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Issue #19513: repr(tuple) now uses _PyUnicodeWriter for better performances

This commit is contained in:
Victor Stinner 2013-11-19 12:59:46 +01:00
parent 4a58707a34
commit 88a9cd9b57
1 changed files with 37 additions and 27 deletions
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64
Objects/tupleobject.c
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@ -255,20 +255,12 @@ static PyObject *
tuplerepr(PyTupleObject *v)
{
Py_ssize_t i, n;
PyObject *s = NULL;
_PyAccu acc;
static PyObject *sep = NULL;
_PyUnicodeWriter writer;
n = Py_SIZE(v);
if (n == 0)
return PyUnicode_FromString("()");
if (sep == NULL) {
sep = PyUnicode_FromString(", ");
if (sep == NULL)
return NULL;
}
/* While not mutable, it is still possible to end up with a cycle in a
tuple through an object that stores itself within a tuple (and thus
infinitely asks for the repr of itself). This should only be
@ -278,40 +270,58 @@ tuplerepr(PyTupleObject *v)
return i > 0 ? PyUnicode_FromString("(...)") : NULL;
}
if (_PyAccu_Init(&acc))
goto error;
_PyUnicodeWriter_Init(&writer);
writer.overallocate = 1;
if (Py_SIZE(v) > 1) {
/* "(" + "1" + ", 2" * (len - 1) + ")" */
writer.min_length = 1 + 1 + (2 + 1) * (Py_SIZE(v) - 1) + 1;
}
else {
/* "(1,)" */
writer.min_length = 4;
}
s = PyUnicode_FromString("(");
if (s == NULL || _PyAccu_Accumulate(&acc, s))
if (_PyUnicodeWriter_WriteChar(&writer, '(') < 0)
goto error;
Py_CLEAR(s);
/* Do repr() on each element. */
for (i = 0; i < n; ++i) {
PyObject *s;
if (i > 0) {
if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0)
goto error;
}
if (Py_EnterRecursiveCall(" while getting the repr of a tuple"))
goto error;
s = PyObject_Repr(v->ob_item[i]);
Py_LeaveRecursiveCall();
if (i > 0 && _PyAccu_Accumulate(&acc, sep))
if (s == NULL)
goto error;
if (s == NULL || _PyAccu_Accumulate(&acc, s))
if (_PyUnicodeWriter_WriteStr(&writer, s) < 0) {
Py_DECREF(s);
goto error;
}
Py_DECREF(s);
}
writer.overallocate = 0;
if (n > 1) {
if (_PyUnicodeWriter_WriteChar(&writer, ')') < 0)
goto error;
}
else {
if (_PyUnicodeWriter_WriteASCIIString(&writer, ",)", 2) < 0)
goto error;
Py_CLEAR(s);
}
if (n > 1)
s = PyUnicode_FromString(")");
else
s = PyUnicode_FromString(",)");
if (s == NULL || _PyAccu_Accumulate(&acc, s))
goto error;
Py_CLEAR(s);
Py_ReprLeave((PyObject *)v);
return _PyAccu_Finish(&acc);
return _PyUnicodeWriter_Finish(&writer);
error:
_PyAccu_Destroy(&acc);
Py_XDECREF(s);
_PyUnicodeWriter_Dealloc(&writer);
Py_ReprLeave((PyObject *)v);
return NULL;
}