gh-133968: Add fast path to PyUnicodeWriter_WriteStr() (#133969)

vstinner · web-flow · commit fe9f6e829a53 · 2025-05-13T15:31:41.000+02:00
Don't call PyObject_Str() if the input type is str.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
@@ -13929,7 +13929,12 @@ _PyUnicodeWriter_WriteStr(_PyUnicodeWriter *writer, PyObject *str)
 int
 PyUnicodeWriter_WriteStr(PyUnicodeWriter *writer, PyObject *obj)
 {
-    if (Py_TYPE(obj) == &PyLong_Type) {
+    PyTypeObject *type = Py_TYPE(obj);
+    if (type == &PyUnicode_Type) {
+        return _PyUnicodeWriter_WriteStr((_PyUnicodeWriter*)writer, obj);
+    }
+
+    if (type == &PyLong_Type) {
         return _PyLong_FormatWriter((_PyUnicodeWriter*)writer, obj, 10, 0);
     }
 

Original file line number	Diff line number	Diff line change
`@@ -13929,7 +13929,12 @@ _PyUnicodeWriter_WriteStr(_PyUnicodeWriter writer, PyObject str)`
`13929`	`13929`	`int`
`13930`	`13930`	`PyUnicodeWriter_WriteStr(PyUnicodeWriter writer, PyObject obj)`
`13931`	`13931`	`{`
`13932`		`- if (Py_TYPE(obj) == &PyLong_Type) {`
	`13932`	`+ PyTypeObject *type = Py_TYPE(obj);`
	`13933`	`+ if (type == &PyUnicode_Type) {`
	`13934`	`+ return _PyUnicodeWriter_WriteStr((_PyUnicodeWriter*)writer, obj);`
	`13935`	`+ }`
	`13936`	`+`
	`13937`	`+ if (type == &PyLong_Type) {`
`13933`	`13938`	`return _PyLong_FormatWriter((_PyUnicodeWriter*)writer, obj, 10, 0);`
`13934`	`13939`	`}`
`13935`	`13940`