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Optimize string slicing to use the new API

This commit is contained in:
Antoine Pitrou 2011-10-04 19:08:01 +02:00
parent b7591d4780
commit 7aec401966
1 changed files with 16 additions and 18 deletions
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26
Objects/unicodeobject.c
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@ -12253,9 +12253,9 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item)
return unicode_getitem((PyObject*)self, i);
} else if (PySlice_Check(item)) {
Py_ssize_t start, stop, step, slicelength, cur, i;
const Py_UNICODE* source_buf;
Py_UNICODE* result_buf;
PyObject *result;
void *src_data, *dest_data;
int kind;
if (PySlice_GetIndicesEx(item, PyUnicode_GET_LENGTH(self),
&start, &stop, &step, &slicelength) < 0) {
@ -12272,22 +12272,20 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item)
} else if (step == 1) {
return PyUnicode_Substring((PyObject*)self,
start, start + slicelength);
} else {
source_buf = PyUnicode_AS_UNICODE((PyObject*)self);
result_buf = (Py_UNICODE *)PyObject_MALLOC(slicelength*
sizeof(Py_UNICODE));
if (result_buf == NULL)
return PyErr_NoMemory();
}
/* General (less optimized) case */
result = PyUnicode_New(slicelength, PyUnicode_MAX_CHAR_VALUE(self));
if (result == NULL)
return NULL;
kind = PyUnicode_KIND(self);
src_data = PyUnicode_DATA(self);
dest_data = PyUnicode_DATA(result);
for (cur = start, i = 0; i < slicelength; cur += step, i++) {
result_buf[i] = source_buf[cur];
Py_UCS4 ch = PyUnicode_READ(kind, src_data, cur);
PyUnicode_WRITE(kind, dest_data, i, ch);
}
result = PyUnicode_FromUnicode(result_buf, slicelength);
PyObject_FREE(result_buf);
return result;
}
} else {
PyErr_SetString(PyExc_TypeError, "string indices must be integers");
return NULL;