ipapython.dn: Use rich comparisons

__cmp__ and cmp were removed from Python 3.

Reviewed-By: David Kupka <dkupka@redhat.com>
Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Martin Basti <mbasti@redhat.com>

ipapython/dn.py

@@ -420,6 +420,7 @@ to the constructor. The result may share underlying structure.
 from __future__ import print_function
 
 import sys
+import functools
 
 from ldap.dn import str2dn, dn2str
 from ldap import DECODING_ERROR
@@ -449,9 +450,11 @@ def _adjust_indices(start, end, length):
 
 
 def _normalize_ava_input(val):
-    if not isinstance(val, six.string_types):
-        val = unicode(val).encode('utf-8')
-    elif isinstance(val, unicode):
+    if six.PY3 and isinstance(val, bytes):
+        raise TypeError('expected str, got bytes: %s' % val)
+    elif not isinstance(val, six.string_types):
+        val = val_encode(six.text_type(val))
+    elif six.PY2 and isinstance(val, unicode):
         val = val.encode('utf-8')
     return val
 
@@ -512,29 +515,47 @@ def get_ava(*args):
 def sort_avas(rdn):
     if len(rdn) <= 1:
         return
-    rdn.sort(cmp=cmp_avas)
+    rdn.sort(key=ava_key)
 
 
-def cmp_avas(a, b):
-    r = cmp(a[0].lower(), b[0].lower())
-    if r == 0:
-        r = cmp(a[1].lower(), b[1].lower())
-    return r
+def ava_key(ava):
+    return ava[0].lower(), ava[1].lower()
 
 
 def cmp_rdns(a, b):
+    key_a = rdn_key(a)
+    key_b = rdn_key(b)
+    if key_a == key_b:
+        return 0
+    elif key_a < key_b:
+        return -1
+    else:
+        return 1
 
-    l = len(a)
-    r = cmp(l, len(b))
-    if r != 0:
-        return r
 
-    for i, ava_a in enumerate(a):
-        r = cmp_avas(ava_a, b[i])
-        if r != 0:
-            return r
-    return 0
+def rdn_key(rdn):
+    return (len(rdn),) + tuple(ava_key(k) for k in rdn)
 
+
+if six.PY2:
+    # Python 2: Input/output is unicode; we store UTF-8 bytes
+    def val_encode(s):
+        return s.encode('utf-8')
+
+    def val_decode(s):
+        return s.decode('utf-8')
+else:
+    # Python 3: Everything is unicode (str)
+    def val_encode(s):
+        if isinstance(s, bytes):
+            raise TypeError('expected str, got bytes: %s' % s)
+        return s
+
+    def val_decode(s):
+        return s
+
+
+@functools.total_ordering
 class AVA(object):
     '''
     AVA(arg0, ...)
@@ -593,23 +614,23 @@ class AVA(object):
         self._ava = get_ava(*args)
 
     def _get_attr(self):
-        return self._ava[0].decode('utf-8')
+        return val_decode(self._ava[0])
 
     def _set_attr(self, new_attr):
         try:
             self._ava[0] = _normalize_ava_input(new_attr)
-        except Exception, e:
+        except Exception as e:
             raise ValueError('unable to convert attr "%s": %s' % (new_attr, e))
 
     attr = property(_get_attr)
 
     def _get_value(self):
-        return self._ava[1].decode('utf-8')
+        return val_decode(self._ava[1])
 
     def _set_value(self, new_value):
         try:
             self._ava[1] = _normalize_ava_input(new_value)
-        except Exception, e:
+        except Exception as e:
             raise ValueError('unable to convert value "%s": %s' % (new_value, e))
 
     value = property(_get_value)
@@ -669,20 +690,21 @@ class AVA(object):
             return False
 
         # Perform comparison between objects of same type
-        return cmp_avas(self._ava, other._ava) == 0
+        return ava_key(self._ava) == ava_key(other._ava)
 
     def __ne__(self, other):
         return not self.__eq__(other)
 
-    def __cmp__(self, other):
+    def __lt__(self, other):
         'comparison is case insensitive, see __eq__ doc for explanation'
 
         if not isinstance(other, AVA):
             raise TypeError("expected AVA but got %s" % (other.__class__.__name__))
 
-        return cmp_avas(self._ava, other._ava)
+        return ava_key(self._ava) < ava_key(other._ava)
 
 
+@functools.total_ordering
 class RDN(object):
     '''
     RDN(arg0, ...)
@@ -843,8 +865,8 @@ class RDN(object):
             return [self._get_ava(ava) for ava in self._avas[key]]
         elif isinstance(key, six.string_types):
             for ava in self._avas:
-                if key == ava[0].decode('utf-8'):
-                    return ava[1].decode('utf-8')
+                if key == val_decode(ava[0]):
+                    return val_decode(ava[1])
             raise KeyError("\"%s\" not found in %s" % (key, self.__str__()))
         else:
             raise TypeError("unsupported type for RDN indexing, must be int, basestring or slice; not %s" % \
@@ -853,25 +875,25 @@ class RDN(object):
     def _get_attr(self):
         if len(self._avas) == 0:
             raise IndexError("No AVA's in this RDN")
-        return self._avas[0][0].decode('utf-8')
+        return val_decode(self._avas[0][0])
 
     def _set_attr(self, new_attr):
         if len(self._avas) == 0:
             raise IndexError("No AVA's in this RDN")
 
-        self._avas[0][0] = unicode(new_attr).encode('utf-8')
+        self._avas[0][0] = val_encode(six.text_type(new_attr))
 
     attr  = property(_get_attr)
 
     def _get_value(self):
         if len(self._avas) == 0:
             raise IndexError("No AVA's in this RDN")
-        return self._avas[0][1].decode('utf-8')
+        return val_decode(self._avas[0][1])
 
     def _set_value(self, new_value):
         if len(self._avas) == 0:
             raise IndexError("No AVA's in this RDN")
-        self._avas[0][1] = unicode(new_value).encode('utf-8')
+        self._avas[0][1] = val_encode(six.text_type(new_value))
 
     value = property(_get_value)
 
@@ -898,16 +920,16 @@ class RDN(object):
             return False
 
         # Perform comparison between objects of same type
-        return cmp_rdns(self._avas, other._avas) == 0
+        return rdn_key(self._avas) == rdn_key(other._avas)
 
     def __ne__(self, other):
         return not self.__eq__(other)
 
-    def __cmp__(self, other):
+    def __lt__(self, other):
         if not isinstance(other, RDN):
             raise TypeError("expected RDN but got %s" % (other.__class__.__name__))
 
-        return cmp_rdns(self._avas, other._avas)
+        return rdn_key(self._avas) < rdn_key(other._avas)
 
     def __add__(self, other):
         result = self.__class__(self)
@@ -927,6 +949,7 @@ class RDN(object):
         return result
 
 
+@functools.total_ordering
 class DN(object):
     '''
     DN(arg0, ...)
@@ -1088,8 +1111,8 @@ class DN(object):
     def _rdns_from_value(self, value):
         if isinstance(value, six.string_types):
             try:
-                if isinstance(value, unicode):
-                    value = value.encode('utf-8')
+                if isinstance(value, six.text_type):
+                    value = val_encode(value)
                 rdns = str2dn(value)
             except DECODING_ERROR:
                 raise ValueError("malformed RDN string = \"%s\"" % value)
@@ -1124,7 +1147,7 @@ class DN(object):
     def __str__(self):
         try:
             return dn2str(self.rdns)
-        except Exception, e:
+        except Exception as e:
             print(len(self.rdns))
             print(self.rdns)
             raise
@@ -1153,8 +1176,8 @@ class DN(object):
         elif isinstance(key, six.string_types):
             for rdn in self.rdns:
                 for ava in rdn:
-                    if key == ava[0].decode('utf-8'):
-                        return ava[1].decode('utf-8')
+                    if key == val_decode(ava[0]):
+                        return val_decode(ava[1])
             raise KeyError("\"%s\" not found in %s" % (key, self.__str__()))
         else:
             raise TypeError("unsupported type for DN indexing, must be int, basestring or slice; not %s" % \
@@ -1187,23 +1210,25 @@ class DN(object):
         if not isinstance(other, DN):
             return False
 
+        if len(self) != len(other):
+            return False
+
         # Perform comparison between objects of same type
-        return self.__cmp__(other) == 0
+        return self._cmp_sequence(other, 0, len(self)) == 0
 
     def __ne__(self, other):
         return not self.__eq__(other)
 
-    def __cmp__(self, other):
+    def __lt__(self, other):
         if not isinstance(other, DN):
             raise TypeError("expected DN but got %s" % (other.__class__.__name__))
 
-        result = cmp(len(self), len(other))
-        if result != 0:
-            return result
-        return self._cmp_sequence(other, 0, len(self))
+        if len(self) != len(other):
+            return len(self) < len(other)
+
+        return self._cmp_sequence(other, 0, len(self)) < 0
 
     def _cmp_sequence(self, pattern, self_start, pat_len):
-
         self_idx = self_start
         self_len = len(self)
         pat_idx = 0

ipatests/test_ipapython/test_dn.py

@@ -4,11 +4,33 @@ import unittest
 
 import six
 
-from ipapython.dn import *
+from ipapython.dn import DN, RDN, AVA
 
 if six.PY3:
     unicode = str
 
+    def cmp(a, b):
+        if a == b:
+            assert not a < b
+            assert not a > b
+            assert not a != b
+            assert a <= b
+            assert a >= b
+            return 0
+        elif a < b:
+            assert not a > b
+            assert a != b
+            assert a <= b
+            assert not a >= b
+            return -1
+        else:
+            assert a > b
+            assert a != b
+            assert not a <= b
+            assert a >= b
+            return 1
+
+
 def expected_class(klass, component):
     if klass is AVA:
         if component == 'self':