dirstate-v2: freeze the on-disk format
It seems the format as reached a good balance. With a core of new capabilities
that motivated it initially and enough new feature and room for future
improvement to be a clear progress we can set a milestone for.
Having the format frozen will help the feature to get real life testing, outside
of the test suite.
The feature itself stay experimental but the config gains a new name to avoid
people enable non-frozen version by default.
If too many bugs are reported during the RC we might move the format back to
experimental and drop its support in future version (in favor of a new one)
Differential Revision: https://phab.mercurial-scm.org/D11709
#require reporevlogstore
A repo with unknown revlogv2 requirement string cannot be opened
$ hg init invalidreq
$ cd invalidreq
$ echo exp-revlogv2.unknown >> .hg/requires
$ hg log
abort: repository requires features unknown to this Mercurial: exp-revlogv2.unknown
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Can create and open repo with revlog v2 requirement
$ cat >> $HGRCPATH << EOF
> [experimental]
> revlogv2 = enable-unstable-format-and-corrupt-my-data
> EOF
$ hg init new-repo
$ cd new-repo
$ cat .hg/requires
dotencode
exp-rc-dirstate-v2 (dirstate-v2 !)
exp-revlogv2.2
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
sparserevlog
store
$ hg log
Unknown flags to revlog are rejected
>>> with open('.hg/store/00changelog.i', 'wb') as fh:
... fh.write(b'\xff\x00\xde\xad') and None
$ hg log
abort: unknown flags (0xff00) in version 57005 revlog 00changelog
[50]
$ cd ..
Writing a simple revlog v2 works
$ hg init simple
$ cd simple
$ touch foo
$ hg -q commit -A -m initial
$ hg log
changeset: 0:96ee1d7354c4
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: initial
Header written as expected
$ f --hexdump --bytes 4 .hg/store/00changelog.i
.hg/store/00changelog.i:
0000: 00 00 de ad |....|
$ f --hexdump --bytes 4 .hg/store/data/foo.i
.hg/store/data/foo.i:
0000: 00 00 de ad |....|
Bundle use a compatible changegroup format
------------------------------------------
$ hg bundle --all ../basic.hg
1 changesets found
$ hg debugbundle --spec ../basic.hg
bzip2-v2
The expected files are generated
--------------------------------
We should have have:
- a docket
- a index file with a unique name
- a data file
$ ls .hg/store/00changelog* .hg/store/00manifest*
.hg/store/00changelog-1335303a.sda
.hg/store/00changelog-6b8ab34b.idx
.hg/store/00changelog-b875dfc5.dat
.hg/store/00changelog.i
.hg/store/00manifest-05a21d65.idx
.hg/store/00manifest-43c37dde.dat
.hg/store/00manifest-e2c9362a.sda
.hg/store/00manifest.i
Local clone works
-----------------
$ hg clone . ../cloned-repo
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tip | tee ../tip-new
changeset: 0:96ee1d7354c4
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: initial
$ hg tip -R ../cloned-repo | tee ../tip-cloned
changeset: 0:96ee1d7354c4
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: initial
The two repository should be identical, this diff MUST be empty
$ cmp ../tip-new ../tip-cloned || diff -U8 ../tip-new ../tip-cloned
hg verify should be happy
-------------------------
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ hg verify -R ../cloned-repo
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files