This removes an invalid View state from the root operation.
Note that the root index will have to be reindexed in order to resolve "root()"
in the root operation. I don't think this would practically matter, so this
patch doesn't bump the index version to invalidate the existing indexes.
See also 48a9f9ef56c1 "repo: use Transaction for creating repo-init operation."
See the next patch for why. It might look odd that OpStore depends on the root
CommitId, but that seems okay because OpStore manages Views, and a View is
basically a set of CommitIds.
Jujutsu's branches do not behave like Git branches, which is a major
hurdle for people adopting it from Git. They rather behave like
Mercurial's (hg) bookmarks.
We've had multiple discussions about it in the last ~1.5 years about this rename in the Discord,
where multiple people agreed that this _false_ familiarity does not help anyone. Initially we were
reluctant to do it but overtime, more and more users agreed that `bookmark` was a better for name
the current mechanism. This may be hard break for current `jj branch` users, but it will immensly
help Jujutsu's future, by defining it as our first own term. The `[experimental-moving-branches]`
config option is currently left alone, to force not another large config update for
users, since the last time this happened was when `jj log -T show` was removed, which immediately
resulted in breaking users and introduced soft deprecations.
This name change will also make it easier to introduce Topics (#3402) as _topological branches_
with a easier model.
This was mostly done via LSP, ripgrep and sed and a whole bunch of manual changes either from
me being lazy or thankfully pointed out by reviewers.
I've wanted to make the Git support optional for a long time. However,
since everyone uses the Git backend (and we want to support it even in
the custom binary at Google), there hasn't been much practical reason
to make Git support optional.
Since we now use jj-lib on the server at Google, it does make sense to
have the server not include Git support. In addition to making the
server binary smaller, it would make it easier for us (jj team at
Googlle) to prove that our server is not affected by some libgit2 or
Gitoxide vulnerability. But to be honest, neither of those problems
have come up, so it's more of an excuse to make the Git support
optional at this point.
It turned out to be much simpler than I expected to make Git support
in the lib crate optional. We have done a pretty good job of keeping
Git-related logic separated there.
If we make Git support optional in the lib crate, it's going to make
it a bit harder to move logic from the CLI crate into the lib crate
(as we have planned to do). Maybe that's good, though, since it helps
remind us to keep Git-related logic separated.
It should be useful at least in the presentation layer to know which
operations correspond to working-copy snapshots. They might be
rendered differently in the graph, for example. Or maybe an undo
command wants to warn if you just undid a snapshot operation. This
patch just introduces a field in the metadata to store the
information.
The `ContentHash` documentation specifies that implementations for enums should
hash the ordinal number of the variant contained in the enum as a 32-bit
little-endian number and then hash the contents of the variant, if any.
The current implementations for `std::Option`, `MergedTreeId`, and
`RemoteRefState` are non-conformant since they hash the ordinal number as a u8
with platform specific endianness.
Fixes#3051
It seems obvious in hindsight to have a virtual root operation just
like we have a virtual root commit. It removes the same kind of
problems by making sure there's always a common ancestor (or multiple)
between any two commits.
I think the reason I didn't add a root operation from the beginning
was that there used to be a mandatory working-copy commit in the view
(this was before support for multiple workspaces).
Perhaps we should remove the "initialize repo" operation now. The only
difference between their view objects is that the "initialize repo"
operation adds the root commit as a head. We could add that to the
root operation, but then the root operation's value depends on the
commit backend.
We've had the public_heads for as long as we've had the View object,
IIRC (I didn't check), but we still don't use it for anything. I don't
have any concrete plans for using it either. Maybe our config for
immutable commits is good enough, or maybe we'll want something more
generic (like Mercurial's phases). For now, I think we should simplify
by removing it the storage for public heads.
Since new operations and views may be added concurrently by another process,
there's a risk of data corruption. The keep_newer parameter is a mitigation
for this problem. It's set to preserve files modified within the last 2 weeks,
which is the default of "git gc". Still, a concurrent process may replace an
existing view which is about to be deleted by the gc process, and the view
file would be lost.
#12
This isn't technically needed, but it prevents API misuse. Another option
is to do some compile-time substitution, but most callers are tests and the
runtime performance wouldn't matter.
The OpStore backends should have a better way to look up operation by id than
traversing from the op heads. The added method is similar to the commit Index
one, but returns an OpStoreResult because the backend operation can fail.
FWIW, if we want .shortest() in the op log template, we'll probably need a
trait method that returns an OpIndex instead.
I'm going to add a prefix resolution method to OpStore, but OpStore is
unrelated to the index. I think ObjectId, HexPrefix, and PrefixResolution can
be extracted to this module.
PersistError is basically a pair of io::Error and NamedTempFile instance. It's
unlikely that we would want to propagate the open file instance to the CLI
error handler, leaving the temporary file alive.
We could instead migrate the storage types to (local_branches, remote_views),
but that would be more involved and break forward compatibility with little
benefit. Maybe we can do that later when we introduce remote tags.
The state field isn't saved yet. git import/export code paths are migrated,
but new tracking state is always calculated based on git.auto-local-branch
setting. So the tracking state is effectively a global flag.
As we don't know whether the existing remote branches have been merged in to
local branches, we assume that remote branches are "tracking" so long as the
local counterparts exist. This means existing locally-deleted branch won't
be pushed without re-tracking it. I think it's rare to leave locally-deleted
branches for long. For "git.auto-local-branch = false" setup, users might have
to untrack branches if they've manually "merged" remote branches and want to
continue that workflow. I considered using git.auto-local-branch setting in the
migration path, but I don't think that would give a better result. The setting
may be toggled after the branches got merged, and I'm planning to change it
default off for better Git interop.
Implementation-wise, the state enum can be a simple bool. It's enum just
because I originally considered to pack "forgotten" concept into it. I have
no idea which will be better for future extension.
This isn't important, but I'm going to change remote_targets to store RemoteRef
instead of RefTarget, so I went ahead and change the other field types as well.
There's a subtle behavior change. Unlike the original remove_remote_branch(),
remote_views entry is not discarded when the branches map becomes empty. The
reasoning here is that the remote view can be added/removed when the remote
is added/removed respectively, though that's not implemented yet. Since the
serialized data cannot represent an empty remote, such view may generate
non-unique content hash.
I've added a boolean flag to the store to ensure that the migration never runs
more than once after the view gets "op restore"-d. I'll probably reorganize the
branches structure to support non-tracking branches later, but updating the
storage format in a single commit would be too involved.
If jj is downgraded, these "git" remote refs would be exported to the Git repo.
Users might have to remove them manually.
I'm going to migrate "refs/heads/" branches to .remote_targets["git"]. This
commit will simplify the story as we won't have to exclude "refs/remotes/git/"
refs when diffing or renaming/removing remote.
Since `Conflict<T>` can also represent a non-conflict state (a single
term), `Merge<T>` seems like better name.
Thanks to @ilyagr for the suggestion in
https://github.com/martinvonz/jj/pull/1774#discussion_r1257547709
Sorry about the churn. It would have been better if I thought of this
name before I introduced `Conflict<T>`.
This is breaking change. Old jj binary will panic if it sees a view saved by
new jj. Alternatively, we can store both new and legacy data for backward
compatibility.
I guess we don't depend on `read_view()` ever returning `NotFound` the
way `read_operation()` does, but it seems like it still should return
`NotFound` when the view doesn't exist.
Copied from MergedTree::has_conflict(). I feel it's slightly better since
RefTarget "is" always a Conflict-based type. It could be inverted to
RefTarget::is_resolved(), but refs are usually resolved, and all callers
have special case for !is_resolved() state.
Alternatively, we can wrap BTreeMap<String, Option<RefTarget>> to flatten
Option<&Option<..>> internally, but doing that would be tedious. It would
also be unclear if map.remove(name) should construct an absent RefTarget if
the ref doesn't exist.
The next commit will change these maps to store Option<RefTarget> entries, but
None entries will still be omitted from the serialized data. Since ContentHash
should describe the serialized data, relying on the generic ContentHash would
cause future hash conflict where absent RefTarget entries will be preserved.
For example, ([remove], [None, add]) will be serialized as ([remove], [add]),
and deserialized to ([remove], [add, None]). If we add support for lossless
serialization, hash(([remove], [None, add])) should differ from the lossy one.
Since RefTarget will be reimplemented on top of Conflict<Option<CommitId>>,
we won't be able to simply return a slice of type &[CommitId]. These functions
are also renamed in order to disambiguate from Conflict::adds()/removes().
