Mercurial > hg
view tests/test-convert-hg-source.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outdated and unsupported repo format.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 | 1538e72209fd |
children | 75be14993fda |
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$ cat >> $HGRCPATH <<EOF > [extensions] > convert= > [convert] > hg.saverev=False > EOF $ hg init orig $ cd orig $ echo foo > foo $ echo bar > bar $ hg ci -qAm 'add foo bar' -d '0 0' $ echo >> foo $ hg ci -m 'change foo' -d '1 0' $ hg up -qC 0 $ hg copy --after --force foo bar $ hg copy foo baz $ hg ci -m 'make bar and baz copies of foo' -d '2 0' created new head Test that template can print all file copies (issue4362) $ hg log -r . --template "{file_copies % ' File: {file_copy}\n'}" File: bar (foo) File: baz (foo) $ hg bookmark premerge1 $ hg merge -r 1 merging baz and foo to baz 1 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m 'merge local copy' -d '3 0' $ hg up -C 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (leaving bookmark premerge1) $ hg bookmark premerge2 $ hg merge 2 merging foo and baz to baz 1 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m 'merge remote copy' -d '4 0' created new head Make and delete some tags $ hg tag that $ hg tag --remove that $ hg tag this #if execbit $ chmod +x baz #else $ echo some other change to make sure we get a rev 5 > baz #endif $ hg ci -m 'mark baz executable' -d '5 0' $ cd .. $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' initializing destination new repository scanning source... sorting... converting... 8 add foo bar 7 change foo 6 make bar and baz copies of foo 5 merge local copy 4 merge remote copy 3 Added tag that for changeset 88586c4e9f02 2 Removed tag that 1 Added tag this for changeset c56a7f387039 0 mark baz executable updating bookmarks $ cd new $ hg out ../orig comparing with ../orig searching for changes no changes found [1] #if execbit $ hg bookmarks premerge1 3:973ef48a98a4 premerge2 8:91d107c423ba #else Different hash because no x bit $ hg bookmarks premerge1 3:973ef48a98a4 premerge2 8:3537b15eaaca #endif Test that redoing a convert results in an identical graph $ cd ../ $ rm new/.hg/shamap $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' scanning source... sorting... converting... 8 add foo bar 7 change foo 6 make bar and baz copies of foo 5 merge local copy 4 merge remote copy 3 Added tag that for changeset 88586c4e9f02 2 Removed tag that 1 Added tag this for changeset c56a7f387039 0 mark baz executable updating bookmarks $ hg -R new log -G -T '{rev} {desc}' o 8 mark baz executable | o 7 Added tag this for changeset c56a7f387039 | o 6 Removed tag that | o 5 Added tag that for changeset 88586c4e9f02 | o 4 merge remote copy |\ +---o 3 merge local copy | |/ | o 2 make bar and baz copies of foo | | o | 1 change foo |/ o 0 add foo bar check shamap LF and CRLF handling $ cat > rewrite.py <<EOF > import sys > # Interlace LF and CRLF > lines = [(l.rstrip() + ((i % 2) and '\n' or '\r\n')) > for i, l in enumerate(file(sys.argv[1]))] > file(sys.argv[1], 'wb').write(''.join(lines)) > EOF $ python rewrite.py new/.hg/shamap $ cd orig $ hg up -qC 1 $ echo foo >> foo $ hg ci -qm 'change foo again' $ hg up -qC 2 $ echo foo >> foo $ hg ci -qm 'change foo again again' $ cd .. $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' scanning source... sorting... converting... 1 change foo again again 0 change foo again updating bookmarks init broken repository $ hg init broken $ cd broken $ echo a >> a $ echo b >> b $ hg ci -qAm init $ echo a >> a $ echo b >> b $ hg copy b c $ hg ci -qAm changeall $ hg up -qC 0 $ echo bc >> b $ hg ci -m changebagain created new head $ HGMERGE=internal:local hg -q merge $ hg ci -m merge $ hg mv b d $ hg ci -m moveb break it $ rm .hg/store/data/b.* $ cd .. $ hg --config convert.hg.ignoreerrors=True convert broken fixed initializing destination fixed repository scanning source... sorting... converting... 4 init ignoring: data/b.i@1e88685f5dde: no match found 3 changeall 2 changebagain 1 merge 0 moveb $ hg -R fixed verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 3 files, 5 changesets, 5 total revisions manifest -r 0 $ hg -R fixed manifest -r 0 a manifest -r tip $ hg -R fixed manifest -r tip a c d