.

go/zodb/connection.go

@@ -149,6 +149,13 @@ func (conn *Connection) newGhost(class string, oid Oid) IPersistent {
 var class2Type = make(map[string]reflect.Type) // {} class -> type
 var type2Class = make(map[reflect.Type]string) // {} type -> class
 
+// zclassOf returns ZODB class of a Go object.
+//
+// If ZODB class was not registered for obj's type, "" is returned.
+func zclassOf(obj IPersistent) string {
+	return type2Class[reflect.TypeOf(obj)]
+}
+
 // RegisterClass registers ZODB class to correspond to Go type.
 //
 // *type must implement IPersistent. XXX and either Stateful or PyStateful
@@ -169,6 +176,8 @@ func RegisterClass(class string, typ reflect.Type) {
 	// XXX check typ has IPersistent embedded
 	// XXX check *typ implements Stateful
 
+	// XXX check if class was already registered
+	// XXX check class != ""
 
 	class2Type[class] = typ
 	type2Class[typ] = class
@@ -186,14 +195,14 @@ func (conn *Connection) newGhost(class string, oid Oid) IPersistent {
 		xpobj = reflect.New(typ)
 	}
 
-	base  := &Persistent{class: class, jar: conn, oid: oid, serial: 0, state: GHOST}
+	base  := &Persistent{jar: conn, oid: oid, serial: 0, state: GHOST}
 	xobj  := xpobj.Elem() // typ
 	xobjBase := xobj.FieldByName("IPersistent")
 	xobjBase.Set(reflect.ValueOf(base))
 
 	obj := xpobj.Interface()
 	base.instance = obj.(interface{IPersistent; Stateful})
-	return obj.(IPersistent)
+	return base.instance
 }
 
 // Broken is used for classes that were not registered.
@@ -258,8 +267,7 @@ func (conn *Connection) get(class string, oid Oid) (IPersistent, error) {
 	conn.objmu.Unlock()
 
 	if checkClass {
-		// XXX get obj class via reflection?
-		if cls := obj.zclass(); class != cls {
+		if cls := zclassOf(obj); class != cls {
 			return nil, &OpError{
 				URL:  conn.stor.URL(),
 				Op:   fmt.Sprintf("@%s: get", conn.at), // XXX abuse

go/zodb/persistent.go

@@ -31,7 +31,7 @@ import (
 //
 // XXX safe to access from multiple goroutines simultaneously.
 type IPersistent interface {
-	zclass() string	// ZODB class of this object. XXX remove from IPersistent?
+	//zclass() string	// ZODB class of this object. XXX remove from IPersistent?
 
 	PJar()    *Connection	// Connection this in-RAM object is part of.
 	POid()    Oid		// object ID in the database.
@@ -119,8 +119,8 @@ const (
 
 // Persistent is common base implementation for in-RAM representation of database objects.
 type Persistent struct {
-	// XXX kill here; move -> Broken
-	class   string // zodb class of this object. XXX try not to store and retrieve via reflect?
+//	// XXX kill here; move -> Broken
+//	class   string // zodb class of this object. XXX try not to store and retrieve via reflect?
 
 	jar	*Connection
 	oid	Oid
@@ -129,12 +129,11 @@ type Persistent struct {
 	mu	 sync.Mutex
 	state	 ObjectState
 	refcnt	 int32
-//	instance IPersistent	// Persistent should be the base for the instance	XXX -> Stateful
 	instance interface{IPersistent; Stateful} // Persistent should be the base for the instance
 	loading  *loadState
 }
 
-func (obj *Persistent) zclass() string		{ return obj.class	}
+//func (obj *Persistent) zclass() string		{ return obj.class	}
 func (obj *Persistent) PJar() *Connection	{ return obj.jar	}
 func (obj *Persistent) POid() Oid		{ return obj.oid	}
 func (obj *Persistent) PSerial() Tid		{ return obj.serial	}

go/zodb/zodbpy.go

@@ -77,13 +77,15 @@ func (pyobj *PyPersistent) SetState(state *mem.Buf) error {
 	}
 
 	class := pyclassPath(pyclass)
-	if class != pyobj.class {
+	obj   := pyobj.pyinstance()
+
+	if objClass := zclassOf(obj); class != objClass {
 		// complain that pyclass changed
 		// (both ref and object data use pyclass so it indeed can be different)
-		return &wrongClassError{want: pyobj.class, have: class} // XXX + err ctx
+		return &wrongClassError{want: objClass, have: class} // XXX + err ctx
 	}
 
-	return pyobj.pyinstance().PySetState(pystate)	// XXX err ctx = ok?
+	return obj.PySetState(pystate)	// XXX err ctx = ok?
 }
 
 // TODO PyPersistent.GetState