localrepo: stop doing special dirstate backup at transaction open
Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).
We needs some special code to deal with the initial empty checkout, but it is
not too complicated.
Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.
In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.
[1] https://xkcd.com/1134/
(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)
$ cat >> $HGRCPATH <<EOF
> [extensions]
> convert =
> [convert]
> hg.saverev = yes
> EOF
$ glog()
> {
> hg -R "$1" log -G --template '{rev} "{desc}" files: {files}\n'
> }
$ hg init source
$ cd source
$ echo a > a
$ echo b > b
$ echo f > f
$ hg ci -d '0 0' -qAm '0: add a b f'
$ echo c > c
$ hg move f d
$ hg ci -d '1 0' -qAm '1: add c, move f to d'
$ hg copy a e
$ echo b >> b
$ hg ci -d '2 0' -qAm '2: copy e from a, change b'
$ hg up -C 0
2 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ echo a >> a
$ hg ci -d '3 0' -qAm '3: change a'
$ hg merge
merging a and e to e
3 files updated, 1 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -d '4 0' -qAm '4: merge 2 and 3'
$ echo a >> a
$ hg ci -d '5 0' -qAm '5: change a'
$ cd ..
Convert from null revision
$ hg convert --config convert.hg.startrev=null source full
initializing destination full repository
scanning source...
sorting...
converting...
5 0: add a b f
4 1: add c, move f to d
3 2: copy e from a, change b
2 3: change a
1 4: merge 2 and 3
0 5: change a
$ glog full
o 5 "5: change a" files: a
|
o 4 "4: merge 2 and 3" files: e
|\
| o 3 "3: change a" files: a
| |
o | 2 "2: copy e from a, change b" files: b e
| |
o | 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
$ rm -Rf full
Convert from zero revision
$ hg convert --config convert.hg.startrev=0 source full
initializing destination full repository
scanning source...
sorting...
converting...
5 0: add a b f
4 1: add c, move f to d
3 2: copy e from a, change b
2 3: change a
1 4: merge 2 and 3
0 5: change a
$ glog full
o 5 "5: change a" files: a
|
o 4 "4: merge 2 and 3" files: e
|\
| o 3 "3: change a" files: a
| |
o | 2 "2: copy e from a, change b" files: b e
| |
o | 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
Convert from merge parent
$ hg convert --config convert.hg.startrev=1 source conv1
initializing destination conv1 repository
scanning source...
sorting...
converting...
3 1: add c, move f to d
2 2: copy e from a, change b
1 4: merge 2 and 3
0 5: change a
$ glog conv1
o 3 "5: change a" files: a
|
o 2 "4: merge 2 and 3" files: a e
|
o 1 "2: copy e from a, change b" files: b e
|
o 0 "1: add c, move f to d" files: a b c d
$ cd conv1
$ hg up -q
Check copy preservation
$ hg st -C --change 2 e
M e
$ hg st -C --change 1 e
A e
a
$ hg st -C --change 0 a
A a
(It seems like a bug in log that the following doesn't show rev 1.)
$ hg log --follow --copies e
changeset: 2:8d3c3fe67bb7
user: test
date: Thu Jan 01 00:00:04 1970 +0000
summary: 4: merge 2 and 3
changeset: 0:23c3be426dce
user: test
date: Thu Jan 01 00:00:01 1970 +0000
summary: 1: add c, move f to d
Check copy removal on missing parent
$ hg log --follow --copies d
changeset: 0:23c3be426dce
user: test
date: Thu Jan 01 00:00:01 1970 +0000
summary: 1: add c, move f to d
$ hg cat -r tip a b
a
a
a
b
b
$ hg -q verify
$ cd ..
Convert from merge
$ hg convert --config convert.hg.startrev=4 source conv4
initializing destination conv4 repository
scanning source...
sorting...
converting...
1 4: merge 2 and 3
0 5: change a
$ glog conv4
o 1 "5: change a" files: a
|
o 0 "4: merge 2 and 3" files: a b c d e
$ cd conv4
$ hg up -C
5 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg cat -r tip a b
a
a
a
b
b
$ hg -q verify
$ cd ..
Convert from revset in convert.hg.revs
$ hg convert --config convert.hg.revs='3:4+0' source revsetrepo
initializing destination revsetrepo repository
scanning source...
sorting...
converting...
2 0: add a b f
1 3: change a
0 4: merge 2 and 3
$ glog revsetrepo
o 2 "4: merge 2 and 3" files: b c d e f
|
o 1 "3: change a" files: a
|
o 0 "0: add a b f" files: a b f
Convert from specified revs
$ hg convert --rev 3 --rev 2 source multiplerevs
initializing destination multiplerevs repository
scanning source...
sorting...
converting...
3 0: add a b f
2 1: add c, move f to d
1 2: copy e from a, change b
0 3: change a
$ glog multiplerevs
o 3 "3: change a" files: a
|
| o 2 "2: copy e from a, change b" files: b e
| |
| o 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
Convert in multiple steps that doesn't overlap - the link to the parent is
preserved anyway
$ hg convert --config convert.hg.revs=::1 source multistep
initializing destination multistep repository
scanning source...
sorting...
converting...
1 0: add a b f
0 1: add c, move f to d
$ hg convert --config convert.hg.revs=2 source multistep
scanning source...
sorting...
converting...
0 2: copy e from a, change b
$ glog multistep
o 2 "2: copy e from a, change b" files: b e
|
o 1 "1: add c, move f to d" files: c d f
|
o 0 "0: add a b f" files: a b f