1 files changed, 62 insertions, 0 deletions

diff --git a/core/state_backend.go b/core/state_backend.go
new file mode 100644
index 0000000..9f9f397
--- /dev/null
+++ b/core/state_backend.go
@@ -0,0 +1,62 @@
+package core
+
+import (
+        "context"
+)
+
+type StateBackend interface {
+        // For Framework ===
+        // SetCurrentKey will perform in Memory
+        SetCurrentKey(key string) error
+        // GetCurrentKey will perform in Memory
+        GetCurrentKey() string
+        SetCurrentNamespace(namespace any) error
+        GetCurrentNamespace() any
+
+        // For User ===
+        // GetValueState will perform in disk
+        GetValueState(ctx context.Context, key string) (ValueState[any], error)
+}
+
+type stateBackendKeyType struct{}
+
+var stateBackendKey stateBackendKeyType
+
+type typedValueState[T any] struct {
+        inner ValueState[any]
+}
+
+func CastValueType[T any](inner ValueState[any]) ValueState[T] {
+        return &typedValueState[T]{inner: inner}
+}
+
+func (s *typedValueState[T]) Value(ctx context.Context) (T, error) {
+        val, err := s.inner.Value(ctx)
+        if err != nil {
+                var zero T
+                return zero, err
+        }
+        if val == nil {
+                var zero T
+                return zero, nil
+        }
+        return val.(T), nil
+}
+
+func (s *typedValueState[T]) Update(ctx context.Context, newVal T) (T, error) {
+        _, err := s.inner.Update(ctx, newVal)
+        return newVal, err
+}
+
+func (s *typedValueState[T]) Clear(ctx context.Context) error {
+        return s.inner.Clear(ctx)
+}
+
+func InjectStateBackend(ctx context.Context, state StateBackend) context.Context {
+        return context.WithValue(ctx, stateBackendKey, state)
+}
+
+func ExtractStateBackend(ctx context.Context) (StateBackend, bool) {
+        backend, ok := ctx.Value(stateBackendKey).(StateBackend)
+        return backend, ok
+}