bpo-27535: Optimize warnings.warn()#4508
bpo-27535: Optimize warnings.warn()#4508vstinner merged 1 commit intopython:masterfrom vstinner:warn_optim2
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* Optimize warnings.filterwarnings(). Replace re.compile('') with
None to avoid the cost of calling a regex.match() method, whereas
it always matchs.
* Optimize get_warnings_attr(): replace PyObject_GetAttrString() with
_PyObject_GetAttrId().
Cleanup also create_filter():
* Use _Py_IDENTIFIER() to allow to cleanup strings at Python
finalization
* Replace Py_FatalError() with a regular exceptions
| } | ||
| else { | ||
| Py_FatalError("unknown action"); | ||
| PyErr_SetString(PyExc_ValueError, "unknown action"); |
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Please revert this change. This is an internal function called with predefined set of arguments. The code in the else branch is a dead code. Here should be Py_FatalError() or Py_UNREACHABLE().
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I like your idea of using _Py_Identifier: I proposed #4516 to implement your idea. It avoids the need to have to unhandle "unknown action".
FYI I'm trying to remove all Py_FatalError() calls from the Python source code, one by one, when it's possible and when it makes sense. I added a new _PyInitError API to report errors at Python initialization, so the caller can decide when Py_FatalError() will be called, and maybe release memory before calling Py_FatalError() (or flush files, or something else).
| static PyObject *default_str = NULL; | ||
| static PyObject *always_str = NULL; | ||
| PyObject *action_obj = NULL; | ||
| _Py_IDENTIFIER(ignore); |
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This optimization doesn't make sense since create_filter() is used only few times at start. It would be better to pass _Py_Identifier * instead of const char *, this could save few lines of code.
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Sorry, I chose to put two changes into the same commit. This change was made to allow to free strings at Python finallization, it's not an optimization.
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None to avoid the cost of calling a regex.match() method, whereas
it always matchs.
_PyObject_GetAttrId().
Cleanup also create_filter():
finalization
https://bugs.python.org/issue27535