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outdated and unsupported repo format.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
$ hg qinit
$ echo x > x
$ hg ci -Ama
adding x
$ hg qnew a.patch
$ echo a > a
$ hg add a
$ hg qrefresh
$ hg qnew b.patch
$ echo b > b
$ hg add b
$ hg qrefresh
$ hg qnew c.patch
$ echo c > c
$ hg add c
$ hg qrefresh
$ hg qpop -a
popping c.patch
popping b.patch
popping a.patch
patch queue now empty
should fail
$ hg qguard does-not-exist.patch +bleh
abort: no patch named does-not-exist.patch
[255]
should fail
$ hg qguard +fail
abort: no patches applied
[255]
$ hg qpush
applying a.patch
now at: a.patch
should guard a.patch
$ hg qguard +a
should print +a
$ hg qguard
a.patch: +a
$ hg qpop
popping a.patch
patch queue now empty
should fail
$ hg qpush a.patch
cannot push 'a.patch' - guarded by '+a'
[1]
$ hg qguard a.patch
a.patch: +a
should push b.patch
$ hg qpush
applying b.patch
now at: b.patch
$ hg qpop
popping b.patch
patch queue now empty
test selection of an empty guard
$ hg qselect ""
abort: guard cannot be an empty string
[255]
$ hg qselect a
number of unguarded, unapplied patches has changed from 2 to 3
should push a.patch
$ hg qpush
applying a.patch
now at: a.patch
$ hg qguard -- c.patch -a
should print -a
$ hg qguard c.patch
c.patch: -a
should skip c.patch
$ hg qpush -a
applying b.patch
skipping c.patch - guarded by '-a'
now at: b.patch
$ hg qnext
all patches applied
[1]
should display b.patch
$ hg qtop
b.patch
$ hg qguard -n c.patch
should push c.patch
$ hg qpush -a
applying c.patch
now at: c.patch
$ hg qpop -a
popping c.patch
popping b.patch
popping a.patch
patch queue now empty
$ hg qselect -n
guards deactivated
number of unguarded, unapplied patches has changed from 3 to 2
should push all
$ hg qpush -a
applying b.patch
applying c.patch
now at: c.patch
$ hg qpop -a
popping c.patch
popping b.patch
patch queue now empty
$ hg qguard a.patch +1
$ hg qguard b.patch +2
$ hg qselect 1
number of unguarded, unapplied patches has changed from 1 to 2
should push a.patch, not b.patch
$ hg qpush
applying a.patch
now at: a.patch
$ hg qpush
applying c.patch
now at: c.patch
$ hg qpop -a
popping c.patch
popping a.patch
patch queue now empty
$ hg qselect 2
should push b.patch
$ hg qpush
applying b.patch
now at: b.patch
$ hg qpush -a
applying c.patch
now at: c.patch
$ hg qprev
b.patch
Used to be an issue with holes in the patch sequence
So, put one hole on the base and ask for topmost patch.
$ hg qtop
c.patch
$ hg qpop -a
popping c.patch
popping b.patch
patch queue now empty
$ hg qselect 1 2
number of unguarded, unapplied patches has changed from 2 to 3
should push a.patch, b.patch
$ hg qpush
applying a.patch
now at: a.patch
$ hg qpush
applying b.patch
now at: b.patch
$ hg qpop -a
popping b.patch
popping a.patch
patch queue now empty
$ hg qguard -- a.patch +1 +2 -3
$ hg qselect 1 2 3
number of unguarded, unapplied patches has changed from 3 to 2
list patches and guards
$ hg qguard -l
a.patch: +1 +2 -3
b.patch: +2
c.patch: unguarded
have at least one patch applied to test coloring
$ hg qpush
applying b.patch
now at: b.patch
list patches and guards with color
$ hg --config extensions.color= qguard --config color.mode=ansi \
> -l --color=always
\x1b[0;30;1ma.patch\x1b[0m: \x1b[0;33m+1\x1b[0m \x1b[0;33m+2\x1b[0m \x1b[0;31m-3\x1b[0m (esc)
\x1b[0;34;1;4mb.patch\x1b[0m: \x1b[0;33m+2\x1b[0m (esc)
\x1b[0;30;1mc.patch\x1b[0m: \x1b[0;32munguarded\x1b[0m (esc)
should pop b.patch
$ hg qpop
popping b.patch
patch queue now empty
list series
$ hg qseries -v
0 G a.patch
1 U b.patch
2 U c.patch
list guards
$ hg qselect
1
2
3
should push b.patch
$ hg qpush
applying b.patch
now at: b.patch
$ hg qpush -a
applying c.patch
now at: c.patch
$ hg qselect -n --reapply -v
guards deactivated
popping guarded patches
popping c.patch
popping b.patch
patch queue now empty
reapplying unguarded patches
skipping a.patch - guarded by '+1' '+2'
skipping b.patch - guarded by '+2'
skipping a.patch - guarded by '+1' '+2'
skipping b.patch - guarded by '+2'
applying c.patch
patching file c
adding c
committing files:
c
committing manifest
committing changelog
now at: c.patch
guards in series file: +1 +2 -3
$ hg qselect -s
+1
+2
-3
should show c.patch
$ hg qapplied
c.patch
$ hg qrename a.patch new.patch
should show :
new.patch: +1 +2 -3
b.patch: +2
c.patch: unguarded
$ hg qguard -l
new.patch: +1 +2 -3
b.patch: +2
c.patch: unguarded
$ hg qnew d.patch
$ hg qpop
popping d.patch
now at: c.patch
should show new.patch and b.patch as Guarded, c.patch as Applied
and d.patch as Unapplied
$ hg qseries -v
0 G new.patch
1 G b.patch
2 A c.patch
3 U d.patch
qseries again, but with color
$ hg --config extensions.color= --config color.mode=ansi qseries -v --color=always
0 G \x1b[0;30;1mnew.patch\x1b[0m (esc)
1 G \x1b[0;30;1mb.patch\x1b[0m (esc)
2 A \x1b[0;34;1;4mc.patch\x1b[0m (esc)
3 U \x1b[0;30;1md.patch\x1b[0m (esc)
$ hg qguard d.patch +2
new.patch, b.patch: Guarded. c.patch: Applied. d.patch: Guarded.
$ hg qseries -v
0 G new.patch
1 G b.patch
2 A c.patch
3 G d.patch
$ qappunappv()
> {
> for command in qapplied "qapplied -v" qunapplied "qunapplied -v"; do
> echo % hg $command
> hg $command
> done
> }
$ hg qpop -a
popping c.patch
patch queue now empty
$ hg qguard -l
new.patch: +1 +2 -3
b.patch: +2
c.patch: unguarded
d.patch: +2
$ qappunappv
% hg qapplied
% hg qapplied -v
% hg qunapplied
c.patch
% hg qunapplied -v
0 G new.patch
1 G b.patch
2 U c.patch
3 G d.patch
$ hg qselect 1
number of unguarded, unapplied patches has changed from 1 to 2
$ qappunappv
% hg qapplied
% hg qapplied -v
% hg qunapplied
new.patch
c.patch
% hg qunapplied -v
0 U new.patch
1 G b.patch
2 U c.patch
3 G d.patch
$ hg qpush -a
applying new.patch
skipping b.patch - guarded by '+2'
applying c.patch
skipping d.patch - guarded by '+2'
now at: c.patch
$ qappunappv
% hg qapplied
new.patch
c.patch
% hg qapplied -v
0 A new.patch
1 G b.patch
2 A c.patch
% hg qunapplied
% hg qunapplied -v
3 G d.patch
$ hg qselect 2
number of unguarded, unapplied patches has changed from 0 to 1
$ qappunappv
% hg qapplied
new.patch
c.patch
% hg qapplied -v
0 A new.patch
1 U b.patch
2 A c.patch
% hg qunapplied
d.patch
% hg qunapplied -v
3 U d.patch
$ for patch in `hg qseries`; do
> echo % hg qapplied $patch
> hg qapplied $patch
> echo % hg qunapplied $patch
> hg qunapplied $patch
> done
% hg qapplied new.patch
new.patch
% hg qunapplied new.patch
b.patch
d.patch
% hg qapplied b.patch
new.patch
% hg qunapplied b.patch
d.patch
% hg qapplied c.patch
new.patch
c.patch
% hg qunapplied c.patch
d.patch
% hg qapplied d.patch
new.patch
c.patch
% hg qunapplied d.patch
hg qseries -m: only b.patch should be shown
the guards file was not ignored in the past
$ hg qdelete -k b.patch
$ hg qseries -m
b.patch
hg qseries -m with color
$ hg --config extensions.color= --config color.mode=ansi qseries -m --color=always
\x1b[0;31;1mb.patch\x1b[0m (esc)
excercise corner cases in "qselect --reapply"
$ hg qpop -a
popping c.patch
popping new.patch
patch queue now empty
$ hg qguard -- new.patch -not-new
$ hg qguard -- c.patch -not-c
$ hg qguard -- d.patch -not-d
$ hg qpush -a
applying new.patch
applying c.patch
applying d.patch
patch d.patch is empty
now at: d.patch
$ hg qguard -l
new.patch: -not-new
c.patch: -not-c
d.patch: -not-d
$ hg qselect --reapply not-d
popping guarded patches
popping d.patch
now at: c.patch
reapplying unguarded patches
cannot push 'd.patch' - guarded by '-not-d'
$ hg qser -v
0 A new.patch
1 A c.patch
2 G d.patch
$ hg qselect --reapply -n
guards deactivated
$ hg qpush
applying d.patch
patch d.patch is empty
now at: d.patch
$ hg qser -v
0 A new.patch
1 A c.patch
2 A d.patch
$ hg qselect --reapply not-c
popping guarded patches
popping d.patch
popping c.patch
now at: new.patch
reapplying unguarded patches
applying d.patch
patch d.patch is empty
now at: d.patch
$ hg qser -v
0 A new.patch
1 G c.patch
2 A d.patch
$ hg qselect --reapply not-new
popping guarded patches
popping d.patch
popping new.patch
patch queue now empty
reapplying unguarded patches
applying c.patch
applying d.patch
patch d.patch is empty
now at: d.patch
$ hg qser -v
0 G new.patch
1 A c.patch
2 A d.patch
test that qselect shows "number of guarded, applied patches" correctly
$ hg qimport -q -e b.patch
adding b.patch to series file
$ hg qguard -- b.patch -not-b
$ hg qpop -a -q
patch queue now empty
$ hg qunapplied -v
0 G new.patch
1 U c.patch
2 U d.patch
3 U b.patch
$ hg qselect not-new not-c
number of unguarded, unapplied patches has changed from 3 to 2
$ hg qpush -q -a
patch d.patch is empty
now at: b.patch
$ hg qapplied -v
0 G new.patch
1 G c.patch
2 A d.patch
3 A b.patch
$ hg qselect --none
guards deactivated
$ hg qselect not-new not-c not-d
number of guarded, applied patches has changed from 0 to 1
test that "qselect --reapply" reapplies patches successfully when the
already applied patch becomes unguarded and it follows the already
guarded (= not yet applied) one.
$ hg qpop -q -a
patch queue now empty
$ hg qselect not-new not-c
number of unguarded, unapplied patches has changed from 1 to 2
$ hg qpush -q -a
patch d.patch is empty
now at: b.patch
$ hg qapplied -v
0 G new.patch
1 G c.patch
2 A d.patch
3 A b.patch
$ hg qselect -q --reapply not-c not-b
now at: d.patch
cannot push 'b.patch' - guarded by '-not-b'
$ hg qseries -v
0 U new.patch
1 G c.patch
2 A d.patch
3 G b.patch
test that "qselect --reapply" checks applied patches correctly when no
applied patches becomes guarded but some of unapplied ones become
unguarded.
$ hg qpop -q -a
patch queue now empty
$ hg qselect not-new not-c not-d
number of unguarded, unapplied patches has changed from 2 to 1
$ hg qpush -q -a
now at: b.patch
$ hg qapplied -v
0 G new.patch
1 G c.patch
2 G d.patch
3 A b.patch
$ hg qselect -q --reapply not-new not-c
$ hg qseries -v
0 G new.patch
1 G c.patch
2 U d.patch
3 A b.patch