[Zope-Checkins] CVS: Zope/lib/python/BTrees - Maintainer.txt:1.10

[Tim Peters]

Update of /cvs-repository/Zope/lib/python/BTrees
In directory cvs.zope.org:/tmp/cvs-serv1031

Modified Files:
	Maintainer.txt 
Log Message:
Recorded some exploitable invariants.


=== Zope/lib/python/BTrees/Maintainer.txt 1.9 => 1.10 ===
   more efficiently than they can store arbitrary Python objects.
 
++ In a non-empty BTree, every bucket node contains at least one key,
+  and every BTree node contains at least one child.  An empty BTree
+  consists solely of a BTree node with len==0 and firstbucket==NULL.
+
++ Although a BTree can become unbalanced under a mix of inserts and
+  deletes (meaning both that there's nothing stronger that can be
+  said about buckets than that they're not empty, and that buckets
+  can appear at different depths), a BTree node always has children
+  of the same kind:  they're all buckets, or they're all BTree nodes.
+
 
 The BTREE_SEARCH Macro
 ======================