Replace float with Decimal

Having float type as a base type for floating point parameters in
ipalib introduces several issues, e.g. problem with representation
or value comparison. Python language provides a Decimal type which
help overcome these issues.

This patch replaces a float type and Float parameter with a
decimal.Decimal type in Decimal parameter. A precision attribute
was added to Decimal parameter that can be used to limit a number
of decimal places in parameter representation. This approach fixes
a problem with API.txt validation where comparison of float values
may fail on different architectures due to float representation error.

In order to safely transfer the parameter value over RPC it is
being converted to string which is then converted back to
decimal.Decimal number on a server side.

https://fedorahosted.org/freeipa/ticket/2260

tests/test_ipalib/test_parameters.py

@@ -25,6 +25,7 @@ Test the `ipalib.parameters` module.
 import re
 import sys
 from types import NoneType
+from decimal import Decimal
 from inspect import isclass
 from tests.util import raises, ClassChecker, read_only
 from tests.util import dummy_ugettext, assert_equal
@@ -1300,77 +1301,77 @@ class test_Int(ClassChecker):
         assert o._convert_scalar(u'0x10')  == 16
         assert o._convert_scalar(u'020')   == 16
 
-class test_Float(ClassChecker):
+class test_Decimal(ClassChecker):
     """
-    Test the `ipalib.parameters.Float` class.
+    Test the `ipalib.parameters.Decimal` class.
     """
-    _cls = parameters.Float
+    _cls = parameters.Decimal
 
     def test_init(self):
         """
-        Test the `ipalib.parameters.Float.__init__` method.
+        Test the `ipalib.parameters.Decimal.__init__` method.
         """
         # Test with no kwargs:
         o = self.cls('my_number')
-        assert o.type is float
-        assert isinstance(o, parameters.Float)
+        assert o.type is Decimal
+        assert isinstance(o, parameters.Decimal)
         assert o.minvalue is None
         assert o.maxvalue is None
 
         # Test when min > max:
-        e = raises(ValueError, self.cls, 'my_number', minvalue=22.5, maxvalue=15.1)
+        e = raises(ValueError, self.cls, 'my_number', minvalue=Decimal('22.5'), maxvalue=Decimal('15.1'))
         assert str(e) == \
-            "Float('my_number'): minvalue > maxvalue (minvalue=22.5, maxvalue=15.1)"
+            "Decimal('my_number'): minvalue > maxvalue (minvalue=22.5, maxvalue=15.1)"
 
     def test_rule_minvalue(self):
         """
-        Test the `ipalib.parameters.Float._rule_minvalue` method.
+        Test the `ipalib.parameters.Decimal._rule_minvalue` method.
         """
-        o = self.cls('my_number', minvalue=3.1)
-        assert o.minvalue == 3.1
+        o = self.cls('my_number', minvalue='3.1')
+        assert o.minvalue == Decimal('3.1')
         rule = o._rule_minvalue
-        translation = u'minvalue=%(minvalue)r'
+        translation = u'minvalue=%(minvalue)s'
         dummy = dummy_ugettext(translation)
         assert dummy.translation is translation
 
         # Test with passing values:
-        for value in (3.2, 99.0):
+        for value in (Decimal('3.2'), Decimal('99.0')):
             assert rule(dummy, value) is None
             assert dummy.called() is False
 
         # Test with failing values:
-        for value in (-1.2, 0.0, 3.0):
+        for value in (Decimal('-1.2'), Decimal('0.0'), Decimal('3.0')):
             assert_equal(
                 rule(dummy, value),
-                translation % dict(minvalue=3.1)
+                translation % dict(minvalue=Decimal('3.1'))
             )
-            assert dummy.message == 'must be at least %(minvalue)f'
+            assert dummy.message == 'must be at least %(minvalue)s'
             assert dummy.called() is True
             dummy.reset()
 
     def test_rule_maxvalue(self):
         """
-        Test the `ipalib.parameters.Float._rule_maxvalue` method.
+        Test the `ipalib.parameters.Decimal._rule_maxvalue` method.
         """
-        o = self.cls('my_number', maxvalue=4.7)
-        assert o.maxvalue == 4.7
+        o = self.cls('my_number', maxvalue='4.7')
+        assert o.maxvalue == Decimal('4.7')
         rule = o._rule_maxvalue
         translation = u'maxvalue=%(maxvalue)r'
         dummy = dummy_ugettext(translation)
         assert dummy.translation is translation
 
         # Test with passing values:
-        for value in (-1.0, 0.1, 4.2):
+        for value in (Decimal('-1.0'), Decimal('0.1'), Decimal('4.2')):
             assert rule(dummy, value) is None
             assert dummy.called() is False
 
         # Test with failing values:
-        for value in (5.3, 99.9):
+        for value in (Decimal('5.3'), Decimal('99.9')):
             assert_equal(
                 rule(dummy, value),
-                translation % dict(maxvalue=4.7)
+                translation % dict(maxvalue=Decimal('4.7'))
             )
-            assert dummy.message == 'can be at most %(maxvalue)f'
+            assert dummy.message == 'can be at most %(maxvalue)s'
             assert dummy.called() is True
             dummy.reset()
 

tests/test_xmlrpc/test_dns_plugin.py

@@ -598,7 +598,7 @@ class test_dns(Declarative):
                     'idnsname': [dnszone1],
                     'mxrecord': [u"0 %s" % dnszone1_mname],
                     'nsrecord': [dnszone1_mname],
-                    'locrecord': [u"49 11 42.4 N 16 36 29.6 E 227.64"],
+                    'locrecord': [u"49 11 42.400 N 16 36 29.600 E 227.64"],
                 },
             },
         ),