Use dictionary specific looping idiom where possible.
Simplifies and speeds-up the code.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 8e70546..cc8d25c 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -369,7 +369,9 @@
set_difference(PySetObject *so, PyObject *other)
{
PySetObject *result, *otherset=NULL;
- PyObject *item, *otherdata, *tgtdata, *it;
+ PyObject *otherdata, *tgtdata;
+ PyObject *key, *value;
+ int pos = 0;
result = (PySetObject *)make_new_set(so->ob_type, NULL);
if (result == NULL)
@@ -389,30 +391,15 @@
otherdata = otherset->data;
}
- it = PyObject_GetIter(so->data);
- if (it == NULL) {
- Py_XDECREF(otherset);
- Py_DECREF(result);
- return NULL;
- }
-
- while ((item = PyIter_Next(it)) != NULL) {
- if (!PyDict_Contains(otherdata, item)) {
- if (PyDict_SetItem(tgtdata, item, Py_True) == -1) {
+ while (PyDict_Next(so->data, &pos, &key, &value)) {
+ if (!PyDict_Contains(otherdata, key)) {
+ if (PyDict_SetItem(tgtdata, key, Py_True) == -1) {
Py_XDECREF(otherset);
- Py_DECREF(it);
- Py_DECREF(item);
return NULL;
}
}
- Py_DECREF(item);
}
- Py_DECREF(it);
Py_XDECREF(otherset);
- if (PyErr_Occurred()) {
- Py_DECREF(result);
- return NULL;
- }
return (PyObject *)result;
}
@@ -482,11 +469,12 @@
static PyObject *
set_symmetric_difference_update(PySetObject *so, PyObject *other)
{
- PyObject *item, *selfdata, *it, *otherdata;
+ PyObject *selfdata, *otherdata;
PySetObject *otherset = NULL;
+ PyObject *key, *value;
+ int pos = 0;
selfdata = so->data;
-
if (PyDict_Check(other))
otherdata = other;
else if (PyAnySet_Check(other))
@@ -498,32 +486,20 @@
otherdata = otherset->data;
}
- it = PyObject_GetIter(otherdata);
- if (it == NULL)
- return NULL;
-
- while ((item = PyIter_Next(it)) != NULL) {
- if (PyDict_Contains(selfdata, item)) {
- if (PyDict_DelItem(selfdata, item) == -1) {
+ while (PyDict_Next(otherdata, &pos, &key, &value)) {
+ if (PyDict_Contains(selfdata, key)) {
+ if (PyDict_DelItem(selfdata, key) == -1) {
Py_XDECREF(otherset);
- Py_DECREF(it);
- Py_DECREF(item);
return NULL;
}
} else {
- if (PyDict_SetItem(selfdata, item, Py_True) == -1) {
+ if (PyDict_SetItem(selfdata, key, Py_True) == -1) {
Py_XDECREF(otherset);
- Py_DECREF(it);
- Py_DECREF(item);
return NULL;
}
}
- Py_DECREF(item);
}
Py_XDECREF(otherset);
- Py_DECREF(it);
- if (PyErr_Occurred())
- return NULL;
Py_RETURN_NONE;
}
@@ -534,7 +510,9 @@
set_symmetric_difference(PySetObject *so, PyObject *other)
{
PySetObject *result;
- PyObject *item, *selfdata, *otherdata, *tgtdata, *it, *rv, *otherset;
+ PyObject *selfdata, *otherdata, *tgtdata, *rv, *otherset;
+ PyObject *key, *value;
+ int pos = 0;
if (PyDict_Check(other))
otherdata = other;
@@ -557,46 +535,23 @@
tgtdata = result->data;
selfdata = so->data;
- it = PyObject_GetIter(otherdata);
- if (it == NULL) {
- Py_DECREF(result);
- return NULL;
- }
- while ((item = PyIter_Next(it)) != NULL) {
- if (!PyDict_Contains(selfdata, item)) {
- if (PyDict_SetItem(tgtdata, item, Py_True) == -1) {
- Py_DECREF(it);
- Py_DECREF(item);
+ while (PyDict_Next(otherdata, &pos, &key, &value)) {
+ if (!PyDict_Contains(selfdata, key)) {
+ if (PyDict_SetItem(tgtdata, key, Py_True) == -1) {
+ Py_DECREF(result);
return NULL;
}
}
- Py_DECREF(item);
- }
- Py_DECREF(it);
- if (PyErr_Occurred()) {
- Py_DECREF(result);
- return NULL;
}
- it = PyObject_GetIter(selfdata);
- if (it == NULL) {
- Py_DECREF(result);
- return NULL;
- }
- while ((item = PyIter_Next(it)) != NULL) {
- if (!PyDict_Contains(otherdata, item)) {
- if (PyDict_SetItem(tgtdata, item, Py_True) == -1) {
- Py_DECREF(it);
- Py_DECREF(item);
+ pos = 0;
+ while (PyDict_Next(selfdata, &pos, &key, &value)) {
+ if (!PyDict_Contains(otherdata, key)) {
+ if (PyDict_SetItem(tgtdata, key, Py_True) == -1) {
+ Py_DECREF(result);
return NULL;
}
}
- Py_DECREF(item);
- }
- Py_DECREF(it);
- if (PyErr_Occurred()) {
- Py_DECREF(result);
- return NULL;
}
return (PyObject *)result;
@@ -637,7 +592,9 @@
static PyObject *
set_issubset(PySetObject *so, PyObject *other)
{
- PyObject *otherdata, *it, *item, *tmp, *result;
+ PyObject *otherdata, *tmp, *result;
+ PyObject *key, *value;
+ int pos = 0;
if (!PyAnySet_Check(other)) {
tmp = make_new_set(&PySet_Type, other);
@@ -649,23 +606,12 @@
}
if (set_len(so) > set_len((PySetObject *)other))
Py_RETURN_FALSE;
-
- it = PyObject_GetIter(so->data);
- if (it == NULL)
- return NULL;
otherdata = ((PySetObject *)other)->data;
- while ((item = PyIter_Next(it)) != NULL) {
- if (!PyDict_Contains(otherdata, item)) {
- Py_DECREF(it);
- Py_DECREF(item);
+ while (PyDict_Next(((PySetObject *)so)->data, &pos, &key, &value)) {
+ if (!PyDict_Contains(otherdata, key))
Py_RETURN_FALSE;
- }
- Py_DECREF(item);
}
- Py_DECREF(it);
- if (PyErr_Occurred())
- return NULL;
Py_RETURN_TRUE;
}
@@ -706,29 +652,22 @@
static long
frozenset_hash(PyObject *self)
{
- PyObject *it, *item;
PySetObject *so = (PySetObject *)self;
- long hash = 0;
+ PyObject *key, *value;
+ int pos = 0;
+ long hash = 0;
if (so->hash != -1)
return so->hash;
-
- it = PyObject_GetIter(((PySetObject *)so)->data);
- if (it == NULL)
- return -1;
- while ((item = PyIter_Next(it)) != NULL) {
+ while (PyDict_Next(so->data, &pos, &key, &value)) {
/* Multiplying by a large prime increases the bit dispersion for
closely spaced hash values. The is important because some
use cases have many combinations of a small number of
elements with nearby hashes so that many distinct combinations
collapse to only a handful of distinct hash values. */
- hash ^= PyObject_Hash(item) * 3644798167u;
- Py_DECREF(item);
+ hash ^= PyObject_Hash(key) * 3644798167u;
}
- Py_DECREF(it);
- if (PyErr_Occurred())
- return -1;
so->hash = hash;
return hash;
}
@@ -788,30 +727,17 @@
static int
set_tp_print(PySetObject *so, FILE *fp, int flags)
{
- PyObject *it, *item;
- int firstpass=1;
+ PyObject *key, *value;
+ int pos = 0;
- it = PyObject_GetIter(so->data);
- if (it == NULL)
- return -1;
fprintf(fp, "%s([", so->ob_type->tp_name);
-
- while ((item = PyIter_Next(it)) != NULL) {
- if (firstpass == 1)
- firstpass = 0;
- else
+ while (PyDict_Next(so->data, &pos, &key, &value)) {
+ if (pos)
fprintf(fp, ", ");
- if (PyObject_Print(item, fp, 0) != 0) {
- Py_DECREF(it);
- Py_DECREF(item);
+ if (PyObject_Print(key, fp, 0) != 0)
return -1;
- }
- Py_DECREF(item);
}
- Py_DECREF(it);
fprintf(fp, "])");
- if (PyErr_Occurred())
- return -1;
return 0;
}