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use crate::{
store::file::{transaction::PackedRefs, Transaction},
transaction::{Change, LogChange, RefEdit, RefLog},
Target,
};
impl<'s> Transaction<'s> {
/// Make all [prepared][Transaction::prepare()] permanent and return the performed edits which represent the current
/// state of the affected refs in the ref store in that instant. Please note that the obtained edits may have been
/// adjusted to contain more dependent edits or additional information.
/// `committer` is used in the reflog.
///
/// On error the transaction may have been performed partially, depending on the nature of the error, and no attempt to roll back
/// partial changes is made.
///
/// In this stage, we perform the following operations:
///
/// * update the ref log
/// * move updated refs into place
/// * delete reflogs and empty parent directories
/// * delete packed refs
/// * delete their corresponding reference (if applicable)
/// along with empty parent directories
///
/// Note that transactions will be prepared automatically as needed.
pub fn commit(self, committer: &git_actor::Signature) -> Result<Vec<RefEdit>, Error> {
let mut updates = self.updates.expect("BUG: must call prepare before commit");
let delete_loose_refs = matches!(
self.packed_refs,
PackedRefs::DeletionsAndNonSymbolicUpdatesRemoveLooseSourceReference(_)
);
// Perform updates first so live commits remain referenced
for change in updates.iter_mut() {
assert!(!change.update.deref, "Deref mode is turned into splits and turned off");
match &change.update.change {
// reflog first, then reference
Change::Update { log, new, expected } => {
let lock = change.lock.take().expect("each ref is locked");
let (update_ref, update_reflog) = match log.mode {
RefLog::Only => (false, true),
RefLog::AndReference => (true, true),
};
if update_reflog {
match new {
Target::Symbolic(_) => {} // no reflog for symref changes
Target::Peeled(new_oid) => {
let previous = match expected {
PreviousValue::MustExistAndMatch(Target::Peeled(oid)) => Some(oid.to_owned()),
_ => None,
}
.or(change.leaf_referent_previous_oid);
let do_update = previous.as_ref().map_or(true, |previous| previous != new_oid);
if do_update {
self.store.reflog_create_or_append(
&lock,
previous,
new_oid,
committer,
log.message.as_ref(),
log.force_create_reflog,
)?;
}
}
}
}
// Don't do anything else while keeping the lock after potentially updating the reflog.
// We delay deletion of the reference and dropping the lock to after the packed-refs were
// safely written.
if delete_loose_refs {
change.lock = Some(lock);
continue;
}
if update_ref {
if let Err(err) = lock.commit() {
// TODO: when Kind::IsADirectory becomes stable, use that.
let err = if err.instance.resource_path().is_dir() {
git_tempfile::remove_dir::empty_depth_first(err.instance.resource_path())
.map_err(|io_err| std::io::Error::new(std::io::ErrorKind::Other, io_err))
.and_then(|_| err.instance.commit().map_err(|err| err.error))
.err()
} else {
Some(err.error)
};
if let Some(err) = err {
return Err(Error::LockCommit {
err,
full_name: change.name(),
});
}
};
}
}
Change::Delete { .. } => {}
}
}
let reflog_root = self.store.reflog_root();
for change in updates.iter_mut() {
match &change.update.change {
Change::Update { .. } => {}
Change::Delete { .. } => {
// Reflog deletion happens first in case it fails a ref without log is less terrible than
// a log without a reference.
let reflog_path = self.store.reflog_path(change.update.name.to_ref());
if let Err(err) = std::fs::remove_file(&reflog_path) {
if err.kind() != std::io::ErrorKind::NotFound {
return Err(Error::DeleteReflog {
err,
full_name: change.name(),
});
}
} else {
git_tempfile::remove_dir::empty_upward_until_boundary(
reflog_path.parent().expect("never without parent"),
&reflog_root,
)
.ok();
}
}
}
}
if let Some(t) = self.packed_transaction {
t.commit().map_err(Error::PackedTransactionCommit)?;
}
for change in updates.iter_mut() {
let take_lock_and_delete = match &change.update.change {
Change::Update {
log: LogChange { mode, .. },
..
} => delete_loose_refs && *mode == RefLog::AndReference,
Change::Delete { log: mode, .. } => *mode == RefLog::AndReference,
};
if take_lock_and_delete {
let lock = change.lock.take().expect("lock must still be present in delete mode");
let reference_path = self.store.reference_path(change.update.name.to_path().as_ref());
if let Err(err) = std::fs::remove_file(reference_path) {
if err.kind() != std::io::ErrorKind::NotFound {
return Err(Error::DeleteReference {
err,
full_name: change.name(),
});
}
}
drop(lock)
}
}
Ok(updates.into_iter().map(|edit| edit.update).collect())
}
}
mod error {
use git_object::bstr::BString;
use quick_error::quick_error;
use crate::store::{file, packed};
quick_error! {
/// The error returned by various [`Transaction`][super::Transaction] methods.
#[derive(Debug)]
#[allow(missing_docs)]
pub enum Error {
PackedTransactionCommit(err: packed::transaction::commit::Error) {
display("The packed-ref transaction could not be committed")
source(err)
}
PreprocessingFailed(err: std::io::Error) {
display("Edit preprocessing failed with error: {}", err.to_string())
source(err)
}
LockCommit{err: std::io::Error, full_name: BString} {
display("THe change for reference {} could not be committed", full_name)
source(err)
}
DeleteReference{ full_name: BString, err: std::io::Error } {
display("The reference '{}' could not be deleted", full_name)
source(err)
}
DeleteReflog{ full_name: BString, err: std::io::Error } {
display("The reflog of reference '{}' could not be deleted", full_name)
source(err)
}
CreateOrUpdateRefLog(err: file::log::create_or_update::Error) {
display("The reflog could not be created or updated")
from()
source(err)
}
}
}
}
pub use error::Error;
use crate::transaction::PreviousValue;