Convert to rich comparisons:

- sort's docompare() calls RichCompare(Py_LT).

- list_contains(), list_index(), listcount(), listremove() call
  RichCompare(Py_EQ).

- Get rid of list_compare(), in favor of new list_richcompare().  The
  latter does some nice shortcuts, like when == or != is requested, it
  first compares the lengths for trivial accept/reject.  Then it goes
  over the items until it finds an index where the items differe; then
  it does more shortcut magic to minimize the number of additional
  comparisons.

- Aligned the comments for large struct initializers.
This commit is contained in:
Guido van Rossum 2001-01-17 22:11:59 +00:00
parent 7d6457743a
commit 65e1cea6e3
1 changed files with 163 additions and 90 deletions

View File

@ -245,19 +245,6 @@ list_repr(PyListObject *v)
return s;
}
static int
list_compare(PyListObject *v, PyListObject *w)
{
int i;
for (i = 0; i < v->ob_size && i < w->ob_size; i++) {
int cmp = PyObject_Compare(v->ob_item[i], w->ob_item[i]);
if (cmp != 0)
return cmp;
}
return v->ob_size - w->ob_size;
}
static int
list_length(PyListObject *a)
{
@ -269,13 +256,14 @@ list_length(PyListObject *a)
static int
list_contains(PyListObject *a, PyObject *el)
{
int i, cmp;
int i;
for (i = 0; i < a->ob_size; ++i) {
cmp = PyObject_Compare(el, PyList_GET_ITEM(a, i));
if (cmp == 0)
int cmp = PyObject_RichCompareBool(el, PyList_GET_ITEM(a, i),
Py_EQ);
if (cmp > 0)
return 1;
if (PyErr_Occurred())
else if (cmp < 0)
return -1;
}
return 0;
@ -725,10 +713,16 @@ docompare(PyObject *x, PyObject *y, PyObject *compare)
int i;
if (compare == NULL) {
i = PyObject_Compare(x, y);
if (i && PyErr_Occurred())
i = CMPERROR;
return i;
/* NOTE: we rely on the fact here that the sorting algorithm
only ever checks whether k<0, i.e., whether x<y. So we
invoke the rich comparison function with Py_LT ('<'), and
return -1 when it returns true and 0 when it returns
false. */
i = PyObject_RichCompareBool(x, y, Py_LT);
if (i < 0)
return CMPERROR;
else
return -i;
}
args = Py_BuildValue("(OO)", x, y);
@ -1344,9 +1338,10 @@ listindex(PyListObject *self, PyObject *args)
if (!PyArg_ParseTuple_Compat1(args, "O:index", &v))
return NULL;
for (i = 0; i < self->ob_size; i++) {
if (PyObject_Compare(self->ob_item[i], v) == 0)
int cmp = PyObject_RichCompareBool(self->ob_item[i], v, Py_EQ);
if (cmp > 0)
return PyInt_FromLong((long)i);
if (PyErr_Occurred())
else if (cmp < 0)
return NULL;
}
PyErr_SetString(PyExc_ValueError, "list.index(x): x not in list");
@ -1363,9 +1358,10 @@ listcount(PyListObject *self, PyObject *args)
if (!PyArg_ParseTuple_Compat1(args, "O:count", &v))
return NULL;
for (i = 0; i < self->ob_size; i++) {
if (PyObject_Compare(self->ob_item[i], v) == 0)
int cmp = PyObject_RichCompareBool(self->ob_item[i], v, Py_EQ);
if (cmp > 0)
count++;
if (PyErr_Occurred())
else if (cmp < 0)
return NULL;
}
return PyInt_FromLong((long)count);
@ -1380,14 +1376,15 @@ listremove(PyListObject *self, PyObject *args)
if (!PyArg_ParseTuple_Compat1(args, "O:remove", &v))
return NULL;
for (i = 0; i < self->ob_size; i++) {
if (PyObject_Compare(self->ob_item[i], v) == 0) {
int cmp = PyObject_RichCompareBool(self->ob_item[i], v, Py_EQ);
if (cmp > 0) {
if (list_ass_slice(self, i, i+1,
(PyObject *)NULL) != 0)
return NULL;
Py_INCREF(Py_None);
return Py_None;
}
if (PyErr_Occurred())
else if (cmp < 0)
return NULL;
}
PyErr_SetString(PyExc_ValueError, "list.remove(x): x not in list");
@ -1418,6 +1415,78 @@ list_clear(PyListObject *lp)
return 0;
}
static PyObject *
list_richcompare(PyObject *v, PyObject *w, int op)
{
PyListObject *vl, *wl;
int i;
if (!PyList_Check(v) || !PyList_Check(w)) {
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
vl = (PyListObject *)v;
wl = (PyListObject *)w;
if (vl->ob_size != wl->ob_size && (op == Py_EQ || op == Py_NE)) {
/* Shortcut: if the lengths differ, the lists differ */
PyObject *res;
if (op == Py_EQ)
res = Py_False;
else
res = Py_True;
Py_INCREF(res);
return res;
}
/* Search for the first index where items are different */
for (i = 0; i < vl->ob_size && i < wl->ob_size; i++) {
int k = PyObject_RichCompareBool(vl->ob_item[i],
wl->ob_item[i], Py_EQ);
if (k < 0)
return NULL;
if (!k)
break;
}
if (i >= vl->ob_size || i >= wl->ob_size) {
/* No more items to compare -- compare sizes */
int vs = vl->ob_size;
int ws = wl->ob_size;
int cmp;
PyObject *res;
switch (op) {
case Py_LT: cmp = vs < ws; break;
case Py_LE: cmp = ws <= ws; break;
case Py_EQ: cmp = vs == ws; break;
case Py_NE: cmp = vs != ws; break;
case Py_GT: cmp = vs > ws; break;
case Py_GE: cmp = vs >= ws; break;
default: return NULL; /* cannot happen */
}
if (cmp)
res = Py_True;
else
res = Py_False;
Py_INCREF(res);
return res;
}
/* We have an item that differs -- shortcuts for EQ/NE */
if (op == Py_EQ) {
Py_INCREF(Py_False);
return Py_False;
}
if (op == Py_NE) {
Py_INCREF(Py_True);
return Py_True;
}
/* Compare the final item again using the proper operator */
return PyObject_RichCompare(vl->ob_item[i], wl->ob_item[i], op);
}
static char append_doc[] =
"L.append(object) -- append object to end";
static char extend_doc[] =
@ -1457,16 +1526,16 @@ list_getattr(PyListObject *f, char *name)
}
static PySequenceMethods list_as_sequence = {
(inquiry)list_length, /*sq_length*/
(binaryfunc)list_concat, /*sq_concat*/
(intargfunc)list_repeat, /*sq_repeat*/
(intargfunc)list_item, /*sq_item*/
(intintargfunc)list_slice, /*sq_slice*/
(intobjargproc)list_ass_item, /*sq_ass_item*/
(intintobjargproc)list_ass_slice, /*sq_ass_slice*/
(objobjproc)list_contains, /*sq_contains*/
(binaryfunc)list_inplace_concat, /*sq_inplace_concat*/
(intargfunc)list_inplace_repeat, /*sq_inplace_repeat*/
(inquiry)list_length, /* sq_length */
(binaryfunc)list_concat, /* sq_concat */
(intargfunc)list_repeat, /* sq_repeat */
(intargfunc)list_item, /* sq_item */
(intintargfunc)list_slice, /* sq_slice */
(intobjargproc)list_ass_item, /* sq_ass_item */
(intintobjargproc)list_ass_slice, /* sq_ass_slice */
(objobjproc)list_contains, /* sq_contains */
(binaryfunc)list_inplace_concat, /* sq_inplace_concat */
(intargfunc)list_inplace_repeat, /* sq_inplace_repeat */
};
PyTypeObject PyList_Type = {
@ -1475,25 +1544,26 @@ PyTypeObject PyList_Type = {
"list",
sizeof(PyListObject) + PyGC_HEAD_SIZE,
0,
(destructor)list_dealloc, /*tp_dealloc*/
(printfunc)list_print, /*tp_print*/
(getattrfunc)list_getattr, /*tp_getattr*/
0, /*tp_setattr*/
(cmpfunc)list_compare, /*tp_compare*/
(reprfunc)list_repr, /*tp_repr*/
0, /*tp_as_number*/
&list_as_sequence, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, /*tp_flags*/
(destructor)list_dealloc, /* tp_dealloc */
(printfunc)list_print, /* tp_print */
(getattrfunc)list_getattr, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
(reprfunc)list_repr, /* tp_repr */
0, /* tp_as_number */
&list_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, /* tp_flags */
0, /* tp_doc */
(traverseproc)list_traverse, /* tp_traverse */
(inquiry)list_clear, /* tp_clear */
list_richcompare, /* tp_richcompare */
};
@ -1536,14 +1606,14 @@ immutable_list_ass(void)
}
static PySequenceMethods immutable_list_as_sequence = {
(inquiry)list_length, /*sq_length*/
(binaryfunc)list_concat, /*sq_concat*/
(intargfunc)list_repeat, /*sq_repeat*/
(intargfunc)list_item, /*sq_item*/
(intintargfunc)list_slice, /*sq_slice*/
(intobjargproc)immutable_list_ass, /*sq_ass_item*/
(intintobjargproc)immutable_list_ass, /*sq_ass_slice*/
(objobjproc)list_contains, /*sq_contains*/
(inquiry)list_length, /* sq_length */
(binaryfunc)list_concat, /* sq_concat */
(intargfunc)list_repeat, /* sq_repeat */
(intargfunc)list_item, /* sq_item */
(intintargfunc)list_slice, /* sq_slice */
(intobjargproc)immutable_list_ass, /* sq_ass_item */
(intintobjargproc)immutable_list_ass, /* sq_ass_slice */
(objobjproc)list_contains, /* sq_contains */
};
static PyTypeObject immutable_list_type = {
@ -1552,22 +1622,25 @@ static PyTypeObject immutable_list_type = {
"list (immutable, during sort)",
sizeof(PyListObject) + PyGC_HEAD_SIZE,
0,
0, /*tp_dealloc*/ /* Cannot happen */
(printfunc)list_print, /*tp_print*/
(getattrfunc)immutable_list_getattr, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/ /* Won't be called */
(reprfunc)list_repr, /*tp_repr*/
0, /*tp_as_number*/
&immutable_list_as_sequence, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, /*tp_flags*/
0, /* Cannot happen */ /* tp_dealloc */
(printfunc)list_print, /* tp_print */
(getattrfunc)immutable_list_getattr, /* tp_getattr */
0, /* tp_setattr */
0, /* Won't be called */ /* tp_compare */
(reprfunc)list_repr, /* tp_repr */
0, /* tp_as_number */
&immutable_list_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, /* tp_flags */
0, /* tp_doc */
(traverseproc)list_traverse, /* tp_traverse */
0, /* tp_clear */
list_richcompare, /* tp_richcompare */
/* NOTE: This is *not* the standard list_type struct! */
};