Add test for PURE_PYTHON environment.

CHANGES.rst

@@ -5,6 +5,9 @@
 4.0.7 (unreleased)
 ------------------
 
+- Add ``PURE_PYTHON`` environment variable support:  if set, the C
+  extensions will not be built or imported.
+
 
 4.0.6 (2013-01-03)
 ------------------

persistent/__init__.py

@@ -15,40 +15,55 @@
 
 Fall back to pure Python implementations.
 """
-try:
-    from persistent.cPersistence import Persistent
-    from persistent.cPersistence import GHOST
-    from persistent.cPersistence import UPTODATE
-    from persistent.cPersistence import CHANGED
-    from persistent.cPersistence import STICKY
-    from persistent.cPersistence import simple_new
-except ImportError: #pragma NO COVER
+import os
+
+PURE_PYTHON = os.environ.get('PURE_PYTHON')
+if not PURE_PYTHON:
+    try:
+        from persistent.cPersistence import Persistent
+        from persistent.cPersistence import GHOST
+        from persistent.cPersistence import UPTODATE
+        from persistent.cPersistence import CHANGED
+        from persistent.cPersistence import STICKY
+        from persistent.cPersistence import simple_new
+    except ImportError: #pragma NO COVER
+        from persistent.persistence import Persistent
+        from persistent.persistence import GHOST
+        from persistent.persistence import UPTODATE
+        from persistent.persistence import CHANGED
+        from persistent.persistence import STICKY
+    else:
+        from persistent._compat import copy_reg
+        copy_reg.constructor(simple_new)
+        # Make an interface declaration for Persistent, if zope.interface
+        # is available.  Note that the Python version already does this.
+        try:
+            from zope.interface import classImplements
+        except ImportError: #pragma NO COVER
+            pass
+        else:
+            from persistent.interfaces import IPersistent
+            classImplements(Persistent, IPersistent)
+
+    try:
+        from persistent.cPickleCache import PickleCache
+    except ImportError: #pragma NO COVER
+        from persistent.picklecache import PickleCache
+
+    try:
+        import persistent.TimeStamp
+    except ImportError: #pragma NO COVER
+        import persistent.timestamp as TimeStamp
+        import sys
+        sys.modules['persistent.TimeStamp'
+                   ] = sys.modules['persistent.timestamp']
+else: #pragma NO COVER
     from persistent.persistence import Persistent
     from persistent.persistence import GHOST
     from persistent.persistence import UPTODATE
     from persistent.persistence import CHANGED
     from persistent.persistence import STICKY
-else:
-    from persistent._compat import copy_reg
-    copy_reg.constructor(simple_new)
-    # Make an interface declaration for Persistent, if zope.interface
-    # is available.  Note that the Python version already does this.
-    try:
-        from zope.interface import classImplements
-    except ImportError: #pragma NO COVER
-        pass
-    else:
-        from persistent.interfaces import IPersistent
-        classImplements(Persistent, IPersistent)
-
-try:
-    from persistent.cPickleCache import PickleCache
-except ImportError: #pragma NO COVER
     from persistent.picklecache import PickleCache
-
-try:
-    import persistent.TimeStamp
-except ImportError: #pragma NO COVER
     import persistent.timestamp as TimeStamp
     import sys
     sys.modules['persistent.TimeStamp'] = sys.modules['persistent.timestamp']

persistent/tests/test_persistence.py

@@ -11,6 +11,7 @@
 # FOR A PARTICULAR PURPOSE.
 #
 ##############################################################################
+import os
 import unittest
 
 class _Persistent_Base(object):
@@ -1321,49 +1322,50 @@ class PyPersistentTests(unittest.TestCase, _Persistent_Base):
  
 _add_to_suite = [PyPersistentTests]
 
-try:
-    from persistent import cPersistence
-except ImportError:
-    pass
-else:
-    class CPersistentTests(unittest.TestCase, _Persistent_Base):
-
-        def _getTargetClass(self):
-            from persistent.cPersistence import Persistent
-            return Persistent
-
-        def _checkMRU(self, jar, value):
-            pass # Figure this out later
-    
-        def _clearMRU(self, jar):
-            pass # Figure this out later
-
-        def _makeCache(self, jar):
-            from persistent.cPickleCache import PickleCache
-            return PickleCache(jar)
-
-    _add_to_suite.append(CPersistentTests)
-
-    class Test_simple_new(unittest.TestCase):
-
-        def _callFUT(self, x):
-            from persistent.cPersistence import simple_new
-            return simple_new(x)
-
-        def test_w_non_type(self):
-            self.assertRaises(TypeError, self._callFUT, '')
-
-        def test_w_type(self):
-            import sys
-            TO_CREATE = [type, list, tuple, object]
-            # Python 3.3 segfaults when destroying a dict created via
-            # PyType_GenericNew.  See http://bugs.python.org/issue16676
-            if sys.version_info < (3, 3):
-                TO_CREATE.append(dict)
-            for typ in TO_CREATE:
-                self.assertTrue(isinstance(self._callFUT(typ), typ))
-
-    _add_to_suite.append(Test_simple_new)
+if not os.environ.get('PURE_PYTHON'):
+    try:
+        from persistent import cPersistence
+    except ImportError:
+        pass
+    else:
+        class CPersistentTests(unittest.TestCase, _Persistent_Base):
+
+            def _getTargetClass(self):
+                from persistent.cPersistence import Persistent
+                return Persistent
+
+            def _checkMRU(self, jar, value):
+                pass # Figure this out later
+        
+            def _clearMRU(self, jar):
+                pass # Figure this out later
+
+            def _makeCache(self, jar):
+                from persistent.cPickleCache import PickleCache
+                return PickleCache(jar)
+
+        _add_to_suite.append(CPersistentTests)
+
+        class Test_simple_new(unittest.TestCase):
+
+            def _callFUT(self, x):
+                from persistent.cPersistence import simple_new
+                return simple_new(x)
+
+            def test_w_non_type(self):
+                self.assertRaises(TypeError, self._callFUT, '')
+
+            def test_w_type(self):
+                import sys
+                TO_CREATE = [type, list, tuple, object]
+                # Python 3.3 segfaults when destroying a dict created via
+                # PyType_GenericNew.  See http://bugs.python.org/issue16676
+                if sys.version_info < (3, 3):
+                    TO_CREATE.append(dict)
+                for typ in TO_CREATE:
+                    self.assertTrue(isinstance(self._callFUT(typ), typ))
+
+        _add_to_suite.append(Test_simple_new)
 
 def test_suite():
     return unittest.TestSuite([unittest.makeSuite(x) for x in _add_to_suite])

setup.py

@@ -31,11 +31,12 @@ README = (open(os.path.join(here, 'README.rst')).read()
 py_impl = getattr(platform, 'python_implementation', lambda: None)
 is_pypy = py_impl() == 'PyPy'
 is_jython = 'java' in sys.platform
+is_pure = os.environ.get('PURE_PYTHON')
 
 # Jython cannot build the C optimizations, while on PyPy they are
 # anti-optimizations (the C extension compatibility layer is known-slow,
 # and defeats JIT opportunities).
-if is_pypy or is_jython:
+if is_pypy or is_jython or is_pure:
     ext_modules = headers = []
 else:
     ext_modules = [Extension(name = 'persistent.cPersistence',

tox.ini

@@ -3,7 +3,7 @@ envlist =
 # Jython support pending 2.7 support, due 2012-07-15 or so.  See:
 # http://fwierzbicki.blogspot.com/2012/03/adconion-to-fund-jython-27.html
 #   py26,py27,py32,jython,pypy,coverage,docs
-    py26,py27,pypy,py32,py33,coverage,docs
+    py26,py27,py27-pure,pypy,py32,py33,coverage,docs
 
 [testenv]
 deps =
@@ -15,6 +15,16 @@ commands =
 commands = 
    jython setup.py test -q
 
+[testenv:py27-pure]
+basepython =
+    python2.7
+setenv =
+    PURE_PYTHON = 1
+deps =
+    zope.interface
+commands = 
+    python setup.py test -q
+
 [testenv:coverage]
 basepython =
     python2.6