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.
from __future__ import absolute_import, print_function
from mercurial import (
util,
wireproto,
)
stringio = util.stringio
class proto(object):
def __init__(self, args):
self.args = args
def getargs(self, spec):
args = self.args
args.setdefault('*', {})
names = spec.split()
return [args[n] for n in names]
class clientpeer(wireproto.wirepeer):
def __init__(self, serverrepo):
self.serverrepo = serverrepo
def _capabilities(self):
return ['batch']
def _call(self, cmd, **args):
return wireproto.dispatch(self.serverrepo, proto(args), cmd)
def _callstream(self, cmd, **args):
return stringio(self._call(cmd, **args))
@wireproto.batchable
def greet(self, name):
f = wireproto.future()
yield {'name': mangle(name)}, f
yield unmangle(f.value)
class serverrepo(object):
def greet(self, name):
return "Hello, " + name
def filtered(self, name):
return self
def mangle(s):
return ''.join(chr(ord(c) + 1) for c in s)
def unmangle(s):
return ''.join(chr(ord(c) - 1) for c in s)
def greet(repo, proto, name):
return mangle(repo.greet(unmangle(name)))
wireproto.commands['greet'] = (greet, 'name',)
srv = serverrepo()
clt = clientpeer(srv)
print(clt.greet("Foobar"))
b = clt.batch()
fs = [b.greet(s) for s in ["Fo, =;:<o", "Bar"]]
b.submit()
print([f.value for f in fs])