.

go/internal/xtesting/xtesting.go

@@ -90,7 +90,7 @@ func NeedPy(t testing.TB, modules ...string) {
 // ZObject represents object state to be committed.
 type ZObject struct {
 	Oid  zodb.Oid
-	Data string
+	Data string // raw serialized zodb data
 }
 
 // ZPyCommit commits new transaction into database @ zurl with data specified by objv.

go/zodb/export_test.go

+// Copyright (C) 2019  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+package zodb
+// things exported for zodb_test package.
+
+import (
+	"lab.nexedi.com/kirr/go123/mem"
+)
+
+func PSerialize(obj IPersistent) *mem.Buf {
+	return obj.pSerialize()
+}

go/zodb/import_test.go

@@ -20,5 +20,4 @@
 package zodb
 // things imported at runtime via import_x_test due to cyclic dependency
 
-var ZPyCommit func(string, Tid, ...interface{}) (Tid, error)	// XXX ZObject
-
+var ZPyCommit func(string, Tid, ...IPersistent) (Tid, error)

go/zodb/import_x_test.go

@@ -28,9 +28,20 @@ import (
 )
 
 // import at runtime few things into zodb, that zodb cannot import itself due to cyclic dependency.
+
 func init() {
-	//zodb.ZPyCommit = xtesting.ZPyCommit
-	zodb.ZPyCommit = func(zurl string, at zodb.Tid, objv ...interface{}) (zodb.Tid, error) {
-		return xtesting.ZPyCommit(zurl, at)	// XXX + objv
+	zodb.ZPyCommit = ZPyCommit
+}
+
+func ZPyCommit(zurl string, at zodb.Tid, objv ...zodb.IPersistent) (zodb.Tid, error) {
+	var zobjv []xtesting.ZObject // raw zodb objects data to commit
+	for _, obj := range objv {
+		zobj := xtesting.ZObject{
+			Oid:  obj.POid(),
+			Data: string(zodb.PSerialize(obj).XData()),
+		}
+		zobjv = append(zobjv, zobj)
 	}
+
+	return xtesting.ZPyCommit(zurl, at, zobjv...)
 }

go/zodb/persistent.go

@@ -121,6 +121,24 @@ type Stateful interface {
 	GetState() *mem.Buf
 }
 
+// ---- serialize ----
+
+// pSerialize implements IPersistent.
+func (obj *Persistent) pSerialize() *mem.Buf {
+	// XXX locking
+	// XXX panic on state == GHOST
+
+	switch istate := obj.istate().(type) {
+	case Stateful:
+		return istate.GetState()
+
+	case PyStateful:
+		return pyGetState(istate, ClassOf(obj))
+
+	default:
+		panic(obj.badf("serialize: !stateful instance"))
+	}
+}
 
 // ---- activate/deactivate/invalidate ----
 

go/zodb/persistent_api.go

 // Copyright (c) 2001, 2002 Zope Foundation and Contributors.
 // All Rights Reserved.
 //
-// Copyright (C) 2018  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
+// Copyright (C) 2018-2019  Nexedi SA and Contributors.
+//                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This software is subject to the provisions of the Zope Public License,
 // Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
@@ -16,6 +16,8 @@ package zodb
 
 import (
 	"context"
+
+	"lab.nexedi.com/kirr/go123/mem"
 )
 
 // IPersistent is the interface that every in-RAM object representing any database object implements.
@@ -97,6 +99,16 @@ type IPersistent interface {
 
 	// XXX probably don't need this.
 	//PState()  ObjectState	// in-RAM object state.
+
+	// XXX move vvv -> iPersistent?
+
+	// pSerialize returns object in serialized form to be saved in the database.
+	//
+	// pSerialize is non-public method that is exposed and used only by ZODB internally.
+	//
+	// XXX more text.
+	// XXX when called? invariants?
+	pSerialize() *mem.Buf
 }
 
 // ObjectState describes state of in-RAM object.

go/zodb/pydata.go

-// Copyright (C) 2016-2018  Nexedi SA and Contributors.
+// Copyright (C) 2016-2019  Nexedi SA and Contributors.
 //                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
@@ -24,6 +24,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"strings"
 
 	pickle "github.com/kisielk/og-rek"
 	"lab.nexedi.com/kirr/go123/xerr"
@@ -59,6 +60,35 @@ func (d PyData) ClassName() string {
 	return pyclassPath(klass)
 }
 
+// encodePyData encodes Python class and state into raw ZODB python data.
+func encodePyData(pyclass pickle.Class, pystate interface{}) PyData {
+	buf := &bytes.Buffer{}
+
+	p := pickle.NewEncoderWithConfig(buf, &pickle.EncoderConfig{
+		// allow pristine python2 to decode the pickle.
+		// TODO 2 -> 3 since ZODB switched to it and uses zodbpickle.
+		Protocol:      2,
+		PersistentRef: persistentRef,
+	})
+
+	// emit: object type
+	err := p.Encode(pyclass)
+	if err != nil {
+		// buf.Write never errors, as well as pickle encoder on supported types.
+		// -> the error here is a bug.
+		panic(fmt.Errorf("pydata: encode: class: %s", err))
+	}
+
+	// emit: object state
+	err = p.Encode(pystate)
+	if err != nil {
+		// see ^^^
+		panic(fmt.Errorf("pydata: encode: state: %s", err))
+	}
+
+	return PyData(buf.Bytes())
+}
+
 // TODO PyData.referencesf
 
 // decode decodes raw ZODB python data into Python class and state.
@@ -90,6 +120,21 @@ func (d PyData) decode(jar *Connection) (pyclass pickle.Class, pystate interface
 	return klass, state, nil
 }
 
+// persistentRef decides whether to encode obj as persistent reference, and if yes - how.
+func persistentRef(obj interface{}) *pickle.Ref {
+	pobj, ok := obj.(IPersistent)
+	if !ok {
+		// regular object - include its state when encoding referee
+		return nil
+	}
+
+	// Persistent object - when encoding someone who references it - don't
+	// include obj state and just reference to obj.
+	return &pickle.Ref{
+		Pid: pickle.Tuple{pobj.POid(), zpyclass(ClassOf(pobj))}, // (oid, class)
+	}
+}
+
 // loadref loads persistent references resolving them through jar.
 //
 // https://github.com/zopefoundation/ZODB/blob/a89485c1/src/ZODB/serialize.py#L80
@@ -122,6 +167,22 @@ func (jar *Connection) loadref(ref pickle.Ref) (_ interface{}, err error) {
 	return jar.get(class, oid)
 }
 
+// zpyclass converts ZODB class into Python class.
+func zpyclass(zclass string) pickle.Class {
+	// BTrees.LOBTree.LOBucket -> BTrees.LOBTree, LOBucket
+	var zmod, zname string
+	dot := strings.LastIndexByte(zclass, '.')
+	if dot == -1 {
+		// zmod remains ""
+		zname = zclass
+	} else {
+		zmod  = zclass[:dot]
+		zname = zclass[dot+1:]
+	}
+
+	return pickle.Class{Module: zmod, Name: zname}
+}
+
 // xpyclass verifies and extracts py class from unpickled value.
 //
 // it normalizes py class that has just been decoded from a serialized ZODB

go/zodb/zodbpy.go

@@ -67,8 +67,13 @@ func pySetState(obj PyStateful, objClass string, state *mem.Buf, jar *Connection
 	return obj.PySetState(pystate)
 }
 
-// TODO pyGetState
-
+// pyGetState encodes obj as zodb/py serialized stream.
+func pyGetState(obj PyStateful, objClass string) *mem.Buf {
+	pyclass := zpyclass(objClass)
+	pystate := obj.PyGetState()
+	data := encodePyData(pyclass, pystate)
+	return &mem.Buf{Data: data} // XXX -> better bufalloc (and in encodePyData)
+}
 
 
 // loadpy loads object specified by oid and decodes it as a ZODB Python object.