.

wcfs/internal/xbtree.py

@@ -177,7 +177,7 @@ class Tree(object):
 class Bucket(object):
     #   .keyv   () of keys
     #   .valuev None | () of values    len(.valuev) == len(.keyv)
-    def __init__(b, keyv, valuev): # XXX syntax sugar for values? (lack of values)?
+    def __init__(b, keyv, valuev):
         _assertIncv(keyv)
         b.keyv = tuple(keyv)
         if valuev is None:
@@ -249,7 +249,7 @@ def StructureOf(znode, onlyKeys=False):
 # Restructure reorganizes ZODB BTree instance (not Tree) according to specified
 # topology structure.
 #
-# The new structure should be given with buckets without values. XXX should -> can?
+# The new structure should be given with key-only buckets.
 #
 # NOTE ZODB BTree package does not tolerate structures with empty BTree nodes
 # except for the sole single case of empty tree.
@@ -265,7 +265,7 @@ def Restructure(ztree, newStructure):
     def _():
         exc = recover() # FIXME for panic - returns unwrapped arg, not PanicError
         if exc is not None:
-            # FIXME %w creates only .Unwrap link, not with .__cause__ -> fix
+            # FIXME %w creates only .Unwrap link, not with .__cause__
             raise fmt.Errorf("Restructure %s -> %s: %w", from_, to_, exc)
     defer(_)
     """
@@ -304,7 +304,7 @@ def Restructure(ztree, newStructure):
     # we will modify nodes from new set:
     # - node.Z              will point to associated znode
     # - bucket.next_bucket  will point to bucket that is coming with next keys in the tree
-    tnew = newStructure.copy()  # XXX onlyKeys=True ?
+    tnew = newStructure.copy()
 
     # assign assigns tree nodes from RNv to ztree nodes from RZv in optimal way.
     # Bj ∈ RNv is mapped into Ai ∈ RZv such that that sum_j D(A_i, Bj) is minimal.
@@ -490,7 +490,14 @@ def Restructure(ztree, newStructure):
 
             # https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BucketTemplate.c#L1195
             if isinstance(node, Bucket):
-                # XXX assert that node.values is None or == kv[k] for k in node
+                # if Bucket was specified with values - verify k->v do not
+                # change from what was in original tree.
+                if node.valuev is not None:
+                    assert len(node.keyv) == len(node.valuev)
+                    for (k,v) in zip(node.keyv, node.valuev):
+                        if kv[k] is not v:
+                            raise ValueError("target bucket changes [%d] %r -> %r", k, kv[k], v)
+
                 zstate = ()
                 for k in node.keyv:
                     zstate += (k, kv.pop(k))            # (k1, v1, k2, v2, ..., kN, vN)
@@ -503,7 +510,7 @@ def Restructure(ztree, newStructure):
             node.Z.__setstate__(zstate)
             zstate2 = node.Z.__getstate__()
             if zstate2 != zstate:
-                panic("BUG: Restructure: node.__getstate__ returns not what "
+                panic("BUG: node.__getstate__ returns not what "
                       "we passed into node.__setstate__.\nnode: %r\n"
                       "__setstate__ <- %r\n__getstate__ -> %r" % (node.Z, zstate, zstate2))
 
@@ -514,7 +521,7 @@ def Restructure(ztree, newStructure):
     _zbcheck(ztree) # verify ztree after our tweaks
     tstruct = StructureOf(ztree, onlyKeys=True)
     if tstruct != newStructure:
-        panic("BUG: Restructure: result structure is not what was"
+        panic("BUG: result structure is not what was"
               " requested:\n%s\n\nwant:\n%s" % (tstruct, newStructure))