view tests/test-mq-qdelete.t @ 35098:66c5a8cf2868

lfs: import the Facebook git-lfs client extension

The purpose of this is the same as the built-in largefiles extension- to handle
huge files outside of the normal storage system, generally to keep the amount of
data cloned to a lower amount.  There are several benefits of implementing the
git-lfs protocol, instead of using the largefiles extension:

  - Bitbucket and Github support (and probably wider support in 3rd party
    hosting sites in general). [1][2]

  - The number of hg internals monkey patched are several orders of magnitude
    lower, so it will be easier to reason about and maintain.  Future commands
    will likely just work, without requiring various wrappers.

  - The "standin" files are only written to the filelog, not the disk.  That
    should avoid weird edge cases where the largefile and standin files get out
    of sync. [3]  It also avoids the occasional printing of the "hidden" standin
    file in various messages.

  - Filesets like size() will work, even if the file isn't present.  (It always
    says 41 bytes for largefiles, whether present or not.)

The only place that I see where largefiles comes out on top is that it works
with `hg serve` for simple sharing, without external infrastructure.  Getting
lfs-test-server working was a hassle, and took awhile to figure out.  Maybe we
can do something to make it work in the future.

Long term, I expect that this will be highly preferred over largefiles.  But if
we are to recommend this to largefile users, there are some UI issues to
bikeshed.  Until they are resolved, I've marked this experimental, and am not
putting a pointer to this in the largefiles help.  The (non exhaustive) list of
issues I've seen so far are:

  - It isn't sufficient to just enable the largefiles extension- you have to
    explicitly add a file with --large before it will pay attention to the
    configured sizes and patterns on future adds.  The justification being that
    once you use it, you're stuck with it.  I've seen people confused by this,
    and haven't liked it myself.  But it's also saved me a few times.  Should we
    do something like have a specific enabling config setting that must be set
    in the local repo config, so that enabling this extension in the user or
    system hgrc doesn't silently start storing lfs files?

  - The largefiles extension adds a repo requirement when the first largefile is
    committed, so that the extension must always be enabled in the future.  This
    extension is not doing that, and since I only enabled it locally to avoid
    infecting other repos, I got a cryptic error about missing flag processors
    when I cloned.  Is there no repo requirement due to shallow/narrow clone
    considerations (or other future advanced things)?

  - In the (small amount of) reading I've done about the git implementation, it
    seems that the files and sizes are stored in a tracked .gitattributes file.
    I think a tracked file for this would be extremely useful for consistency
    across developers, but this kind of touches on the tracked hgrc file
    proposal a few months back.

  - The git client can specify file patterns, not just sizes.

  - The largefiles extension has a cache directory in the local repo, but also a
    system wide one.  We should probably implement a system wide cache too, so
    that multiple clones don't have to refetch the files from the server.

  - Jun mentioned other missing features, like SSH authentication, gc, etc.

The code corresponds to c0492b73c7ef in hg-experimental. [4]  The only tweaks
are to load the extension in the tests with 'lfs=' instead of
'lfs=$TESTDIR/../hgext3rd/lfs', change the import in the *.py test to hgext
(from hgext3rd), add the 'testedwith' declaration, and mark it experimental for
now.  The infinite-push, p4fastimport, and remotefilelog tests were left behind.

The devel-warnings for unregistered config options are not corrected yet, nor
are the import check warnings.

[1] https://www.mercurial-scm.org/pipermail/mercurial/2017-November/050699.html
[2] https://bitbucket.org/site/master/issues/3843/largefiles-support-bb-3903
[3] https://bz.mercurial-scm.org/show_bug.cgi?id=5738
[4] https://bitbucket.org/facebook/hg-experimental

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew -d '1 0' pc

  $ hg qdel
  abort: qdelete requires at least one revision or patch name
  [255]

  $ hg qdel pc
  abort: cannot delete applied patch pc
  [255]

  $ hg qpop
  popping pc
  now at: pb

Delete the same patch twice in one command (issue2427)

  $ hg qdel pc pc

  $ hg qseries
  pa
  pb

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qpop
  popping pb
  now at: pa

  $ hg qdel -k 1

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qdel -r pa
  patch pa finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  1 [mq]: pa
  0 base

  $ hg qnew pd
  $ hg qnew pe
  $ hg qnew pf

  $ hg qdel -r pe
  abort: cannot delete revision 3 above applied patches
  [255]

  $ hg qdel -r qbase:pe
  patch pd finalized without changeset message
  patch pe finalized without changeset message

  $ hg qapplied
  pf

  $ hg log --template '{rev} {desc}\n'
  4 [mq]: pf
  3 [mq]: pe
  2 [mq]: pd
  1 [mq]: pa
  0 base

  $ cd ..

  $ hg init b
  $ cd b

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qfinish
  abort: no revisions specified
  [255]

  $ hg qfinish -a
  no patches applied

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew pc # XXX fails to apply by /usr/bin/patch if we put a date

  $ hg qfinish 0
  abort: revision 0 is not managed
  [255]

  $ hg qfinish pb
  abort: cannot delete revision 2 above applied patches
  [255]

  $ hg qpop
  popping pc
  now at: pb

  $ hg qfinish -a pc
  abort: unknown revision 'pc'!
  [255]

  $ hg qpush
  applying pc
  patch pc is empty
  now at: pc

  $ hg qfinish qbase:pb
  patch pa finalized without changeset message
  patch pb finalized without changeset message

  $ hg qapplied
  pc

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ hg qfinish -a pc
  patch pc finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ ls .hg/patches
  series
  status

qdel -k X && hg qimp -e X used to trigger spurious output with versioned queues

  $ hg init --mq
  $ hg qimport -r 3
  $ hg qpop
  popping imported_patch_pc
  patch queue now empty
  $ hg qdel -k imported_patch_pc
  $ hg qimp -e imported_patch_pc
  adding imported_patch_pc to series file
  $ hg qfinish -a
  no patches applied


resilience to inconsistency: qfinish -a with applied patches not in series

  $ hg qser
  imported_patch_pc
  $ hg qapplied
  $ hg qpush
  applying imported_patch_pc
  patch imported_patch_pc is empty
  now at: imported_patch_pc
  $ echo next >>  base
  $ hg qrefresh -d '1 0'
  $ echo > .hg/patches/series # remove 3.diff from series to confuse mq
  $ hg qfinish -a
  revision 47dfa8501675 refers to unknown patches: imported_patch_pc

more complex state 'both known and unknown patches

  $ echo hip >>  base
  $ hg qnew -f -d '1 0' -m 4 4.diff
  $ echo hop >>  base
  $ hg qnew -f -d '1 0' -m 5 5.diff
  $ echo > .hg/patches/series # remove 4.diff and 5.diff from series to confuse mq
  $ echo hup >>  base
  $ hg qnew -f -d '1 0' -m 6 6.diff
  $ echo pup > base
  $ hg qfinish -a
  warning: uncommitted changes in the working directory
  revision 2b1c98802260 refers to unknown patches: 5.diff
  revision 33a6861311c0 refers to unknown patches: 4.diff

  $ cd ..