gh-119182: Optimize PyUnicode_FromFormat() (#120796)

Use strchr() and ucs1lib_find_max_char() to optimize the code path
formatting sub-strings between '%' formats.
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Victor Stinner 2024-06-20 21:06:16 +02:00 committed by GitHub
parent 85d90b59e2
commit 5150795b1c
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GPG Key ID: B5690EEEBB952194
1 changed files with 26 additions and 26 deletions

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@ -2875,47 +2875,47 @@ unicode_fromformat_arg(_PyUnicodeWriter *writer,
static int
unicode_from_format(_PyUnicodeWriter *writer, const char *format, va_list vargs)
{
writer->min_length += strlen(format) + 100;
Py_ssize_t len = strlen(format);
writer->min_length += len + 100;
writer->overallocate = 1;
va_list vargs2;
const char *f;
// Copy varags to be able to pass a reference to a subfunction.
va_list vargs2;
va_copy(vargs2, vargs);
for (f = format; *f; ) {
// _PyUnicodeWriter_WriteASCIIString() below requires the format string
// to be encoded to ASCII.
int is_ascii = (ucs1lib_find_max_char((Py_UCS1*)format, (Py_UCS1*)format + len) < 128);
if (!is_ascii) {
Py_ssize_t i;
for (i=0; i < len && (unsigned char)format[i] <= 127; i++);
PyErr_Format(PyExc_ValueError,
"PyUnicode_FromFormatV() expects an ASCII-encoded format "
"string, got a non-ASCII byte: 0x%02x",
(unsigned char)format[i]);
goto fail;
}
for (const char *f = format; *f; ) {
if (*f == '%') {
f = unicode_fromformat_arg(writer, f, &vargs2);
if (f == NULL)
goto fail;
}
else {
const char *p;
Py_ssize_t len;
p = f;
do
{
if ((unsigned char)*p > 127) {
PyErr_Format(PyExc_ValueError,
"PyUnicode_FromFormatV() expects an ASCII-encoded format "
"string, got a non-ASCII byte: 0x%02x",
(unsigned char)*p);
goto fail;
}
p++;
const char *p = strchr(f, '%');
if (p != NULL) {
len = p - f;
}
while (*p != '\0' && *p != '%');
len = p - f;
if (*p == '\0')
else {
len = strlen(f);
writer->overallocate = 0;
}
if (_PyUnicodeWriter_WriteASCIIString(writer, f, len) < 0)
if (_PyUnicodeWriter_WriteASCIIString(writer, f, len) < 0) {
goto fail;
f = p;
}
f += len;
}
}
va_end(vargs2);