This helps to map initialization error to BackendError without too general
From impl. I don't think io::Error (or our PathError) should be automatically
translated to BackendError::Other because BackendError has more specific
variants depending on context. If the error is specific to initialization,
it makes sense to translate it to Other variant.
It was convenient that what the git backend stored in its "extras"
table is exactly a subset of the fields that local backend stores, but
it's bit ugly and limiting. For example, it makes it possible to
populate the `author` field in the git extras, but that would have no
effect. It's better that it's not possible to do that (we store the
author field in the git commit, of course).
What made me notice this now was that I'm working on tree-level
conflicts (#1624) and I'm thinking of adding a field to the git extras
saying "this commit has single tree, but it's still a new-style
commit", so we can know not to walking such trees to find path-level
conflicts. That's only needed for the git backend because we don't
care about compatibility for the local backend.
This commit fixes#1305
Before this commit, running `jj init --git-repo=./` in a folder that
does not have a .git would cause jj to panick and leave an unfinished corrupted jj repo.
This commit fixes that by changing the call chain to return an error
instead of calling .unwrap() and panicking. This commit also adds logic to delete the unfinished jj
repository when the git backend initialization failed.
Before this commit, running the above command would result in the following
```
Running `jj/target/debug/jj init --git-repo=./`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error { code: -3, klass: 2, message: "failed to resolve path '/Users/kevincliao/github/jj/test-repo/.jj/repo/store/../../../.git': No such file or directory" }', lib/src/git_backend.rs:83:75
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
After this commit, the result is the following and the jj repo is deleted:
```
Running `jj/target/debug/jj init --git-repo=./`
Error: Failed to access the repository: Error: Failed to open git repository: failed to resolve path '/Users/kevincliao/github/jj/test-repo/.jj/repo/store/../../../.git': No such file or directory; class=Os (2); code=NotFound (-3)
```
Otherwise, "jj init --git-repo ." would create extra table files per commit,
and merge them.
I considered adding an explicit GitBackend method to be called from
git::import_refs(), but the call order matters. The method should be invoked
before calling store.get_commit(..) or mut_repo.add_head(..). Since commits
are likely to be loaded from the head, we can instead make read_commit()
import ancestor metadata at all.
Alternatively, we could make a Git commit hidden until it's inserted into
the extra table. It's rather big change, and I wouldn't like to do that
without thinking more thoroughly.
I'm going to extract a helper function that converts git2::Commit to
backend::Commit struct, and the commit id can also be obtained from the
git2::Commit object.
My first attempt was to fix up corrupted index when merging, but it turned
out to be not easy because the self side may contain corrupted data. It's
also possible that two concurrent commit operations have exactly the same
view state (because change id isn't hashed into commit id), and only the
table heads diverge.
#924
Now that we return the written commit from `write_commit()`, let's
make the timestamps match what was actually written, accounting for
the whole-second precision and the adjustment we do to avoid
collisions.
The internal backend at Google doesn't let you write any value you
want for in the committer field. The `Store` type still caches the
value it attempted to write, which gets a little weird when the
written value is not what we tried to write. We should use the value
the backend actually wrote. However, we don't know if the backend
changed anything without reading the value back, which is often
wasteful. This commit changes the API to return the written value.
I only changed the signature of `write_commit()` for now. Maybe we
should make a similar change to `write_tree()`.
This has several advantages:
* Makes it possible to downcast to non-Git custom backends (might be
useful at Google, but we haven't needed it yet)
* Lets us access more specific functionality on the `GitBackend`,
making it possible to access the `git2::Repository` without
creating a copy of it.
* Removes the dependency on Git from the backend
It took a while before I realized that conflicts could be modeled as
simple algebraic expressions with positive and negative terms (they
were modeled as recursive 3-way conflicts initially). We've been
thinking of them that way for a while now, so let's make the
`ConflictPart` name match that model.
Our internal backend at Google uses a 32-byte change id, so I'd like
to make the backend able to decide the length. To start with, let's
make the backend able to decide what the root change id should
be. That's consistent with how we already let the backend decide what
the root commit id should be.
The function is currently only about the length of commit IDs, so
let's clarify that. I'm going to add another function for the length
of change IDs next. I don't know if we're going to care about lengths
of other hashes in the future. We might even be able to remove the
current restriction that all commit IDs and all change IDs have the
same length.
I think the CLI currently checks that the backend is not told to write
a merge commit with the root as one parent, but we should not panic if
those checks fail.
By inlining `wite_commit_internal()` into `write_commit()`, we can
avoid redoing some steps when we retry. This includes taking the mutex
lock, and reading the tree object and parent commits. It also means
that we avoid cloning the input commit object, which we otherwise
would even in the non-retrying case. I haven't measured if any of this
makes a significant difference, but I think it also slightly
simplifies the code, so it doesn't have to.
We don't care the ref content as long as it is unique, so using threaded
RNG should be fine.
This change means refs/jj/keep will now contain refs of the following
forms:
- new create_no_gc_ref(): 0f8d6cd9721823906cfb55dac99d7bf5
- old create_no_gc_ref(): 0f6d93fe-0507-4db8-ad0a-6317f02e27b9
- prevent_gc(commit_id): 0f9c15100b6f1373f38186357e274a829fb6c4e2
I needed this in the course of debugging an error. Before this commit, the error looked like this:
```
Error: Unexpected error from backend: Object not found
```
After this commit, it looks like this:
```
Error: Unexpected error from backend: Object with CommitId 8f59646bc9bb6bb44b5624f1248f4a708f37003c not found: object not found - no match for id (8f59646bc9bb6bb44b5624f1248f4a708f37003c); class=Odb (9); code=NotFound (-3)
```
Strictly speaking, we could rely on e.g. `git2::Oid::from_str` to produce an error, but I figure that having an explicit error for a mismatching hash length might demystify some error condition in the future, since commit IDs and change IDs and potentially other backends' IDs may have different lengths, so this could flag a mismatch earlier/more obviously.
Performance on repositories with many commits is limited somewhat by repeatedly
stating the tablestore directory to work out what the head is. By caching the
table rather than looking it up from disk on every request, we can much more
rapidly satisfy requests.
This avoids the pathological case in #845 where jj operations take several
minutes to complete.
This patch doesn't change the normal flow of the write path: that will still
always call get_head() on the underlying TableStore, which will stat the
directory before writing out changes. It will however empty the cache when the
metadata has been written.
Fixes#845.
I ran an upgraded Clippy on the codebase. All the changes seem to be
about using variables directly in format strings instead of passing
them as separate arguments.
To prevent git's GC from breaking a repo, we already add a git ref to
commits we create in the git backend. However, we don't add refs to
commits we import from git. This fixes that.
Closes#815.
Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
There are no "non-normal" files, so "normal" is not needed. We have
symlinks and conflicts, but they are not files, so I think just "file"
is unambiguous.
I left `testutils::write_normal_file()` because there it's used to
mean "not executable file" (there's also a `write_executable_file()`).
I left `working_copy::FileType::Normal` since renaming `Normal` there
to `File` would also suggest we should rename `FileType`, and I don't
know what would be a better name for that type.
The `testutils` module should ideally not be part of the library
dependencies. Since they're used by the integration tests (and the CLI
tests), we need to move them to a separate crate to achieve that.
I was reading a draft of "Git Rev News: Edition 91" [1] where Peff
mentions some unfinished patches to allow negative timestamps in
Git. So I figured I should add support for that before I forget. I
haven't checked if libgit2 supports it, so it might be that our Git
backend still doesn't support it after this patch.
[1] https://github.com/git/git.github.io/blob/master/rev_news/drafts/edition-91.md
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.
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.
This moves the logic for handling the root commit when writing commits
from `CommitBuilder` into the individual backends. It always bothered
me a bit that the `commit::Commit` wrapper had a different idea of the
number of parents than the wrapped `backend::Commit` had.
With this change, the `LocalBackend` will now write the root commit in
the list of parents if it's there in the argument to
`write_commit()`. Note that root commit itself won't be written. The
main argument for not writing it is that we can then keep the fake
all-zeros hash for it. One argument for writing it, if we were to do
so, is that it would make the set of written objects consistent, so
any future processing of them (such as GC) doesn't have to know to
ignore the root commit in the list of parents.
We still treat the two backends the same, so the user won't be allowed
to create merges including the root commit even when using the
`LocalBackend`.
I had made the backends unaware of the virtual root commit because
they don't need to know about it, and we could avoid some duplicated
code by putting that in `Store` instead. However, as we saw in
b21a123bc894, the root commit being virtual has some user-visible
effects (they can't create a merge with the root and some other
commit). So I'm thinking that we may want to make the root commit an
actual commit, depending on which backend is used. Specificially, when
using the Git backend, we cannot record the root commit as an actual
parent since Git would fail when trying to look it up. Backends that
don't need compatibility can make the root commit an actual commit,
however.
This commit therefore makes the backends aware of the root commit. It
makes it remain a virtual commit in the Git backend, and makes it an
actual commit in the `LocalBackend`.
This commit breaks any existing repos using the `LocalBackend`, but
there shouldn't be any such repos other than for testing.
The regular `Display` format is (not surprisingly) more user-friendly,
as pointed out by @yuja.
I also switched to using format strings for these cases, and some
nearby strings for consistency.
