util: copy in nummedobj from pyutil

diff --git a/src/allmydata/util/nummedobj.py b/src/allmydata/util/nummedobj.py
new file mode 100644 (file)
index 0000000..e60505f
--- /dev/null
+++ b/src/allmydata/util/nummedobj.py
@@ -0,0 +1,48 @@
+import dictutil
+
+class NummedObj(object):
+    """
+    This is useful for nicer debug printouts.  Instead of objects of the same class being
+    distinguished from one another by their memory address, they each get a unique number, which
+    can be read as "the first object of this class", "the second object of this class", etc.  This
+    is especially useful because separate runs of a program will yield identical debug output,
+    (assuming that the objects get created in the same order in each run).  This makes it possible
+    to diff outputs from separate runs to see what changed, without having to ignore a difference
+    on every line due to different memory addresses of objects.
+    """
+    objnums = dictutil.NumDict() # key: class names, value: highest used object number
+
+    def __init__(self, klass=None):
+        """
+        @param klass: in which class are you counted?  If default value of `None', then self.__class__ will be used.
+        """
+        if klass is None:
+            klass = self.__class__
+        self._classname = klass.__name__
+            
+        NummedObj.objnums.inc(self._classname)
+        self._objid = NummedObj.objnums[self._classname]
+
+    def __repr__(self):
+        return "<%s #%d>" % (self._classname, self._objid,)
+
+    def __lt__(self, other):
+        return (self._objid, self._classname,) < (other._objid, other._classname,)
+
+    def __le__(self, other):
+        return (self._objid, self._classname,) <= (other._objid, other._classname,)
+
+    def __eq__(self, other):
+        return (self._objid, self._classname,) == (other._objid, other._classname,)
+
+    def __ne__(self, other):
+        return (self._objid, self._classname,) != (other._objid, other._classname,)
+
+    def __gt__(self, other):
+        return (self._objid, self._classname,) > (other._objid, other._classname,)
+
+    def __ge__(self, other):
+        return (self._objid, self._classname,) >= (other._objid, other._classname,)
+
+    def __hash__(self):
+        return id(self)