Mercurial > hg
view tests/test-bdiff.py @ 39594:bdb41eaa8b59
snapshot: fix line order when skipping over empty deltas
The code movement in 37957e07138c introduced an error.
Since 8f83a953dddf, we discarded some revisions because they are identical to
their delta base (and use that delta base instead). That logic is good,
however, in 37957e07138c we mixed up the order of two line, adding the "new"
revision to the set of already tested one, instead of the discarded one. So in
practice, we were never investigating any revisions in a chain starting with
an empty delta. Creating significantly worst delta chain (eg: Mercurial's
manifest move goes from about 60MB up to about 80MB).
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Mon, 10 Sep 2018 10:11:21 +0200 |
parents | 0c73634d0570 |
children | e05d7c71f209 |
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line source
from __future__ import absolute_import, print_function import collections import struct import unittest from mercurial import ( mdiff, ) class diffreplace( collections.namedtuple('diffreplace', 'start end from_ to')): def __repr__(self): return 'diffreplace(%r, %r, %r, %r)' % self class BdiffTests(unittest.TestCase): def assert_bdiff_applies(self, a, b): d = mdiff.textdiff(a, b) c = a if d: c = mdiff.patches(a, [d]) self.assertEqual( c, b, ("bad diff+patch result from\n %r to\n " "%r: \nbdiff: %r\npatched: %r" % (a, b, d, c[:200]))) def assert_bdiff(self, a, b): self.assert_bdiff_applies(a, b) self.assert_bdiff_applies(b, a) def test_bdiff_basic(self): cases = [ ("a\nc\n\n\n\n", "a\nb\n\n\n"), ("a\nb\nc\n", "a\nc\n"), ("", ""), ("a\nb\nc", "a\nb\nc"), ("a\nb\nc\nd\n", "a\nd\n"), ("a\nb\nc\nd\n", "a\nc\ne\n"), ("a\nb\nc\n", "a\nc\n"), ("a\n", "c\na\nb\n"), ("a\n", ""), ("a\n", "b\nc\n"), ("a\n", "c\na\n"), ("", "adjfkjdjksdhfksj"), ("", "ab"), ("", "abc"), ("a", "a"), ("ab", "ab"), ("abc", "abc"), ("a\n", "a\n"), ("a\nb", "a\nb"), ] for a, b in cases: self.assert_bdiff(a, b) def showdiff(self, a, b): bin = mdiff.textdiff(a, b) pos = 0 q = 0 actions = [] while pos < len(bin): p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12]) pos += 12 if p1: actions.append(a[q:p1]) actions.append(diffreplace(p1, p2, a[p1:p2], bin[pos:pos + l])) pos += l q = p2 if q < len(a): actions.append(a[q:]) return actions def test_issue1295(self): cases = [ ("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\nx\n\nz\n", ['x\n\nx\n\n', diffreplace(6, 6, '', 'y\n\n'), 'x\n\nx\n\nz\n']), ("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n", ['x\n\nx\n\n', diffreplace(6, 6, '', 'y\n\n'), 'x\n\n', diffreplace(9, 9, '', 'y\n\n'), 'x\n\nz\n']), ] for old, new, want in cases: self.assertEqual(self.showdiff(old, new), want) def test_issue1295_varies_on_pure(self): # we should pick up abbbc. rather than bc.de as the longest match got = self.showdiff("a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n", "a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n") want_c = ['a\nb\nb\n', diffreplace(6, 6, '', 'a\nb\nb\nb\nc\n.\n'), 'b\nc\n.\nd\ne\n', diffreplace(16, 18, '.\n', ''), 'f\n'] want_pure = [diffreplace(0, 0, '', 'a\nb\nb\n'), 'a\nb\nb\nb\nc\n.\n', diffreplace(12, 12, '', 'b\nc\n.\n'), 'd\ne\n', diffreplace(16, 18, '.\n', ''), 'f\n'] self.assert_(got in (want_c, want_pure), 'got: %r, wanted either %r or %r' % ( got, want_c, want_pure)) def test_fixws(self): cases = [ (" \ta\r b\t\n", "ab\n", 1), (" \ta\r b\t\n", " a b\n", 0), ("", "", 1), ("", "", 0), ] for a, b, allws in cases: c = mdiff.fixws(a, allws) self.assertEqual( c, b, 'fixws(%r) want %r got %r (allws=%r)' % (a, b, c, allws)) def test_nice_diff_for_trivial_change(self): self.assertEqual(self.showdiff( ''.join('<%s\n-\n' % i for i in range(5)), ''.join('>%s\n-\n' % i for i in range(5))), [diffreplace(0, 3, '<0\n', '>0\n'), '-\n', diffreplace(5, 8, '<1\n', '>1\n'), '-\n', diffreplace(10, 13, '<2\n', '>2\n'), '-\n', diffreplace(15, 18, '<3\n', '>3\n'), '-\n', diffreplace(20, 23, '<4\n', '>4\n'), '-\n']) def test_prefer_appending(self): # 1 line to 3 lines self.assertEqual(self.showdiff('a\n', 'a\n' * 3), ['a\n', diffreplace(2, 2, '', 'a\na\n')]) # 1 line to 5 lines self.assertEqual(self.showdiff('a\n', 'a\n' * 5), ['a\n', diffreplace(2, 2, '', 'a\na\na\na\n')]) def test_prefer_removing_trailing(self): # 3 lines to 1 line self.assertEqual(self.showdiff('a\n' * 3, 'a\n'), ['a\n', diffreplace(2, 6, 'a\na\n', '')]) # 5 lines to 1 line self.assertEqual(self.showdiff('a\n' * 5, 'a\n'), ['a\n', diffreplace(2, 10, 'a\na\na\na\n', '')]) if __name__ == '__main__': import silenttestrunner silenttestrunner.main(__name__)