Issue #11303: Added shortcuts for utf8 and latin1 encodings.
Documented the list of optimized encodings as CPython implementation
detail.
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index c9222ca..0bffdb3 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -904,6 +904,15 @@
case or use a hyphen instead of an underscore are also valid aliases; therefore,
e.g. ``'utf-8'`` is a valid alias for the ``'utf_8'`` codec.
+.. impl-detail::
+
+ Some common encodings can bypass the codecs lookup machinery to
+ improve performance. These optimization opportunities are only
+ recognized by CPython for a limited set of aliases: utf-8, utf8,
+ latin-1, latin1, iso-8859-1, mbcs (Windows only), ascii, utf-16,
+ and utf-32. Using alternative spellings for these encodings may
+ result in slower execution.
+
Many of the character sets support the same languages. They vary in individual
characters (e.g. whether the EURO SIGN is supported or not), and in the
assignment of characters to code positions. For the European languages in
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index e7bbd80..48ea0a2 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1462,13 +1462,15 @@
char lower[11]; /* Enough for any encoding shortcut */
if (encoding == NULL)
- encoding = PyUnicode_GetDefaultEncoding();
+ return PyUnicode_DecodeUTF8(s, size, errors);
/* Shortcuts for common default encodings */
if (normalize_encoding(encoding, lower, sizeof(lower))) {
- if (strcmp(lower, "utf-8") == 0)
+ if ((strcmp(lower, "utf-8") == 0) ||
+ (strcmp(lower, "utf8") == 0))
return PyUnicode_DecodeUTF8(s, size, errors);
else if ((strcmp(lower, "latin-1") == 0) ||
+ (strcmp(lower, "latin1") == 0) ||
(strcmp(lower, "iso-8859-1") == 0))
return PyUnicode_DecodeLatin1(s, size, errors);
#if defined(MS_WINDOWS) && defined(HAVE_USABLE_WCHAR_T)
@@ -1670,15 +1672,19 @@
}
if (encoding == NULL)
- encoding = PyUnicode_GetDefaultEncoding();
+ return PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(unicode),
+ PyUnicode_GET_SIZE(unicode),
+ errors);
/* Shortcuts for common default encodings */
if (normalize_encoding(encoding, lower, sizeof(lower))) {
- if (strcmp(lower, "utf-8") == 0)
+ if ((strcmp(lower, "utf-8") == 0) ||
+ (strcmp(lower, "utf8") == 0))
return PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(unicode),
PyUnicode_GET_SIZE(unicode),
errors);
else if ((strcmp(lower, "latin-1") == 0) ||
+ (strcmp(lower, "latin1") == 0) ||
(strcmp(lower, "iso-8859-1") == 0))
return PyUnicode_EncodeLatin1(PyUnicode_AS_UNICODE(unicode),
PyUnicode_GET_SIZE(unicode),