Cache requests for top streams

package.json

@@ -30,6 +30,7 @@
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.0",
     "lodash": "^4.17.21",
+    "node-cache": "^5.1.2",
     "reflect-metadata": "^0.1.13",
     "rimraf": "^3.0.2",
     "rxjs": "^7.2.0"

src/stream-mappings/stream-mappings.e2e.spec.ts

@@ -1,7 +1,7 @@
 import { INestApplication, ValidationPipe } from '@nestjs/common';
 import { ConfigModule } from '@nestjs/config';
 import { Test } from '@nestjs/testing';
-import * as request from 'supertest';
+import request from 'supertest';
 import { StreamMappingBuilder, SupabaseMock } from 'test/supabase-mock';
 
 import { TestFixture } from 'test/test-fixture';

src/stream-mappings/stream-mappings.service.ts

@@ -1,6 +1,7 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { SupabaseClient } from '@supabase/supabase-js';
 import { groupBy, sortBy } from 'lodash';
+import NodeCache from 'node-cache';
 import { CreateStreamMappingDto } from './dto/create-stream-mapping.dto';
 import { DeleteStreamMappingDto } from './dto/delete-stream-maping.dto';
 
@@ -24,12 +25,15 @@ export type StreamIdWithScore = {
 @Injectable()
 export class StreamMappingsService {
   private client: SupabaseClient;
+  private cache: NodeCache;
 
   constructor() {
     this.client = new SupabaseClient(
       process.env.SUPABASE_URL ?? '',
       process.env.SUPABASE_KEY ?? '',
     );
+
+    this.cache = new NodeCache({ stdTTL: 60, checkperiod: 60 });
   }
 
   private async findAllByArtistTitleAndSource(
@@ -82,6 +86,13 @@ export class StreamMappingsService {
     source: 'Youtube',
     author_id?: string,
   ): Promise<StreamIdWithScore | null> {
+    const cacheKey = `${artist}:${title}:${source}:`;
+    const cachedStream: StreamIdWithScore | undefined =
+      this.cache.get(cacheKey);
+    if (cachedStream) {
+      return cachedStream;
+    }
+
     const streamMappings = await this.findAllByArtistTitleAndSource(
       artist,
       title,
@@ -105,17 +116,21 @@ export class StreamMappingsService {
       (streamMapping) => streamMapping.author_id === author_id,
     );
 
+    let topStream: StreamIdWithScore;
     if (verifiedByCurrentUser) {
-      return {
+      topStream = {
         ...(streamIdsWithScores.find(
           (streamIdWithScore) =>
             streamIdWithScore.stream_id === verifiedByCurrentUser.stream_id,
         ) as StreamIdWithScore),
         self_verified: true,
       };
     } else {
-      return sortBy(streamIdsWithScores, 'score').reverse()[0];
+      topStream = sortBy(streamIdsWithScores, 'score').reverse()[0];
     }
+
+    this.cache.set(cacheKey, topStream);
+    return topStream;
   }
 
   async verifyTrack(

test/supabase-mock.ts

@@ -1,5 +1,5 @@
 import { matches } from 'lodash';
-import * as nock from 'nock';
+import nock from 'nock';
 import { CreateStreamMappingDto } from 'src/stream-mappings/dto/create-stream-mapping.dto';
 import { DeleteStreamMappingDto } from 'src/stream-mappings/dto/delete-stream-maping.dto';
 

tsconfig.json

@@ -16,6 +16,7 @@
     "noImplicitAny": false,
     "strictBindCallApply": true,
     "forceConsistentCasingInFileNames": true,
-    "noFallthroughCasesInSwitch": true
+    "noFallthroughCasesInSwitch": true,
+    "esModuleInterop": true
   }
 }