Mercurial > hgsubversion
view tests/test_fetch_command_regexes.py @ 1233:0d0132cba155
editor: fix edge case with in memory file-store size limit
There are a few cases where we will set a single file into to the
editor's FileStore object more than once. Notably, for copied and
then modified files, we will set it at least twice. Three times if
editing fails (which it can for symlinks).
If we pass the in-memory storage limit in between the first (or second
if editing fails) time we set the file and the last time we set the
file, we will write the data to the in memory store the first time and
the file store the last time. We didn't remove it form the in-memory
store though, and we always prefer reading from the in-memory store.
This means we can sometimes end up with the wrong version of a file.
This is fairly unlikely to happen in normal use since you need to hit
the memory limit between two writes to the store for the same file.
We only write a file multiple times if a) the file (and not one of
it's parent directories) is copied and then modified or b) editing
fails. From what I can tell, it's only common for editing to fail for
symlinks, and they ten to be relatively small data that is unlikely to
push over the limit. Finally, the default limit is 100MB which I
would expect to be most often either well over (source code) or well
under (binaries or automated changes) the size of the changes files in
a single commit.
The easiest way to reproduce this is to set the in-memory cache size
to 0 and then commit a copied and modified symlink. The empty-string
version from the failed editing will be the one that persists. I
happened to stumble upon this while trying (and failing) to test a
bug-fix for a related bug with identical symptoms (empty simlink). I
have seen this in the wild, once, but couldn't reproduce it at the
time. The repo in question is quite large and quite active, so I am
quite confident in my estimation that this is a real, but very rare,
problem.
The test changes attached to this was mneant to test a related bug,
but turned out not to actually cover the bug in question. They did
trigger this bug though, and are worthwhile to test, so I kept them.
| author | David Schleimer <dschleimer@fb.com> |
|---|---|
| date | Mon, 07 Apr 2014 17:51:59 -0700 |
| parents | d741f536f23a |
| children |
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import unittest import test_util from hgsubversion import stupid two_empties = """Index: __init__.py =================================================================== Index: bar/__init__.py =================================================================== Index: bar/test_muhaha.py =================================================================== --- bar/test_muhaha.py (revision 0) +++ bar/test_muhaha.py (revision 1) @@ -0,0 +1,2 @@ + +blah blah blah, I'm a fake patch \ No newline at end of file """ binary_delta = """Index: trunk/functional_tests/doc_tests/test_doctest_fixtures/doctest_fixtures_fixtures.pyc =================================================================== Cannot display: file marked as a binary type. svn:mime-type = application/octet-stream Property changes on: trunk/functional_tests/doc_tests/test_doctest_fixtures/doctest_fixtures_fixtures.pyc ___________________________________________________________________ Added: svn:mime-type + application/octet-stream Index: trunk/functional_tests/doc_tests/test_doctest_fixtures/doctest_fixtures.rst =================================================================== """ special_delta = """Index: delta =================================================================== --- delta(revision 0) +++ delta(revision 9) @@ -0,0 +1 @@ +link alpha \ No newline at end of file Property changes on: delta ___________________________________________________________________ Name: svn:special + * """ class RegexTests(unittest.TestCase): def test_empty_file_re(self): changed = stupid.parsediff(two_empties) self.assertEqual(3, len(changed)) self.assertEqual('__init__.py', changed[0].name) self.assert_(changed[0].isempty()) self.assertEqual('bar/__init__.py', changed[1].name) self.assert_(changed[1].isempty()) self.assertEqual('bar/test_muhaha.py', changed[2].name) self.assert_(not changed[2].isempty()) def test_any_matches_just_one(self): pat = '''Index: trunk/django/contrib/admin/urls/__init__.py =================================================================== ''' changed = stupid.parsediff(pat) self.assertEqual(['trunk/django/contrib/admin/urls/__init__.py'], [f.name for f in changed]) def test_special_re(self): changed = stupid.parsediff(special_delta) self.assertEqual(1, len(changed)) self.assert_(changed[0].symlink) def test_any_file_re(self): changed = stupid.parsediff(two_empties) self.assertEqual(['__init__.py', 'bar/__init__.py', 'bar/test_muhaha.py'], [f.name for f in changed]) def test_binary_file_re(self): changed = stupid.parsediff(binary_delta) binaries = [f.name for f in changed if f.binary] self.assertEqual(['trunk/functional_tests/doc_tests/test_doctest_fixtures/doctest_fixtures_fixtures.pyc'], binaries) def test_diff16(self): data = """Index: d3/d =================================================================== --- d3/d (revision 0) +++ d3/d (revision 6) @@ -0,0 +1 @@ +d Property changes on: d3 ___________________________________________________________________ Added: svn:externals + ^/trunk/common/ext ext3 Property changes on: . ___________________________________________________________________ Added: svn:mergeinfo Merged /branches/branch:r4-5 """ changed = stupid.parsediff(data) self.assertEqual(['d3/d', 'd3', '.'], [f.name for f in changed]) data = """Property changes on: empty1 ___________________________________________________________________ Deleted: svn:executable - * Property changes on: empty2 ___________________________________________________________________ Added: svn:executable + * Property changes on: binary1 ___________________________________________________________________ Deleted: svn:executable - * Property changes on: text1 ___________________________________________________________________ Deleted: svn:executable - * Property changes on: binary2 ___________________________________________________________________ Added: svn:executable + * Property changes on: text2 ___________________________________________________________________ Added: svn:executable + * """ changed = stupid.parsediff(data) self.assertEqual(['empty1', 'empty2', 'binary1', 'text1', 'binary2', 'text2'], [f.name for f in changed])