tests/test-mdiff.py

mmapindex: set default to 1MB

mmapping index is more efficient if we only need a small part of it.

The 1MB value has been picked arbitrarily, a lower value might be better.

On a large repository with a 60MB index, we see the following performance
gain:

hg perfindex
before: ! wall 0.032023 comb 0.040000 user 0.000000 sys 0.040000 (best of 100)
after:  ! wall 0.000196 comb 0.000000 user 0.000000 sys 0.000000 (best of 1060)

The speed boost benefit all cases, including the one where the full index
needs to be parsed.

hg perfindex --rev 0
before: ! wall 0.040673 comb 0.030000 user 0.000000 sys 0.030000 (best of 100)
after   ! wall 0.010713 comb 0.020000 user 0.010000 sys 0.010000 (best of 212)

This gain reflect in higher level operation:

hg perfbookmarks --clear-revlogs
before: ! wall 0.161339 comb 0.160000 user 0.130000 sys 0.030000 (best of 56)
after:  ! wall 0.123228 comb 0.120000 user 0.120000 sys 0.000000 (best of 68)

from __future__ import absolute_import
from __future__ import print_function

import unittest

from mercurial import (
    mdiff,
)

class splitnewlinesTests(unittest.TestCase):

    def test_splitnewlines(self):
        cases = {b'a\nb\nc\n': [b'a\n', b'b\n', b'c\n'],
                 b'a\nb\nc': [b'a\n', b'b\n', b'c'],
                 b'a\nb\nc\n\n': [b'a\n', b'b\n', b'c\n', b'\n'],
                 b'': [],
                 b'abcabc': [b'abcabc'],
                 }
        for inp, want in cases.items():
            self.assertEqual(mdiff.splitnewlines(inp), want)

if __name__ == '__main__':
    import silenttestrunner
    silenttestrunner.main(__name__)