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.

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# Extension to write out fake unsupported records into the merge state

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#

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#

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from __future__ import absolute_import

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from mercurial import (

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    cmdutil,

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    merge,

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)

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cmdtable = {}

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command = cmdutil.command(cmdtable)

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@command('fakemergerecord',

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         [('X', 'mandatory', None, 'add a fake mandatory record'),

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          ('x', 'advisory', None, 'add a fake advisory record')], '')

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def fakemergerecord(ui, repo, *pats, **opts):

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    with repo.wlock():

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        ms = merge.mergestate.read(repo)

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        records = ms._makerecords()

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        if opts.get('mandatory'):

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            records.append(('X', 'mandatory record'))

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        if opts.get('advisory'):

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            records.append(('x', 'advisory record'))

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        ms._writerecords(records)