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Diffstat (limited to 'refs.c')
-rw-r--r--refs.c195
1 files changed, 150 insertions, 45 deletions
diff --git a/refs.c b/refs.c
index 28d5eca..728a761 100644
--- a/refs.c
+++ b/refs.c
@@ -3243,9 +3243,9 @@ static struct ref_lock *update_ref_lock(const char *refname,
if (!lock) {
const char *str = "Cannot lock the ref '%s'.";
switch (onerr) {
- case MSG_ON_ERR: error(str, refname); break;
- case DIE_ON_ERR: die(str, refname); break;
- case QUIET_ON_ERR: break;
+ case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
+ case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
+ case UPDATE_REFS_QUIET_ON_ERR: break;
}
}
return lock;
@@ -3258,15 +3258,118 @@ static int update_ref_write(const char *action, const char *refname,
if (write_ref_sha1(lock, sha1, action) < 0) {
const char *str = "Cannot update the ref '%s'.";
switch (onerr) {
- case MSG_ON_ERR: error(str, refname); break;
- case DIE_ON_ERR: die(str, refname); break;
- case QUIET_ON_ERR: break;
+ case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
+ case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
+ case UPDATE_REFS_QUIET_ON_ERR: break;
}
return 1;
}
return 0;
}
+/**
+ * Information needed for a single ref update. Set new_sha1 to the
+ * new value or to zero to delete the ref. To check the old value
+ * while locking the ref, set have_old to 1 and set old_sha1 to the
+ * value or to zero to ensure the ref does not exist before update.
+ */
+struct ref_update {
+ unsigned char new_sha1[20];
+ unsigned char old_sha1[20];
+ int flags; /* REF_NODEREF? */
+ int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
+ struct ref_lock *lock;
+ int type;
+ const char refname[FLEX_ARRAY];
+};
+
+/*
+ * 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.
+ */
+struct ref_transaction {
+ struct ref_update **updates;
+ size_t alloc;
+ size_t nr;
+};
+
+struct ref_transaction *ref_transaction_begin(void)
+{
+ return xcalloc(1, sizeof(struct ref_transaction));
+}
+
+static void ref_transaction_free(struct ref_transaction *transaction)
+{
+ int i;
+
+ for (i = 0; i < transaction->nr; i++)
+ free(transaction->updates[i]);
+
+ free(transaction->updates);
+ free(transaction);
+}
+
+void ref_transaction_rollback(struct ref_transaction *transaction)
+{
+ ref_transaction_free(transaction);
+}
+
+static struct ref_update *add_update(struct ref_transaction *transaction,
+ const char *refname)
+{
+ size_t len = strlen(refname);
+ struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
+
+ strcpy((char *)update->refname, refname);
+ ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
+ transaction->updates[transaction->nr++] = update;
+ return update;
+}
+
+void ref_transaction_update(struct ref_transaction *transaction,
+ const char *refname,
+ unsigned char *new_sha1, unsigned char *old_sha1,
+ int flags, int have_old)
+{
+ struct ref_update *update = add_update(transaction, refname);
+
+ hashcpy(update->new_sha1, new_sha1);
+ update->flags = flags;
+ update->have_old = have_old;
+ if (have_old)
+ hashcpy(update->old_sha1, old_sha1);
+}
+
+void ref_transaction_create(struct ref_transaction *transaction,
+ const char *refname,
+ unsigned char *new_sha1,
+ int flags)
+{
+ struct ref_update *update = add_update(transaction, refname);
+
+ assert(!is_null_sha1(new_sha1));
+ hashcpy(update->new_sha1, new_sha1);
+ hashclr(update->old_sha1);
+ update->flags = flags;
+ update->have_old = 1;
+}
+
+void ref_transaction_delete(struct ref_transaction *transaction,
+ const char *refname,
+ unsigned char *old_sha1,
+ int flags, int have_old)
+{
+ struct ref_update *update = add_update(transaction, refname);
+
+ update->flags = flags;
+ update->have_old = have_old;
+ if (have_old) {
+ assert(!is_null_sha1(old_sha1));
+ hashcpy(update->old_sha1, old_sha1);
+ }
+}
+
int update_ref(const char *action, const char *refname,
const unsigned char *sha1, const unsigned char *oldval,
int flags, enum action_on_err onerr)
@@ -3282,7 +3385,7 @@ static int ref_update_compare(const void *r1, const void *r2)
{
const struct ref_update * const *u1 = r1;
const struct ref_update * const *u2 = r2;
- return strcmp((*u1)->ref_name, (*u2)->ref_name);
+ return strcmp((*u1)->refname, (*u2)->refname);
}
static int ref_update_reject_duplicates(struct ref_update **updates, int n,
@@ -3290,15 +3393,15 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
{
int i;
for (i = 1; i < n; i++)
- if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
+ if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
const char *str =
"Multiple updates for ref '%s' not allowed.";
switch (onerr) {
- case MSG_ON_ERR:
- error(str, updates[i]->ref_name); break;
- case DIE_ON_ERR:
- die(str, updates[i]->ref_name); break;
- case QUIET_ON_ERR:
+ case UPDATE_REFS_MSG_ON_ERR:
+ error(str, updates[i]->refname); break;
+ case UPDATE_REFS_DIE_ON_ERR:
+ die(str, updates[i]->refname); break;
+ case UPDATE_REFS_QUIET_ON_ERR:
break;
}
return 1;
@@ -3306,26 +3409,21 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
return 0;
}
-int update_refs(const char *action, const struct ref_update **updates_orig,
- int n, enum action_on_err onerr)
+int ref_transaction_commit(struct ref_transaction *transaction,
+ const char *msg, enum action_on_err onerr)
{
int ret = 0, delnum = 0, i;
- struct ref_update **updates;
- int *types;
- struct ref_lock **locks;
const char **delnames;
+ int n = transaction->nr;
+ struct ref_update **updates = transaction->updates;
- if (!updates_orig || !n)
+ if (!n)
return 0;
/* Allocate work space */
- updates = xmalloc(sizeof(*updates) * n);
- types = xmalloc(sizeof(*types) * n);
- locks = xcalloc(n, sizeof(*locks));
delnames = xmalloc(sizeof(*delnames) * n);
/* Copy, sort, and reject duplicate refs */
- memcpy(updates, updates_orig, sizeof(*updates) * n);
qsort(updates, n, sizeof(*updates), ref_update_compare);
ret = ref_update_reject_duplicates(updates, n, onerr);
if (ret)
@@ -3333,35 +3431,44 @@ int update_refs(const char *action, const struct ref_update **updates_orig,
/* Acquire all locks while verifying old values */
for (i = 0; i < n; i++) {
- locks[i] = update_ref_lock(updates[i]->ref_name,
- (updates[i]->have_old ?
- updates[i]->old_sha1 : NULL),
- updates[i]->flags,
- &types[i], onerr);
- if (!locks[i]) {
+ struct ref_update *update = updates[i];
+
+ update->lock = update_ref_lock(update->refname,
+ (update->have_old ?
+ update->old_sha1 : NULL),
+ update->flags,
+ &update->type, onerr);
+ if (!update->lock) {
ret = 1;
goto cleanup;
}
}
/* Perform updates first so live commits remain referenced */
- for (i = 0; i < n; i++)
- if (!is_null_sha1(updates[i]->new_sha1)) {
- ret = update_ref_write(action,
- updates[i]->ref_name,
- updates[i]->new_sha1,
- locks[i], onerr);
- locks[i] = NULL; /* freed by update_ref_write */
+ for (i = 0; i < n; i++) {
+ struct ref_update *update = updates[i];
+
+ if (!is_null_sha1(update->new_sha1)) {
+ ret = update_ref_write(msg,
+ update->refname,
+ update->new_sha1,
+ update->lock, onerr);
+ update->lock = NULL; /* freed by update_ref_write */
if (ret)
goto cleanup;
}
+ }
/* Perform deletes now that updates are safely completed */
- for (i = 0; i < n; i++)
- if (locks[i]) {
- delnames[delnum++] = locks[i]->ref_name;
- ret |= delete_ref_loose(locks[i], types[i]);
+ for (i = 0; i < n; i++) {
+ struct ref_update *update = updates[i];
+
+ if (update->lock) {
+ delnames[delnum++] = update->lock->ref_name;
+ ret |= delete_ref_loose(update->lock, update->type);
}
+ }
+
ret |= repack_without_refs(delnames, delnum);
for (i = 0; i < delnum; i++)
unlink_or_warn(git_path("logs/%s", delnames[i]));
@@ -3369,12 +3476,10 @@ int update_refs(const char *action, const struct ref_update **updates_orig,
cleanup:
for (i = 0; i < n; i++)
- if (locks[i])
- unlock_ref(locks[i]);
- free(updates);
- free(types);
- free(locks);
+ if (updates[i]->lock)
+ unlock_ref(updates[i]->lock);
free(delnames);
+ ref_transaction_free(transaction);
return ret;
}