sapling/hgext3rd/generic_bisect.py
Stanislau Hlebik 470276319f fastpartialmatch: use bisect to quickly find matching revisions
Summary:
Since we have some of the nodes sorted we can now use bisect to quickly find
matching nodes.

Test Plan: arc unit

Reviewers: #sourcecontrol

Subscribers: mjpieters

Differential Revision: https://phabricator.intern.facebook.com/D4494419
2017-02-02 05:12:10 -08:00

23 lines
519 B
Python

def bisect(l, r, comp, val):
'''Bisect algorithm with custom compare function
Returns smallest index between l and r whose value is equal to val.
Returns None if there are no such index.
'''
if r < l:
return None
while l < r:
m = (l + r) / 2
cmpresult = comp(m, val)
if cmpresult == -1:
l = m + 1
elif cmpresult == 0:
r = m
else:
r = m - 1
if r < l or comp(l, val) != 0:
return None
return l