batching recommendations

packages/api/src/apollo.ts

@@ -33,6 +33,7 @@ import ScalarResolvers from './scalars'
 import typeDefs from './schema'
 import { batchGetHighlightsFromLibraryItemIds } from './services/highlights'
 import { batchGetLabelsFromLibraryItemIds } from './services/labels'
+import { batchGetRecommendationsFromLibraryItemIds } from './services/recommendation'
 import {
   countDailyServiceUsage,
   createServiceUsage,
@@ -106,6 +107,9 @@ const contextFunc: ContextFunction<ExpressContext, ResolverContext> = async ({
     dataLoaders: {
       labels: new DataLoader(batchGetLabelsFromLibraryItemIds),
       highlights: new DataLoader(batchGetHighlightsFromLibraryItemIds),
+      recommendations: new DataLoader(
+        batchGetRecommendationsFromLibraryItemIds
+      ),
     },
   }
 

packages/api/src/resolvers/function_resolvers.ts

@@ -25,7 +25,6 @@ import {
 } from '../generated/graphql'
 import { getAISummary } from '../services/ai-summaries'
 import { findUserFeatures } from '../services/features'
-import { findRecommendationsByLibraryItemId } from '../services/recommendation'
 import { findUploadFileById } from '../services/upload_file'
 import {
   highlightDataToHighlight,
@@ -536,10 +535,9 @@ export const functionResolvers = {
     ) {
       if (item.recommendations) return item.recommendations
 
-      if (item.recommenderNames && item.recommenderNames.length > 0) {
-        const recommendations = await findRecommendationsByLibraryItemId(
-          item.id,
-          ctx.uid
+      if (item.recommenderNames) {
+        const recommendations = await ctx.dataLoaders.recommendations.load(
+          item.id
         )
         return recommendations.map(recommandationDataToRecommendation)
       }

packages/api/src/resolvers/types.ts

@@ -8,6 +8,7 @@ import winston from 'winston'
 import { ReadingProgressDataSource } from '../datasources/reading_progress_data_source'
 import { Highlight } from '../entity/highlight'
 import { Label } from '../entity/label'
+import { Recommendation } from '../entity/recommendation'
 import { PubsubClient } from '../pubsub'
 
 export interface Claims {
@@ -47,6 +48,7 @@ export interface RequestContext {
   dataLoaders: {
     labels: DataLoader<string, Label[]>
     highlights: DataLoader<string, Highlight[]>
+    recommendations: DataLoader<string, Recommendation[]>
   }
 }
 

packages/api/src/services/recommendation.ts

@@ -1,5 +1,5 @@
 import { nanoid } from 'nanoid'
-import { DeepPartial } from 'typeorm'
+import { DeepPartial, In } from 'typeorm'
 import { LibraryItem } from '../entity/library_item'
 import { Recommendation } from '../entity/recommendation'
 import { authTrx } from '../repository'
@@ -12,6 +12,23 @@ import {
   updateLibraryItem,
 } from './library_item'
 
+export const batchGetRecommendationsFromLibraryItemIds = async (
+  libraryItemIds: readonly string[]
+): Promise<Recommendation[][]> => {
+  const libraryItems = await authTrx(async (tx) =>
+    tx.getRepository(LibraryItem).find({
+      where: { id: In(libraryItemIds as string[]) },
+      relations: ['recommendations'],
+    })
+  )
+
+  return libraryItemIds.map(
+    (libraryItemId) =>
+      libraryItems.find((libraryItem) => libraryItem.id === libraryItemId)
+        ?.recommendations || []
+  )
+}
+
 export const addRecommendation = async (
   item: LibraryItem,
   recommendation: Recommendation,