.

wcfs/zodb.go

@@ -79,6 +79,11 @@ type Object interface {
 	//	  application must care to make sure it does not access the
 	//	  object data simultaneously.
 	PInvalidate()
+
+
+	// Object must be stateful for persistency to work
+	// XXX try to move out of Object?
+	Stateful
 }
 
 // ObjectState describes state of in-RAM object.
@@ -100,7 +105,7 @@ type object struct {
 	mu	 sync.Mutex
 	state	 ObjectState
 	refcnt	 int32
-	instance Stateful
+	instance Object
 	loading  *loadState
 }
 

wcfs/zodbpy.go

@@ -31,10 +31,11 @@ type PyObject interface {
 	PyClass() pickle.Class // python class of this object
 //	PyState() interface{}  // object state. python passes this to pyclass.__new__().__setstate__()
 
-	// XXX want to hide from PyObject. Rationale: we do not want e.g. PySetState to
+	// PyObject must be statefule for persistency to work
+	// XXX try to move out of PyObject? Rationale: we do not want e.g. PySetState to
 	// be available to user who holds PyObject interface: it is confusing to have
 	// both PActivate and PySetState at the same time.
-//	PyStateful
+	PyStateful
 }
 
 // pyObject is common base implementation for in-RAM representation of ZODB Python objects.
@@ -62,6 +63,14 @@ type PyStateful interface {
 
 // ---- pyObject <-> object state exchange ----
 
+// pyinstance returns .instance upcasted to PyObject.
+//
+// this should be always safe because we always create pyObjects via
+// newGhost which passes PyObject as instance to Object.
+func (pyobj *pyObject) pyinstance() PyObject {
+	return pyobj.instance.(PyObject)
+}
+
 func (pyobj *pyObject) SetState(state *mem.Buf) error {
 	pyclass, pystate, err := zodb.PyData(state.Data).Decode()
 	if err != nil {
@@ -74,22 +83,24 @@ func (pyobj *pyObject) SetState(state *mem.Buf) error {
 		return &wrongClassError{want: pyobj.pyclass, have: pyclass} // XXX + err ctx
 	}
 
-	return pyobj.instance.PySetState(pystate)	// XXX err ctx = ok?
+	return pyobj.pyinstance().PySetState(pystate)	// XXX err ctx = ok?
 }
 
 // TODO pyObject.GetState
 
 // ---- pyclass -> new ghost ----
 
+type pyClassNewFunc func(base *pyObject) PyObject
+
 // path(pyclass) -> new(pyobj)
-var classTab = make(map[string]func(base *pyObject)PyObject)
+var pyClassTab = make(map[string]pyClassNewFunc)
 
 // registerPyClass registers python class to be transformed to Go instance
 // created via classNew.
 //
 // must be called from global init().
-func registerPyClass(pyClassPath string, classNew func(base *pyObject)PyObject) {
-	classTab[pyClassPath] = classNew
+func registerPyClass(pyClassPath string, classNew pyClassNewFunc) {
+	pyClassTab[pyClassPath] = classNew
 }
 
 // newGhost creates new ghost object corresponding to pyclass and oid.
@@ -100,7 +111,7 @@ func (conn *Connection) newGhost(pyclass pickle.Class, oid zodb.Oid) PyObject {
 	}
 
 	// switch on pyclass and transform e.g. "zodb.BTree.Bucket" -> *ZBucket
-	classNew := classTab[pyclass.Module + "." + pyclass.Name]
+	classNew := pyClassTab[pyclass.Module + "." + pyclass.Name]
 	var instance PyObject
 	if classNew != nil {
 		instance = classNew(pyobj)