boilerplate code

internal/domains/sensors/repository.go

@@ -0,0 +1,150 @@
+package sensors
+
+import (
+	"log/slog"
+	"sync"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type Repository interface {
+	RegisterSensor(s Sensor) error
+	UpdateSensorConfig(s Sensor) error
+	ReadSensor(id int) (Sensor, error)
+	ReadSensorValues(id int, from, to time.Time) ([]SensorData, error)
+	ReadAllSensors() ([]Sensor, error)
+}
+
+type pgxRepo struct {
+	pool *pgxpool.Pool
+}
+
+func newPGXRepo(pool *pgxpool.Pool) Repository {
+	return &pgxRepo{
+		pool: pool,
+	}
+}
+
+func (p *pgxRepo) ReadSensor(id int) (Sensor, error) {
+	panic("unimplemented")
+}
+
+func (p *pgxRepo) UpdateSensorConfig(s Sensor) error {
+	panic("unimplemented")
+}
+
+func (p *pgxRepo) RegisterSensor(s Sensor) error {
+	panic("unimplemented")
+}
+
+func (p *pgxRepo) ReadSensorValues(id int, from time.Time, to time.Time) ([]SensorData, error) {
+	panic("unimplemented")
+}
+
+func (p *pgxRepo) ReadAllSensors() ([]Sensor, error) {
+	panic("unimplemented")
+}
+
+type inMemory struct {
+	sensors map[string]*Sensor
+	mu      *sync.Mutex
+}
+
+func newInMemoryRepo() Repository {
+	return &inMemory{
+		sensors: make(map[string]*Sensor),
+	}
+}
+
+func (i *inMemory) RegisterSensor(s Sensor) error {
+	panic("unimplemented")
+}
+
+func (i *inMemory) UpdateSensorConfig(s Sensor) error {
+	panic("unimplemented")
+}
+
+func (i *inMemory) ReadSensor(id int) (Sensor, error) {
+	panic("unimplemented")
+}
+
+func (i *inMemory) ReadSensorValues(id int, from time.Time, to time.Time) ([]SensorData, error) {
+	// holds only last 100 values for every sensor
+
+	panic("unimplemented")
+}
+
+func (i *inMemory) ReadAllSensors() ([]Sensor, error) {
+	panic("unimplemented")
+}
+
+type DecoratorRepo struct {
+	db     Repository
+	memory Repository
+}
+
+func NewDecoratorRepo(pool *pgxpool.Pool) Repository {
+
+	db := newPGXRepo(pool)
+	memory := newInMemoryRepo()
+
+	sensors, err := db.ReadAllSensors()
+	if err != nil {
+		slog.Error("error warming up cache")
+	}
+
+	for _, s := range sensors {
+		_ = memory.RegisterSensor(s)
+	}
+
+	return &DecoratorRepo{
+		db:     db,
+		memory: memory,
+	}
+}
+
+func (d *DecoratorRepo) RegisterSensor(s Sensor) error {
+	if err := d.db.RegisterSensor(s); err != nil {
+		return err
+	}
+
+	_ = d.memory.RegisterSensor(s)
+	return nil
+}
+
+func (d *DecoratorRepo) UpdateSensorConfig(s Sensor) error {
+	if err := d.db.UpdateSensorConfig(s); err != nil {
+		return err
+	}
+
+	_ = d.memory.UpdateSensorConfig(s)
+	return nil
+}
+
+func (d *DecoratorRepo) ReadSensor(id int) (Sensor, error) {
+	sensor, err := d.memory.ReadSensor(id)
+	if err == nil {
+		return sensor, nil
+	}
+
+	return d.db.ReadSensor(id)
+}
+
+func (d *DecoratorRepo) ReadSensorValues(id int, from, to time.Time) ([]SensorData, error) {
+	values, err := d.memory.ReadSensorValues(id, from, to)
+	if err == nil && len(values) > 0 {
+		return values, nil
+	}
+
+	return d.db.ReadSensorValues(id, from, to)
+}
+
+func (d *DecoratorRepo) ReadAllSensors() ([]Sensor, error) {
+	sensors, err := d.memory.ReadAllSensors()
+	if err == nil && len(sensors) > 0 {
+		return sensors, nil
+	}
+
+	return d.db.ReadAllSensors()
+}