[Python-checkins] cpython: Issue #12744: Fix inefficient representation of integers

Sat Aug 13 20:19:40 CEST 2011

http://hg.python.org/cpython/rev/8e824e09924a
changeset: 71860:8e824e09924a
user: Antoine Pitrou <solipsis at pitrou.net>
date: Sat Aug 13 20:15:19 2011 +0200
summary:
 Issue #12744: Fix inefficient representation of integers
between 2**31 and 2**63 on systems with a 64-bit C "long".
files:
 Lib/test/pickletester.py | 10 ++++++++++
 Misc/NEWS | 3 +++
 Modules/_pickle.c | 2 +-
 3 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -1118,6 +1118,16 @@
 empty = self.loads(b'\x80\x03U\x00q\x00.', encoding='koi8-r')
 self.assertEqual(empty, '')
 
+ def test_int_pickling_efficiency(self):
+ # Test compacity of int representation (see issue #12744)
+ for proto in protocols:
+ sizes = [len(self.dumps(2**n, proto)) for n in range(70)]
+ # the size function is monotonous
+ self.assertEqual(sorted(sizes), sizes)
+ if proto >= 2:
+ self.assertLessEqual(sizes[-1], 14)
+
+
 # Test classes for reduce_ex
 
 class REX_one(object):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -254,6 +254,9 @@
 Library
 -------
 
+- Issue #12744: Fix inefficient representation of integers between 2**31 and
+ 2**63 on systems with a 64-bit C "long".
+
 - Issue #12646: Add an 'eof' attribute to zlib.Decompress, to make it easier to
 detect truncated input streams.
 
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1540,7 +1540,7 @@
 /* out of range for int pickling */
 PyErr_Clear();
 }
- else
+ else if (val <= 0x7fffffffL && val >= -0x80000000L)
 return save_int(self, val);
 
 if (self->proto >= 2) {
-- 
Repository URL: http://hg.python.org/cpython
