mirrors/git
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

refs: allow multiple reflog entries for the same refname

Browse Source 
The reference transaction only allows a single update for a given
reference to avoid conflicts. This, however, isn't an issue for reflogs.
There are no conflicts to be resolved in reflogs and when migrating
reflogs between backends we'd have multiple reflog entries for the same
refname.

So allow multiple reflog updates within a single transaction. Also the
reflog creation logic isn't exposed to the end user. While this might
change in the future, currently, this reduces the scope of issues to
think about.

In the reftable backend, the writer sorts all updates based on the
update_index before writing to the block. When there are multiple
reflogs for a given refname, it is essential that the order of the
reflogs is maintained. So add the `index` value to the `update_index`.
The `index` field is only set when multiple reflog entries for a given
refname are added and as such in most scenarios the old behavior
remains.

This is required to add reflog migration support to `git refs migrate`.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Karthik Nayak
2024-12-16 17:44:32 +01:00
committed by Junio C Hamano
parent 84675fa271
commit 297c09eabb
2 changed files with 30 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
refs/files-backend.c
View File

@ -2611,6 +2611,9 @@ static int lock_ref_for_update(struct files_ref_store *refs,
update->backend_data = lock;
if (update->flags & REF_LOG_ONLY)
goto out;
if (update->type & REF_ISSYMREF) {
if (update->flags & REF_NO_DEREF) {
/*
@ -2829,13 +2832,16 @@ static int files_transaction_prepare(struct ref_store *ref_store,
*/
for (i = 0; i < transaction->nr; i++) {
struct ref_update *update = transaction->updates[i];
struct string_list_item *item =
string_list_append(&affected_refnames, update->refname);
struct string_list_item *item;
if ((update->flags & REF_IS_PRUNING) &&
!(update->flags & REF_NO_DEREF))
BUG("REF_IS_PRUNING set without REF_NO_DEREF");
if (update->flags & REF_LOG_ONLY)
continue;
item = string_list_append(&affected_refnames, update->refname);
/*
* We store a pointer to update in item->util, but at
* the moment we never use the value of this field
@ -3035,8 +3041,9 @@ static int files_transaction_finish_initial(struct files_ref_store *refs,
/* Fail if a refname appears more than once in the transaction: */
for (i = 0; i < transaction->nr; i++)
string_list_append(&affected_refnames,
transaction->updates[i]->refname);
if (!(transaction->updates[i]->flags & REF_LOG_ONLY))
string_list_append(&affected_refnames,
transaction->updates[i]->refname);
string_list_sort(&affected_refnames);
if (ref_update_reject_duplicates(&affected_refnames, err)) {
ret = TRANSACTION_GENERIC_ERROR;