Writer APIs: use empty string singletons

Modify _PyBytesWriter_Finish() and _PyUnicodeWriter_Finish() to return the
empty bytes/Unicode string if the string is empty.
This commit is contained in:
Victor Stinner 2015-10-12 13:29:43 +02:00
parent c29e29bed1
commit 6c2cdae9e6
2 changed files with 33 additions and 19 deletions

View file

@ -13715,17 +13715,26 @@ _PyUnicodeWriter_Finish(_PyUnicodeWriter *writer)
assert(PyUnicode_GET_LENGTH(str) == writer->pos);
return str;
}
if (PyUnicode_GET_LENGTH(writer->buffer) != writer->pos) {
PyObject *newbuffer;
newbuffer = resize_compact(writer->buffer, writer->pos);
if (newbuffer == NULL) {
Py_CLEAR(writer->buffer);
return NULL;
}
writer->buffer = newbuffer;
if (writer->pos == 0) {
Py_CLEAR(writer->buffer);
/* Get the empty Unicode string singleton ('') */
_Py_INCREF_UNICODE_EMPTY();
str = unicode_empty;
}
str = writer->buffer;
writer->buffer = NULL;
else {
str = writer->buffer;
writer->buffer = NULL;
if (PyUnicode_GET_LENGTH(str) != writer->pos) {
PyObject *str2;
str2 = resize_compact(str, writer->pos);
if (str2 == NULL)
return NULL;
str = str2;
}
}
assert(_PyUnicode_CheckConsistency(str, 1));
return unicode_result_ready(str);
}