Initial cloud-services repo - gateway service + pkg modules

pkg/cache/drivers.go

@@ -0,0 +1,141 @@
+package cache
+
+import (
+	"fiskerinc.com/modules/common"
+	"fiskerinc.com/modules/db/queries"
+	"fiskerinc.com/modules/logger"
+	"fiskerinc.com/modules/redis"
+	"github.com/pkg/errors"
+)
+
+func NewDriversCache(redisClient redis.ClientPoolInterface, cars queries.CarsInterface) *DriversCache {
+	return &DriversCache{
+		redisClientPool: redisClient,
+		cars:        cars,
+	}
+}
+
+type DriversCache struct {
+	redisClientPool redis.ClientPoolInterface
+	cars        queries.CarsInterface
+}
+
+func (dc *DriversCache) RedisClientPool() redis.ClientPoolInterface {
+	return dc.redisClientPool
+}
+
+func (dc *DriversCache) Cars() queries.CarsInterface {
+	return dc.cars
+}
+
+func (dc *DriversCache) hasCachedNoDrivers(drivers []string) bool {
+	// Redis will return []string{""} for no drivers
+	return len(drivers) == 1 && len(drivers[0]) == 0
+}
+
+func (dc *DriversCache) cacheDrivers(key string, drivers []string) error {
+	client := dc.redisClientPool.GetFromPool()
+	defer client.Close()
+	// cache driver IDs
+	if len(drivers) > 0 {
+		return client.NewSet(key, drivers, redisObjectExpire)
+	}
+
+	// Redis will not take an empty array as an arg
+	return client.NewSet(key, nil, redisObjectExpire)
+}
+
+// RetrieveDriverIDs retrieves IDs from redis or from DB and proceeds to cache both the drivers and IDs
+// redis keys:
+//
+//	car:<VIN>:drivers
+func (dc *DriversCache) RetrieveDriverIDs(vin string) ([]string, error) {
+	var driverIDs []string
+	driverIDsKey := redis.CarToAllDriversKey(vin)
+
+	// retrieve IDs from redis
+	client := dc.redisClientPool.GetFromPool()
+	err := client.GetSet(driverIDsKey, &driverIDs)
+	if err != nil {
+		logger.Warn().Err(err).Send()
+	}
+	client.Close()
+
+	if dc.hasCachedNoDrivers(driverIDs) {
+		return []string{}, nil
+	}
+	if len(driverIDs) > 0 {
+		return driverIDs, nil
+	}
+
+	// if IDs not present in redis perform DB lookup
+	var drivers []common.CarToDriver
+	drivers, err = dc.cars.GetDrivers(vin)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, driver := range drivers {
+		driverIDs = append(driverIDs, driver.DriverID)
+	}
+
+	err = dc.cacheDrivers(driverIDsKey, driverIDs)
+	if err != nil {
+		return driverIDs, err
+	}
+
+	return driverIDs, nil
+}
+
+// RetrieveDriverIDsAsSet retrieves IDs from redis or from DB and proceeds to cache both the drivers and IDs
+// redis keys:
+//
+//	car:<VIN>:drivers
+func (dc *DriversCache) RetrieveDriverIDsAsSet(vin string) (map[string]struct{}, error) {
+	driverIDs, err := dc.RetrieveDriverIDs(vin)
+	if err != nil {
+		return nil, err
+	}
+
+	var dIDsSet = make(map[string]struct{})
+	for _, did := range driverIDs {
+		dIDsSet[did] = struct{}{}
+	}
+
+	return dIDsSet, nil
+}
+
+func (dc *DriversCache) IsDriverOfVIN(vin string, driverid string) (bool, error) {
+	ids, err := dc.RetrieveDriverIDs(vin)
+	if err != nil {
+		return false, err
+	}
+
+	for _, id := range ids {
+		if id == driverid {
+			return true, nil
+		}
+	}
+
+	return false, dc.NotDriverError(vin, driverid)
+}
+
+// Add driver to database and cache
+func (dc *DriversCache) AddDriver(car *common.Car, driver *common.Driver, role string) (*common.CarToDriver, error) {
+
+	relation, err := dc.cars.AddDriver(car, driver, role)
+	if err != nil {
+		return nil, err
+	}
+
+	driverIDsKey := redis.CarToAllDriversKey(car.VIN)
+
+	client := dc.redisClientPool.GetFromPool()
+	defer client.Close()
+	client.AddToSet(driverIDsKey, driver.ID, redisObjectExpire)
+	return relation, nil
+}
+
+func (dc DriversCache) NotDriverError(vin string, driverid string) error {
+	return errors.Errorf("id %s is not a driver for vin %v", driverid, vin)
+}