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Merged revisions 60364-60378 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk ........ r60364 | neal.norwitz | 2008-01-27 19:09:48 +0100 (Sun, 27 Jan 2008) | 4 lines Update the comment and remove the close. If we close we can't flush anymore. We might still need to close after the for loop if flushing 6! times still doesn't cause the signal/exception. ........ r60365 | georg.brandl | 2008-01-27 19:14:43 +0100 (Sun, 27 Jan 2008) | 2 lines Remove effectless expression statement. ........ r60367 | neal.norwitz | 2008-01-27 19:19:04 +0100 (Sun, 27 Jan 2008) | 1 line Try to handle socket.errors properly in is_unavailable ........ r60370 | christian.heimes | 2008-01-27 20:01:45 +0100 (Sun, 27 Jan 2008) | 1 line Change isbasestring function as discussed on the cvs list a while ago ........ r60372 | neal.norwitz | 2008-01-27 21:03:13 +0100 (Sun, 27 Jan 2008) | 3 lines socket.error doesn't have a headers attribute like ProtocolError. Handle that situation where we catch socket.errors. ........ r60375 | georg.brandl | 2008-01-27 21:25:12 +0100 (Sun, 27 Jan 2008) | 2 lines Add refcounting extension to build config. ........ r60377 | jeffrey.yasskin | 2008-01-28 00:08:46 +0100 (Mon, 28 Jan 2008) | 6 lines Moved Rational._binary_float_to_ratio() to float.as_integer_ratio() because it's useful outside of rational numbers. This is my first C code that had to do anything significant. Please be more careful when looking over it. ........ r60378 | christian.heimes | 2008-01-28 00:34:59 +0100 (Mon, 28 Jan 2008) | 1 line Added clear cache methods to clear the internal type lookup cache for ref leak test runs. ........
This commit is contained in:
Christian Heimes
parent
7b69c6c3af
commit
2685563583
14 changed files with 254 additions and 71 deletions
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@ -1073,6 +1073,163 @@ float_float(PyObject *v)
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return v;
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}
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static PyObject *
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float_as_integer_ratio(PyObject *v)
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{
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double self;
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double float_part;
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int exponent;
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int is_negative;
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const int chunk_size = 28;
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PyObject *prev;
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PyObject *py_chunk = NULL;
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PyObject *py_exponent = NULL;
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PyObject *numerator = NULL;
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PyObject *denominator = NULL;
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PyObject *result_pair = NULL;
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PyNumberMethods *long_methods;
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#define INPLACE_UPDATE(obj, call) \
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prev = obj; \
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obj = call; \
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Py_DECREF(prev); \
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CONVERT_TO_DOUBLE(v, self);
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if (Py_IS_INFINITY(self)) {
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PyErr_SetString(PyExc_OverflowError,
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"Cannot pass infinity to float.as_integer_ratio.");
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return NULL;
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}
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#ifdef Py_NAN
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if (Py_IS_NAN(self)) {
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PyErr_SetString(PyExc_ValueError,
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"Cannot pass nan to float.as_integer_ratio.");
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return NULL;
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}
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#endif
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if (self == 0) {
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numerator = PyLong_FromLong(0);
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if (numerator == NULL) goto error;
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denominator = PyLong_FromLong(1);
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if (denominator == NULL) goto error;
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result_pair = PyTuple_Pack(2, numerator, denominator);
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/* Hand ownership over to the tuple. If the tuple
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wasn't created successfully, we want to delete the
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ints anyway. */
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Py_DECREF(numerator);
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Py_DECREF(denominator);
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return result_pair;
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}
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/* XXX: Could perhaps handle FLT_RADIX!=2 by using ilogb and
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scalbn, but those may not be in C89. */
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PyFPE_START_PROTECT("as_integer_ratio", goto error);
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float_part = frexp(self, &exponent);
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is_negative = 0;
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if (float_part < 0) {
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float_part = -float_part;
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is_negative = 1;
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/* 0.5 <= float_part < 1.0 */
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}
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PyFPE_END_PROTECT(float_part);
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/* abs(self) == float_part * 2**exponent exactly */
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/* Suck up chunk_size bits at a time; 28 is enough so that we
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suck up all bits in 2 iterations for all known binary
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double-precision formats, and small enough to fit in a
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long. */
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numerator = PyLong_FromLong(0);
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if (numerator == NULL) goto error;
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long_methods = PyLong_Type.tp_as_number;
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py_chunk = PyLong_FromLong(chunk_size);
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if (py_chunk == NULL) goto error;
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while (float_part != 0) {
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/* invariant: abs(self) ==
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(numerator + float_part) * 2**exponent exactly */
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long digit;
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PyObject *py_digit;
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PyFPE_START_PROTECT("as_integer_ratio", goto error);
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/* Pull chunk_size bits out of float_part, into digits. */
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float_part = ldexp(float_part, chunk_size);
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digit = (long)float_part;
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float_part -= digit;
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/* 0 <= float_part < 1 */
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exponent -= chunk_size;
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PyFPE_END_PROTECT(float_part);
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/* Shift digits into numerator. */
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// numerator <<= chunk_size
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INPLACE_UPDATE(numerator,
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long_methods->nb_lshift(numerator, py_chunk));
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if (numerator == NULL) goto error;
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// numerator |= digit
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py_digit = PyLong_FromLong(digit);
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if (py_digit == NULL) goto error;
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INPLACE_UPDATE(numerator,
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long_methods->nb_or(numerator, py_digit));
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Py_DECREF(py_digit);
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if (numerator == NULL) goto error;
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}
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/* Add in the sign bit. */
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if (is_negative) {
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INPLACE_UPDATE(numerator,
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long_methods->nb_negative(numerator));
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if (numerator == NULL) goto error;
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}
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/* now self = numerator * 2**exponent exactly; fold in 2**exponent */
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denominator = PyLong_FromLong(1);
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py_exponent = PyLong_FromLong(labs(exponent));
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if (py_exponent == NULL) goto error;
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INPLACE_UPDATE(py_exponent,
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long_methods->nb_lshift(denominator, py_exponent));
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if (py_exponent == NULL) goto error;
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if (exponent > 0) {
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INPLACE_UPDATE(numerator,
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long_methods->nb_multiply(numerator,
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py_exponent));
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if (numerator == NULL) goto error;
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}
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else {
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Py_DECREF(denominator);
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denominator = py_exponent;
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py_exponent = NULL;
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}
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result_pair = PyTuple_Pack(2, numerator, denominator);
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#undef INPLACE_UPDATE
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error:
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Py_XDECREF(py_exponent);
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Py_XDECREF(py_chunk);
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Py_XDECREF(denominator);
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Py_XDECREF(numerator);
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return result_pair;
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}
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PyDoc_STRVAR(float_as_integer_ratio_doc,
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"float.as_integer_ratio() -> (int, int)\n"
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"\n"
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"Returns a pair of integers, not necessarily in lowest terms, whose\n"
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"ratio is exactly equal to the original float. This method raises an\n"
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"OverflowError on infinities and a ValueError on nans. The resulting\n"
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"denominator will be positive.\n"
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"\n"
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">>> (10.0).as_integer_ratio()\n"
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"(167772160L, 16777216L)\n"
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">>> (0.0).as_integer_ratio()\n"
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"(0, 1)\n"
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">>> (-.25).as_integer_ratio()\n"
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"(-134217728L, 536870912L)");
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static PyObject *
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float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
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@ -1281,6 +1438,8 @@ static PyMethodDef float_methods[] = {
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{"__round__", (PyCFunction)float_round, METH_VARARGS,
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"Returns the Integral closest to x, rounding half toward even.\n"
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"When an argument is passed, works like built-in round(x, ndigits)."},
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{"as_integer_ratio", (PyCFunction)float_as_integer_ratio, METH_NOARGS,
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float_as_integer_ratio_doc},
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{"__getnewargs__", (PyCFunction)float_getnewargs, METH_NOARGS},
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{"__getformat__", (PyCFunction)float_getformat,
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METH_O|METH_CLASS, float_getformat_doc},
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