mirrors/jj
1
0
Fork 1
mirror of https://github.com/martinvonz/jj.git synced 2025-01-05 20:55:05 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 7

backend: Inline gix::Repository::commit_as to prepare for signing

Browse source 
Additional bonus is that this allows us to avoid creating keep refs for the
intermediate commits in the data race preventing loop.
This commit is contained in:
Anton Bulakh 2023-11-12 03:40:23 +02:00 committed by Anton Bulakh
parent 811ac5ff23
commit 5ab00e197a
1 changed files with 31 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

57
lib/src/git_backend.rs
View file

@ -25,6 +25,7 @@ use async_trait::async_trait;
use gix::objs::CommitRefIter;
use itertools::Itertools;
use prost::Message;
use smallvec::SmallVec;
use thiserror::Error;
use crate::backend::{
@ -538,13 +539,7 @@ fn deserialize_extras(commit: &mut Commit, bytes: &[u8]) {
}
}
/// Creates a random ref in refs/jj/. Used for preventing GC of commits we
/// create.
fn create_no_gc_ref() -> String {
let random_bytes: [u8; 16] = rand::random();
format!("{NO_GC_REF_NAMESPACE}{}", hex::encode(random_bytes))
}
/// Creates a ref in refs/jj/. Used for preventing GC of commits we create.
fn prevent_gc(git_repo: &gix::Repository, id: &CommitId) -> Result<(), BackendError> {
git_repo
.reference(
@ -923,7 +918,7 @@ impl Backend for GitBackend {
"Cannot write a commit with no parents".into(),
));
}
let mut parents = vec![];
let mut parents = SmallVec::new();
for parent_id in &contents.parents {
if *parent_id == self.root_commit_id {
// Git doesn't have a root commit, so if the parent is the root commit, we don't
@ -942,6 +937,7 @@ impl Backend for GitBackend {
}
}
let extras = serialize_extras(&contents);
// If two writers write commits of the same id with different metadata, they
// will both succeed and the metadata entries will be "merged" later. Since
// metadata entry is keyed by the commit id, one of the entries would be lost.
@ -950,31 +946,40 @@ impl Backend for GitBackend {
// repository is rsync-ed.
let (table, table_lock) = self.read_extra_metadata_table_locked()?;
let id = loop {
let git_id = locked_repo
.commit_as(
committer,
author,
create_no_gc_ref(),
message,
git_tree_id,
parents.iter().copied(),
)
.map_err(|err| BackendError::WriteObject {
object_type: "commit",
source: Box::new(err),
})?;
let id = CommitId::from_bytes(git_id.as_bytes());
match table.get_value(id.as_bytes()) {
let commit = gix::objs::Commit {
message: message.to_owned().into(),
tree: git_tree_id,
author: author.into(),
committer: committer.into(),
encoding: None,
parents: parents.clone(),
extra_headers: Default::default(),
};
// todo sign commits here
let git_id =
locked_repo
.write_object(&commit)
.map_err(|err| BackendError::WriteObject {
object_type: "commit",
source: Box::new(err),
})?;
match table.get_value(git_id.as_bytes()) {
Some(existing_extras) if existing_extras != extras => {
// It's possible a commit already exists with the same commit id but different
// change id. Adjust the timestamp until this is no longer the case.
committer.time.seconds -= 1;
}
_ => {
break id;
}
_ => break CommitId::from_bytes(git_id.as_bytes()),
}
};
// Everything up to this point had no permanent effect on the repo except
// GC-able objects
prevent_gc(&locked_repo, &id)?;
// Update the signature to match the one that was actually written to the object
// store
contents.committer.timestamp.timestamp = MillisSinceEpoch(committer.time.seconds * 1000);