Refactor & fix storing struct-values in redis keyvalue

pkg/modules/keyvalue/keyvalue.go

@@ -26,6 +26,7 @@ import (
 type Storage interface {
 	Put(key string, value interface{}) (err error)
 	Get(key string) (value interface{}, exists bool, err error)
+	GetWithValue(key string, value interface{}) (exists bool, err error)
 	Del(key string) (err error)
 	IncrBy(key string, update int64) (err error)
 	DecrBy(key string, update int64) (err error)
@@ -55,6 +56,10 @@ func Get(key string) (value interface{}, exists bool, err error) {
 	return store.Get(key)
 }
 
+func GetWithValue(key string, value interface{}) (exists bool, err error) {
+	return store.GetWithValue(key, value)
+}
+
 // Del removes a save value from a storage backend
 func Del(key string) (err error) {
 	return store.Del(key)

pkg/modules/keyvalue/memory/memory.go

@@ -17,6 +17,7 @@
 package memory
 
 import (
+	"reflect"
 	"sync"
 
 	e "code.vikunja.io/api/pkg/modules/keyvalue/error"
@@ -52,6 +53,21 @@ func (s *Storage) Get(key string) (value interface{}, exists bool, err error) {
 	return
 }
 
+func (s *Storage) GetWithValue(key string, value interface{}) (exists bool, err error) {
+	v, exists, err := s.Get(key)
+	if !exists {
+		return exists, err
+	}
+
+	val := reflect.ValueOf(value)
+	if val.Kind() != reflect.Ptr {
+		panic("some: check must be a pointer")
+	}
+
+	val.Elem().Set(reflect.ValueOf(v))
+	return exists, err
+}
+
 // Del removes a saved value from a memory storage
 func (s *Storage) Del(key string) (err error) {
 	s.mutex.Lock()

pkg/modules/keyvalue/redis/redis.go

@@ -17,8 +17,10 @@
 package redis
 
 import (
+	"bytes"
 	"context"
-	"encoding/json"
+	"encoding/gob"
+	"errors"
 
 	"code.vikunja.io/api/pkg/red"
 	"github.com/go-redis/redis/v8"
@@ -40,9 +42,28 @@ func NewStorage() *Storage {
 
 // Put puts a value into redis
 func (s *Storage) Put(key string, value interface{}) (err error) {
-	v, err := json.Marshal(value)
-	if err != nil {
-		return err
+
+	var v interface{}
+
+	switch value.(type) {
+	case int:
+		v = value
+	case int8:
+		v = value
+	case int16:
+		v = value
+	case int32:
+		v = value
+	case int64:
+		v = value
+	default:
+		var buf bytes.Buffer
+		enc := gob.NewEncoder(&buf)
+		err = enc.Encode(value)
+		if err != nil {
+			return err
+		}
+		return s.client.Set(context.Background(), key, buf.Bytes(), 0).Err()
 	}
 
 	return s.client.Set(context.Background(), key, v, 0).Err()
@@ -50,13 +71,32 @@ func (s *Storage) Put(key string, value interface{}) (err error) {
 
 // Get retrieves a saved value from redis
 func (s *Storage) Get(key string) (value interface{}, exists bool, err error) {
+	value, err = s.client.Get(context.Background(), key).Result()
+	if err != nil && errors.Is(err, redis.Nil) {
+		return nil, false, nil
+	}
+	return value, true, err
+}
+
+func (s *Storage) GetWithValue(key string, value interface{}) (exists bool, err error) {
 	b, err := s.client.Get(context.Background(), key).Bytes()
 	if err != nil {
-		return nil, false, err
+		if errors.Is(err, redis.Nil) {
+			return false, nil
+		}
+
+		return
 	}
 
-	err = json.Unmarshal(b, value)
-	return
+	var buf bytes.Buffer
+	_, err = buf.Write(b)
+	if err != nil {
+		return
+	}
+
+	dec := gob.NewDecoder(&buf)
+	err = dec.Decode(value)
+	return true, err
 }
 
 // Del removed a value from redis