1 files changed, 101 insertions, 1 deletions

diff --git a/Modules/_decimal/_decimal.c b/Modules/_decimal/_decimal.c
index 112b44f..e19bbf2 100644
--- a/Modules/_decimal/_decimal.c
+++ b/Modules/_decimal/_decimal.c
@@ -36,7 +36,6 @@
 #include <stdlib.h>
 
 #include "docstrings.h"
-#include "memory.h"
 
 
 #if !defined(MPD_VERSION_HEX) || MPD_VERSION_HEX < 0x02040100
@@ -3380,6 +3379,106 @@ dec_as_long(PyObject *dec, PyObject *context, int round)
     return (PyObject *) pylong;
 }
 
+/* Convert a Decimal to its exact integer ratio representation. */
+static PyObject *
+dec_as_integer_ratio(PyObject *self, PyObject *args UNUSED)
+{
+    PyObject *numerator = NULL;
+    PyObject *denominator = NULL;
+    PyObject *exponent = NULL;
+    PyObject *result = NULL;
+    PyObject *tmp;
+    mpd_ssize_t exp;
+    PyObject *context;
+    uint32_t status = 0;
+    PyNumberMethods *long_methods = PyLong_Type.tp_as_number;
+
+    if (mpd_isspecial(MPD(self))) {
+        if (mpd_isnan(MPD(self))) {
+            PyErr_SetString(PyExc_ValueError,
+                "cannot convert NaN to integer ratio");
+        }
+        else {
+            PyErr_SetString(PyExc_OverflowError,
+                "cannot convert Infinity to integer ratio");
+        }
+        return NULL;
+    }
+
+    CURRENT_CONTEXT(context);
+
+    tmp = dec_alloc();
+    if (tmp == NULL) {
+        return NULL;
+    }
+
+    if (!mpd_qcopy(MPD(tmp), MPD(self), &status)) {
+        Py_DECREF(tmp);
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    exp = mpd_iszero(MPD(tmp)) ? 0 : MPD(tmp)->exp;
+    MPD(tmp)->exp = 0;
+
+    /* context and rounding are unused here: the conversion is exact */
+    numerator = dec_as_long(tmp, context, MPD_ROUND_FLOOR);
+    Py_DECREF(tmp);
+    if (numerator == NULL) {
+        goto error;
+    }
+
+    exponent = PyLong_FromSsize_t(exp < 0 ? -exp : exp);
+    if (exponent == NULL) {
+        goto error;
+    }
+
+    tmp = PyLong_FromLong(10);
+    if (tmp == NULL) {
+        goto error;
+    }
+
+    Py_SETREF(exponent, long_methods->nb_power(tmp, exponent, Py_None));
+    Py_DECREF(tmp);
+    if (exponent == NULL) {
+        goto error;
+    }
+
+    if (exp >= 0) {
+        Py_SETREF(numerator, long_methods->nb_multiply(numerator, exponent));
+        if (numerator == NULL) {
+            goto error;
+        }
+        denominator = PyLong_FromLong(1);
+        if (denominator == NULL) {
+            goto error;
+        }
+    }
+    else {
+        denominator = exponent;
+        exponent = NULL;
+        tmp = _PyLong_GCD(numerator, denominator);
+        if (tmp == NULL) {
+            goto error;
+        }
+        Py_SETREF(numerator, long_methods->nb_floor_divide(numerator, tmp));
+        Py_SETREF(denominator, long_methods->nb_floor_divide(denominator, tmp));
+        Py_DECREF(tmp);
+        if (numerator == NULL || denominator == NULL) {
+            goto error;
+        }
+    }
+
+    result = PyTuple_Pack(2, numerator, denominator);
+
+
+error:
+    Py_XDECREF(exponent);
+    Py_XDECREF(denominator);
+    Py_XDECREF(numerator);
+    return result;
+}
+
 static PyObject *
 PyDec_ToIntegralValue(PyObject *dec, PyObject *args, PyObject *kwds)
 {
@@ -4688,6 +4787,7 @@ static PyMethodDef dec_methods [] =
   /* Miscellaneous */
   { "from_float", dec_from_float, METH_O|METH_CLASS, doc_from_float },
   { "as_tuple", PyDec_AsTuple, METH_NOARGS, doc_as_tuple },
+  { "as_integer_ratio", dec_as_integer_ratio, METH_NOARGS, doc_as_integer_ratio },
 
   /* Special methods */
   { "__copy__", dec_copy, METH_NOARGS, NULL },