emitrevision: simplify the fallback to computed delta
Not using the stored delta, or having a full snapshot on disk behave the same
ways, so lets use the same code path for that, this is simpler, and it update
will be simpler.
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 = [
(b"a\nc\n\n\n\n", b"a\nb\n\n\n"),
(b"a\nb\nc\n", b"a\nc\n"),
(b"", b""),
(b"a\nb\nc", b"a\nb\nc"),
(b"a\nb\nc\nd\n", b"a\nd\n"),
(b"a\nb\nc\nd\n", b"a\nc\ne\n"),
(b"a\nb\nc\n", b"a\nc\n"),
(b"a\n", b"c\na\nb\n"),
(b"a\n", b""),
(b"a\n", b"b\nc\n"),
(b"a\n", b"c\na\n"),
(b"", b"adjfkjdjksdhfksj"),
(b"", b"ab"),
(b"", b"abc"),
(b"a", b"a"),
(b"ab", b"ab"),
(b"abc", b"abc"),
(b"a\n", b"a\n"),
(b"a\nb", b"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 = [
(
b"x\n\nx\n\nx\n\nx\n\nz\n",
b"x\n\nx\n\ny\n\nx\n\nx\n\nz\n",
[
b'x\n\nx\n\n',
diffreplace(6, 6, b'', b'y\n\n'),
b'x\n\nx\n\nz\n',
],
),
(
b"x\n\nx\n\nx\n\nx\n\nz\n",
b"x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n",
[
b'x\n\nx\n\n',
diffreplace(6, 6, b'', b'y\n\n'),
b'x\n\n',
diffreplace(9, 9, b'', b'y\n\n'),
b'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(
b"a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n",
b"a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n",
)
want_c = [
b'a\nb\nb\n',
diffreplace(6, 6, b'', b'a\nb\nb\nb\nc\n.\n'),
b'b\nc\n.\nd\ne\n',
diffreplace(16, 18, b'.\n', b''),
b'f\n',
]
want_pure = [
diffreplace(0, 0, b'', b'a\nb\nb\n'),
b'a\nb\nb\nb\nc\n.\n',
diffreplace(12, 12, b'', b'b\nc\n.\n'),
b'd\ne\n',
diffreplace(16, 18, b'.\n', b''),
b'f\n',
]
self.assertTrue(
got in (want_c, want_pure),
'got: %r, wanted either %r or %r' % (got, want_c, want_pure),
)
def test_fixws(self):
cases = [
(b" \ta\r b\t\n", b"ab\n", 1),
(b" \ta\r b\t\n", b" a b\n", 0),
(b"", b"", 1),
(b"", b"", 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(
b''.join(b'<%d\n-\n' % i for i in range(5)),
b''.join(b'>%d\n-\n' % i for i in range(5)),
),
[
diffreplace(0, 3, b'<0\n', b'>0\n'),
b'-\n',
diffreplace(5, 8, b'<1\n', b'>1\n'),
b'-\n',
diffreplace(10, 13, b'<2\n', b'>2\n'),
b'-\n',
diffreplace(15, 18, b'<3\n', b'>3\n'),
b'-\n',
diffreplace(20, 23, b'<4\n', b'>4\n'),
b'-\n',
],
)
def test_prefer_appending(self):
# 1 line to 3 lines
self.assertEqual(
self.showdiff(b'a\n', b'a\n' * 3),
[b'a\n', diffreplace(2, 2, b'', b'a\na\n')],
)
# 1 line to 5 lines
self.assertEqual(
self.showdiff(b'a\n', b'a\n' * 5),
[b'a\n', diffreplace(2, 2, b'', b'a\na\na\na\n')],
)
def test_prefer_removing_trailing(self):
# 3 lines to 1 line
self.assertEqual(
self.showdiff(b'a\n' * 3, b'a\n'),
[b'a\n', diffreplace(2, 6, b'a\na\n', b'')],
)
# 5 lines to 1 line
self.assertEqual(
self.showdiff(b'a\n' * 5, b'a\n'),
[b'a\n', diffreplace(2, 10, b'a\na\na\na\n', b'')],
)
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)