Optimize bytearray % args

Issue #25399: Don't create temporary bytes objects: modify _PyBytes_Format() to
create work directly on bytearray objects.

* Rename _PyBytes_Format() to _PyBytes_FormatEx() just in case if something
  outside CPython uses it
* _PyBytes_FormatEx() now uses (char*, Py_ssize_t) for the input string, so
  bytearray_format() doesn't need tot create a temporary input bytes object
* Add use_bytearray parameter to _PyBytes_FormatEx() which is passed to
  _PyBytesWriter, to create a bytearray buffer instead of a bytes buffer

Most formatting operations are now between 2.5 and 5 times faster.

1 files changed, 5 insertions, 1 deletions

diff --git a/Include/bytesobject.h b/Include/bytesobject.h
index fbb6322..b5b37ef 100644
--- a/Include/bytesobject.h
+++ b/Include/bytesobject.h
@@ -62,7 +62,11 @@ PyAPI_FUNC(void) PyBytes_Concat(PyObject **, PyObject *);
 PyAPI_FUNC(void) PyBytes_ConcatAndDel(PyObject **, PyObject *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyBytes_Resize(PyObject **, Py_ssize_t);
-PyAPI_FUNC(PyObject *) _PyBytes_Format(PyObject *, PyObject *);
+PyAPI_FUNC(PyObject*) _PyBytes_FormatEx(
+    const char *format,
+    Py_ssize_t format_len,
+    PyObject *args,
+    int use_bytearray);
 #endif
 PyAPI_FUNC(PyObject *) PyBytes_DecodeEscape(const char *, Py_ssize_t,
 						   const char *, Py_ssize_t,