Mercurial > hg
view tests/test-merge7.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outdated and unsupported repo format.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.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 May 2017 20:29:11 -0700 |
parents | ce3a133f71b3 |
children | eb586ed5d8ce |
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initial $ hg init test-a $ cd test-a $ cat >test.txt <<"EOF" > 1 > 2 > 3 > EOF $ hg add test.txt $ hg commit -m "Initial" clone $ cd .. $ hg clone test-a test-b updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved change test-a $ cd test-a $ cat >test.txt <<"EOF" > one > two > three > EOF $ hg commit -m "Numbers as words" change test-b $ cd ../test-b $ cat >test.txt <<"EOF" > 1 > 2.5 > 3 > EOF $ hg commit -m "2 -> 2.5" now pull and merge from test-a $ hg pull ../test-a pulling from ../test-a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg merge merging test.txt warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark') 0 files updated, 0 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon [1] resolve conflict $ cat >test.txt <<"EOF" > one > two-point-five > three > EOF $ rm -f *.orig $ hg resolve -m test.txt (no more unresolved files) $ hg commit -m "Merge 1" change test-a again $ cd ../test-a $ cat >test.txt <<"EOF" > one > two-point-one > three > EOF $ hg commit -m "two -> two-point-one" pull and merge from test-a again $ cd ../test-b $ hg pull ../test-a pulling from ../test-a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg merge --debug searching for copies back to rev 1 resolving manifests branchmerge: True, force: False, partial: False ancestor: 96b70246a118, local: 50c3a7e29886+, remote: 40d11a4173a8 preserving test.txt for resolve of test.txt starting 4 threads for background file closing (?) test.txt: versions differ -> m (premerge) picked tool ':merge' for test.txt (binary False symlink False changedelete False) merging test.txt my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118 test.txt: versions differ -> m (merge) picked tool ':merge' for test.txt (binary False symlink False changedelete False) my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118 warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark') 0 files updated, 0 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon [1] $ cat test.txt one <<<<<<< working copy: 50c3a7e29886 - test: Merge 1 two-point-five ======= two-point-one >>>>>>> merge rev: 40d11a4173a8 - test: two -> two-point-one three $ hg debugindex test.txt rev offset length ..... linkrev nodeid p1 p2 (re) 0 0 7 ..... 0 01365c4cca56 000000000000 000000000000 (re) 1 7 9 ..... 1 7b013192566a 01365c4cca56 000000000000 (re) 2 16 15 ..... 2 8fe46a3eb557 01365c4cca56 000000000000 (re) 3 31 2. ..... 3 fc3148072371 7b013192566a 8fe46a3eb557 (re) 4 5. 25 ..... 4 d40249267ae3 8fe46a3eb557 000000000000 (re) $ hg log changeset: 4:40d11a4173a8 tag: tip parent: 2:96b70246a118 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: two -> two-point-one changeset: 3:50c3a7e29886 parent: 1:d1e159716d41 parent: 2:96b70246a118 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Merge 1 changeset: 2:96b70246a118 parent: 0:b1832b9d912a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Numbers as words changeset: 1:d1e159716d41 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 2 -> 2.5 changeset: 0:b1832b9d912a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Initial $ cd ..