Most tests need a repo but don't need a working copy. Let's have a
function for setting up a test repo. But first, let's free up the name
`init_repo()` by renaming it to `init_workspace()` (which is also more
accurate).
It's harmless but potentially confusing to have multiple workspaces
with the same ID (it would mean that they always have the same
checkout). Let's just prevent it for now. We can add an override later
if people think of usecases for it.
When you run `jj co abc123` and that commit is already checked out, we
just print a message. The condition for that assumed that the checkout
existed, which it won't if you just ran `jj workspace forget`. Let's
avoid that crash, especially since `jj co` is an easy way to restore
the working copy if you had accidentally run `jj workspace forget`
(though `jj undo` is even easier).
It seems helpful to show in the log output which commit is checked out
in which workspace, so let's try that. I made it only show the
information if there are multiple checkouts for now.
In workspaces added after the initial one, the idea is to have
`.jj/repo` be a file whose contents is a path to the location of the
repo directory in some other workspace.
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.
Because we record each workspace's checkout in the repo view, we can
-- unlike other VCSs -- let the user refer to any workspace's checkout
in revsets. This patch adds syntax for that, so you can show the
contents of the checkout in workspace "foo" with `jj show foo@`. That
won't automatically commit that workspace's working copy, however.
If the workspace is shared with a Git repo, we sometimes update Git's
HEAD ref. We should get the new checkout from the right workspace ID
when doing that (though I'm not sure we'll ever support sharing the
working copy with Git in a non-default workspace).
When importing Git HEAD, we already use the right workspace ID for the
new checkout, but the old checkout we abandon is always the default
workspace's. We should fix that even if we will never support sharing
a working copy with Git in a non-default workspace.
Before committing the working copy, we check if the working copy is
checked out to the commit we expect based on the repo's view. We
always use the default workspace's checkout, so we need to fix that.
We detect concurrent working copy changes by checking that the old
commit matches the repo's view. We should use the current workspace
when looking up the checkout in the view.
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).
This patch teaches the `View` object to keep track of the checkout in
each workspace. It serializes that information into the `OpStore`. For
compatibility with existing repos, the existing field for a single
workspace's checkout is interpreted as being for the workspace called
"default".
This is just an early step towards support for multiple
workspaces. Remaining things to do:
* Record the workspace ID somewhere in `.jj/` (maybe in
`.jj/working_copy/`)
* Update existing code to use the workspace ID instead of assuming
it's always "default" as we do after this patch
* Add a way of indicating in `.jj/` that the repo lives elsewhere and
make it possible to load a repo from such workspaces
* Add a command for creating additional workspaces
* Show each workspace's checkout in log output
The `.jj/` directory contains information about two distinct parts:
the repo and the working copy. Most subdirectories are related to the
repo; only `.jj/working_copy/` is about the working copy. Let's move
the repo-related bits into a new `.jj/repo/` subdirectory. That makes
it clearer that they're related to the repo. It will probably also be
easier to manage when we have support for multiple workspaces backed
by a single repo.
