Since `Conflict`s can represent the resolved state, so
`Conflict<ContentHunk>` can represent the states that we use
`MergeHunk` for. `MergeHunk` does force the user to handle the
resolved case, which may be useful. I suppose one could use the same
argument for making `Conflict` an enum, i.e. if we think that
`MergeHunk`'s two variants are beneficial, then we should consider
making `Conflict` an enum with those two variants.
It's useful to have a more readable `Debug` format for `Vec<u8>`
(`"foo"` is better than `[102, 111, 111]`). It might also make types
in function signatures and elsewhere more readable.
This only parses the fields relevant to us, i.e.:
- name: the stable identifier of the submodule
- path: the path to the submodule in the current commit
- url: the remote we can clone the submodule from
The full list of .gitmodules fields can be found at
https://git-scm.com/docs/gitmodules.
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)
```
..and other assorted boilerplate. These are just stubs for now, but now
that we've reserved the `submodule_store` subdirectory, we can start
adding more functionality.
Before we had `conflicts::Conflict`, most of these functions took a
`backend::Conflict`. I think I didn't want to pollute the `backend`
module with this kind of logic, trying to keep it focused on
storage. Now that we have the type in `conflicts`, however, I think it
makes sense to move these functions onto it.
This gets rid of round-trip conversion from queries like "(main..)-". I have
such expression in my default log/disambiguation revset, and the query could
take ~150ms to convert head positions back and forth if the repository had
tons of unmerged commits.
For tree-level conflicts (#1624), I plan to remove `ConflictId`
completely. This commit removes `ConflictId` from
`update_conflict_from_content()` by instead making it take a
`Conflict<Option<TreeValue>>` and return a possibly different such
value.
I made the call site in `working_copy` avoid writing the conflict to
the store if it's unchanged, but I didn't make the same optimization
in `merge_tools` becuase it's much more likely to have changed there.
Use `br@git` instead.
Before, if there is not a local branch `br`, jj tried to resolve
it as a git ref `refs/heads/br`. Unchanged from before, `br` can
still be resolved as a tag `refs/tag/br`.
Currently, if the user modifies a modify/delete conflict, we always
consider the result resolved. That happens because we materialize the
missing side of the conflict as an empty string but when we parse the
conflict, we expect only the number of sides in the input
conflict. For example, if the input is a regular modify/delete
conflict with one remove and one add, the materialized markers will
have one remove and two adds (one of them empty), but when we try to
parse it, we expect one remove and only one add. When we fail to parse
it, we consider it resolved.
This commit fixes the bug by using
`conflicts::Conflict<Option<TreeValue>>` and keeping track of which
sides were supposed to be empty. We could have fixed the bug without
switching to `conflicts::Conflict`, but we want to switch anyway, and
the fix happens naturally when switching.
I made a typo and got something like this:
```
Error: Commit or change id prefix "wl" is ambiguous
```
Since we can tell commit ids from change ids these days, let's make
the error message say which kind of id it is. Changing that also kind
of forced me to make a special error for empty strings. Otherwise we
would have to arbitrarily say that an empty string is a commit id or
change id. A specific error message for empty strings seems helpful,
so that's probably for the better anyway.
We can't get rid of the other "impl Index"es because .as_composite() must
return a real reference type. Maybe we could turn CompositeIndex into an
owned wrapper, but I don't know if that would be worth the effort.
It might sound scary to add public .mutable_index() accessor, but I think
it's okay because immutable MutableIndex reference has no more power than
Index.
This allows us to implement Index for lifetime-bound type such as
CompositeIndex<'_>.
The idea is that .as_composite() is equivalent to .as_index(), but for the
implementation type. I'm going to add "impl Index for CompositeIndex" to
clean up index references passed to revset engine.
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.
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
This bug concerns the way `import_refs` that gets called by `fetch` computes
the heads that should be visible after the import.
Previously, the list of such heads was computed *before* local branches were
updated based on changes to the remote branches. So, commits that should have
been abandoned based on this update of the local branches weren't properly
abandoned.
Now, `import_refs` tracks the heads that need to be visible because of some ref
in a mapping keyed by the ref. If the ref moves or is deleted, the
corresponding heads are updated.
Fixes#864
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.
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
In large repos, the unique prefixes can get somewhat long (~6 hex
digits seems typical in the Linux repo), which makes them less useful
for manually entering on the CLI. The user typically cares most about
a small set of commits, so it would be nice to give shorter unique ids
to those. That's what Mercurial enables with its
`experimental.revisions.disambiguatewithin` config. This commit
provides an implementation of that feature in `IdPrefixContext`.
In very large repos, it can also be slow to calculate the unique
prefixes, especially if it involves a request to a server. This
feature becomes much more important in such repos.
When creating `RevsetExpression` programmatically, I think we should
use commit ids instead of symbols in the expression. This commit adds
a check for that by using a `SymbolResolver` that always errors
out.
I would eventually want the `SymbolResolver` to be customizable (in
custom `jj` binaries), so we want to make sure we always use the
customized version of it.
I left `RevsetExpression::resolve()` unchanged. I consider that to be
for programmatically created expressions.
The current behavior was introduced by 20eb9ecec1 "git: don't abandon
HEAD commit when it loses a branch." While the change made HEAD mutation
behavior more consistent with a plain ref operation, HEAD can also move on
checkout, and checkout shouldn't be considered a history rewriting operation.
I'm not saying the new behavior is always correct, but I think it's safer
than losing old HEAD branch. I also think this change will help if we want
to extract HEAD management function from git::import_refs().
Fixes#1042.
The substitution rule and tests are copied from ancestors/parents. The backend
logic will be reimplemented later. For now, it naively repeats children().
It no longer needs to be on the `Index` trait, thereby removing the
last direct use of `IndexEntry` in the trait (it's still used
indirectly in `walk_revs()`).
New ResolvedExpression enum ensures that the evaluation engine doesn't have
to know the symbol resolution details. In this commit, I've moved Filter
and NotIn resolution to resolve_visibility(). Implicit All/VisibleHeads
resolution will be migrated later.
It's tempting to combine resolve_symbols() and resolve_visibility() to get
rid of panic!()s, but the resolution might have to be two passes to first
resolve&collect explicit commit ids, and then substitute "all()" with
"(:visible_heads())|commit_id|..". It's also possible to apply some tree
transformation after symbol resolution.
The `heads()` revset function with one argument is the counterpart to
`roots()`. Without arguments, it returns the visible heads in the
repo, i.e. `heads(all())`. The two use cases are quite different, and
I think it would be good to clarify that the no-arg form returns the
visible heads, so let's split that out to a new `visible_heads()`
function.
This basically removes hidden 'all() &' from union/negation of filters. To
achieve that, I have two options: 1. add separate evaluation path (like the
one this commit introduced), or 2. wrap "all()" revset to override predicate
as Box::new(|_| true) function. I took the former since it's less ad-hoc.
We can add an explicit RevsetExpression node to branch between evaluate()
and evaluate_predicate(), but I don't think it would simplify the
implementation at this point. We might need such node if we want to resolve
"all()" at resolve_symbols(). It might be even better to extract a subset of
RevsetExpression enum, which only contains evaluatable nodes.
The cost of 'all() &' isn't significant for most filters. '~merges()' is
the exception. For jj repo,
revsets/:v0.3.0 & (author(martinvonz) | committer(martinvonz))
--------------------------------------------------------------
base 1.06 11.2±0.04m
new 1.00 10.5±0.05m
revsets/~merges()
-----------------
base 1.69 750.0±8.47µ
new 1.00 444.1±3.50µ
This makes it clear that RevsetExpression::Present node is noop at the
evaluation stage.
RevsetEvaluationError::StoreError is unused right now, but I'm not sure if
it should be removed. It makes some sense that evaluate() can propagate
StoreError as it has access to the store.
The `Repo` is a higher-level type that the index shouldn't have to
know about. With this change, a custom revset implementation should be
able evaluate the revset on a server without knowing which repo it
refers to.
The `public_heads()` revset only contains the root commit in
practice. I'm not sure what we want to do about phases, but since we
don't have any real support for them yet, let's just remove this
revset. I didn't update the changelog because we don't seem to have
documented the revset function (and it seems unlikely that users who
found out about it found it useful enough to use it when they could
just use `root`).
This serves the role of limit() in Mercurial. Since revsets in JJ is
(conceptually) an unordered set, a "limit" predicate should define its
ordering criteria. That's why the added predicate is named as "latest".
Closes#1110
There are no remaining places where we iterate over a revset and need
the `IndexEntry`s, so we can now make `Revset::iter()` yield
`CommitId`s instead.
I'm about to make `Revset::iter()` yield just `CommitId`s, but the
tests in `test_default_revset_graph_iterator.rs` need an `IndexEntry`
iterator so they can pass it into `RevsetGraphIterator::new()`. This
commits prepares for the change by adding a
`RevsetImpl::iter_graph_impl()` that returns `RevsetGraphIterator`,
keeping `InternalRevset` still hidden within the revset engine. We
could instead have made that (and `ToPredicateFn`) visible to tests. I
can't say which is better.
One of the remaining places we depend on index positions is when
creating a `ChangeIdIndex`. This moves that into the revset engine
(which is coupled to the commit index implementation) by adding a
`Revset::change_id_index()` method. We will also use this function
later when add support for resolving change id prefixes within a small
revset.
The current implementation simply creates an in-memory index using the
existing `IdIndex` we have in `repo.rs`.
The custom implementation at Google might do the same for small
revsets that are available on the client, but for revsets involving
many commits on the server, it might use a suboptimmal implementation
that uses longer-than-necessary prefixes for performance reasons. That
can be done by querying a server-side index including changes not in
the revset, and then verifying that the resulting commits are actually
in the revset.
The function is only used in tests, so it doesn't belong in
`default_revset_engine`. Also, it's not specific to that
implementation, so I rewrote as a revset evaluation.
I'd like to be able to pass a `self` of `type `&ReadonlyRepo` to
functions that take a `&dyn Repo`. For that, we need `ReadonlyRepo`
itself to implement `Repo` instead of having `Arc<ReadonlyRepo>`
implement it. I could have solved it in a different way, but the `Arc`
requirement seems like an unnecessary constraint.
The index position is specific to the default index implementation and
we don't want to use it in outside of there. This commit removes the
use of it as a key for nodes in the graphlog.
I timed it on the git.git repo using `jj log -r 'all()' -T commit_id`
(the worst case I can think of) and it slowed down from ~2.02 s to
~2.20 s (~9%).
For large repos, it's useful to be able to use shorter change id and
commit id prefixes by resolving the prefix in a limited subset of the
repo (typically the same subset that you'd want to see in your default
log output). For very large repos, like Google's internal one, the
shortest unique prefix evaluated within the whole repo is practically
useless because it's long enough that the user would want to copy and
paste it anyway.
Mercurial supports this with its `revisions.disambiguatewithin` config
(added in https://www.mercurial-scm.org/repo/hg/rev/503f936489dd). I'd
like to add the same feature to jj. Mercurial's implementation works
by attempting to resolve the prefix in the whole repo and then, if the
prefix was ambiguous, it resolves it in the configured subset
instead. The advantage of doing it that way is that there's no extra
cost of resolving the revset defining the subset if the prefix was not
ambiguous within the whole repo. However, there are two important
reasons to do it differently in jj:
* We support very large repos using custom backends, and it's probably
cheaper to resolve a prefix within the subset because it can all be
cached on the client. Resolving the prefix within the whole repo
requires a roundtrip to the server.
* We want to be able to resolve change id prefixes, which is always
done in *some* revset. That revset is currently `all()`, i.e. all
visible commits. Even on local disk, it's probably cheaper to
resolve a small revset first and then resolve the prefix within that
than it is to build up the index of all visible change ids.
We could achieve the goal by letting each revset engine respect the
configured subset, but since the solution proposed above makes sense
also for local-disk repos, I think it's better to do it outside of the
revset engine, so all revset engines can share the code.
This commit prepares for the new functionality by moving the symbol
resolution out of `Index::evaluate_revset()`.
We want to allow custom revset engines define their own graph
iterator. This commit helps with that by adding a
`Revset::iter_graph()` function that returns an abstract iterator.
The current `RevsetGraphIterator` can be configured to skip or include
transitive edges. It skips them by default and we don't expose option
in the CLI. I didn't bother including that functionality in the new
`iter_graph()` either. At least for now, it will be up to the
implementation whether it includes such edges (it would of course be
free to ignore the caller's request even if we added an option for it
in the API).
We want to allow customization of the revset engine, so it can query
server indexes, for example. The current revset implementation will be
our default implementation for now. What's left in the `revset` module
after this commit is mostly parsing code.
The tests adding and removing heads to the repo mostly want to verify
that the set of heads is expected. Some of them also check that
commits are available in the index. But they shouldn't care about the
exact index stats.
I don't think there's much to gain from making the index match exactly
what's reachable from the view. FWIW, our cloud-based implementation
at Google will probably make everyone's commits visible in the index
regardless of which operation they're at.
This is another step towards allowing a custom `jj` binary to have its
own index type. We're going to have a server-backed index
implementation at Google, for example.
In `git_fetch()`, any glob present in `globs` is an "allow" mark. Using
`&[]` to represent an "allow-all" may be misleading, as it could
indicate that no branch (only the git HEAD) should be fetched.
By using an `Option<&[&str]>`, it is clearer that `None` means that
all branches are fetched.
To be able to make e.g. `jj log some/path` perform well on cloud-based
repos, a custom revset engine needs to be able to see the paths to
filter by. That way it is able pass those to a server-side index. This
commit helps with that by effectively converting `jj log -r foo
some/path` into `jj log -r 'foo & file(some/path)'`.
I'm about to make `RepoLoader::init()` return a `Result`, and I don't
want to have to wrap that in a new error in
`ReadonlyRepo::load_at_head()` since that's only used in tests.
This should fix#1304. I think the added test simulates the behavior of
multiple rebase conflicts, but I don't have expertise around this.
add_index could be replaced with a peekable iterator, but the iterator version
wouldn't be as readable as the current implementation.
The type doesn't seem to provide any benefit. I don't think I had a
good reason for creating it in the first place; it was probably just
unfamiliarity with Rust.
