mirror of https://github.com/python/cpython
297 lines
8.0 KiB
C
297 lines
8.0 KiB
C
/* Bisection algorithms. Drop in replacement for bisect.py
|
|
|
|
Converted to C by Dmitry Vasiliev (dima at hlabs.spb.ru).
|
|
*/
|
|
|
|
#define PY_SSIZE_T_CLEAN
|
|
#include "Python.h"
|
|
|
|
/*[clinic input]
|
|
module _bisect
|
|
[clinic start generated code]*/
|
|
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=4d56a2b2033b462b]*/
|
|
|
|
#include "clinic/_bisectmodule.c.h"
|
|
|
|
static inline Py_ssize_t
|
|
internal_bisect_right(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi,
|
|
PyObject* key)
|
|
{
|
|
PyObject *litem;
|
|
Py_ssize_t mid;
|
|
int res;
|
|
|
|
if (lo < 0) {
|
|
PyErr_SetString(PyExc_ValueError, "lo must be non-negative");
|
|
return -1;
|
|
}
|
|
if (hi == -1) {
|
|
hi = PySequence_Size(list);
|
|
if (hi < 0)
|
|
return -1;
|
|
}
|
|
while (lo < hi) {
|
|
/* The (size_t)cast ensures that the addition and subsequent division
|
|
are performed as unsigned operations, avoiding difficulties from
|
|
signed overflow. (See issue 13496.) */
|
|
mid = ((size_t)lo + hi) / 2;
|
|
litem = PySequence_GetItem(list, mid);
|
|
if (litem == NULL)
|
|
return -1;
|
|
if (key != Py_None) {
|
|
PyObject *newitem = PyObject_CallOneArg(key, litem);
|
|
if (newitem == NULL) {
|
|
Py_DECREF(litem);
|
|
return -1;
|
|
}
|
|
Py_SETREF(litem, newitem);
|
|
}
|
|
res = PyObject_RichCompareBool(item, litem, Py_LT);
|
|
Py_DECREF(litem);
|
|
if (res < 0)
|
|
return -1;
|
|
if (res)
|
|
hi = mid;
|
|
else
|
|
lo = mid + 1;
|
|
}
|
|
return lo;
|
|
}
|
|
|
|
/*[clinic input]
|
|
_bisect.bisect_right -> Py_ssize_t
|
|
|
|
a: object
|
|
x: object
|
|
lo: Py_ssize_t = 0
|
|
hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
|
|
*
|
|
key: object = None
|
|
|
|
Return the index where to insert item x in list a, assuming a is sorted.
|
|
|
|
The return value i is such that all e in a[:i] have e <= x, and all e in
|
|
a[i:] have e > x. So if x already appears in the list, a.insert(i, x) will
|
|
insert just after the rightmost x already there.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
[clinic start generated code]*/
|
|
|
|
static Py_ssize_t
|
|
_bisect_bisect_right_impl(PyObject *module, PyObject *a, PyObject *x,
|
|
Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
|
|
/*[clinic end generated code: output=3a4bc09cc7c8a73d input=40fcc5afa06ae593]*/
|
|
{
|
|
return internal_bisect_right(a, x, lo, hi, key);
|
|
}
|
|
|
|
/*[clinic input]
|
|
_bisect.insort_right
|
|
|
|
a: object
|
|
x: object
|
|
lo: Py_ssize_t = 0
|
|
hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
|
|
*
|
|
key: object = None
|
|
|
|
Insert item x in list a, and keep it sorted assuming a is sorted.
|
|
|
|
If x is already in a, insert it to the right of the rightmost x.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
[clinic start generated code]*/
|
|
|
|
static PyObject *
|
|
_bisect_insort_right_impl(PyObject *module, PyObject *a, PyObject *x,
|
|
Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
|
|
/*[clinic end generated code: output=ac3bf26d07aedda2 input=44e1708e26b7b802]*/
|
|
{
|
|
PyObject *result, *key_x;
|
|
Py_ssize_t index;
|
|
|
|
if (key == Py_None) {
|
|
index = internal_bisect_right(a, x, lo, hi, key);
|
|
} else {
|
|
key_x = PyObject_CallOneArg(key, x);
|
|
if (x == NULL) {
|
|
return NULL;
|
|
}
|
|
index = internal_bisect_right(a, key_x, lo, hi, key);
|
|
Py_DECREF(key_x);
|
|
}
|
|
if (index < 0)
|
|
return NULL;
|
|
if (PyList_CheckExact(a)) {
|
|
if (PyList_Insert(a, index, x) < 0)
|
|
return NULL;
|
|
}
|
|
else {
|
|
result = PyObject_CallMethod(a, "insert", "nO", index, x);
|
|
if (result == NULL)
|
|
return NULL;
|
|
Py_DECREF(result);
|
|
}
|
|
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
static inline Py_ssize_t
|
|
internal_bisect_left(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi,
|
|
PyObject *key)
|
|
{
|
|
PyObject *litem;
|
|
Py_ssize_t mid;
|
|
int res;
|
|
|
|
if (lo < 0) {
|
|
PyErr_SetString(PyExc_ValueError, "lo must be non-negative");
|
|
return -1;
|
|
}
|
|
if (hi == -1) {
|
|
hi = PySequence_Size(list);
|
|
if (hi < 0)
|
|
return -1;
|
|
}
|
|
while (lo < hi) {
|
|
/* The (size_t)cast ensures that the addition and subsequent division
|
|
are performed as unsigned operations, avoiding difficulties from
|
|
signed overflow. (See issue 13496.) */
|
|
mid = ((size_t)lo + hi) / 2;
|
|
litem = PySequence_GetItem(list, mid);
|
|
if (litem == NULL)
|
|
return -1;
|
|
if (key != Py_None) {
|
|
PyObject *newitem = PyObject_CallOneArg(key, litem);
|
|
if (newitem == NULL) {
|
|
Py_DECREF(litem);
|
|
return -1;
|
|
}
|
|
Py_SETREF(litem, newitem);
|
|
}
|
|
res = PyObject_RichCompareBool(litem, item, Py_LT);
|
|
Py_DECREF(litem);
|
|
if (res < 0)
|
|
return -1;
|
|
if (res)
|
|
lo = mid + 1;
|
|
else
|
|
hi = mid;
|
|
}
|
|
return lo;
|
|
}
|
|
|
|
|
|
/*[clinic input]
|
|
_bisect.bisect_left -> Py_ssize_t
|
|
|
|
a: object
|
|
x: object
|
|
lo: Py_ssize_t = 0
|
|
hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
|
|
*
|
|
key: object = None
|
|
|
|
Return the index where to insert item x in list a, assuming a is sorted.
|
|
|
|
The return value i is such that all e in a[:i] have e < x, and all e in
|
|
a[i:] have e >= x. So if x already appears in the list, a.insert(i, x) will
|
|
insert just before the leftmost x already there.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
[clinic start generated code]*/
|
|
|
|
static Py_ssize_t
|
|
_bisect_bisect_left_impl(PyObject *module, PyObject *a, PyObject *x,
|
|
Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
|
|
/*[clinic end generated code: output=70749d6e5cae9284 input=90dd35b50ceb05e3]*/
|
|
{
|
|
return internal_bisect_left(a, x, lo, hi, key);
|
|
}
|
|
|
|
|
|
/*[clinic input]
|
|
_bisect.insort_left
|
|
|
|
a: object
|
|
x: object
|
|
lo: Py_ssize_t = 0
|
|
hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
|
|
*
|
|
key: object = None
|
|
|
|
Insert item x in list a, and keep it sorted assuming a is sorted.
|
|
|
|
If x is already in a, insert it to the left of the leftmost x.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
[clinic start generated code]*/
|
|
|
|
static PyObject *
|
|
_bisect_insort_left_impl(PyObject *module, PyObject *a, PyObject *x,
|
|
Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
|
|
/*[clinic end generated code: output=b1d33e5e7ffff11e input=3ab65d8784f585b1]*/
|
|
{
|
|
PyObject *result, *key_x;
|
|
Py_ssize_t index;
|
|
|
|
if (key == Py_None) {
|
|
index = internal_bisect_left(a, x, lo, hi, key);
|
|
} else {
|
|
key_x = PyObject_CallOneArg(key, x);
|
|
if (x == NULL) {
|
|
return NULL;
|
|
}
|
|
index = internal_bisect_left(a, key_x, lo, hi, key);
|
|
Py_DECREF(key_x);
|
|
}
|
|
if (index < 0)
|
|
return NULL;
|
|
if (PyList_CheckExact(a)) {
|
|
if (PyList_Insert(a, index, x) < 0)
|
|
return NULL;
|
|
} else {
|
|
result = PyObject_CallMethod(a, "insert", "nO", index, x);
|
|
if (result == NULL)
|
|
return NULL;
|
|
Py_DECREF(result);
|
|
}
|
|
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
static PyMethodDef bisect_methods[] = {
|
|
_BISECT_BISECT_RIGHT_METHODDEF
|
|
_BISECT_INSORT_RIGHT_METHODDEF
|
|
_BISECT_BISECT_LEFT_METHODDEF
|
|
_BISECT_INSORT_LEFT_METHODDEF
|
|
{NULL, NULL} /* sentinel */
|
|
};
|
|
|
|
PyDoc_STRVAR(module_doc,
|
|
"Bisection algorithms.\n\
|
|
\n\
|
|
This module provides support for maintaining a list in sorted order without\n\
|
|
having to sort the list after each insertion. For long lists of items with\n\
|
|
expensive comparison operations, this can be an improvement over the more\n\
|
|
common approach.\n");
|
|
|
|
|
|
static struct PyModuleDef _bisectmodule = {
|
|
PyModuleDef_HEAD_INIT,
|
|
.m_name = "_bisect",
|
|
.m_doc = module_doc,
|
|
.m_methods = bisect_methods,
|
|
.m_size = 0
|
|
};
|
|
|
|
PyMODINIT_FUNC
|
|
PyInit__bisect(void)
|
|
{
|
|
return PyModuleDef_Init(&_bisectmodule);
|
|
}
|