use std::fmt::Formatter; use git_hash::ObjectId;use git_object::bstr::BString; use crate::{    store_impl::{file, file::Transaction},    transaction::RefEdit,}; /// A function receiving an object id to resolve, returning its decompressed bytes,/// used to obtain the peeled object ids for storage in packed-refs files.////// Resolution means to follow tag objects until the end of the chain.pub type FindObjectFn<'a> = dyn FnMut(        git_hash::ObjectId,        &mut Vec<u8>,    ) -> Result<Option<git_object::Kind>, Box<dyn std::error::Error + Send + Sync + 'static>>    + 'a; /// How to handle packed refs during a transactionpub enum PackedRefs<'a> {    /// Only propagate deletions of references. This is the default    DeletionsOnly,    /// Propagate deletions as well as updates to references which are peeled, that is contain an object id    DeletionsAndNonSymbolicUpdates(Box<FindObjectFn<'a>>),    /// Propagate deletions as well as updates to references which are peeled, that is contain an object id. Furthermore delete the    /// reference which is originally updated if it exists. If it doesn't, the new value will be written into the packed ref right away.    /// Note that this doesn't affect symbolic references at all, which can't be placed into packed refs.    DeletionsAndNonSymbolicUpdatesRemoveLooseSourceReference(Box<FindObjectFn<'a>>),} impl Default for PackedRefs<'_> {    fn default() -> Self {        PackedRefs::DeletionsOnly    }} #[derive(Debug)]pub(in crate::store_impl::file) struct Edit {    update: RefEdit,    lock: Option<git_lock::Marker>,    /// Set if this update is coming from a symbolic reference and used to make it appear like it is the one that is handled,    /// instead of the referent reference.    parent_index: Option<usize>,    /// For symbolic refs, this is the previous OID to put into the reflog instead of our own previous value. It's the    /// peeled value of the leaf referent.    leaf_referent_previous_oid: Option<ObjectId>,} impl Edit {    fn name(&self) -> BString {        self.update.name.0.clone()    }} impl std::borrow::Borrow<RefEdit> for Edit {    fn borrow(&self) -> &RefEdit {        &self.update    }} impl std::borrow::BorrowMut<RefEdit> for Edit {    fn borrow_mut(&mut self) -> &mut RefEdit {        &mut self.update    }} /// Editsimpl file::Store {    /// Open a transaction with the given `edits`, and determine how to fail if a `lock` cannot be obtained.    /// A snapshot of packed references will be obtained automatically if needed to fulfill this transaction    /// and will be provided as result of a successful transaction. Note that upon transaction failure, packed-refs    /// will never have been altered.    ///    /// The transaction inherits the parent namespace.    pub fn transaction(&self) -> Transaction<'_, '_> {        Transaction {            store: self,            packed_transaction: None,            updates: None,            packed_refs: PackedRefs::default(),        }    }} impl<'s, 'p> Transaction<'s, 'p> {    /// Configure the way packed refs are handled during the transaction    pub fn packed_refs(mut self, packed_refs: PackedRefs<'p>) -> Self {        self.packed_refs = packed_refs;        self    }} impl std::fmt::Debug for Transaction<'_, '_> {    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {        f.debug_struct("Transaction")            .field("store", self.store)            .field("edits", &self.updates.as_ref().map(|u| u.len()))            .finish_non_exhaustive()    }} ///pub mod prepare; ///pub mod commit;