fix: use hash map when excluding read items

base/options_test.go

@@ -10,7 +10,7 @@ func TestRuntimeOptions(t *testing.T) {
 	var opt1 *RuntimeOptions
 	assert.Equal(t, true, opt1.GetVerbose())
 	assert.Equal(t, 1, opt1.GetFitJobs())
-	assert.Equal(t, 1,  opt1.GetCVJobs())
+	assert.Equal(t, 1, opt1.GetCVJobs())
 	// Check options
 	opt2 := &RuntimeOptions{false, 10, 5}
 	assert.Equal(t, false, opt2.GetVerbose())

cmd/rest.go

@@ -277,16 +277,19 @@ func getRecommends(request *restful.Request, response *restful.Response) {
 	}
 	if engineConfig.Recommend.Once {
 		// Get read recommended items
-		reads, err := db.GetIdentList(engine.BucketReads, userId, 0)
+		readItems, err := db.GetIdentList(engine.BucketReads, userId, 0)
+		readSet := make(map[string]bool)
+		for _, item := range readItems {
+			readSet[item.ItemId] = true
+		}
 		var subItems []engine.RecommendedItem
 		change := false
 		notRecommended := false
 		if err != nil {
 			change = false
 		} else {
 			for i := range items {
-				exist := engine.ExistRecommendedItem(items[i].ItemId, reads)
-				if !exist {
+				if _, exist := readSet[items[i].ItemId]; !exist {
 					subItems = append(subItems, items[i])
 					change = true
 				}
@@ -301,9 +304,9 @@ func getRecommends(request *restful.Request, response *restful.Response) {
 		} else if change {
 			subItems = engine.Ranking(subItems, number, p, t, c)
 			for i := range subItems {
-				reads = append(reads, subItems[i])
+				readItems = append(readItems, subItems[i])
 			}
-			if err := db.PutIdentList(engine.BucketReads, userId, reads); err != nil {
+			if err := db.PutIdentList(engine.BucketReads, userId, readItems); err != nil {
 				badRequest(response, err)
 			}
 			// Send result
@@ -312,9 +315,9 @@ func getRecommends(request *restful.Request, response *restful.Response) {
 			// Send result
 			items = engine.Ranking(items, number, p, t, c)
 			for i := range items {
-				reads = append(reads, items[i])
+				readItems = append(readItems, items[i])
 			}
-			if err := db.PutIdentList(engine.BucketReads, userId, reads); err != nil {
+			if err := db.PutIdentList(engine.BucketReads, userId, readItems); err != nil {
 				badRequest(response, err)
 			}
 			json(response, items)

core/ranking.go

@@ -69,4 +69,4 @@ func Popularity(dataSet DataSetInterface) (itemId []string, popularity []float64
 		itemId[itemIndex] = dataSet.ItemIndexer().ToID(itemIndex)
 	}
 	return
-}
+}

core/ranking_test.go

@@ -52,4 +52,4 @@ func TestNeighbors(t *testing.T) {
 	// Find N nearest neighbors
 	neighbors, _ := Neighbors(dataSet, "1", 5, base.MSDSimilarity)
 	assert.Equal(t, []string{"2", "3", "4", "5", "6"}, neighbors)
-}
+}

engine/config_test.go

@@ -27,6 +27,7 @@ func TestLoadConfig(t *testing.T) {
 	assert.Equal(t, 10, config.Recommend.UpdateThreshold)
 	assert.Equal(t, 1, config.Recommend.CheckPeriod)
 	assert.Equal(t, 10, config.Recommend.FitJobs)
+	assert.Equal(t, true, config.Recommend.Once)
 	// params configuration
 	assert.Equal(t, 0.05, config.Params.Lr)
 	assert.Equal(t, 0.01, config.Params.Reg)
@@ -43,7 +44,6 @@ func TestLoadConfig(t *testing.T) {
 	assert.Equal(t, "pearson", config.Params.Similarity)
 	assert.Equal(t, 100, config.Params.K)
 	assert.Equal(t, 5, config.Params.MinK)
-	//assert.Equal(t, "bpr", config.Params.Optimizer)
 	assert.Equal(t, 1.0, config.Params.Alpha)
 }
 
@@ -93,6 +93,7 @@ func TestTomlConfig_FillDefault(t *testing.T) {
 	assert.Equal(t, 10, config.Recommend.UpdateThreshold)
 	assert.Equal(t, 1, config.Recommend.CheckPeriod)
 	assert.Equal(t, 1, config.Recommend.FitJobs)
+	assert.Equal(t, false, config.Recommend.Once)
 }
 
 func TestLoadSimilarity(t *testing.T) {

engine/offline.go

@@ -79,14 +79,6 @@ func UpdateNeighbors(name string, cacheSize int, dataSet core.DataSetInterface,
 	}
 	return nil
 }
-func ExistRecommendedItem(item string, reads []RecommendedItem) bool {
-	for i := range reads {
-		if reads[i].Item.ItemId == item {
-			return true
-		}
-	}
-	return false
-}
 
 // UpdateRecommends updates personalized recommendations for the database.
 func UpdateRecommends(name string, params base.Params, cacheSize int, fitJobs int, once bool, dataSet core.DataSetInterface, db *DB) error {
@@ -106,25 +98,27 @@ func UpdateRecommends(name string, params base.Params, cacheSize int, fitJobs in
 	for userIndex := 0; userIndex < dataSet.UserCount(); userIndex++ {
 		userId := dataSet.UserIndexer().ToID(userIndex)
 		exclude := dataSet.UserByIndex(userIndex)
-		// get read items
-		subItems := make(map[string]bool)
+		// exclude read items
+		candidateItems := items
 		if once {
-			reads, err := db.GetIdentList(BucketReads, userId, 0)
-			if err != nil {
-				// reads is empty
-				subItems = items
+			candidateItems = make(map[string]bool)
+			var err error
+			var readItems []RecommendedItem
+			if readItems, err = db.GetIdentList(BucketReads, userId, 0); err != nil {
+				candidateItems = items
 			} else {
-				for itemID := range items {
-					exist := ExistRecommendedItem(itemID, reads)
-					if !exist {
-						subItems[itemID] = true
+				readSet := make(map[string]bool)
+				for _, item := range readItems {
+					readSet[item.ItemId] = true
+				}
+				for itemId := range items {
+					if _, exist := readSet[itemId]; !exist {
+						candidateItems[itemId] = true
 					}
 				}
 			}
-		} else {
-			subItems = items
 		}
-		recommendItems, ratings := core.Top(subItems, userId, cacheSize, exclude, model)
+		recommendItems, ratings := core.Top(candidateItems, userId, cacheSize, exclude, model)
 		recommends := make([]RecommendedItem, len(recommendItems))
 		items, err := db.GetItemsByID(recommendItems)
 		if err != nil {

engine/offline_test.go

@@ -171,7 +171,7 @@ func TestUpdateRecommends(t *testing.T) {
 		base.InitMean:   0,
 		base.InitStdDev: 0.001,
 	}
-	if err = UpdateRecommends("bpr", params, 10, runtime.NumCPU(),false, trainSet, db); err != nil {
+	if err = UpdateRecommends("bpr", params, 10, runtime.NumCPU(), false, trainSet, db); err != nil {
 		t.Fatal(err)
 	}
 	// Check result
@@ -230,7 +230,7 @@ func TestUpdateRecommendsInvalidModel(t *testing.T) {
 	if err = db.InsertItems(itemId, nil); err != nil {
 		t.Fatal(err)
 	}
-	if err = UpdateRecommends("invalid-model", nil, 10, runtime.NumCPU(), false,dataSet, db); err == nil {
+	if err = UpdateRecommends("invalid-model", nil, 10, runtime.NumCPU(), false, dataSet, db); err == nil {
 		t.Fatal("function should return an error")
 	}
 	// Close database

example/file_config/config_test.toml

@@ -15,6 +15,7 @@ cache_size = 100        # the number of cached recommendations
 update_threshold = 10   # update model when more than 10 ratings are added
 check_period = 1        # check for update every one minute
 fit_jobs = 10           # concurrent jobs for fitting
+once = true             # recommend once
 
 # This section declares hyperparameters for the recommendation model.
 [params]