Always format 8-byte oids as ints in hexadecimal.

Fixes #95

Built on #97 as they touch the same code.

CHANGES.rst

@@ -9,6 +9,10 @@
   and the behaviour prior to 4.4.0. See `issue 92
   <https://github.com/zopefoundation/persistent/issues/92>`_.
 
+- Change the repr of persistent objects to format the OID as in
+  integer in hexadecimal notation if it is an 8-byte byte string, as
+  ZODB does. This eliminates some issues in doctests. See `issue 95
+  <https://github.com/zopefoundation/persistent/pull/95>`_.
 
 4.4.2 (2018-08-28)
 ------------------

persistent/cPersistence.c

@@ -1429,6 +1429,9 @@ Per_repr(cPersistentObject *self)
     PyObject *jar_str = NULL;
     PyObject *result = NULL;
 
+    unsigned char* oid_bytes;
+    unsigned long long oid_value;
+
     prepr = PyObject_GetAttrString((PyObject*)Py_TYPE(self), "_p_repr");
     if (prepr)
     {
@@ -1448,9 +1451,24 @@ Per_repr(cPersistentObject *self)
         prepr_exc_str = PyUnicode_FromString("");
     }
 
-    oid_str = repr_helper(self->oid, " oid %R");
-    if (!oid_str)
-        goto cleanup;
+    if (self->oid && PyBytes_Check(self->oid) && PyBytes_GET_SIZE(self->oid) == 8) {
+        oid_bytes = (unsigned char*)PyBytes_AS_STRING(self->oid);
+        oid_value = ((unsigned long long)oid_bytes[0] << 56)
+            | ((unsigned long long)oid_bytes[1] << 48)
+            | ((unsigned long long)oid_bytes[2] << 40)
+            | ((unsigned long long)oid_bytes[3] << 32)
+            | ((unsigned long long)oid_bytes[4] << 24)
+            | ((unsigned long long)oid_bytes[5] << 16)
+            | ((unsigned long long)oid_bytes[6] << 8)
+            | ((unsigned long long)oid_bytes[7]);
+        oid_str = PyUnicode_FromFormat(" oid 0x%x", oid_value);
+    }
+
+    if (!oid_str) {
+        oid_str = repr_helper(self->oid, " oid %R");
+        if (!oid_str)
+            goto cleanup;
+    }
 
     jar_str = repr_helper(self->jar, " in %R");
     if (!jar_str)

persistent/persistence.py

@@ -11,7 +11,7 @@
 # FOR A PARTICULAR PURPOSE.
 #
 ##############################################################################
-
+import struct
 
 from zope.interface import implementer
 
@@ -52,6 +52,11 @@
 # check in __getattribute__
 _SPECIAL_NAMES = set(SPECIAL_NAMES)
 
+# Represent 8-byte OIDs as hex integer, just like
+# ZODB does.
+_OID_STRUCT = struct.Struct('>Q')
+_OID_UNPACK = _OID_STRUCT.unpack
+
 @implementer(IPersistent)
 class Persistent(object):
     """ Pure Python implmentation of Persistent base class
@@ -574,7 +579,10 @@ def __repr__(self):
 
         if oid is not None:
             try:
-                oid_str = ' oid %r' % (oid,)
+                if isinstance(oid, bytes) and len(oid) == 8:
+                    oid_str = ' oid 0x%x' % (_OID_UNPACK(oid)[0],)
+                else:
+                    oid_str = ' oid %r' % (oid,)
             except Exception as e:
                 oid_str = ' oid %r' % (e,)
 

persistent/tests/test_persistence.py

@@ -1697,13 +1697,16 @@ class TestPersistent(self._getTargetClass()):
         self.assertEqual(candidate._p_state, GHOST)
         self.assertEqual(candidate.set_by_new, 1)
 
+    # The number 12345678 as a p64, 8-byte string
+    _PACKED_OID = b'\x00\x00\x00\x00\x00\xbcaN'
+    # The number 12345678 printed in hex
+    _HEX_OID = '0xbc614e'
+
     def _normalize_repr(self, r):
         # addresses
-        r = re.sub(r'0x[0-9a-fA-F]*', '0xdeadbeef', r)
+        r = re.sub(r'at 0x[0-9a-fA-F]*', 'at 0xdeadbeef', r)
         # Python 3.7 removed the trailing , in exception reprs
         r = r.replace("',)", "')")
-        # Python 2 doesn't have a leading b prefix for byte literals
-        r = r.replace("oid '", "oid b'")
         return r
 
     def _normalized_repr(self, o):
@@ -1730,12 +1733,12 @@ def __repr__(self):
 
     def test_repr_oid_no_jar(self):
         p = self._makeOne()
-        p._p_oid = b'12345678'
+        p._p_oid = self._PACKED_OID
 
         result = self._normalized_repr(p)
         self.assertEqual(
             result,
-            "<persistent.Persistent object at 0xdeadbeef oid b'12345678'>")
+            "<persistent.Persistent object at 0xdeadbeef oid " + self._HEX_OID + ">")
 
     def test_repr_no_oid_repr_jar_raises_exception(self):
         p = self._makeOne()
@@ -1758,7 +1761,17 @@ def test_repr_oid_raises_exception_no_jar(self):
         class BadOID(bytes):
             def __repr__(self):
                 raise Exception("oid repr failed")
-        p._p_oid = BadOID(b'12345678')
+
+        # Our OID is bytes, 8 bytes long. We don't call its repr.
+        p._p_oid = BadOID(self._PACKED_OID)
+
+        result = self._normalized_repr(p)
+        self.assertEqual(
+            result,
+            "<persistent.Persistent object at 0xdeadbeef oid " + self._HEX_OID + ">")
+
+        # Anything other than 8 bytes, though, we do.
+        p._p_oid = BadOID(b'1234567')
 
         result = self._normalized_repr(p)
         self.assertEqual(
@@ -1772,7 +1785,7 @@ def test_repr_oid_and_jar_raise_exception(self):
         class BadOID(bytes):
             def __repr__(self):
                 raise Exception("oid repr failed")
-        p._p_oid = BadOID(b'12345678')
+        p._p_oid = BadOID(b'1234567')
 
         class Jar(object):
             def __repr__(self):
@@ -1806,12 +1819,17 @@ def __repr__(self):
                 raise BaseException("oid repr failed")
         p._p_oid = BadOID(b'12345678')
 
+        # An 8 byte byte string doesn't have repr called.
+        repr(p)
+
+        # Anything other does.
+        p._p_oid = BadOID(b'1234567')
         with self.assertRaisesRegex(BaseException, 'oid repr failed'):
             repr(p)
 
     def test_repr_oid_and_jar(self):
         p = self._makeOne()
-        p._p_oid = b'12345678'
+        p._p_oid = self._PACKED_OID
 
         class Jar(object):
             def __repr__(self):
@@ -1822,7 +1840,7 @@ def __repr__(self):
         result = self._normalized_repr(p)
         self.assertEqual(
             result,
-            "<persistent.Persistent object at 0xdeadbeef oid b'12345678' in <SomeJar>>")
+            "<persistent.Persistent object at 0xdeadbeef oid " + self._HEX_OID + " in <SomeJar>>")
 
     def test__p_repr(self):
         class P(self._getTargetClass()):
@@ -1842,12 +1860,12 @@ def _p_repr(self):
             "<persistent.tests.test_persistence.P object at 0xdeadbeef"
             " _p_repr Exception('_p_repr failed')>")
 
-        p._p_oid = b'12345678'
+        p._p_oid = self._PACKED_OID
         result = self._normalized_repr(p)
         self.assertEqual(
             result,
-            "<persistent.tests.test_persistence.P object at 0xdeadbeef oid b'12345678'"
-            " _p_repr Exception('_p_repr failed')>")
+            "<persistent.tests.test_persistence.P object at 0xdeadbeef oid " + self._HEX_OID
+            + " _p_repr Exception('_p_repr failed')>")
 
         class Jar(object):
             def __repr__(self):
@@ -1857,8 +1875,8 @@ def __repr__(self):
         result = self._normalized_repr(p)
         self.assertEqual(
             result,
-            "<persistent.tests.test_persistence.P object at 0xdeadbeef oid b'12345678'"
-            " in <SomeJar> _p_repr Exception('_p_repr failed')>")
+            "<persistent.tests.test_persistence.P object at 0xdeadbeef oid " + self._HEX_OID
+            + " in <SomeJar> _p_repr Exception('_p_repr failed')>")
 
     def test__p_repr_in_instance_ignored(self):
         class P(self._getTargetClass()):