backend: provide a safer, less efficient way of querying the InMemory…

…Database
grafana · Jul 14, 2023 · 3846126 · 3846126
1 parent 0282fa8
commit 3846126
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Showing 2 changed files with 29 additions and 19 deletions.
diff --git a/pkg/database/database.go b/pkg/database/database.go
@@ -35,11 +35,21 @@ type InMemoryDatabase struct {
 }
 
 // Transaction provides a thread-safe, read-only view of the data in the database.
-func (db *InMemoryDatabase) Transaction(readF func(data *Data)) {
+func (db *InMemoryDatabase) Transaction(readF func(data Data)) {
 	db.mx.Lock()
-	defer db.mx.Unlock()
-
-	readF(&db.data)
+	dataCopy := Data{}
+	dataCopy.Doughs = append(dataCopy.Doughs, db.data.Doughs...)
+	dataCopy.OliveOils = append(dataCopy.OliveOils, db.data.OliveOils...)
+	dataCopy.Tomatoes = append(dataCopy.Tomatoes, db.data.Tomatoes...)
+	dataCopy.Mozzarellas = append(dataCopy.Mozzarellas, db.data.Mozzarellas...)
+	dataCopy.Toppings = append(dataCopy.Toppings, db.data.Toppings...)
+	dataCopy.Tools = append(dataCopy.Tools, db.data.Tools...)
+	dataCopy.Adjectives = append(dataCopy.Adjectives, db.data.Adjectives...)
+	dataCopy.ClassicNames = append(dataCopy.ClassicNames, db.data.ClassicNames...)
+	dataCopy.Quotes = append(dataCopy.Quotes, db.data.Quotes...)
+	db.mx.Unlock()
+
+	readF(dataCopy)
 }
 
 func (db *InMemoryDatabase) PopulateFromFile(path string) error {

diff --git a/pkg/http/http.go b/pkg/http/http.go
@@ -257,16 +257,16 @@ func (s *Server) WithCatalog(db *database.InMemoryDatabase) *Server {
 			isVegetarian := r.URL.Query().Get("is_vegetarian")
 
 			var ingredients []pizza.Ingredient
-			db.Transaction(func(data *database.Data) {
+			db.Transaction(func(data database.Data) {
 				switch ingredientType {
 				case "olive_oil":
-					ingredients = append(ingredients, data.OliveOils...)
+					ingredients = data.OliveOils
 				case "tomato":
-					ingredients = append(ingredients, data.Tomatoes...)
+					ingredients = data.Tomatoes
 				case "mozzarella":
-					ingredients = append(ingredients, data.Mozzarellas...)
+					ingredients = data.Mozzarellas
 				case "topping":
-					ingredients = append(ingredients, data.Toppings...)
+					ingredients = data.Toppings
 				}
 			})
 
@@ -299,8 +299,8 @@ func (s *Server) WithCatalog(db *database.InMemoryDatabase) *Server {
 			logger.Info("Doughs requested")
 
 			var doughs []pizza.Dough
-			db.Transaction(func(data *database.Data) {
-				doughs = append(doughs, data.Doughs...)
+			db.Transaction(func(data database.Data) {
+				doughs = data.Doughs
 			})
 
 			err := json.NewEncoder(w).Encode(map[string][]pizza.Dough{"doughs": doughs})
@@ -316,8 +316,8 @@ func (s *Server) WithCatalog(db *database.InMemoryDatabase) *Server {
 			logger.Info("Tools requested")
 
 			var tools []string
-			db.Transaction(func(data *database.Data) {
-				tools = append(tools, data.Tools...)
+			db.Transaction(func(data database.Data) {
+				tools = data.Tools
 			})
 
 			err := json.NewEncoder(w).Encode(map[string][]string{"tools": tools})
@@ -434,8 +434,8 @@ func (s *Server) WithCopy(db *database.InMemoryDatabase) *Server {
 			logger.Info("Quotes requested")
 
 			var quotes []string
-			db.Transaction(func(data *database.Data) {
-				quotes = append(quotes, data.Quotes...)
+			db.Transaction(func(data database.Data) {
+				quotes = data.Quotes
 			})
 
 			err := json.NewEncoder(w).Encode(map[string][]string{"quotes": quotes})
@@ -451,8 +451,8 @@ func (s *Server) WithCopy(db *database.InMemoryDatabase) *Server {
 			logger.Info("Names requested")
 
 			var names []string
-			db.Transaction(func(data *database.Data) {
-				names = append(names, data.ClassicNames...)
+			db.Transaction(func(data database.Data) {
+				names = data.ClassicNames
 			})
 
 			err := json.NewEncoder(w).Encode(map[string][]string{"names": names})
@@ -468,8 +468,8 @@ func (s *Server) WithCopy(db *database.InMemoryDatabase) *Server {
 			logger.Info("Adjectives requested")
 
 			var adjs []string
-			db.Transaction(func(data *database.Data) {
-				adjs = append(adjs, data.Adjectives...)
+			db.Transaction(func(data database.Data) {
+				adjs = data.Adjectives
 			})
 
 			err := json.NewEncoder(w).Encode(map[string][]string{"adjectives": adjs})