Track the state of a transaction in a new state field. Check the field for
sanity, i.e. that state must be OPEN when _commit/_create/_delete or
_update is called or else die(BUG:...)
Signed-off-by: Ronnie Sahlberg <sahlb...@google.com>
---
refs.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index 9cb7908..d015285 100644
--- a/refs.c
+++ b/refs.c
@@ -3387,6 +3387,25 @@ struct ref_update {
};
/*
+ * Transaction states.
+ * OPEN: The transaction is in a valid state and can accept new updates.
+ * An OPEN transaction can be committed.
+ * CLOSED: If an open transaction is successfully committed the state will
+ * change to CLOSED. No further changes can be made to a CLOSED
+ * transaction.
+ * CLOSED means that all updates have been successfully committed and
+ * the only thing that remains is to free the completed transaction.
+ * ERROR: The transaction has failed and is no longer committable.
+ * No further changes can be made to a CLOSED transaction and it must
+ * be rolled back using transaction_free.
+ */
+enum ref_transaction_state {
+ REF_TRANSACTION_OPEN = 0,
+ REF_TRANSACTION_CLOSED = 1,
+ REF_TRANSACTION_ERROR = 2,
+};
+
+/*
* Data structure for holding a reference transaction, which can
* consist of checks and updates to multiple references, carried out
* as atomically as possible. This structure is opaque to callers.
@@ -3395,6 +3414,7 @@ struct ref_transaction {
struct ref_update **updates;
size_t alloc;
size_t nr;
+ enum ref_transaction_state state;
};
struct ref_transaction *ref_transaction_begin(struct strbuf *err)
@@ -3437,6 +3457,9 @@ int ref_transaction_update(struct ref_transaction
*transaction,
{
struct ref_update *update;
+ if (transaction->state != REF_TRANSACTION_OPEN)
+ die("BUG: update called for transaction that is not open");
+
if (have_old && !old_sha1)
die("BUG: have_old is true but old_sha1 is NULL");
@@ -3457,6 +3480,9 @@ int ref_transaction_create(struct ref_transaction
*transaction,
{
struct ref_update *update;
+ if (transaction->state != REF_TRANSACTION_OPEN)
+ die("BUG: create called for transaction that is not open");
+
if (!new_sha1 || is_null_sha1(new_sha1))
die("BUG: create ref with null new_sha1");
@@ -3477,6 +3503,9 @@ int ref_transaction_delete(struct ref_transaction
*transaction,
{
struct ref_update *update;
+ if (transaction->state != REF_TRANSACTION_OPEN)
+ die("BUG: delete called for transaction that is not open");
+
if (have_old && !old_sha1)
die("BUG: have_old is true but old_sha1 is NULL");
@@ -3532,8 +3561,13 @@ int ref_transaction_commit(struct ref_transaction
*transaction,
int n = transaction->nr;
struct ref_update **updates = transaction->updates;
- if (!n)
+ if (transaction->state != REF_TRANSACTION_OPEN)
+ die("BUG: commit called for transaction that is not open");
+
+ if (!n) {
+ transaction->state = REF_TRANSACTION_CLOSED;
return 0;
+ }
/* Allocate work space */
delnames = xmalloc(sizeof(*delnames) * n);
@@ -3595,6 +3629,9 @@ int ref_transaction_commit(struct ref_transaction
*transaction,
clear_loose_ref_cache(&ref_cache);
cleanup:
+ transaction->state = ret ? REF_TRANSACTION_ERROR
+ : REF_TRANSACTION_CLOSED;
+
for (i = 0; i < n; i++)
if (updates[i]->lock)
unlock_ref(updates[i]->lock);
--
2.0.1.442.g7fe6834.dirty
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