GitBackend::gc() will recreate no-gc refs for the indexed heads. We could
collect all historical heads by traversing operation log, but it isn't enough
because there may be predecessor links to hidden commits, and "git gc" isn't
aware of predecessors.
This also means that we can implement GC without taking care of extra
metadata. I haven't tried, but it wouldn't be easy to keep Git refs and extra
table in sync.
The idea is that GC, if implemented, will clean up objects based on the Index
knowledge. It's probably okay to leave some extra metadata of unreachable
objects, but GC-ed refs should be recreated if the corresponding heads get
reimported. See also the next patch.
This will allow us to issue multiple prevent_gc() requests all at once. It's
not important here, but will be unavoidable when implementing GC. Deleting
tons of refs from packed refs is super slow if the requests were processed one
by one.
* Move canonicalization of the external git repo path into the Workspace::init_git_external().
This keeps necessary code together.
* Add a new variant of WorkspaceInitError for reporting path not found errors. The user error
string is written to pass existing tests.
Because the default index cuts off the traversal at min(generations), including
the root id means all ancestors will be visited. This could be worked around at
the index side, but I think it's the repo/view's responsibility. That being
said, it's not uncommon to pad a revset with "root()", so it might make sense
for the index to special case the root id.
I also removed the redundant .clone().
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.
This function respects --ignore-working-copy and --at-op arguments, but the
name snapshot() sounds like it could forcibly trigger the snapshotting. Let's
clarify the actual behavior.
import_git_refs_and_head() and snapshot_working_copy() are unchecked functions,
and there are no external callers.
When debugging behavior of badly-GCed repos, I find it's annoying that "op log"
fails because the index can't be loaded. Since "op log" doesn't need a repo, I
think it's better to display the exact op-heads state without merging.
I thought this would be done by dag_walk::topo_order_reverse_lazy_ok(), but
apparently I made it preserve the input order in a way topo_order_reverse()
would do.
I'm going to make "op log" not load a repo nor resolve concurrent operations,
so there will be the case where no unique "current" operation exists. Since the
"current" operation represents the repo to be loaded, I think it's better to
not consider multi-head operations as the "current" ones. That's why the
templater field isn't Vec<_> but Option<_>.
Sadly, ripgrep won't honor the .gitignore files in the absence of a
.git directory, so we need to pass an annoying flag (for non-colocated
repos).
That seems worth adding despite the existing suggestion, because rg is
faster, and for existing users for rg, it would teach them how to make
rg work as expected.
Since hidden commits can be looked up by remote_branches() revset for example,
reindexing should traverse ancestors from all named refs in addition to the
visible heads.
If indexing failed due to missing commit objects, the repo won't be loadable
without --ignore-working-copy (at least in colocated environment.) In that
case, we can use "op abandon" to recover, but we had to work around the failed
index loading by --ignore-working-copy. Since "op abandon" isn't a repo-level
command, it's better to bypass working-copy snapshot and import of git refs at
all.
--at-op is rejected because it's useless and we'll need extra care for "@"
expression resolution and working-copy updates.
The formatting is closer to hg than git just because it's easier to
conditionalize the whole line per keyword. Our template language doesn't
have infix logical operators.
Unlike the other default templates, all remote branches are displayed because
it's "detailed" output.
Closes#2509
If the existing index was corrupt, it would have to be rebuilt while loading a
repo (at least in colocated environment.) Then, the index will be rebuilt again.
