Issue #14744: Use the new _PyUnicodeWriter internal API to speed up str%args and str.format(args)
* Formatting string, int, float and complex use the _PyUnicodeWriter API. It
avoids a temporary buffer in most cases.
* Add _PyUnicodeWriter_WriteStr() to restore the PyAccu optimization: just
keep a reference to the string if the output is only composed of one string
* Disable overallocation when formatting the last argument of str%args and
str.format(args)
* Overallocation allocates at least 100 characters: add min_length attribute
to the _PyUnicodeWriter structure
* Add new private functions: _PyUnicode_FastCopyCharacters(),
_PyUnicode_FastFill() and _PyUnicode_FromASCII()
The speed up is around 20% in average.
diff --git a/Objects/stringlib/asciilib.h b/Objects/stringlib/asciilib.h
index ab5bae7..f62813d 100644
--- a/Objects/stringlib/asciilib.h
+++ b/Objects/stringlib/asciilib.h
@@ -18,7 +18,7 @@
#define STRINGLIB_TODECIMAL Py_UNICODE_TODECIMAL
#define STRINGLIB_STR PyUnicode_1BYTE_DATA
#define STRINGLIB_LEN PyUnicode_GET_LENGTH
-#define STRINGLIB_NEW unicode_fromascii
+#define STRINGLIB_NEW(STR,LEN) _PyUnicode_FromASCII((char*)(STR),(LEN))
#define STRINGLIB_RESIZE not_supported
#define STRINGLIB_CHECK PyUnicode_Check
#define STRINGLIB_CHECK_EXACT PyUnicode_CheckExact