From 2bdc785fd7f699669a582f7a83f5b81192d24d88 Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <sahlberg@google.com>
Date: Tue, 29 Apr 2014 12:06:19 -0700
Subject: [PATCH] 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>
---
refs.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index 9cb79081b5..cc6305630c 100644
--- a/refs.c
+++ b/refs.c
@@ -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+ * CLOSED: A closed transaction is no longer active and no other operations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);