Rev 4670: Fix bug #471193, allow tuples into the CHK code. in http://bazaar.launchpad.net/~jameinel/bzr/2.1.0b2-471193-st-and-chk-map

[John Arbash Meinel]

At http://bazaar.launchpad.net/~jameinel/bzr/2.1.0b2-471193-st-and-chk-map

------------------------------------------------------------
revno: 4670
revision-id: john at arbash-meinel.com-20091102171520-8udwpeq12bnz1vkb
parent: pqm at pqm.ubuntu.com-20091031025119-p9o49k7xb50npphw
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: 2.1.0b2-471193-st-and-chk-map
timestamp: Mon 2009-11-02 11:15:20 -0600
message:
  Fix bug #471193, allow tuples into the CHK code.
  
  Instead of raising a TypeError immediately, add a debug flag and only
  raise TypeErrors if that flag is set. Sort of like how we did
  ensure_unicode() for api changes.
-------------- next part --------------
=== modified file 'NEWS'
--- a/NEWS	2009-10-30 16:09:06 +0000
+++ b/NEWS	2009-11-02 17:15:20 +0000
@@ -31,6 +31,11 @@
   they do occur.  This fixes some causes of ``TooManyConcurrentRequests``
   and similar errors.  (Andrew Bennetts, #429747, #243391)
 
+* Reduce the strictness for StaticTuple, instead add a debug flag
+  ``-Dstatic_tuple`` which will change apis to be strict and raise errors.
+  This way, most users won't see failures, but developers can improve
+  internals. (John Arbash Meinel, #471193)
+
 * TreeTransform.adjust_path updates the limbo paths of descendants of adjusted
   files.  (Aaron Bentley)
 

=== modified file 'bzrlib/chk_map.py'
--- a/bzrlib/chk_map.py	2009-10-23 18:46:03 +0000
+++ b/bzrlib/chk_map.py	2009-11-02 17:15:20 +0000
@@ -720,6 +720,7 @@
         :param bytes: The bytes of the node.
         :param key: The key that the serialised node has.
         """
+        key = static_tuple.expect_static_tuple(key)
         return _deserialise_leaf_node(bytes, key,
                                       search_key_func=search_key_func)
 
@@ -1018,9 +1019,7 @@
         :param key: The key that the serialised node has.
         :return: An InternalNode instance.
         """
-        if type(key) is not StaticTuple:
-            raise AssertionError('deserialise should be called with a'
-                                 ' StaticTuple not %s' % (type(key),))
+        key = static_tuple.expect_static_tuple(key)
         return _deserialise_internal_node(bytes, key,
                                           search_key_func=search_key_func)
 

=== modified file 'bzrlib/help_topics/en/debug-flags.txt'
--- a/bzrlib/help_topics/en/debug-flags.txt	2009-10-07 08:19:19 +0000
+++ b/bzrlib/help_topics/en/debug-flags.txt	2009-11-02 17:15:20 +0000
@@ -30,6 +30,7 @@
 -Drelock          Emit a message every time a branch or repository object is
                   unlocked then relocked the same way.
 -Dsftp            Trace SFTP internals.
+-Dstatic_tuple    Error when a tuple is used where a StaticTuple is expected
 -Dstream          Trace fetch streams.
 -Dstrict_locks    Trace when OS locks are potentially used in a non-portable
                   manner.

=== modified file 'bzrlib/static_tuple.py'
--- a/bzrlib/static_tuple.py	2009-10-12 20:02:27 +0000
+++ b/bzrlib/static_tuple.py	2009-11-02 17:15:20 +0000
@@ -16,6 +16,8 @@
 
 """Interface thunk for a StaticTuple implementation."""
 
+from bzrlib import debug
+
 try:
     from bzrlib._static_tuple_c import StaticTuple
 except ImportError, e:
@@ -23,3 +25,15 @@
     osutils.failed_to_load_extension(e)
     from bzrlib._static_tuple_py import StaticTuple
 
+
+def expect_static_tuple(obj):
+    """Check if the passed object is a StaticTuple.
+
+    Cast it if necessary, but if the 'static_tuple' debug flag is set, raise an
+    error instead.
+    """
+    if 'static_tuple' not in debug.debug_flags:
+        return StaticTuple.from_sequence(obj)
+    if type(obj) is not StaticTuple:
+        raise TypeError('We expected a StaticTuple not a %s' % (type(obj),))
+    return obj

=== modified file 'bzrlib/tests/test__static_tuple.py'
--- a/bzrlib/tests/test__static_tuple.py	2009-10-27 14:07:16 +0000
+++ b/bzrlib/tests/test__static_tuple.py	2009-11-02 17:15:20 +0000
@@ -22,6 +22,7 @@
 
 from bzrlib import (
     _static_tuple_py,
+    debug,
     errors,
     osutils,
     static_tuple,
@@ -620,3 +621,28 @@
                 return
         self.assertIs(static_tuple.StaticTuple,
                       self.module.StaticTuple)
+
+
+class TestEnsureStaticTuple(tests.TestCase):
+
+    def test_is_static_tuple(self):
+        st = static_tuple.StaticTuple('foo')
+        st2 = static_tuple.expect_static_tuple(st)
+        self.assertIs(st, st2)
+
+    def test_is_tuple(self):
+        t = ('foo',)
+        st = static_tuple.expect_static_tuple(t)
+        self.assertIsInstance(st, static_tuple.StaticTuple)
+        self.assertEqual(t, st)
+
+    def test_flagged_is_static_tuple(self):
+        debug.debug_flags.add('static_tuple')
+        st = static_tuple.StaticTuple('foo')
+        st2 = static_tuple.expect_static_tuple(st)
+        self.assertIs(st, st2)
+
+    def test_flagged_is_tuple(self):
+        debug.debug_flags.add('static_tuple')
+        t = ('foo',)
+        self.assertRaises(TypeError, static_tuple.expect_static_tuple, t)