diff options
Diffstat (limited to 'Modules/_heapqmodule.c')
| -rw-r--r-- | Modules/_heapqmodule.c | 61 |
1 files changed, 45 insertions, 16 deletions
diff --git a/Modules/_heapqmodule.c b/Modules/_heapqmodule.c index 97ccd86..a5a5605 100644 --- a/Modules/_heapqmodule.c +++ b/Modules/_heapqmodule.c @@ -8,6 +8,25 @@ annotated by François Pinard, and converted to C by Raymond Hettinger. #include "Python.h" +/* Older implementations of heapq used Py_LE for comparisons. Now, it uses + Py_LT so it will match min(), sorted(), and bisect(). Unfortunately, some + client code (Twisted for example) relied on Py_LE, so this little function + restores compatability by trying both. +*/ +static int +cmp_lt(PyObject *x, PyObject *y) +{ + int cmp; + cmp = PyObject_RichCompareBool(x, y, Py_LT); + if (cmp == -1 && PyErr_ExceptionMatches(PyExc_AttributeError)) { + PyErr_Clear(); + cmp = PyObject_RichCompareBool(y, x, Py_LE); + if (cmp != -1) + cmp = 1 - cmp; + } + return cmp; +} + static int _siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) { @@ -28,12 +47,12 @@ _siftdown(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) while (pos > startpos){ parentpos = (pos - 1) >> 1; parent = PyList_GET_ITEM(heap, parentpos); - cmp = PyObject_RichCompareBool(parent, newitem, Py_LE); + cmp = cmp_lt(newitem, parent); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) break; Py_INCREF(parent); Py_DECREF(PyList_GET_ITEM(heap, pos)); @@ -68,15 +87,14 @@ _siftup(PyListObject *heap, Py_ssize_t pos) /* Set childpos to index of smaller child. */ rightpos = childpos + 1; if (rightpos < endpos) { - cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, rightpos), + cmp = cmp_lt( PyList_GET_ITEM(heap, childpos), - Py_LE); + PyList_GET_ITEM(heap, rightpos)); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) childpos = rightpos; } /* Move the smaller child up. */ @@ -214,10 +232,10 @@ heappushpop(PyObject *self, PyObject *args) return item; } - cmp = PyObject_RichCompareBool(item, PyList_GET_ITEM(heap, 0), Py_LE); + cmp = cmp_lt(PyList_GET_ITEM(heap, 0), item); if (cmp == -1) return NULL; - if (cmp == 1) { + if (cmp == 0) { Py_INCREF(item); return item; } @@ -270,6 +288,7 @@ nlargest(PyObject *self, PyObject *args) { PyObject *heap=NULL, *elem, *iterable, *sol, *it, *oldelem; Py_ssize_t i, n; + int cmp; if (!PyArg_ParseTuple(args, "nO:nlargest", &n, &iterable)) return NULL; @@ -312,7 +331,12 @@ nlargest(PyObject *self, PyObject *args) else goto sortit; } - if (PyObject_RichCompareBool(elem, sol, Py_LE)) { + cmp = cmp_lt(sol, elem); + if (cmp == -1) { + Py_DECREF(elem); + goto fail; + } + if (cmp == 0) { Py_DECREF(elem); continue; } @@ -362,12 +386,12 @@ _siftdownmax(PyListObject *heap, Py_ssize_t startpos, Py_ssize_t pos) while (pos > startpos){ parentpos = (pos - 1) >> 1; parent = PyList_GET_ITEM(heap, parentpos); - cmp = PyObject_RichCompareBool(newitem, parent, Py_LE); + cmp = cmp_lt(parent, newitem); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) break; Py_INCREF(parent); Py_DECREF(PyList_GET_ITEM(heap, pos)); @@ -402,15 +426,14 @@ _siftupmax(PyListObject *heap, Py_ssize_t pos) /* Set childpos to index of smaller child. */ rightpos = childpos + 1; if (rightpos < endpos) { - cmp = PyObject_RichCompareBool( - PyList_GET_ITEM(heap, childpos), + cmp = cmp_lt( PyList_GET_ITEM(heap, rightpos), - Py_LE); + PyList_GET_ITEM(heap, childpos)); if (cmp == -1) { Py_DECREF(newitem); return -1; } - if (cmp == 1) + if (cmp == 0) childpos = rightpos; } /* Move the smaller child up. */ @@ -434,6 +457,7 @@ nsmallest(PyObject *self, PyObject *args) { PyObject *heap=NULL, *elem, *iterable, *los, *it, *oldelem; Py_ssize_t i, n; + int cmp; if (!PyArg_ParseTuple(args, "nO:nsmallest", &n, &iterable)) return NULL; @@ -477,7 +501,12 @@ nsmallest(PyObject *self, PyObject *args) else goto sortit; } - if (PyObject_RichCompareBool(los, elem, Py_LE)) { + cmp = cmp_lt(elem, los); + if (cmp == -1) { + Py_DECREF(elem); + goto fail; + } + if (cmp == 0) { Py_DECREF(elem); continue; } |