feat: add prefix key support to keyvalue store (#1038)

feat: add prefix key operations to keyvalue store

pkg/modules/keyvalue/keyvalue.go

@@ -30,6 +30,8 @@ type Storage interface {
 	Del(key string) (err error)
 	IncrBy(key string, update int64) (err error)
 	DecrBy(key string, update int64) (err error)
+	ListKeys(prefix string) ([]string, error)
+	DelPrefix(prefix string) error
 }
 
 var store Storage
@@ -74,3 +76,13 @@ func IncrBy(key string, update int64) (err error) {
 func DecrBy(key string, update int64) (err error) {
 	return store.DecrBy(key, update)
 }
+
+// ListKeys returns all keys beginning with prefix from the configured backend
+func ListKeys(prefix string) ([]string, error) {
+	return store.ListKeys(prefix)
+}
+
+// DelPrefix deletes all keys with the given prefix in the backend
+func DelPrefix(prefix string) error {
+	return store.DelPrefix(prefix)
+}

pkg/modules/keyvalue/memory/memory.go

@@ -18,6 +18,7 @@ package memory
 
 import (
 	"reflect"
+	"strings"
 	"sync"
 
 	e "code.vikunja.io/api/pkg/modules/keyvalue/error"
@@ -125,3 +126,32 @@ func (s *Storage) DecrBy(key string, update int64) (err error) {
 	s.store[key] = val - update
 	return nil
 }
+
+// ListKeys returns all keys in the storage which start with the given prefix
+func (s *Storage) ListKeys(prefix string) ([]string, error) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	keys := make([]string, 0)
+	for k := range s.store {
+		if strings.HasPrefix(k, prefix) {
+			keys = append(keys, k)
+		}
+	}
+
+	return keys, nil
+}
+
+// DelPrefix removes all keys which start with the given prefix
+func (s *Storage) DelPrefix(prefix string) error {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	for k := range s.store {
+		if strings.HasPrefix(k, prefix) {
+			delete(s.store, k)
+		}
+	}
+
+	return nil
+}

pkg/modules/keyvalue/redis/redis.go

@@ -113,3 +113,37 @@ func (s *Storage) IncrBy(key string, update int64) (err error) {
 func (s *Storage) DecrBy(key string, update int64) (err error) {
 	return s.client.DecrBy(context.Background(), key, update).Err()
 }
+
+// ListKeys returns all keys in redis starting with the given prefix
+func (s *Storage) ListKeys(prefix string) ([]string, error) {
+	ctx := context.Background()
+	pattern := prefix + "*"
+	var cursor uint64
+	var keys []string
+
+	for {
+		k, c, err := s.client.Scan(ctx, cursor, pattern, 100).Result()
+		if err != nil {
+			return nil, err
+		}
+		keys = append(keys, k...)
+		cursor = c
+		if cursor == 0 {
+			break
+		}
+	}
+
+	return keys, nil
+}
+
+// DelPrefix removes all keys in redis which start with the given prefix
+func (s *Storage) DelPrefix(prefix string) error {
+	keys, err := s.ListKeys(prefix)
+	if err != nil {
+		return err
+	}
+	if len(keys) == 0 {
+		return nil
+	}
+	return s.client.Del(context.Background(), keys...).Err()
+}