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Fast path in buffered_iternext is never taken due to incorrect type check #144380
Description
Bug report
Bug description:
Bug report
Bug description:
In Modules/_io/bufferedio.c, the buffered_iternext function has a fast path that calls _buffered_readline directly to avoid method call overhead.
However, due to an incorrect type check, this fast path is never executed.
tp = Py_TYPE(self);
if (Py_IS_TYPE(tp, state->PyBufferedReader_Type) ||
Py_IS_TYPE(tp, state->PyBufferedRandom_Type))because Py_IS_TYPE will call Py_TYPE internally, will cause Py_TYPE(Py_TYPE(ob)) == type,
<class 'type'> != state->PyBufferedReader_Type
All iteration over buffered binary files is affected:
with open('data.txt', 'rb') as f:
for line in f:
process(line)CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux
Activity
pythongh-144380: add news entry for BufferedReader performance improv…
pythongh-144380: Fix incorrect type check in buffered_iternext()
gh-144380: Fix incorrect type check in `buffered_iternext()` (#144381)
pythongh-144380: Fix incorrect type check in `buffered_iternext()` (p…
pythongh-144380: Fix incorrect type check in `buffered_iternext()` (p…
[3.13] gh-144380: Fix incorrect type check in `buffered_iternext()` (G…
[3.14] gh-144380: Fix incorrect type check in `buffered_iternext()` (G…
pythongh-144380: Fix incorrect type check in `buffered_iternext()` (p…
pythongh-144380: Fix incorrect type check in `buffered_iternext()` (p…