Initial cloud-services repo - gateway service + pkg modules

pkg/cache/vins.go

@@ -0,0 +1,60 @@
+package cache
+
+import (
+	"errors"
+
+	"fiskerinc.com/modules/common"
+	"fiskerinc.com/modules/db/queries"
+	"fiskerinc.com/modules/logger"
+	"fiskerinc.com/modules/redis"
+)
+
+// RetrieveVINs retrieves VINs from redis or from DB based on driver ID and proceeds to cache VINs
+// redis keys:
+//
+//	driver:<ID>:cars
+func RetrieveVINs(client redis.Client, db queries.CarsInterface, id string) ([]string, error) {
+	var vins []string
+	driverVINsKey := redis.DriverToVINsKey(id)
+
+	// retrieve VINs from redis
+	err := client.GetCache(driverVINsKey, &vins, 0)
+	if err != nil && !errors.Is(err, redis.ErrNilObject) {
+		logger.Warn().Err(err).Send()
+	} else if len(vins) > 0 {
+		return vins, nil
+	}
+
+	// if VINs not present in redis perform DB lookup
+	var vehicles []common.CarToDriver
+	vehicles, err = db.GetCarsForDriver(id)
+	if err != nil {
+		return vins, err
+	}
+
+	for _, vehicle := range vehicles {
+		vins = append(vins, vehicle.VIN)
+	}
+
+	// cache drivers vehicles
+	err = client.SetCache(driverVINsKey, vins, redisObjectExpire)
+	if err != nil {
+		return vins, err
+	}
+
+	return vins, nil
+}
+
+func RetrieveVINsAsSet(client redis.Client, db queries.CarsInterface, id string) (map[string]struct{}, error) {
+	vins, err := RetrieveVINs(client, db, id)
+	if err != nil {
+		return nil, err
+	}
+
+	var vinsSet = make(map[string]struct{})
+	for _, vin := range vins {
+		vinsSet[vin] = struct{}{}
+	}
+
+	return vinsSet, nil
+}