SF Patch #864863: Bisect C implementation
(Contributed by Dmitry Vasiliev.)
diff --git a/Doc/whatsnew/whatsnew24.tex b/Doc/whatsnew/whatsnew24.tex
index 5967d6d..b7e404b 100644
--- a/Doc/whatsnew/whatsnew24.tex
+++ b/Doc/whatsnew/whatsnew24.tex
@@ -305,6 +305,10 @@
supports transparency, this makes it possible to use a transparent background.
(Contributed by J\"org Lehmann.)
+\item The \module{bisect} module now has an underlying C implementation
+ for improved performance.
+ (Contributed by Dmitry Vasiliev.)
+
\item The \module{heapq} module has been converted to C. The resulting
ten-fold improvement in speed makes the module suitable for handling
high volumes of data.
diff --git a/Lib/bisect.py b/Lib/bisect.py
index c9e6c60..152f6c7 100644
--- a/Lib/bisect.py
+++ b/Lib/bisect.py
@@ -76,3 +76,9 @@
if a[mid] < x: lo = mid+1
else: hi = mid
return lo
+
+# Overwrite above definitions with a fast C implementation
+try:
+ from _bisect import bisect_right, bisect_left, insort_left, insort_right, insort, bisect
+except ImportError:
+ pass
diff --git a/Lib/test/test_bisect.py b/Lib/test/test_bisect.py
index 549978d..809d8af 100644
--- a/Lib/test/test_bisect.py
+++ b/Lib/test/test_bisect.py
@@ -1,6 +1,7 @@
import unittest
from test import test_support
from bisect import bisect_right, bisect_left, insort_left, insort_right, insort, bisect
+from UserList import UserList
class TestBisect(unittest.TestCase):
@@ -89,6 +90,7 @@
def test_precomputed(self):
for func, data, elem, expected in self.precomputedCases:
self.assertEqual(func(data, elem), expected)
+ self.assertEqual(func(UserList(data), elem), expected)
def test_random(self, n=25):
from random import randrange
@@ -132,22 +134,17 @@
class TestInsort(unittest.TestCase):
- def test_vsListSort(self, n=500):
+ def test_vsBuiltinSort(self, n=500):
from random import choice
- digits = "0123456789"
- raw = []
- insorted = []
- for i in range(n):
- digit = choice(digits)
- raw.append(digit)
- if digit in "02468":
- f = insort_left
- else:
- f = insort_right
- f(insorted, digit)
- sorted = raw[:]
- sorted.sort()
- self.assertEqual(sorted, insorted)
+ for insorted in (list(), UserList()):
+ for i in xrange(n):
+ digit = choice("0123456789")
+ if digit in "02468":
+ f = insort_left
+ else:
+ f = insort_right
+ f(insorted, digit)
+ self.assertEqual(sorted(insorted), insorted)
def test_backcompatibility(self):
self.assertEqual(insort, insort_right)
diff --git a/Misc/ACKS b/Misc/ACKS
index 4ddd6a3..eea665a 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -565,6 +565,7 @@
Doobee R. Tzeck
Lionel Ulmer
Hector Urtubia
+Dmitry Vasiliev
Frank Vercruesse
Jaap Vermeulen
Al Vezza
diff --git a/Misc/NEWS b/Misc/NEWS
index 18f1348..63b3321 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -210,7 +210,8 @@
- Plugged a minor hole in tempfile.mktemp() due to the use of
os.path.exists(), switched to using os.lstat() directly if possible.
-- heapq.py has been converted to C for improved performance
+- bisect.py and heapq.py now have underlying C implementations
+ for better performance
- traceback.format_exc has been added (similar to print_exc but it returns
a string).
diff --git a/Modules/_bisectmodule.c b/Modules/_bisectmodule.c
new file mode 100644
index 0000000..d336158
--- /dev/null
+++ b/Modules/_bisectmodule.c
@@ -0,0 +1,228 @@
+/* Bisection algorithms. Drop in replacement for bisect.py
+
+Converted to C by Dmitry Vasiliev (dima at hlabs.spb.ru).
+*/
+
+#include "Python.h"
+
+static int
+internal_bisect_right(PyObject *list, PyObject *item, int lo, int hi)
+{
+ PyObject *litem;
+ int mid, res;
+
+ if (hi == -1) {
+ hi = PySequence_Size(list);
+ if (hi < 0)
+ return -1;
+ }
+ while (lo < hi) {
+ mid = (lo + hi) / 2;
+ litem = PySequence_GetItem(list, mid);
+ if (litem == NULL)
+ return -1;
+ 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;
+}
+
+static PyObject *
+bisect_right(PyObject *self, PyObject *args)
+{
+ PyObject *list, *item;
+ int lo = 0;
+ int hi = -1;
+ int index;
+
+ if (!PyArg_ParseTuple(args, "OO|ii:bisect_right",
+ &list, &item, &lo, &hi))
+ return NULL;
+ index = internal_bisect_right(list, item, lo, hi);
+ if (index < 0)
+ return NULL;
+ return PyInt_FromLong(index);
+}
+
+PyDoc_STRVAR(bisect_right_doc,
+"bisect_right(list, item[, lo[, hi]]) -> index\n\
+\n\
+Return the index where to insert item x in list a, assuming a is sorted.\n\
+\n\
+The return value i is such that all e in a[:i] have e <= x, and all e in\n\
+a[i:] have e > x. So if x already appears in the list, i points just\n\
+beyond the rightmost x already there\n\
+\n\
+Optional args lo (default 0) and hi (default len(a)) bound the\n\
+slice of a to be searched.\n");
+
+static PyObject *
+insort_right(PyObject *self, PyObject *args)
+{
+ PyObject *list, *item;
+ int lo = 0;
+ int hi = -1;
+ int index;
+
+ if (!PyArg_ParseTuple(args, "OO|ii:insort_right",
+ &list, &item, &lo, &hi))
+ return NULL;
+ index = internal_bisect_right(list, item, lo, hi);
+ if (index < 0)
+ return NULL;
+ if (PyList_Check(list)) {
+ if (PyList_Insert(list, index, item) < 0)
+ return NULL;
+ } else {
+ if (PyObject_CallMethod(list, "insert", "iO", index, item)
+ == NULL)
+ return NULL;
+ }
+
+ Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(insort_right_doc,
+"insort_right(list, item[, lo[, hi]])\n\
+\n\
+Insert item x in list a, and keep it sorted assuming a is sorted.\n\
+\n\
+If x is already in a, insert it to the right of the rightmost x.\n\
+\n\
+Optional args lo (default 0) and hi (default len(a)) bound the\n\
+slice of a to be searched.\n");
+
+static int
+internal_bisect_left(PyObject *list, PyObject *item, int lo, int hi)
+{
+ PyObject *litem;
+ int mid, res;
+
+ if (hi == -1) {
+ hi = PySequence_Size(list);
+ if (hi < 0)
+ return -1;
+ }
+ while (lo < hi) {
+ mid = (lo + hi) / 2;
+ litem = PySequence_GetItem(list, mid);
+ if (litem == NULL)
+ return -1;
+ 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;
+}
+
+static PyObject *
+bisect_left(PyObject *self, PyObject *args)
+{
+ PyObject *list, *item;
+ int lo = 0;
+ int hi = -1;
+ int index;
+
+ if (!PyArg_ParseTuple(args, "OO|ii:bisect_left",
+ &list, &item, &lo, &hi))
+ return NULL;
+ index = internal_bisect_left(list, item, lo, hi);
+ if (index < 0)
+ return NULL;
+ return PyInt_FromLong(index);
+}
+
+PyDoc_STRVAR(bisect_left_doc,
+"bisect_left(list, item[, lo[, hi]]) -> index\n\
+\n\
+Return the index where to insert item x in list a, assuming a is sorted.\n\
+\n\
+The return value i is such that all e in a[:i] have e < x, and all e in\n\
+a[i:] have e >= x. So if x already appears in the list, i points just\n\
+before the leftmost x already there.\n\
+\n\
+Optional args lo (default 0) and hi (default len(a)) bound the\n\
+slice of a to be searched.\n");
+
+static PyObject *
+insort_left(PyObject *self, PyObject *args)
+{
+ PyObject *list, *item;
+ int lo = 0;
+ int hi = -1;
+ int index;
+
+ if (!PyArg_ParseTuple(args, "OO|ii:insort_left",
+ &list, &item, &lo, &hi))
+ return NULL;
+ index = internal_bisect_left(list, item, lo, hi);
+ if (index < 0)
+ return NULL;
+ if (PyList_Check(list)) {
+ if (PyList_Insert(list, index, item) < 0)
+ return NULL;
+ } else {
+ if (PyObject_CallMethod(list, "insert", "iO", index, item)
+ == NULL)
+ return NULL;
+ }
+
+ Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(insort_left_doc,
+"insort_left(list, item[, lo[, hi]])\n\
+\n\
+Insert item x in list a, and keep it sorted assuming a is sorted.\n\
+\n\
+If x is already in a, insert it to the left of the leftmost x.\n\
+\n\
+Optional args lo (default 0) and hi (default len(a)) bound the\n\
+slice of a to be searched.\n");
+
+PyDoc_STRVAR(bisect_doc, "Alias for bisect_right().\n");
+PyDoc_STRVAR(insort_doc, "Alias for insort_right().\n");
+
+static PyMethodDef bisect_methods[] = {
+ {"bisect_right", (PyCFunction)bisect_right,
+ METH_VARARGS, bisect_right_doc},
+ {"bisect", (PyCFunction)bisect_right,
+ METH_VARARGS, bisect_doc},
+ {"insort_right", (PyCFunction)insort_right,
+ METH_VARARGS, insort_right_doc},
+ {"insort", (PyCFunction)insort_right,
+ METH_VARARGS, insort_doc},
+ {"bisect_left", (PyCFunction)bisect_left,
+ METH_VARARGS, bisect_left_doc},
+ {"insort_left", (PyCFunction)insort_left,
+ METH_VARARGS, insort_left_doc},
+ {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");
+
+PyMODINIT_FUNC
+init_bisect(void)
+{
+ PyObject *m;
+
+ m = Py_InitModule3("_bisect", bisect_methods, module_doc);
+}
+
diff --git a/PC/VC6/pythoncore.dsp b/PC/VC6/pythoncore.dsp
index dfc2bad..0e8b42a 100644
--- a/PC/VC6/pythoncore.dsp
+++ b/PC/VC6/pythoncore.dsp
@@ -93,6 +93,10 @@
# Name "pythoncore - Win32 Debug"
# Begin Source File
+SOURCE=..\..\Modules\_bisectmodule.c
+# End Source File
+# Begin Source File
+
SOURCE=..\..\Modules\_codecsmodule.c
# End Source File
# Begin Source File
diff --git a/PC/config.c b/PC/config.c
index 7bf31b0..15671f6 100644
--- a/PC/config.c
+++ b/PC/config.c
@@ -47,6 +47,7 @@
extern void init_random(void);
extern void inititertools(void);
extern void initheapq(void);
+extern void init_bisect(void);
extern void init_symtable(void);
extern void initmmap(void);
extern void init_csv(void);
@@ -106,6 +107,7 @@
{"_weakref", init_weakref},
{"_hotshot", init_hotshot},
{"_random", init_random},
+ {"_bisect", init_bisect},
{"heapq", initheapq},
{"itertools", inititertools},
{"_symtable", init_symtable},
diff --git a/setup.py b/setup.py
index 2c3eae6..39873d3 100644
--- a/setup.py
+++ b/setup.py
@@ -322,6 +322,8 @@
exts.append( Extension("_random", ["_randommodule.c"]) )
# fast iterator tools implemented in C
exts.append( Extension("itertools", ["itertoolsmodule.c"]) )
+ # bisect
+ exts.append( Extension("_bisect", ["_bisectmodule.c"]) )
# heapq
exts.append( Extension("heapq", ["heapqmodule.c"]) )
# operator.add() and similar goodies