[Python-checkins] cpython: Issue #21233: Revert bytearray(int) optimization using calloc()

Mon Jun 2 22:23:26 CEST 2014

http://hg.python.org/cpython/rev/dff6b4b61cac
changeset: 90981:dff6b4b61cac
user: Victor Stinner <victor.stinner at gmail.com>
date: Mon Jun 02 22:22:42 2014 +0200
summary:
 Issue #21233: Revert bytearray(int) optimization using calloc()
files:
 Doc/whatsnew/3.5.rst | 5 ++---
 Misc/NEWS | 7 +++----
 Objects/bytearrayobject.c | 16 ++--------------
 3 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -196,9 +196,8 @@
 
 The following performance enhancements have been added:
 
-* Construction of ``bytes(int)`` and ``bytearray(int)`` (filled by zero bytes)
- is faster and use less memory (until the bytearray buffer is filled with
- data) for large objects. ``calloc()`` is used instead of ``malloc()`` to
+* Construction of ``bytes(int)`` (filled by zero bytes) is faster and use less
+ memory for large objects. ``calloc()`` is used instead of ``malloc()`` to
 allocate memory for these objects.
 
 * Some operations on :class:`~ipaddress.IPv4Network` and
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -26,10 +26,9 @@
 internal iteration logic.
 
 - Issue #21233: Add new C functions: PyMem_RawCalloc(), PyMem_Calloc(),
- PyObject_Calloc(), _PyObject_GC_Calloc(). bytes(int) and bytearray(int)
- are now using ``calloc()`` instead of ``malloc()`` for large objects which
- is faster and use less memory (until the bytearray buffer is filled with
- data).
+ PyObject_Calloc(), _PyObject_GC_Calloc(). bytes(int) is now using
+ ``calloc()`` instead of ``malloc()`` for large objects which is faster and
+ use less memory.
 
 - Issue #21377: PyBytes_Concat() now tries to concatenate in-place when the
 first argument has a reference count of 1. Patch by Nikolaus Rath.
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -813,21 +813,9 @@
 }
 else {
 if (count > 0) {
- void *sval;
- Py_ssize_t alloc;
-
- assert (Py_SIZE(self) == 0);
-
- alloc = count + 1;
- sval = PyObject_Calloc(1, alloc);
- if (sval == NULL)
+ if (PyByteArray_Resize((PyObject *)self, count))
 return -1;
-
- PyObject_Free(self->ob_bytes);
-
- self->ob_bytes = self->ob_start = sval;
- Py_SIZE(self) = count;
- self->ob_alloc = alloc;
+ memset(PyByteArray_AS_STRING(self), 0, count);
 }
 return 0;
 }
-- 
Repository URL: http://hg.python.org/cpython
