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.

     1

from __future__ import absolute_import

     2

from mercurial import (

     3

    util,

     4

)

     5

     6

def makedate():

     7

    return 0, 0

     8

def getuser():

     9

    return 'bob'

    10

def getpid():

    11

    return 5000

    12

    13

# mock the date and user apis so the output is always the same

    14

def uisetup(ui):

    15

    util.makedate = makedate

    16

    util.getuser = getuser

    17

    util.getpid = getpid