refs.c: add transaction.status and track OPEN/CLOSED

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 <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Ronnie Sahlberg 2014-04-29 12:06:19 -07:00 committed by Junio C Hamano
parent 93a644ea9d
commit 2bdc785fd7

34
refs.c
View file

@ -3386,6 +3386,21 @@ struct ref_update {
const char refname[FLEX_ARRAY];
};
/*
* Transaction states.
* OPEN: The transaction is in a valid state and can accept new updates.
* An OPEN transaction can be committed.
* CLOSED: A closed transaction is no longer active and no other operations
* than free can be used on it in this state.
* A transaction can either become closed by successfully committing
* an active transaction or if there is a failure while building
* the transaction thus rendering it failed/inactive.
*/
enum ref_transaction_state {
REF_TRANSACTION_OPEN = 0,
REF_TRANSACTION_CLOSED = 1
};
/*
* Data structure for holding a reference transaction, which can
* consist of checks and updates to multiple references, carried out
@ -3395,6 +3410,7 @@ 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 +3453,9 @@ 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 +3476,9 @@ 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 +3499,9 @@ 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 +3557,13 @@ 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 +3625,8 @@ int ref_transaction_commit(struct ref_transaction *transaction,
clear_loose_ref_cache(&ref_cache);
cleanup:
transaction->state = REF_TRANSACTION_CLOSED;
for (i = 0; i < n; i++)
if (updates[i]->lock)
unlock_ref(updates[i]->lock);