This should help us reason about the safety implication. New inner module
is added to encapsulate unsafe access.
DirtyCell provides .with_ref(callback) instead of .borrow(). This isn't
strictly needed, but should clarify the intent of the temporary reference.
This also allows us to rewrite DirtyCell without unsafe code, if needed,
by leveraging OnceCell<T> x RefCell<Option<T>> pair.
If you remove all refs from the backing Git repo and then run `jj git
import`, we would see that all commits disappeared from the Git repo,
so we would remove them from the jj repo too. However, we do that by
doing a history walk from old heads to the new heads, which includes
the root commit when the new heads is an empty set. That means that we
mark the root commit as abandoned, which led to a crash in
`rewrite.rs` (when we try pick the root commit's first parent to use
as parent for rebased commits).
The function has only one caller since 25b922cd0ba6 and it's pretty
small. Inlining also means we can reuse the joined paths created in
it, so I did that by extracting variables for them.
This changes `RepoLoader` to take a map of functions that load a
specific type of backend, keyed by the backend type. The backend type
is read from `.jj/repo/store/backend`.
We currently determine if the repo uses the Git backend or the local
backend by checking for presence of a `.jj/repo/store/git_target`
file. To make it easier to add out-of-tree backends, let's instead add
a file that indicates which backend to use.
The `ReadonlyRepo::init_*()` functions were unused or used only in
tests. Let's remove them, thereby making the repo less aware of
specific backend implementations.
In many of these places, we don't need an owned value, so using a
reference means we don't force the caller to clone the value. I really
doubt it will have any noticeable impact on performance (I think these
are all once-per-repo paths); it's just a little simpler this way.
I feel it doesn't make sense for a simple getter function to create an
owned vec after 010867308714 "backend: let each backend handle root commit
on write."
`wc_commit` seems clearer than `checkout` and not too much longer. I
considered `working_copy` but it was less clear (could be the path to
the working copy, or an instance of `WorkingCopy`). I also considered
`working_copy_commit`, but that seems a bit too long.
There is a bit of duplicated across the three functions for creating a
`Workspace` and `Repo`. This patch reduces that duplication by passing
in a closure.
In addition to reducing duplication, this is a step towards making it
easier to add new backends.
The `CommitBuilder::store` field is used only in
`CommitBuilder::write_to_repo()`, but we can easily get access to the
`Store` from the `repo` argument there, so let's remove the field.
We depend on comparing the workspace root with the Git repo's path to
know if we're sharing the working copy with it. For that to work
reliably, we need the paths to be canonicalized, so that's what this
patch tries to do.
This involved copying `UnresolvedHeadRepo::resolve()` into the CLI
crate (and modifying it a bit to print number of rebased commit),
which is unfortunate.
The function is now pretty simple, and there's only one caller, so
let's inline it. It probably makes sense to move the code out of
`repo.rs` at some point.
It's the transaction's job to create a new operation, and that's where
the knowledge of parent operations is. By moving the logic for merging
in another operation there, we can make it contiuously update its set
of parent operations. That removes the risk of forgetting to add the
merged-in operation as a parent. It also makes it easier to reuse the
function from the CLI so we can inform the user about the process
(which is what I was investigating when I noticed that this cleanup
was possible).
If we have recorded in `MutableRepo` that commits have been abandoned
or rewritten, we should always rebase descendants before committing
the transaction (otherwise there's no reason to record the
rewrites). That's not much of a risk in the CLI because we already
have that logic in a central place there (`finish_transaction()`), but
other users of the library crate could easily miss it. Perhaps we
should automatically do any necessary rebasing we commit the
transaction in the library crate instead, but for now let's just have
a check for that to catch such bugs.
Certain commands should never rewrite commits, or they take care of
rebasing descendants themselves. We have an optimization in
`commands.rs` for those commands, so they skip the usual automatic
rebasing before committing the transaction. That's risky to have to
remember and `MutableRepo` already knows if any commits have been
rewritten (that wasn't the case before, in the Evolution-based
code). So let's just have `MutableRepo` do the check instead.
It's useful for the UI layer to know that there's been concurrent
operations, so it can inform the user that that happened. It'll be
even more useful when we soon start making the resolution involve
rebasing commits, since that's even more important for the UI layer to
present to the user. This patch gets us a bit closer to that by moving
the resolution to the repo level.
I want to make it so when we apply a repo-level change that removes a
head, we rebase descendants of that head onto the closes visible
ancestor, or onto its successor if the head has been rewritten (see
#111 for details). The view itself doesn't have enough information for
that; we need repo-level information (to figure out relationships
between commits).
The view doesn't have enough information to do the.
It's unusual for the current commit to have descendants, but it can
happen. In particular, it can easily happen when you run `jj new`. You
probably don't want to abandon it in those cases.
1b6efdc3f8ed moved `.jj/git/` into `.jj/store/` for consistency with
the layout of native stores. It provided automatic format upgrades for
repos with the old format. It's been about four months now, so let's
remove the migration code.
As part of creating a new repository, we create an open commit on top
of the root and set that as the current checkout. Now that we have
support for multiple checkouts in the model, we also have support for
zero checkouts, which means we don't need to create that commit on top
of the root when creating the repo. We can therefore move out of
`ReadonlyRepo`'s initialization code and let `Workspace` instead take
care of it. A user-visible effect of this change is that we now create
one operation for initilizing the repo and another one for checking
out the root commit. That seems fine, and will be consistent with the
additional operation we will create when adding further workspaces.
When checking out a new commit, we look at the old checkout to see if
it's empty so we should abandon it. We current use the default
workspace's checkout. We need to respect the workspace ID we're given
in `MutableRepo::check_out()`, and we need to be able to deal with
that workspace not existing yet (i.e. this being the first checkout in
that workspace).
