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)
test sparse with --verbose and -T json
$ hg init myrepo
$ cd myrepo
$ cat > .hg/hgrc <<EOF
> [extensions]
> sparse=
> strip=
> EOF
$ echo a > show
$ echo x > hide
$ hg ci -Aqm 'initial'
$ echo b > show
$ echo y > hide
$ echo aa > show2
$ echo xx > hide2
$ hg ci -Aqm 'two'
Verify basic --include and --reset
$ hg up -q 0
$ hg debugsparse --include 'hide' -Tjson
[
{
"exclude_rules_added": 0,
"files_added": 0,
"files_conflicting": 0,
"files_dropped": 1,
"include_rules_added": 1,
"profiles_added": 0
}
]
$ hg debugsparse --clear-rules
$ hg debugsparse --include 'hide' --verbose
removing show
Profiles changed: 0
Include rules changed: 1
Exclude rules changed: 0
$ hg debugsparse --reset -Tjson
[
{
"exclude_rules_added": 0,
"files_added": 1,
"files_conflicting": 0,
"files_dropped": 0,
"include_rules_added": -1,
"profiles_added": 0
}
]
$ hg debugsparse --include 'hide'
$ hg debugsparse --reset --verbose
getting show
Profiles changed: 0
Include rules changed: -1
Exclude rules changed: 0
Verifying that problematic files still allow us to see the deltas when forcing:
$ hg debugsparse --include 'show*'
$ touch hide
$ hg debugsparse --delete 'show*' --force -Tjson
pending changes to 'hide'
[
{
"exclude_rules_added": 0,
"files_added": 0,
"files_conflicting": 1,
"files_dropped": 0,
"include_rules_added": -1,
"profiles_added": 0
}
]
$ hg debugsparse --include 'show*' --force
pending changes to 'hide'
$ hg debugsparse --delete 'show*' --force --verbose
pending changes to 'hide'
Profiles changed: 0
Include rules changed: -1
Exclude rules changed: 0