On Thu, May 1, 2014 at 4:37 PM, Ronnie Sahlberg <sahlb...@google.com> wrote:
> Allow passing a list of refs to ckip checking to name_conflict_fn.
s/ckip/skip/
> There are some conditions where we want to allow a temporary conflict and skip
> checking those refs. For example if we have a transaction that
> 1, guarantees that m is a packed refs and there is no loose ref for m
> 2, the transaction will delete m from the packed ref
> 3, the transaction will create conflicting m/m
>
> For this case we want to be able to lock anc create m/m since we know that the
s/anc/and/
> conflict is only transient. I.e. the conflict will be automatically resolved
> by the transaction when it deletes m.
>
> Signed-off-by: Ronnie Sahlberg <sahlb...@google.com>
> ---
> refs.c | 43 +++++++++++++++++++++++++++++++++----------
> 1 file changed, 33 insertions(+), 10 deletions(-)
>
> diff --git a/refs.c b/refs.c
> index b525076..eb75927 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -789,11 +789,19 @@ struct name_conflict_cb {
> const char *refname;
> const char *oldrefname;
> const char *conflicting_refname;
> + const char **skip;
> + int skipnum;
> };
>
> static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
> {
> struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
> + int i;
> + for(i = 0; i < data->skipnum; i++) {
> + if (!strcmp(entry->name, data->skip[i])) {
> + return 0;
> + }
> + }
> if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
> return 0;
> if (names_conflict(data->refname, entry->name)) {
> @@ -808,15 +816,21 @@ static int name_conflict_fn(struct ref_entry *entry,
> void *cb_data)
> * conflicting with the name of an existing reference in dir. If
> * oldrefname is non-NULL, ignore potential conflicts with oldrefname
> * (e.g., because oldrefname is scheduled for deletion in the same
> - * operation).
> + * operation). skip contains a list of refs we want to skip checking for
> + * conflicts with. Refs may be skipped due to us knowing that it will
> + * be deleted later during a transaction that deletes one reference and then
> + * creates a new conflicting reference. For example a rename from m to m/m.
> */
> static int is_refname_available(const char *refname, const char *oldrefname,
> - struct ref_dir *dir)
> + struct ref_dir *dir,
> + const char **skip, int skipnum)
> {
> struct name_conflict_cb data;
> data.refname = refname;
> data.oldrefname = oldrefname;
> data.conflicting_refname = NULL;
> + data.skip = skip;
> + data.skipnum = skipnum;
>
> sort_ref_dir(dir);
> if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
> @@ -2032,7 +2046,8 @@ int dwim_log(const char *str, int len, unsigned char
> *sha1, char **log)
>
> static struct ref_lock *lock_ref_sha1_basic(const char *refname,
> const unsigned char *old_sha1,
> - int flags, int *type_p)
> + int flags, int *type_p,
> + const char **skip, int skipnum)
> {
> char *ref_file;
> const char *orig_refname = refname;
> @@ -2079,7 +2094,9 @@ static struct ref_lock *lock_ref_sha1_basic(const char
> *refname,
> * name is a proper prefix of our refname.
> */
> if (missing &&
> - !is_refname_available(refname, NULL,
> get_packed_refs(&ref_cache))) {
> + !is_refname_available(refname, NULL,
> + get_packed_refs(&ref_cache),
> + skip, skipnum)) {
> last_errno = ENOTDIR;
> goto error_return;
> }
> @@ -2137,7 +2154,7 @@ struct ref_lock *lock_any_ref_for_update(const char
> *refname,
> const unsigned char *old_sha1,
> int flags, int *type_p)
> {
> - return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
> + return lock_ref_sha1_basic(refname, old_sha1, flags, type_p, NULL, 0);
> }
>
> /*
> @@ -2576,6 +2593,9 @@ int rename_ref(const char *oldrefname, const char
> *newrefname, const char *logms
> int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
> const char *symref = NULL;
>
> + if (!strcmp(oldrefname, newrefname))
> + return 0;
> +
> if (log && S_ISLNK(loginfo.st_mode))
> return error("reflog for %s is a symlink", oldrefname);
>
> @@ -2586,10 +2606,12 @@ int rename_ref(const char *oldrefname, const char
> *newrefname, const char *logms
> if (!symref)
> return error("refname %s not found", oldrefname);
>
> - if (!is_refname_available(newrefname, oldrefname,
> get_packed_refs(&ref_cache)))
> + if (!is_refname_available(newrefname, oldrefname,
> + get_packed_refs(&ref_cache), NULL, 0))
> return 1;
>
> - if (!is_refname_available(newrefname, oldrefname,
> get_loose_refs(&ref_cache)))
> + if (!is_refname_available(newrefname, oldrefname,
> + get_loose_refs(&ref_cache), NULL, 0))
> return 1;
>
> if (log && rename(git_path("logs/%s", oldrefname),
> git_path(TMP_RENAMED_LOG)))
> @@ -2622,7 +2644,7 @@ int rename_ref(const char *oldrefname, const char
> *newrefname, const char *logms
>
> logmoved = log;
>
> - lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
> + lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL, NULL, 0);
> if (!lock) {
> error("unable to lock %s for update", newrefname);
> goto rollback;
> @@ -2637,7 +2659,7 @@ int rename_ref(const char *oldrefname, const char
> *newrefname, const char *logms
> return 0;
>
> rollback:
> - lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
> + lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL, NULL, 0);
> if (!lock) {
> error("unable to lock %s for rollback", oldrefname);
> goto rollbacklog;
> @@ -3483,7 +3505,8 @@ int ref_transaction_commit(struct ref_transaction
> *transaction,
> update->old_sha1 :
> NULL),
> update->flags,
> - &update->type);
> + &update->type,
> + delnames, delnum);
> if (!update->lock) {
> if (err)
> strbuf_addf(err ,"Cannot lock the ref '%s'.",
> --
> 2.0.0.rc1.351.g4d2c8e4
>
> --
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