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gh-60107: Remove a copy from RawIOBase.read #141532

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Merged
vstinner merged 12 commits into from
Nov 20, 2025
Merged

gh-60107: Remove a copy from RawIOBase.read #141532

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f904fce
gh-60107: Remove a copy from RawIOBase.read
cmaloney Nov 13, 2025
6c9d14e
Add missing res = NULL
cmaloney Nov 13, 2025
847c7ed
Better place for test. Remove excess newlines. Remove old TODO
cmaloney Nov 13, 2025
bfb0c71
Fix indentation
cmaloney Nov 13, 2025
3709cf9
Simplify with Py_CLEAR
cmaloney Nov 13, 2025
63ceed7
Simplify with gotos
cmaloney Nov 13, 2025
a1daaae
Fix ubsan
cmaloney Nov 13, 2025
13abb41
Just use the C API... Sorry for the onoise...
cmaloney Nov 13, 2025
7dc7e92
Merge branch 'main' into gh60107_take_bytes
cmaloney Nov 15, 2025
82643f8
Update Modules/_io/iobase.c
cmaloney Nov 18, 2025
a9a1f14
Regen globals and simplify more
cmaloney Nov 18, 2025
8ca1cef
Update Misc/NEWS.d/next/Library/2025-11-13-13-11-02.gh-issue-60107.LZ…
vstinner Nov 20, 2025
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Simplify with gotos
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@cmaloney
cmaloney committed Nov 13, 2025
commit 63ceed7fae8257af9e5946663537180227c94c79
19 changes: 9 additions & 10 deletions Modules/_io/iobase.c
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Original file line number Diff line number Diff line change
Expand Up @@ -928,41 +928,40 @@ _io__RawIOBase_read_impl(PyObject *self, Py_ssize_t n)
}

b = PyByteArray_FromStringAndSize(NULL, n);
if (b == NULL)
if (b == NULL) {
return NULL;
}

res = PyObject_CallMethodObjArgs(self, &_Py_ID(readinto), b, NULL);
if (res == NULL || res == Py_None) {
Py_DECREF(b);
return res;
goto cleanup;
}

Py_ssize_t bytes_filled = PyNumber_AsSsize_t(res, PyExc_ValueError);
Py_DECREF(res);
Py_CLEAR(res);
if (bytes_filled == -1 && PyErr_Occurred()) {
Py_DECREF(b);
return NULL;
goto cleanup;
}
if (bytes_filled < 0 || bytes_filled > n) {
Py_DECREF(b);
PyErr_Format(PyExc_ValueError,
"readinto returned %zd outside buffer size %zd",
bytes_filled, n);
return NULL;
goto cleanup;
}

res = PyObject_CallMethod(b, "resize", "i", bytes_filled);
if (res != Py_None) {
Py_DECREF(b);
if (res != NULL) {
PyErr_Format(PyExc_ValueError,
"resize returned unexpected value %R",
res);
Py_CLEAR(res);
}
return res;
goto cleanup;
}
res = PyObject_CallMethod(b, "take_bytes", NULL);

@cmaloney cmaloney Nov 13, 2025 •
edited
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@vstinner : Not sure how common this "resize/discard then take_bytes" is going to be; might make sense to change to take_bytes(n=None, /, *, discard=False)

@cmaloney cmaloney Nov 13, 2025

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for now planning to keep that in back pocket until need many ways (ba.resize(n) or del ba[:n] gives the same capability)

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cleanup:
Py_DECREF(b);
return res;
}
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