bdiff: don't check border condition in loop
This is pretty much a copy of d500ddae7494, just to a different loop.
The condition `p == plast` (`plast == a + len - 1`) was only true on
the final iteration of the loop. So it was wasteful to check for it
on every iteration. We decrease the iteration count by 1 and add an
explicit check for `p == plast` after the loop.
Again, we see modest wins.
From the mozilla-unified repository:
$ perfbdiff -m 3041e4d59df2
! wall 0.035502 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
! wall 0.030480 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)
$ perfbdiff 0e9928989e9c --alldata --count 100
! wall 4.097394 comb 4.100000 user 4.100000 sys 0.000000 (best of 3)
! wall 3.597798 comb 3.600000 user 3.600000 sys 0.000000 (best of 3)
The 2nd example throws a total of ~3.3GB of data at bdiff. This
change increases the throughput from ~811 MB/s to ~924 MB/s.
#!/usr/bin/env python
from __future__ import absolute_import
"""
Small and dumb HTTP server for use in tests.
"""
import optparse
import signal
import sys
from mercurial import (
cmdutil,
util,
)
httpserver = util.httpserver
OptionParser = optparse.OptionParser
class simplehttpservice(object):
def __init__(self, host, port):
self.address = (host, port)
def init(self):
self.httpd = httpserver.httpserver(
self.address, httpserver.simplehttprequesthandler)
def run(self):
self.httpd.serve_forever()
if __name__ == '__main__':
parser = OptionParser()
parser.add_option('-p', '--port', dest='port', type='int', default=8000,
help='TCP port to listen on', metavar='PORT')
parser.add_option('-H', '--host', dest='host', default='localhost',
help='hostname or IP to listen on', metavar='HOST')
parser.add_option('--pid', dest='pid',
help='file name where the PID of the server is stored')
parser.add_option('-f', '--foreground', dest='foreground',
action='store_true',
help='do not start the HTTP server in the background')
parser.add_option('--daemon-postexec', action='append')
(options, args) = parser.parse_args()
signal.signal(signal.SIGTERM, lambda x, y: sys.exit(0))
if options.foreground and options.pid:
parser.error("options --pid and --foreground are mutually exclusive")
opts = {'pid_file': options.pid,
'daemon': not options.foreground,
'daemon_postexec': options.daemon_postexec}
service = simplehttpservice(options.host, options.port)
cmdutil.service(opts, initfn=service.init, runfn=service.run,
runargs=[sys.executable, __file__] + sys.argv[1:])