Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 04:49:35 +0100] rev 50141
dirstate: remove the dedicated backup logic
When alone, the dirstate can now take care of its commit/rollback pattern
itself.
When in a transaction, the transaction deal with commit/rollback pattern quite
fine.
Why did you have a dedicated backup logic?
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 04:02:36 +0100] rev 50140
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)
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 11:42:43 +0100] rev 50139
localrepo: "blindly" do a dirstate backup at the end of the transaction
Having the file backup mechanism dealing with file backup as benefit. So lets
move closer to that.
The fact `hg rollback` even needs this is sad. I hope to have the time to
implement one of the alternative soon.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 17:12:21 +0100] rev 50138
test-hardlink: stop explicitly listing `undo.dirstate`
The files is on its way out.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 04:04:40 +0100] rev 50137
localrepo: enforce a clean dirstate when the transaction open
This is important to simplify the backup process. This also seems like a quite
reasonable expectation. See inline documentation for details.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 10:43:22 +0100] rev 50136
dirstate: explicitly backup the datafile
Since the transaction does not know about this file, we need to explicitly mark
it for backup before touching it.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 04:41:38 +0100] rev 50135
mq: write the dirstate before stripping
I am not certain why it is dirty (probably the `repo.setparent` call a right
before. However I know we need it flushed before the repository starts to be
stripped.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 03:08:00 +0100] rev 50134
dirstate: simplify the shelve hack to not go through the disk
We already have the data in memory, so why not simply keep the data in memory?
This avoid abusing the `savebackup/restorebackup` logic and will make our life
easier.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 02:44:07 +0100] rev 50133
dirstate: detect potential fishy transaction patterns while changing
If we rely on the transaction more, we should be more careful about the
transaction. Adding extra security seems reasonable.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 02:34:54 +0100] rev 50132
dirstate: generalize the dirstate's invalidation on transaction abort
The previous code was too specific, we should add the invalidation at next to
the `addfilegenerator` in the `write` call.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 02:22:13 +0100] rev 50131
dirstate: simplify some methods' decorator
Since `changing_parents` and `changing_files` are mutually exclusive, having
both `@requires_changing_files` and `@requires_not_changing_parents` on a method
is redundant.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 02:19:56 +0100] rev 50130
dirstate: document the functions that need consolidation
They are more functions that make the dirstate dirty but does not currently
enforce a clean change scoping, we add comments in front of each of them so
clarify this. There is no urgency to it, but the world will be a better place
when all of them have proper scoping in place.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 05:03:28 +0100] rev 50129
dirstate: make `restorebackup` more robust when it is a noop
If there are no data_file, we might not be able to determine its filename.
Which can be safely ignored.
(all this code is on the way out anyway)
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 00:33:15 +0100] rev 50128
dirstate-guard: remove the feature
The dirstate guard duplicated some of the logic already implemented in the
transaction (and now the changing_* context).
However the feature was incomplete, for example, living only in memory meant we
could not recover from the hardest crash. In addition this duplicated with the
transaction logic meant things could go out of sync or step on each other.
Removing the feature now that we no longer needs it seems the safest.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 00:14:21 +0100] rev 50127
rollback: remove the dirstateguard usage
Thanks to the previous changeset, we no longer needs it.
begone !
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 10:00:59 +0100] rev 50126
rollback: explicitly skip dirstate rollback when applicable
instead of letting the transaction logic overwrite the dirstate and then
overwrite that overwrite with a backup. We simply do not restore the dirstate
related file during the _playback call.
This open the way to removing the last dirstate guard usage.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 16 Feb 2023 00:26:24 +0100] rev 50125
rollback: detect "parentgone" case earlier
Detecting this earlier will help us to affect the rollback process sooner, which
will help the next changesets.
To keep things simple, we degrade the behavior a bit when the `undo.desc` is
missing. However since `hg rollback` is not supposed to be used and the
`undo.desc` file have been introduced in mercurial 1.6 (2010). I think this is
an acceptable evil.
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 23:39:10 +0100] rev 50124
rollback: avoid a `hg commit --addremove` at a critical point
The rollback behavior around `hg commit --addremove` has changed slightly. It
does not really matters here but keeping that variant out of the way cannot
hurt.
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 20:48:51 +0100] rev 50123
rollback: display some graphlog before/after a test piece
This make the situation clearer.
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 20:47:08 +0100] rev 50122
rollback: show that the safety works in a associated test
That test section is checking that --force is overcoming the safety check,
however we did not check that the safety properly detect the situation.
We now do for clarity.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 14 Feb 2023 00:40:27 +0100] rev 50121
dirstate-guard: remove its usage in `backout`
We can simply replace it with a transaction.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 14 Feb 2023 00:42:00 +0100] rev 50120
dirstate-guard: remove the usage in `import`
It is now redundant with the transaction spawning the same scope.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 14 Feb 2023 00:39:49 +0100] rev 50119
dirstate-guard: replace a usage in `rebase` with a transaction
Opening the transaction sooner will provide us with the same benefit.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 14 Feb 2023 00:31:41 +0100] rev 50118
dirstate-guard: remove usage in `rebase`
Now that the dirstate change and write are clearer, it does not seems we need to
use a dirstate-guard here anymore. The transaction already wrap the full
operation.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 14 Feb 2023 00:31:23 +0100] rev 50117
dirstate-guard: remove it usage in `mq`
The code it covered is also covered by a `changing_parents` context.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 26 Jan 2023 17:46:54 +0100] rev 50116
dirstate: enforce the use of `changing_files` context to change tracking
Now that everything is using the new context, we can start enforcing its usage.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 13 Dec 2022 03:55:14 +0100] rev 50115
dirstate: warn if we write to the dirstate without holding the wlock
Writing the dirstate without holding the wlock can race with other update and
overwrite important change. The comment questionning the current state of
things was right, we should the `wlock` should always cover the dirstate.
(Yes, this is me, agreeing with myself, half a decade later).
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 21:31:37 +0100] rev 50114
dirstate: avoid transaction backup/restore if we do not hold the lock
Doing overwriting the dirstate content without holding the lock is a recipe for
disaster.
Pierre-Yves David <pierre-yves.david@octobus.net> [Tue, 13 Dec 2022 09:59:22 +0100] rev 50113
dirstate: issue a developer warning on implicit write on wlock release
Our goal is to get rid of all these to clarify the writing pattern, so it is
time to warn about this (and later, forbid it).
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 23:29:04 +0100] rev 50112
status: fix post status invalidation
If the dirstate changed under us, we should throw away what we have a reload it,
should we not ?
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 15 Feb 2023 23:28:20 +0100] rev 50111
status: fix post status writing
With dirstate-v2, the status process itself might update internal states. So we
make sure this get written on disk
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 15 Dec 2022 02:54:06 +0100] rev 50110
dirstate: use `dirstate.change_files` to scope the change in `shelve`
This is the way.