Always handle non-normal (per-worktree or pseudo) refs in the files
backend instead of alternate backends.
Sometimes a ref transaction will update both a per-worktree ref and a
normal ref. For instance, an ordinary commit might update
refs/heads/master and HEAD (or at least HEAD's reflog).
Updates to normal refs continue to go through the chosen backend.
Updates to non-normal refs are moved to a separate files backend
transaction.
Signed-off-by: David Turner <dturner@xxxxxxxxxxxxxxxx>
---
refs.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++--
refs/refs-internal.h | 2 ++
2 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/refs.c b/refs.c
index 2496b91..67b0280 100644
--- a/refs.c
+++ b/refs.c
@@ -9,6 +9,11 @@
#include "object.h"
#include "tag.h"
+static const char split_transaction_fail_warning[] =
+ "A ref transaction was split across two refs backends. Part of the "
+ "transaction succeeded, but then the update to the per-worktree refs "
+ "failed. Your repository may be in an inconsistent state.";
+
/*
* We always have a files backend and it is the default.
*/
@@ -781,6 +786,13 @@ void ref_transaction_free(struct ref_transaction *transaction)
free(transaction);
}
+static void add_update_obj(struct ref_transaction *transaction,
+ struct ref_update *update)
+{
+ ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
+ transaction->updates[transaction->nr++] = update;
+}
+
static struct ref_update *add_update(struct ref_transaction *transaction,
const char *refname)
{
@@ -788,8 +800,7 @@ static struct ref_update *add_update(struct ref_transaction *transaction,
struct ref_update *update = xcalloc(1, sizeof(*update) + len);
memcpy((char *)update->refname, refname, len); /* includes NUL */
- ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
- transaction->updates[transaction->nr++] = update;
+ add_update_obj(transaction, update);
return update;
}
@@ -1192,11 +1203,39 @@ static int dereference_symrefs(struct ref_transaction *transaction,
return 0;
}
+/*
+ * Move all non-normal ref updates into a specially-created
+ * files-backend transaction
+ */
+static int move_abnormal_ref_updates(struct ref_transaction *transaction,
+ struct ref_transaction *files_transaction,
+ struct strbuf *err)
+{
+ int i;
+
+ for (i = 0; i < transaction->nr; i++) {
+ int last;
+ struct ref_update *update = transaction->updates[i];
+
+ if (ref_type(update->refname) == REF_TYPE_NORMAL)
+ continue;
+
+ last = --transaction->nr;
+ transaction->updates[i] = transaction->updates[last];
+ files_transaction->updates[files_transaction->nr++] = update;
+ }
+
+ return 0;
+}
+
int ref_transaction_commit(struct ref_transaction *transaction,
struct strbuf *err)
{
int ret = -1;
struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
+ struct string_list files_affected_refnames = STRING_LIST_INIT_NODUP;
+ struct string_list_item *item;
+ struct ref_transaction *files_transaction = NULL;
assert(err);
@@ -1212,6 +1251,26 @@ int ref_transaction_commit(struct ref_transaction *transaction,
if (ret)
goto done;
+ if (the_refs_backend != &refs_be_files) {
+ files_transaction = ref_transaction_begin(err);
+ if (!files_transaction)
+ goto done;
+
+ ret = move_abnormal_ref_updates(transaction, files_transaction,
+ err);
+ if (ret)
+ goto done;
+
+ /* files backend commit */
+ if (get_affected_refnames(files_transaction,
+ &files_affected_refnames,
+ err)) {
+ ret = TRANSACTION_GENERIC_ERROR;
+ goto done;
+ }
+ }
+
+ /* main backend commit */
if (get_affected_refnames(transaction, &affected_refnames, err)) {
ret = TRANSACTION_GENERIC_ERROR;
goto done;
@@ -1219,8 +1278,24 @@ int ref_transaction_commit(struct ref_transaction *transaction,
ret = the_refs_backend->transaction_commit(transaction,
&affected_refnames, err);
+ if (ret)
+ goto done;
+
+ if (files_transaction) {
+ ret = refs_be_files.transaction_commit(files_transaction,
+ &files_affected_refnames,
+ err);
+ if (ret) {
+ warning(split_transaction_fail_warning);
+ goto done;
+ }
+ }
+
done:
string_list_clear(&affected_refnames, 0);
+ string_list_clear(&files_affected_refnames, 0);
+ if (files_transaction)
+ ref_transaction_free(files_transaction);
return ret;
}
@@ -1276,6 +1351,9 @@ int peel_ref(const char *refname, unsigned char *sha1)
int create_symref(const char *ref_target, const char *refs_heads_master,
const char *logmsg)
{
+ if (ref_type(ref_target) != REF_TYPE_NORMAL)
+ return refs_be_files.create_symref(ref_target, refs_heads_master,
+ logmsg);
return the_refs_backend->create_symref(ref_target, refs_heads_master,
logmsg);
}
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 971f450..dd035f5 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -323,4 +323,6 @@ struct ref_storage_be {
for_each_replace_ref_fn *for_each_replace_ref;
};
+extern struct ref_storage_be refs_be_files;
+
#endif /* REFS_REFS_INTERNAL_H */
--
2.4.2.749.g730654d-twtrsrc
--
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