.

wcfs/internal/xbtree.py

@@ -200,6 +200,9 @@ def Restructure(ztree, newStructure):
 
     _bcheck(ztree)  # verify ztree before our tweaks
 
+    # dict with all k->v from ztree
+    kv = dict(ztree)
+
     # walk original and new strucutres level by level.
     # for each level we have A1...An "old" nodes, and B1...Bm "new" nodes.
     # XXX buckets - push till end
@@ -224,10 +227,58 @@ def Restructure(ztree, newStructure):
     #
     tnew = newStructure.copy()
 
-    zlevelv = _zwalkBFS(ztree)
-    levelv  = _walkBFS(tnew)
+    zlevelv = list(_zwalkBFS(ztree))
+    levelv  = list( _walkBFS(tnew))
+
+    # assotiate every node in tnew to a znode
+    # XXX check for end
+
+    zlevel = zlevel.pop(0)
+    level  =  level.pop(0)
+
+    if len(zlevel) == len(level):   # map 1-1
+        for (znode, node) in zip(zlevel, level):
+            node.Z = znode
+
+    else:
+        panic("TODO")
+
+
+    # set znode states according to established tnew->znode association
+    for nodev in levelv:
+        for node in nodev:
+            znode = node.Z
+
+            if isinstance(node, Bucket):
+                # https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BucketTemplate.c#L1195
+                zstate = ()
+                for k in node.keyv:
+                    zstate += (k, kv[k])                # (k1, v1, k2, v2, ..., kN, vN)
+                zstate = (zstate,)
+
+                if node.next_bucket is not None:        # next
+                    zstate += (node.next_bucket.Z,)
+
+            else:
+                assert isinstance(node, Tree)
+                # https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeTemplate.c#L1087
+                if len(node.keyv) == 0:
+                    panic("TODO: empty tree + tree with bucket without oid")
+
+                zstate = ()
+                assert len(node.children) == len(node.keyv) + 1
+                zstate += node.children[0]
+                for (child, k) in zip(node.children[1:], node.keyv):
+                    zstate += (k, child)                # (child0, k0, child1, k1, ..., childN, kN, childN+1)
+                zstate = (zstate,)
+
+                # firstbucket
+                zstate += (None,)   # XXX
+
+            znode.__setstate__(zstate)
 
 
+    assert tnew.Z is ztree
 
     _bcheck(ztree)  # verify ztree after our tweaks
     tstruct = StructureOf(ztree)