https://github.com/python/cpython/commit/e9c538dd54d1e270bcb33e10f919cc9e8e7cb934
commit: e9c538dd54d1e270bcb33e10f919cc9e8e7cb934
branch: main
author: Victor Stinner <[email protected]>
committer: vstinner <[email protected]>
date: 2025-09-25T11:42:16+02:00
summary:
gh-139156: Optimize _PyUnicode_EncodeCharmap() (#139306)
Specialize _PyUnicode_EncodeCharmap() for EncodingMapType which is
used by Python codecs such as iso8859_15.
files:
M Objects/unicodeobject.c
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 5f6384afd1b209..11ba147a744692 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -6435,6 +6435,8 @@ _PyUnicode_EncodeUTF16(PyObject *str,
#endif
if (kind == PyUnicode_1BYTE_KIND) {
+ // gh-139156: Don't use PyBytesWriter API here since it has an overhead
+ // on short strings
PyObject *v = PyBytes_FromStringAndSize(NULL, nsize * 2);
if (v == NULL) {
return NULL;
@@ -8852,11 +8854,15 @@ charmapencode_output(Py_UCS4 c, PyObject *mapping,
if (Py_IS_TYPE(mapping, &EncodingMapType)) {
int res = encoding_map_lookup(c, mapping);
Py_ssize_t requiredsize = *outpos+1;
- if (res == -1)
+ if (res == -1) {
return enc_FAILED;
- if (outsize<requiredsize)
- if (charmapencode_resize(writer, outpos, requiredsize))
+ }
+
+ if (outsize<requiredsize) {
+ if (charmapencode_resize(writer, outpos, requiredsize)) {
return enc_EXCEPTION;
+ }
+ }
outstart = _PyBytesWriter_GetData(writer);
outstart[(*outpos)++] = (char)res;
return enc_SUCCESS;
@@ -8897,7 +8903,7 @@ charmapencode_output(Py_UCS4 c, PyObject *mapping,
return enc_SUCCESS;
}
-/* handle an error in PyUnicode_EncodeCharmap
+/* handle an error in _PyUnicode_EncodeCharmap()
Return 0 on success, -1 on error */
static int
charmap_encoding_error(
@@ -9075,23 +9081,64 @@ _PyUnicode_EncodeCharmap(PyObject *unicode,
Py_ssize_t respos = 0;
_Py_error_handler error_handler = _Py_ERROR_UNKNOWN;
- while (inpos<size) {
- Py_UCS4 ch = PyUnicode_READ(kind, data, inpos);
- /* try to encode it */
- charmapencode_result x = charmapencode_output(ch, mapping, writer,
&respos);
- if (x==enc_EXCEPTION) /* error */
- goto onError;
- if (x==enc_FAILED) { /* unencodable character */
+ if (Py_IS_TYPE(mapping, &EncodingMapType)) {
+ char *outstart = _PyBytesWriter_GetData(writer);
+ Py_ssize_t outsize = _PyBytesWriter_GetSize(writer);
+
+ while (inpos<size) {
+ Py_UCS4 ch = PyUnicode_READ(kind, data, inpos);
+
+ /* try to encode it */
+ int res = encoding_map_lookup(ch, mapping);
+ Py_ssize_t requiredsize = respos+1;
+ if (res == -1) {
+ goto enc_FAILED;
+ }
+
+ if (outsize<requiredsize) {
+ if (charmapencode_resize(writer, &respos, requiredsize)) {
+ goto onError;
+ }
+ outstart = _PyBytesWriter_GetData(writer);
+ outsize = _PyBytesWriter_GetSize(writer);
+ }
+ outstart[respos++] = (char)res;
+
+ /* done with this character => adjust input position */
+ ++inpos;
+ continue;
+
+enc_FAILED:
if (charmap_encoding_error(unicode, &inpos, mapping,
&exc,
&error_handler, &error_handler_obj,
errors,
writer, &respos)) {
goto onError;
}
+ outstart = _PyBytesWriter_GetData(writer);
+ outsize = _PyBytesWriter_GetSize(writer);
}
- else {
- /* done with this character => adjust input position */
- ++inpos;
+ }
+ else {
+ while (inpos<size) {
+ Py_UCS4 ch = PyUnicode_READ(kind, data, inpos);
+ /* try to encode it */
+ charmapencode_result x = charmapencode_output(ch, mapping, writer,
&respos);
+ if (x==enc_EXCEPTION) { /* error */
+ goto onError;
+ }
+ if (x==enc_FAILED) { /* unencodable character */
+ if (charmap_encoding_error(unicode, &inpos, mapping,
+ &exc,
+ &error_handler, &error_handler_obj,
errors,
+ writer, &respos)) {
+ goto onError;
+ }
+ }
+ else {
+ /* done with this character => adjust input position */
+ ++inpos;
+ }
}
}
_______________________________________________
Python-checkins mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mailman3//lists/python-checkins.python.org
Member address: [email protected]
