view tests/test-mq-qqueue.t @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

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

  $ hg init foo
  $ cd foo
  $ echo a > a
  $ hg ci -qAm a

Default queue:

  $ hg qqueue
  patches (active)

  $ echo b > a
  $ hg qnew -fgDU somestuff

Applied patches in default queue:

  $ hg qap
  somestuff

Try to change patch (create succeeds, switch fails):

  $ hg qqueue foo --create
  abort: new queue created, but cannot make active as patches are applied
  [255]

  $ hg qqueue
  foo
  patches (active)

Empty default queue:

  $ hg qpop
  popping somestuff
  patch queue now empty

Switch queue:

  $ hg qqueue foo
  $ hg qqueue
  foo (active)
  patches

List queues, quiet:

  $ hg qqueue --quiet
  foo
  patches

Fail creating queue with already existing name:

  $ hg qqueue --create foo
  abort: queue "foo" already exists
  [255]

  $ hg qqueue
  foo (active)
  patches

Create new queue for rename:

  $ hg qqueue --create bar

  $ hg qqueue
  bar (active)
  foo
  patches

Rename queue, same name:

  $ hg qqueue --rename bar
  abort: can't rename "bar" to its current name
  [255]

Rename queue to existing:

  $ hg qqueue --rename foo
  abort: queue "foo" already exists
  [255]

Rename queue:

  $ hg qqueue --rename buz

  $ hg qqueue
  buz (active)
  foo
  patches

Switch back to previous queue:

  $ hg qqueue foo
  $ hg qqueue --delete buz

  $ hg qqueue
  foo (active)
  patches

Create queue for purge:

  $ hg qqueue --create purge-me

  $ hg qqueue
  foo
  patches
  purge-me (active)

Create patch for purge:

  $ hg qnew patch-purge-me

  $ ls -1d .hg/patches-purge-me 2>/dev/null || true
  .hg/patches-purge-me

  $ hg qpop -a
  popping patch-purge-me
  patch queue now empty

Purge queue:

  $ hg qqueue foo
  $ hg qqueue --purge purge-me

  $ hg qqueue
  foo (active)
  patches

  $ ls -1d .hg/patches-purge-me 2>/dev/null || true

Unapplied patches:

  $ hg qun
  $ echo c > a
  $ hg qnew -fgDU otherstuff

Fail switching back:

  $ hg qqueue patches
  abort: new queue created, but cannot make active as patches are applied
  [255]

Fail deleting current:

  $ hg qqueue foo --delete
  abort: cannot delete currently active queue
  [255]

Switch back and delete foo:

  $ hg qpop -a
  popping otherstuff
  patch queue now empty

  $ hg qqueue patches
  $ hg qqueue foo --delete
  $ hg qqueue
  patches (active)

Tricky cases:

  $ hg qqueue store --create
  $ hg qnew journal

  $ hg qqueue
  patches
  store (active)

  $ hg qpop -a
  popping journal
  patch queue now empty

  $ hg qqueue patches
  $ hg qun
  somestuff

Invalid names:

  $ hg qqueue test/../../bar --create
  abort: invalid queue name, may not contain the characters ":\/."
  [255]

  $ hg qqueue . --create
  abort: invalid queue name, may not contain the characters ":\/."
  [255]

  $ cd ..