.

wcfs/internal/xbtree.py

@@ -26,41 +26,78 @@ It is primarily used to verify ΔBTail in wcfs.
 XXX Typology:
 """
 
+from __future__ import print_function, absolute_import
+
 from BTrees import check as bcheck
+from golang import panic
+import re
+
 
 # Tree represents a tree node.
 class Tree:
     #   .keyv       () of keys
     #   .children   () of children  len(.children) == len(.keyv) + 1
-    def __init__(tree, keyv, *children):
+    def __init__(t, keyv, *children):
         assert len(children) == len(keyv) + 1, (keyv, children)
         # XXX assert keyv ↑
         # XXX assert children keys consistent?
-        tree.keyv     = tuple(keyv)
-        tree.children = tuple(children)
+        # XXX assert all children are of the same type
+        t.keyv     = tuple(keyv)
+        t.children = tuple(children)
 
     def __eq__(a, b):
         if not isinstance(b, Tree):
             return False
         return (a.keyv == b.keyv) and (a.children == b.children)    # XXX don't compare .children here?
-    def __hash__(tree):
-        return hash(tree.keyv) ^ hash(tree.children)                # XXX children ^^^
+    def __hash__(t):
+        return hash(t.keyv) ^ hash(t.children)                      # XXX children ^^^
+
+
+# Bucked represents a bucket node.
+class Bucket:
+    #   .keyv   () of keys
+    def __init__(b, keyv):
+        # XXX assert keyv ↑
+        b.keyv = tuple(keyv)
+
+    def __eq__(a, b):
+        if not isinstance(b, Bucket):
+            return False
+        return a.keyv == b.keyv
+    def __hash__(b):
+        return hash(b.keyv)
 
 
-# StructureOf returns internal structure of the tree.
-def StructureOf(tree):
-    typ = type(tree)
-    assert "Tree" in typ.__name__, typ
+# StructureOf returns internal structure of a tree.
+def StructureOf(node):
+    typ = type(node)
+    print(typ.__name__)
+    print(typ.__bases__)
+    is_tree   = ("Tree"   in typ.__name__)
+    is_set    = ("Set"    in typ.__name__)
+    is_bucket = (("Bucket" in typ.__name__) or re.match("..Set", typ.__name__))
+    is_map    = (not is_set)
 
-    kind, keys, children = bcheck.crack_btree(tree, True)
+    if is_bucket:
+        keys, _ = bcheck.crack_bucket(node, is_map)
+        return Bucket(keys)
+
+    if is_tree:
+        kind, keys, children = bcheck.crack_btree(node, is_map)
         if kind == bcheck.BTREE_EMPTY:
             return Tree([])
+
         if kind == bcheck.BTREE_ONE:
-        return Tree([])
+            b = node._bucket_type()
+            b.__setstate__(keys)    # it is keys+values for BTREE_ONE case
+            return StructureOf(b)
+
         if kind == bcheck.BTREE_NORMAL:
             return Tree(keys, *[StructureOf(_) for _ in children])
 
-    panic("bad kind %r" % kind)
+        panic("bad tree kind %r" % kind)
+
+    panic("unknown node type %r" % typ)