static int
_siftupmax(heap_t *h, __TYPE spos, __TYPE epos)
{
__TYPE endpos, childpos, rightpos;
__TYPE newitem, *heap, pos;
endpos = h->len;
heap = h->ary;
#ifdef ERROR_CHK
if (pos >= endpos) {
fprintf(stderr, "_siftupmax: index out of range: %u, len: %u\n", pos, endpos);
return -1;
}
#endif
do {
pos = spos;
/* Bubble up the smaller child until hitting a leaf. */
newitem = heap[pos];
childpos = (pos << 1) + 1; /* leftmost child position */
while (childpos < endpos) {
/* Set childpos to index of smaller child. */
rightpos = childpos + 1;
if (rightpos < endpos) {
if (heap[rightpos] < heap[childpos])
childpos = rightpos;
}
/* Move the smaller child up. */
heap[pos] = heap[childpos];
pos = childpos;
childpos = (pos << 1) + 1;
}
/* The leaf at pos is empty now. Put newitem there, and and bubble
it up to its final resting place (by sifting its parents down). */
heap[pos] = newitem;
#ifdef ERROR_CHK
if (_siftdownmax(h, spos, pos) == -1)
return (-1);
#else
_siftdownmax(h, spos, pos);
#endif
spos--;
} while (spos >= epos);
return (0);
}
static int
_siftupmax(PyListObject *heap, Py_ssize_t pos)
{
Py_ssize_t startpos, endpos, childpos, rightpos;
int cmp;
PyObject *newitem, *tmp;
assert(PyList_Check(heap));
endpos = PyList_GET_SIZE(heap);
startpos = pos;
if (pos >= endpos) {
PyErr_SetString(PyExc_IndexError, "index out of range");
return -1;
}
newitem = PyList_GET_ITEM(heap, pos);
Py_INCREF(newitem);
/* Bubble up the smaller child until hitting a leaf. */
childpos = 2*pos + 1; /* leftmost child position */
while (childpos < endpos) {
/* Set childpos to index of smaller child. */
rightpos = childpos + 1;
if (rightpos < endpos) {
cmp = PyObject_RichCompareBool(
PyList_GET_ITEM(heap, rightpos),
PyList_GET_ITEM(heap, childpos),
Py_LT);
if (cmp == -1) {
Py_DECREF(newitem);
return -1;
}
if (cmp == 0)
childpos = rightpos;
}
/* Move the smaller child up. */
tmp = PyList_GET_ITEM(heap, childpos);
Py_INCREF(tmp);
Py_DECREF(PyList_GET_ITEM(heap, pos));
PyList_SET_ITEM(heap, pos, tmp);
pos = childpos;
childpos = 2*pos + 1;
}
/* The leaf at pos is empty now. Put newitem there, and bubble
it up to its final resting place (by sifting its parents down). */
Py_DECREF(PyList_GET_ITEM(heap, pos));
PyList_SET_ITEM(heap, pos, newitem);
return _siftdownmax(heap, startpos, pos);
}
static int
_siftupmax(PyListObject *heap, Py_ssize_t pos)
{
Py_ssize_t startpos, endpos, childpos, rightpos, limit;
PyObject *tmp1, *tmp2;
int cmp;
assert(PyList_Check(heap));
endpos = PyList_GET_SIZE(heap);
startpos = pos;
if (pos >= endpos) {
PyErr_SetString(PyExc_IndexError, "index out of range");
return -1;
}
/* Bubble up the smaller child until hitting a leaf. */
limit = endpos / 2; /* smallest pos that has no child */
while (pos < limit) {
/* Set childpos to index of smaller child. */
childpos = 2*pos + 1; /* leftmost child position */
rightpos = childpos + 1;
if (rightpos < endpos) {
cmp = PyObject_RichCompareBool(
PyList_GET_ITEM(heap, rightpos),
PyList_GET_ITEM(heap, childpos),
Py_LT);
if (cmp == -1)
return -1;
if (cmp == 0)
childpos = rightpos;
if (endpos != PyList_GET_SIZE(heap)) {
PyErr_SetString(PyExc_RuntimeError,
"list changed size during iteration");
return -1;
}
}
/* Move the smaller child up. */
tmp1 = PyList_GET_ITEM(heap, childpos);
tmp2 = PyList_GET_ITEM(heap, pos);
PyList_SET_ITEM(heap, childpos, tmp2);
PyList_SET_ITEM(heap, pos, tmp1);
pos = childpos;
}
/* Bubble it up to its final resting place (by sifting its parents down). */
return _siftdownmax(heap, startpos, pos);
}
