath}?t=${searchFunction}&${JSON.stringify(params)}&apikey=${this.apiKey}`;
-    const result = await this.searchCache.wrap(
+
-      () => this.request(searchFunction, this.SearchResultSchema, params),
+    return searchWithBackgroundRefresh({
-      cacheKey,
+      searchCache: this.searchCache as Cache<string, SearchResponse<N>>,
-      Env.BUILTIN_NAB_SEARCH_CACHE_TTL
+      searchCacheKey: cacheKey,
-    );
+      bgCacheKey: `nab:${cacheKey}`,
-    return result as SearchResponse<N>;
+      cacheTTL: Env.BUILTIN_NAB_SEARCH_CACHE_TTL,
+      fetchFn: () =>
+        this.request(
+          searchFunction,
+          this.SearchResultSchema,
+          params
+        ) as Promise<SearchResponse<N>>,
+      isEmptyResult: (result) => result.results.length === 0,
+      logger: this.logger,
+    });
   }
 
   private removeTrailingSlash = (path: string) =>

packages/core/src/builtins/knaben/api.ts

@@ -2,6 +2,7 @@ import { Cache } from '../../utils/cache.js';
 import { Env } from '../../utils/env.js';
 import { formatZodError, makeRequest } from '../../utils/index.js';
 import { createLogger } from '../../utils/index.js';
+import { searchWithBackgroundRefresh } from '../utils/general.js';
 
 import { z } from 'zod';
 
@@ -102,9 +103,10 @@ const API_VERSION = '1';
 class KnabenAPI {
   private headers: Record<string, string>;
 
-  private readonly searchCache = Cache.getInstance<string, any>(
+  private readonly searchCache = Cache.getInstance<
-    'knaben:search'
+    string,
-  );
+    KnabenSearchResponse
+  >('knaben:search');
 
   constructor() {
     this.headers = {
@@ -117,18 +119,23 @@ class KnabenAPI {
 
   async search(options: KnabenSearchOptions): Promise<KnabenSearchResponse> {
     const body = KnabenSearchOptionsRequest.parse(options);
+    const cacheKey = JSON.stringify(options);
 
-    return this.searchCache.wrap(
+    return searchWithBackgroundRefresh({
-      () =>
+      searchCache: this.searchCache,
+      searchCacheKey: cacheKey,
+      bgCacheKey: `knaben:${cacheKey}`,
+      cacheTTL: Env.BUILTIN_KNABEN_SEARCH_CACHE_TTL,
+      fetchFn: () =>
         this.request<KnabenSearchResponse>('', {
           schema: KnabenSearchResponse,
           method: 'POST',
           timeout: Env.BUILTIN_KNABEN_SEARCH_TIMEOUT,
           body,
         }),
-      `knaben:search:${JSON.stringify(options)}`,
+      isEmptyResult: (result) => result.hits.length === 0,
-      Env.BUILTIN_KNABEN_SEARCH_CACHE_TTL
+      logger,
-    );
+    });
   }
 
   private async request<T>(

packages/core/src/builtins/prowlarr/api.ts

@@ -1,12 +1,14 @@
 import { fetch } from 'undici';
 import {
   Cache,
+  createLogger,
   DistributedLock,
   Env,
   formatZodError,
   makeRequest,
 } from '../../utils/index.js';
 import z from 'zod';
+import { searchWithBackgroundRefresh } from '../utils/general.js';
 
 interface ResponseMeta {
   headers: Record<string, string>;
@@ -80,6 +82,8 @@ const ProwlarrApiSearchItemSchema = z.object({
 
 const ProwlarrApiSearchSchema = z.array(ProwlarrApiSearchItemSchema);
 
+const logger = createLogger('prowlarr');
+
 export type ProwlarrApiSearchItem = z.infer<typeof ProwlarrApiSearchItemSchema>;
 
 class ProwlarrApi {
@@ -90,7 +94,7 @@ class ProwlarrApi {
 
   private readonly searchCache = Cache.getInstance<
     string,
-    ProwlarrApiSearchItem[]
+    ProwlarrApiResponse<ProwlarrApiSearchItem[]>
   >('prowlarr-api:search');
 
   private readonly indexersCache = Cache.getInstance<
@@ -156,8 +160,14 @@ class ProwlarrApi {
     limit?: number;
     offset?: number;
   }): Promise<ProwlarrApiResponse<ProwlarrApiSearchItem[]>> {
-    return this.searchCache.wrap(
+    const cacheKey = `${this.baseUrl}:${type}:${query}:${indexerIds.join(',')}:${limit}:${offset}`;
-      () =>
+
+    return searchWithBackgroundRefresh({
+      searchCache: this.searchCache,
+      searchCacheKey: cacheKey,
+      bgCacheKey: `prowlarr:${cacheKey}`,
+      cacheTTL: Env.BUILTIN_PROWLARR_SEARCH_CACHE_TTL,
+      fetchFn: () =>
         this.request<ProwlarrApiSearchItem[]>(
           'search',
           {
@@ -169,9 +179,9 @@ class ProwlarrApi {
           },
           ProwlarrApiSearchSchema
         ),
-      `${this.baseUrl}:${type}:${query}:${indexerIds.join(',')}:${limit}:${offset}`,
+      isEmptyResult: (result) => result.data.length === 0,
-      Env.BUILTIN_PROWLARR_SEARCH_CACHE_TTL
+      logger,
-    );
+    });
   }
 
   private getPath(endpoint: string) {

packages/core/src/builtins/torrent-galaxy/api.ts

@@ -2,6 +2,7 @@ import { Cache } from '../../utils/cache.js';
 import { Env } from '../../utils/env.js';
 import { formatZodError, makeRequest } from '../../utils/index.js';
 import { createLogger } from '../../utils/index.js';
+import { searchWithBackgroundRefresh } from '../utils/general.js';
 
 import { z } from 'zod';
 
@@ -75,9 +76,10 @@ const API_BASE_URL = Env.BUILTIN_TORRENT_GALAXY_URL;
 class TorrentGalaxyAPI {
   private headers: Record<string, string>;
 
-  private readonly searchCache = Cache.getInstance<string, any>(
+  private readonly searchCache = Cache.getInstance<
-    'torrent-galaxy:search'
+    string,
-  );
+    TorrentGalaxySearchResponse
+  >('torrent-galaxy:search');
 
   constructor() {
     this.headers = {
@@ -95,8 +97,13 @@ class TorrentGalaxyAPI {
     if (options.page) {
       queryParams.set('page', options.page.toString());
     }
-    return this.searchCache.wrap(
+    const cacheKey = JSON.stringify(options);
-      () =>
+    return searchWithBackgroundRefresh({
+      searchCache: this.searchCache,
+      searchCacheKey: cacheKey,
+      bgCacheKey: `tgx:${cacheKey}`,
+      cacheTTL: Env.BUILTIN_TORRENT_GALAXY_SEARCH_CACHE_TTL,
+      fetchFn: () =>
         this.request<TorrentGalaxySearchResponse>(
           `/get-posts/keywords:${encodeURIComponent(options.query)}:format:json`,
           {
@@ -105,9 +112,9 @@ class TorrentGalaxyAPI {
             queryParams,
           }
         ),
-      `${JSON.stringify(options)}`,
+      isEmptyResult: (result) => result.results.length === 0,
-      Env.BUILTIN_TORRENT_GALAXY_SEARCH_CACHE_TTL
+      logger,
-    );
+    });
   }
 
   private async request<T>(

packages/core/src/builtins/utils/general.ts

@@ -1,4 +1,7 @@
+import { Logger } from 'winston';
+import { Cache } from '../../utils/cache.js';
 import { Env } from '../../utils/env.js';
+import { createLogger } from '../../utils/index.js';
 import pLimit from 'p-limit';
 
 export const createQueryLimit = () =>
@@ -37,3 +40,134 @@ export function useAllTitles(url: string): boolean {
   }
   return !!Env.BUILTIN_SCRAPE_WITH_ALL_TITLES;
 }
+
+export const bgRefreshCache = Cache.getInstance<string, number>(
+  'builtins:bg-refresh'
+);
+
+/**
+ * Options for the searchWithBackgroundRefresh function
+ */
+interface SearchWithBgRefreshOptions<T> {
+  searchCache: Cache<string, T>;
+  searchCacheKey: string;
+  bgCacheKey: string;
+  cacheTTL: number;
+  fetchFn: () => Promise<T>;
+  isEmptyResult: (result: T) => boolean;
+  logger: Logger;
+}
+
+/**
+ * Performs a cached search with background refresh support.
+ *
+ * When a cached result exists:
+ * - Returns the cached result immediately
+ * - Schedules a background refresh if the minimum interval has passed
+ *
+ * When no cached result exists:
+ * - Performs the search synchronously
+ * - Caches the result (unless empty)
+ * - Records the refresh timestamp
+ *
+ * @param options - Configuration options for the search
+ * @returns The search result (cached or fresh)
+ */
+export async function searchWithBackgroundRefresh<T>(
+  options: SearchWithBgRefreshOptions<T>
+): Promise<T> {
+  const {
+    searchCacheKey,
+    bgCacheKey,
+    searchCache,
+    cacheTTL,
+    fetchFn,
+    isEmptyResult,
+    logger,
+  } = options;
+
+  const cachedResult = await searchCache.get(searchCacheKey);
+
+  if (cachedResult !== undefined) {
+    triggerBackgroundRefresh({
+      searchCache,
+      searchCacheKey,
+      bgCacheKey,
+      cacheTTL,
+      fetchFn,
+      isEmptyResult,
+      logger,
+    });
+    return cachedResult;
+  }
+
+  const result = await fetchFn();
+
+  // Don't cache empty results
+  if (!isEmptyResult(result)) {
+    await searchCache.set(searchCacheKey, result, cacheTTL);
+    await bgRefreshCache.set(
+      bgCacheKey,
+      Date.now(),
+      Env.BUILTIN_MINIMUM_BACKGROUND_REFRESH_INTERVAL
+    );
+  }
+
+  return result;
+}
+
+/**
+ * Triggers a background refresh if the minimum interval has passed.
+ * This function is fire-and-forget and does not block.
+ */
+function triggerBackgroundRefresh<T>(options: {
+  searchCache: Cache<string, T>;
+  searchCacheKey: string;
+  bgCacheKey: string;
+  cacheTTL: number;
+  fetchFn: () => Promise<T>;
+  isEmptyResult: (result: T) => boolean;
+  logger: Logger;
+}): void {
+  const {
+    searchCacheKey,
+    bgCacheKey,
+    searchCache,
+    cacheTTL,
+    fetchFn,
+    isEmptyResult,
+    logger,
+  } = options;
+
+  (async () => {
+    try {
+      const lastRefresh = await bgRefreshCache.get(bgCacheKey);
+      const now = Date.now();
+      const intervalMs = Env.BUILTIN_MINIMUM_BACKGROUND_REFRESH_INTERVAL * 1000;
+
+      if (lastRefresh && now - lastRefresh < intervalMs) {
+        // Not enough time has passed since last refresh
+        return;
+      }
+
+      // Perform background refresh
+      logger.debug(`Starting background refresh for: ${searchCacheKey}`);
+      const freshResult = await fetchFn();
+
+      // Update cache if result is not empty
+      if (!isEmptyResult(freshResult)) {
+        await searchCache.set(searchCacheKey, freshResult, cacheTTL, true);
+        await bgRefreshCache.set(
+          bgCacheKey,
+          now,
+          Env.BUILTIN_MINIMUM_BACKGROUND_REFRESH_INTERVAL
+        );
+        logger.info(`Background refreshed cache for: ${searchCacheKey}`);
+      }
+    } catch (error) {
+      logger.error(
+        `Background refresh failed for: ${searchCacheKey} - ${error instanceof Error ? error.message : 'Unknown error'}`
+      );
+    }
+  })();
+}

packages/core/src/utils/env.ts

@@ -1696,6 +1696,10 @@ export const Env = cleanEnv(process.env, {
     default: 7 * 24 * 60 * 60, // 7 days
     desc: 'Builtin Torrent metadata cache TTL',
   }),
+  BUILTIN_MINIMUM_BACKGROUND_REFRESH_INTERVAL: num({
+    default: 1 * 24 * 60 * 60, // 1 day
+    desc: 'Minimum interval between background refreshes for built-in addon search caches. Triggered during normal searches.',
+  }),
 
   BUILTIN_GDRIVE_CLIENT_ID: str({
     default: undefined,

packages/core/src/utils/torrent.ts

@@ -23,7 +23,9 @@ interface TorrentMetadata {
 
 export class TorrentClient {
   static readonly #metadataCache = Cache.getInstance<string, TorrentMetadata>(
-    'torrent-metadata'
+    'torrent-metadata',
+    undefined,
+    Env.REDIS_URI ? 'redis' : 'sql'
   );
 
   // Track in-progress fetches to avoid duplicate requests