better api and tests added

* _copy_results = deepcopy for better performance
* _copy_results_exclude to deepcopy but exclude certain fields. Pop
fields that do not need to be deep copied. Re-assign popped fields
after deep copy so we don't modify the original, to be copied, object.
* _copy_results_exclude unit tests

lib/ansible/plugins/callback/__init__.py

@@ -22,7 +22,7 @@
 import json
 import difflib
 import warnings
-from copy import copy, deepcopy
+from copy import deepcopy
 
 from ansible.compat.six import string_types
 
@@ -59,9 +59,20 @@ def __init__(self, display=None):
             version = getattr(self, 'CALLBACK_VERSION', '1.0')
             self._display.vvvv('Loaded callback %s of type %s, v%s' % (name, ctype, version))
 
-    def _copy_result(self, result):
-        ''' helper for callbacks, so they don't all have to include deepcopy '''
-        return deepcopy(result)
+    ''' helper for callbacks, so they don't all have to include deepcopy '''
+    _copy_result = deepcopy
+
+    def _copy_result_exclude(self, result, exclude):
+        values = []
+        for e in exclude:
+            values.append(getattr(result, e))
+            setattr(result, e, None)
+
+        result_copy = deepcopy(result)
+        for i,e in enumerate(exclude):
+            setattr(result, e, values[i])
+
+        return result_copy
 
     def _dump_results(self, result, indent=None, sort_keys=True, keep_invocation=False):
         if result.get('_ansible_no_log', False):
@@ -128,18 +139,9 @@ def _get_item(self, result):
 
         return item
 
-    def deepcopy_exclude(self, copyme, exclude=[]):
-        res = copy(copyme)
-        try:
-            setattr(res, exclude, None)
-        except TypeError:
-            for e in exclude:
-                setattr(res, e, None)
-        return deepcopy(res)
-
     def _process_items(self, result):
         for res in result._result['results']:
-            newres = self.deepcopy_exclude(result, '_result')
+            newres = self._copy_result_exclude(result, ['_result'])
             res['item'] = self._get_item(res)
             newres._result = res
             if 'failed' in res and res['failed']:

test/units/plugins/callback/test_callback.py

@@ -0,0 +1,81 @@
+# (c) 2012-2014, Chris Meyers <chris.meyers.fsu@gmail.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from six import PY3
+from copy import deepcopy
+
+from ansible.compat.tests import unittest
+from ansible.compat.tests.mock import patch, mock_open
+
+from ansible.plugins.callback import CallbackBase
+import ansible.plugins.callback as callish
+
+class TestCopyResultExclude(unittest.TestCase):
+    def setUp(self):
+        class DummyClass():
+            def __init__(self):
+                self.bar = [ 1, 2, 3 ]
+                self.a = {
+                    "b": 2,
+                    "c": 3,
+                }
+                self.b = {
+                    "c": 3,
+                    "d": 4,
+                }
+        self.foo = DummyClass()
+        self.cb = CallbackBase()
+
+    def tearDown(self):
+        pass
+
+    def test_copy_logic(self):
+        res = self.cb._copy_result_exclude(self.foo, ())
+        self.assertEqual(self.foo.bar, res.bar)
+
+    def test_copy_deep(self):
+        res = self.cb._copy_result_exclude(self.foo, ())
+        self.assertNotEqual(id(self.foo.bar), id(res.bar))
+
+    def test_no_exclude(self):
+        res = self.cb._copy_result_exclude(self.foo, ())
+        self.assertEqual(self.foo.bar, res.bar)
+        self.assertEqual(self.foo.a, res.a)
+        self.assertEqual(self.foo.b, res.b)
+
+    def test_exclude(self):
+        res = self.cb._copy_result_exclude(self.foo, ['bar', 'b'])
+        self.assertIsNone(res.bar)
+        self.assertIsNone(res.b)
+        self.assertEqual(self.foo.a, res.a)
+
+    def test_result_unmodified(self):
+        bar_id = id(self.foo.bar)
+        a_id = id(self.foo.a)
+        res = self.cb._copy_result_exclude(self.foo, ['bar', 'a'])
+
+        self.assertEqual(self.foo.bar, [ 1, 2, 3 ])
+        self.assertEqual(bar_id, id(self.foo.bar))
+
+        self.assertEqual(self.foo.a, dict(b=2, c=3))
+        self.assertEqual(a_id, id(self.foo.a))
+
+