Instead remove enough data from it that this regression test tests what
it needs to.
Moving the database was the last thing that made the test suite
unstable, including sometimes hanging completely. It seems that, despite
closeDb being called before the move, sqlite was not quite done with it,
and somehow this causes other sqlite handles to become unstable. Not
good.
With this change, the test suite has successfully run 100+ times without
any issues.
Should be redundant, but test suite is ending up with
a lot of extra sqlite connections before unused keys database handles
get garbage collected.
While running the test suite, I often saw 2-4+ open fds to the same
repo's keys database. After this change, it seems to mostly have 1,
occasionally 2.
And that might explain some of the strange sqlite failures in the test suite.
Especially the failures of test_lock_v7_force, where the keys database
gets renamed to a new directory out from under sqlite.
I suspect this may be due to SQLITE_IOERR_SHORT_READ, but have not
verified.
I was able to reproduce it on Linux after running the test suite in a loop
for 1-3 hours until it failed.
The WAL mode entry change in 3963c5fcf5
may have hidden the problem I was seeing; I have not seen an ErrorIO
since then.
Cache high-resolution mtimes for improved detection of modified files in v7
(and direct mode).
Including on Windows.
With back-compat support so old low-res mtimes won't break anything, and
so the new information also won't break old versions of git-annex.
Luckily, this did not affect any git-annex log files, since they all
include the trailing 's' for backwards compatability reasons.
But, if I later want to drop that, this is the first commit where
git-annex can be trusted to parse that right.
The misparse caused it to be off by up to 10 seconds.
I've seen intermittent failures of the test suite with v6 for a long time,
it seems to have possibly gotten worse with the changes around v7. Or just
being unlucky; all tests failed today.
Seen on amd64 and i386 builders, repeatedly but intermittently:
unused: FAIL (4.86s)
Test.hs:928:
git diff did not show changes to unlocked file
And I think other such failures, all involving v7/v6 mode tests.
I managed to reproduce the unused failure with --keep-failures,
and inside the repo, git diff was indeed not showing any changes for
the modified unlocked file.
The two stats will be the same other than mtime; the old and new files have
the same size and inode, since the test case writes to the file and then
overwrites it.
Indeed, notice the identical timestamps:
builder@orca:~/gitbuilder/build/.t/tmprepo335$ echo 1 > foo; stat foo; echo 2 > foo; stat foo
File: foo
Size: 2 Blocks: 8 IO Block: 4096 regular file
Device: 801h/2049d Inode: 3546179 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1000/ builder) Gid: ( 1000/ builder)
Access: 2018-10-29 22:14:10.894942036 +0000
Modify: 2018-10-29 22:14:10.894942036 +0000
Change: 2018-10-29 22:14:10.894942036 +0000
Birth: -
File: foo
Size: 2 Blocks: 8 IO Block: 4096 regular file
Device: 801h/2049d Inode: 3546179 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1000/ builder) Gid: ( 1000/ builder)
Access: 2018-10-29 22:14:10.894942036 +0000
Modify: 2018-10-29 22:14:10.898942036 +0000
Change: 2018-10-29 22:14:10.898942036 +0000
Birth: -
I'm seeing this in Linux VMs; it doesn't happen on my laptop. I've also
not experienced the intermittent test suite failures on my laptop.
So, I hope that this small delay will avoid the problem.
Update: I didn't, indeed I then reproduced the same failure on my
laptop, so it must be due to something else. But keeping this change anyway
since not needing to worry about lowish-resolution mtime in the test suite seems
worthwhile.
