diff options
Diffstat (limited to 'Modules/_heapqmodule.c')
| -rw-r--r-- | Modules/_heapqmodule.c | 80 |
1 files changed, 43 insertions, 37 deletions
diff --git a/Modules/_heapqmodule.c b/Modules/_heapqmodule.c index d709dd4..c343862 100644 --- a/Modules/_heapqmodule.c +++ b/Modules/_heapqmodule.c @@ -11,7 +11,7 @@ annotated by François Pinard, and converted to C by Raymond Hettinger. static int siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) { - PyObject *newitem, *parent; + PyObject *newitem, *parent, **arr; Py_ssize_t parentpos, size; int cmp; @@ -24,12 +24,13 @@ siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) /* Follow the path to the root, moving parents down until finding a place newitem fits. */ - newitem = PyList_GET_ITEM(heap, pos); + arr = _PyList_ITEMS(heap); + newitem = arr[pos]; while (pos > startpos) { parentpos = (pos - 1) >> 1; - parent = PyList_GET_ITEM(heap, parentpos); + parent = arr[parentpos]; cmp = PyObject_RichCompareBool(newitem, parent, Py_LT); - if (cmp == -1) + if (cmp < 0) return -1; if (size != PyList_GET_SIZE(heap)) { PyErr_SetString(PyExc_RuntimeError, @@ -38,10 +39,11 @@ siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) } if (cmp == 0) break; - parent = PyList_GET_ITEM(heap, parentpos); - newitem = PyList_GET_ITEM(heap, pos); - PyList_SET_ITEM(heap, parentpos, newitem); - PyList_SET_ITEM(heap, pos, parent); + arr = _PyList_ITEMS(heap); + parent = arr[parentpos]; + newitem = arr[pos]; + arr[parentpos] = newitem; + arr[pos] = parent; pos = parentpos; } return 0; @@ -51,7 +53,7 @@ static int siftup(PyListObject *heap, Py_ssize_t pos) { Py_ssize_t startpos, endpos, childpos, limit; - PyObject *tmp1, *tmp2; + PyObject *tmp1, *tmp2, **arr; int cmp; assert(PyList_Check(heap)); @@ -63,19 +65,19 @@ siftup(PyListObject *heap, Py_ssize_t pos) } /* Bubble up the smaller child until hitting a leaf. */ + arr = _PyList_ITEMS(heap); 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 */ if (childpos + 1 < endpos) { cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, childpos), - PyList_GET_ITEM(heap, childpos + 1), + arr[childpos], + arr[childpos + 1], Py_LT); - if (cmp == -1) + if (cmp < 0) return -1; - if (cmp == 0) - childpos++; /* rightmost child is smallest */ + childpos += ((unsigned)cmp ^ 1); /* increment when cmp==0 */ if (endpos != PyList_GET_SIZE(heap)) { PyErr_SetString(PyExc_RuntimeError, "list changed size during iteration"); @@ -83,10 +85,11 @@ siftup(PyListObject *heap, Py_ssize_t pos) } } /* 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); + arr = _PyList_ITEMS(heap); + tmp1 = arr[childpos]; + tmp2 = arr[pos]; + arr[childpos] = tmp2; + arr[pos] = tmp1; pos = childpos; } /* Bubble it up to its final resting place (by sifting its parents down). */ @@ -227,7 +230,7 @@ heappushpop(PyObject *self, PyObject *args) } cmp = PyObject_RichCompareBool(PyList_GET_ITEM(heap, 0), item, Py_LT); - if (cmp == -1) + if (cmp < 0) return NULL; if (cmp == 0) { Py_INCREF(item); @@ -362,7 +365,7 @@ PyDoc_STRVAR(heapify_doc, static int siftdown_max(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) { - PyObject *newitem, *parent; + PyObject *newitem, *parent, **arr; Py_ssize_t parentpos, size; int cmp; @@ -375,12 +378,13 @@ siftdown_max(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) /* Follow the path to the root, moving parents down until finding a place newitem fits. */ - newitem = PyList_GET_ITEM(heap, pos); + arr = _PyList_ITEMS(heap); + newitem = arr[pos]; while (pos > startpos) { parentpos = (pos - 1) >> 1; - parent = PyList_GET_ITEM(heap, parentpos); + parent = arr[parentpos]; cmp = PyObject_RichCompareBool(parent, newitem, Py_LT); - if (cmp == -1) + if (cmp < 0) return -1; if (size != PyList_GET_SIZE(heap)) { PyErr_SetString(PyExc_RuntimeError, @@ -389,10 +393,11 @@ siftdown_max(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) } if (cmp == 0) break; - parent = PyList_GET_ITEM(heap, parentpos); - newitem = PyList_GET_ITEM(heap, pos); - PyList_SET_ITEM(heap, parentpos, newitem); - PyList_SET_ITEM(heap, pos, parent); + arr = _PyList_ITEMS(heap); + parent = arr[parentpos]; + newitem = arr[pos]; + arr[parentpos] = newitem; + arr[pos] = parent; pos = parentpos; } return 0; @@ -402,7 +407,7 @@ static int siftup_max(PyListObject *heap, Py_ssize_t pos) { Py_ssize_t startpos, endpos, childpos, limit; - PyObject *tmp1, *tmp2; + PyObject *tmp1, *tmp2, **arr; int cmp; assert(PyList_Check(heap)); @@ -414,19 +419,19 @@ siftup_max(PyListObject *heap, Py_ssize_t pos) } /* Bubble up the smaller child until hitting a leaf. */ + arr = _PyList_ITEMS(heap); 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 */ if (childpos + 1 < endpos) { cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, childpos + 1), - PyList_GET_ITEM(heap, childpos), + arr[childpos + 1], + arr[childpos], Py_LT); - if (cmp == -1) + if (cmp < 0) return -1; - if (cmp == 0) - childpos++; /* rightmost child is smallest */ + childpos += ((unsigned)cmp ^ 1); /* increment when cmp==0 */ if (endpos != PyList_GET_SIZE(heap)) { PyErr_SetString(PyExc_RuntimeError, "list changed size during iteration"); @@ -434,10 +439,11 @@ siftup_max(PyListObject *heap, Py_ssize_t pos) } } /* 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); + arr = _PyList_ITEMS(heap); + tmp1 = arr[childpos]; + tmp2 = arr[pos]; + arr[childpos] = tmp2; + arr[pos] = tmp1; pos = childpos; } /* Bubble it up to its final resting place (by sifting its parents down). */ |