diff options
Diffstat (limited to 'AppPkg/Applications/Python/Python-2.7.10/Objects/rangeobject.c')
| -rw-r--r-- | AppPkg/Applications/Python/Python-2.7.10/Objects/rangeobject.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/AppPkg/Applications/Python/Python-2.7.10/Objects/rangeobject.c b/AppPkg/Applications/Python/Python-2.7.10/Objects/rangeobject.c new file mode 100644 index 0000000000..ae8cb67adb --- /dev/null +++ b/AppPkg/Applications/Python/Python-2.7.10/Objects/rangeobject.c @@ -0,0 +1,347 @@ +/* Range object implementation */
+
+#include "Python.h"
+
+typedef struct {
+ PyObject_HEAD
+ long start;
+ long step;
+ long len;
+} rangeobject;
+
+/* Return number of items in range (lo, hi, step). step != 0
+ * required. The result always fits in an unsigned long.
+ */
+static unsigned long
+get_len_of_range(long lo, long hi, long step)
+{
+ /* -------------------------------------------------------------
+ If step > 0 and lo >= hi, or step < 0 and lo <= hi, the range is empty.
+ Else for step > 0, if n values are in the range, the last one is
+ lo + (n-1)*step, which must be <= hi-1. Rearranging,
+ n <= (hi - lo - 1)/step + 1, so taking the floor of the RHS gives
+ the proper value. Since lo < hi in this case, hi-lo-1 >= 0, so
+ the RHS is non-negative and so truncation is the same as the
+ floor. Letting M be the largest positive long, the worst case
+ for the RHS numerator is hi=M, lo=-M-1, and then
+ hi-lo-1 = M-(-M-1)-1 = 2*M. Therefore unsigned long has enough
+ precision to compute the RHS exactly. The analysis for step < 0
+ is similar.
+ ---------------------------------------------------------------*/
+ assert(step != 0);
+ if (step > 0 && lo < hi)
+ return 1UL + (hi - 1UL - lo) / step;
+ else if (step < 0 && lo > hi)
+ return 1UL + (lo - 1UL - hi) / (0UL - step);
+ else
+ return 0UL;
+}
+
+/* Return a stop value suitable for reconstructing the xrange from
+ * a (start, stop, step) triple. Used in range_repr and range_reduce.
+ * Computes start + len * step, clipped to the range [LONG_MIN, LONG_MAX].
+ */
+static long
+get_stop_for_range(rangeobject *r)
+{
+ long last;
+
+ if (r->len == 0)
+ return r->start;
+
+ /* The tricky bit is avoiding overflow. We first compute the last entry in
+ the xrange, start + (len - 1) * step, which is guaranteed to lie within
+ the range of a long, and then add step to it. See the range_reverse
+ comments for an explanation of the casts below.
+ */
+ last = (long)(r->start + (unsigned long)(r->len - 1) * r->step);
+ if (r->step > 0)
+ return last > LONG_MAX - r->step ? LONG_MAX : last + r->step;
+ else
+ return last < LONG_MIN - r->step ? LONG_MIN : last + r->step;
+}
+
+static PyObject *
+range_new(PyTypeObject *type, PyObject *args, PyObject *kw)
+{
+ rangeobject *obj;
+ long ilow = 0, ihigh = 0, istep = 1;
+ unsigned long n;
+
+ if (!_PyArg_NoKeywords("xrange()", kw))
+ return NULL;
+
+ if (PyTuple_Size(args) <= 1) {
+ if (!PyArg_ParseTuple(args,
+ "l;xrange() requires 1-3 int arguments",
+ &ihigh))
+ return NULL;
+ }
+ else {
+ if (!PyArg_ParseTuple(args,
+ "ll|l;xrange() requires 1-3 int arguments",
+ &ilow, &ihigh, &istep))
+ return NULL;
+ }
+ if (istep == 0) {
+ PyErr_SetString(PyExc_ValueError, "xrange() arg 3 must not be zero");
+ return NULL;
+ }
+ n = get_len_of_range(ilow, ihigh, istep);
+ if (n > (unsigned long)LONG_MAX || (long)n > PY_SSIZE_T_MAX) {
+ PyErr_SetString(PyExc_OverflowError,
+ "xrange() result has too many items");
+ return NULL;
+ }
+
+ obj = PyObject_New(rangeobject, &PyRange_Type);
+ if (obj == NULL)
+ return NULL;
+ obj->start = ilow;
+ obj->len = (long)n;
+ obj->step = istep;
+ return (PyObject *) obj;
+}
+
+PyDoc_STRVAR(range_doc,
+"xrange(stop) -> xrange object\n\
+xrange(start, stop[, step]) -> xrange object\n\
+\n\
+Like range(), but instead of returning a list, returns an object that\n\
+generates the numbers in the range on demand. For looping, this is \n\
+slightly faster than range() and more memory efficient.");
+
+static PyObject *
+range_item(rangeobject *r, Py_ssize_t i)
+{
+ if (i < 0 || i >= r->len) {
+ PyErr_SetString(PyExc_IndexError,
+ "xrange object index out of range");
+ return NULL;
+ }
+ /* do calculation entirely using unsigned longs, to avoid
+ undefined behaviour due to signed overflow. */
+ return PyInt_FromLong((long)(r->start + (unsigned long)i * r->step));
+}
+
+static Py_ssize_t
+range_length(rangeobject *r)
+{
+ return (Py_ssize_t)(r->len);
+}
+
+static PyObject *
+range_repr(rangeobject *r)
+{
+ PyObject *rtn;
+
+ if (r->start == 0 && r->step == 1)
+ rtn = PyString_FromFormat("xrange(%ld)",
+ get_stop_for_range(r));
+
+ else if (r->step == 1)
+ rtn = PyString_FromFormat("xrange(%ld, %ld)",
+ r->start,
+ get_stop_for_range(r));
+
+ else
+ rtn = PyString_FromFormat("xrange(%ld, %ld, %ld)",
+ r->start,
+ get_stop_for_range(r),
+ r->step);
+ return rtn;
+}
+
+/* Pickling support */
+static PyObject *
+range_reduce(rangeobject *r, PyObject *args)
+{
+ return Py_BuildValue("(O(lll))", Py_TYPE(r),
+ r->start,
+ get_stop_for_range(r),
+ r->step);
+}
+
+static PySequenceMethods range_as_sequence = {
+ (lenfunc)range_length, /* sq_length */
+ 0, /* sq_concat */
+ 0, /* sq_repeat */
+ (ssizeargfunc)range_item, /* sq_item */
+ 0, /* sq_slice */
+};
+
+static PyObject * range_iter(PyObject *seq);
+static PyObject * range_reverse(PyObject *seq);
+
+PyDoc_STRVAR(reverse_doc,
+"Returns a reverse iterator.");
+
+static PyMethodDef range_methods[] = {
+ {"__reversed__", (PyCFunction)range_reverse, METH_NOARGS, reverse_doc},
+ {"__reduce__", (PyCFunction)range_reduce, METH_VARARGS},
+ {NULL, NULL} /* sentinel */
+};
+
+PyTypeObject PyRange_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* Number of items for varobject */
+ "xrange", /* Name of this type */
+ sizeof(rangeobject), /* Basic object size */
+ 0, /* Item size for varobject */
+ (destructor)PyObject_Del, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ (reprfunc)range_repr, /* tp_repr */
+ 0, /* tp_as_number */
+ &range_as_sequence, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT, /* tp_flags */
+ range_doc, /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ range_iter, /* tp_iter */
+ 0, /* tp_iternext */
+ range_methods, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ 0, /* tp_alloc */
+ range_new, /* tp_new */
+};
+
+/*********************** Xrange Iterator **************************/
+
+typedef struct {
+ PyObject_HEAD
+ long index;
+ long start;
+ long step;
+ long len;
+} rangeiterobject;
+
+static PyObject *
+rangeiter_next(rangeiterobject *r)
+{
+ if (r->index < r->len)
+ return PyInt_FromLong(r->start + (r->index++) * r->step);
+ return NULL;
+}
+
+static PyObject *
+rangeiter_len(rangeiterobject *r)
+{
+ return PyInt_FromLong(r->len - r->index);
+}
+
+PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
+
+static PyMethodDef rangeiter_methods[] = {
+ {"__length_hint__", (PyCFunction)rangeiter_len, METH_NOARGS, length_hint_doc},
+ {NULL, NULL} /* sentinel */
+};
+
+static PyTypeObject Pyrangeiter_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* ob_size */
+ "rangeiterator", /* tp_name */
+ sizeof(rangeiterobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)PyObject_Del, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT, /* tp_flags */
+ 0, /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ PyObject_SelfIter, /* tp_iter */
+ (iternextfunc)rangeiter_next, /* tp_iternext */
+ rangeiter_methods, /* tp_methods */
+ 0,
+};
+
+static PyObject *
+range_iter(PyObject *seq)
+{
+ rangeiterobject *it;
+
+ if (!PyRange_Check(seq)) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+ it = PyObject_New(rangeiterobject, &Pyrangeiter_Type);
+ if (it == NULL)
+ return NULL;
+ it->index = 0;
+ it->start = ((rangeobject *)seq)->start;
+ it->step = ((rangeobject *)seq)->step;
+ it->len = ((rangeobject *)seq)->len;
+ return (PyObject *)it;
+}
+
+static PyObject *
+range_reverse(PyObject *seq)
+{
+ rangeiterobject *it;
+ long start, step, len;
+
+ if (!PyRange_Check(seq)) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+ it = PyObject_New(rangeiterobject, &Pyrangeiter_Type);
+ if (it == NULL)
+ return NULL;
+
+ start = ((rangeobject *)seq)->start;
+ step = ((rangeobject *)seq)->step;
+ len = ((rangeobject *)seq)->len;
+
+ it->index = 0;
+ it->len = len;
+ /* the casts below guard against signed overflow by turning it
+ into unsigned overflow instead. The correctness of this
+ code still depends on conversion from unsigned long to long
+ wrapping modulo ULONG_MAX+1, which isn't guaranteed (see
+ C99 6.3.1.3p3) but seems to hold in practice for all
+ platforms we're likely to meet.
+
+ If step == LONG_MIN then we still end up with LONG_MIN
+ after negation; but this works out, since we've still got
+ the correct value modulo ULONG_MAX+1, and the range_item
+ calculation is also done modulo ULONG_MAX+1.
+ */
+ it->start = (long)(start + (unsigned long)(len-1) * step);
+ it->step = (long)(0UL-step);
+
+ return (PyObject *)it;
+}
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