From 5fe7d825da8af83a9a3b9bc7f3295f836b6e3a75 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Thu, 1 May 2014 11:16:07 -0700 Subject: [PATCH] refs.c: pass a list of names to skip to is_refname_available Change is_refname_available to take a list of strings to exclude when checking for conflicts instead of just one single name. We can already exclude a single name for the sake of renames. This generalizes that support. ref_transaction_commit already tracks a set of refs that are being deleted in an array. This array is then used to exclude refs from being written to the packed-refs file. At some stage we will want to change this array to a struct string_list and then we can pass it to is_refname_available via the call to lock_ref_sha1_basic. That will allow us to perform transactions that perform multiple renames as long as there are no conflicts within the starting or ending state. For example, that would allow a single transaction that contains two renames that are both individually conflicting: m -> n/n n -> m/m No functional change intended yet. Signed-off-by: Ronnie Sahlberg Signed-off-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- refs.c | 50 ++++++++++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 18 deletions(-) diff --git a/refs.c b/refs.c index b591b9c321..a007cf3257 100644 --- a/refs.c +++ b/refs.c @@ -787,13 +787,13 @@ static void prime_ref_dir(struct ref_dir *dir) } } -static int entry_matches(struct ref_entry *entry, const char *refname) +static int entry_matches(struct ref_entry *entry, const struct string_list *list) { - return refname && !strcmp(entry->name, refname); + return list && string_list_has_string(list, entry->name); } struct nonmatching_ref_data { - const char *skip; + const struct string_list *skip; struct ref_entry *found; }; @@ -817,16 +817,19 @@ static void report_refname_conflict(struct ref_entry *entry, /* * Return true iff a reference named refname could be created without * 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 + * skip is non-NULL, ignore potential conflicts with refs in skip + * (e.g., because they are scheduled for deletion in the same * operation). * * Two reference names conflict if one of them exactly matches the * leading components of the other; e.g., "foo/bar" conflicts with * both "foo" and with "foo/bar/baz" but not with "foo/bar" or * "foo/barbados". + * + * skip must be sorted. */ -static int is_refname_available(const char *refname, const char *oldrefname, +static int is_refname_available(const char *refname, + const struct string_list *skip, struct ref_dir *dir) { const char *slash; @@ -840,12 +843,12 @@ static int is_refname_available(const char *refname, const char *oldrefname, * looking for a conflict with a leaf entry. * * If we find one, we still must make sure it is - * not "oldrefname". + * not in "skip". */ pos = search_ref_dir(dir, refname, slash - refname); if (pos >= 0) { struct ref_entry *entry = dir->entries[pos]; - if (entry_matches(entry, oldrefname)) + if (entry_matches(entry, skip)) return 1; report_refname_conflict(entry, refname); return 0; @@ -878,13 +881,13 @@ static int is_refname_available(const char *refname, const char *oldrefname, /* * We found a directory named "refname". It is a * problem iff it contains any ref that is not - * "oldrefname". + * in "skip". */ struct ref_entry *entry = dir->entries[pos]; struct ref_dir *dir = get_ref_dir(entry); struct nonmatching_ref_data data; - data.skip = oldrefname; + data.skip = skip; sort_ref_dir(dir); if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) return 1; @@ -2139,6 +2142,7 @@ 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, + const struct string_list *skip, int flags, int *type_p) { char *ref_file; @@ -2188,7 +2192,7 @@ 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, skip, get_packed_refs(&ref_cache))) { last_errno = ENOTDIR; goto error_return; } @@ -2246,7 +2250,7 @@ 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, NULL, flags, type_p); } /* @@ -2690,6 +2694,18 @@ static int rename_tmp_log(const char *newrefname) return 0; } +static int rename_ref_available(const char *oldname, const char *newname) +{ + struct string_list skip = STRING_LIST_INIT_NODUP; + int ret; + + string_list_insert(&skip, oldname); + ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache)) + && is_refname_available(newname, &skip, get_loose_refs(&ref_cache)); + string_list_clear(&skip, 0); + return ret; +} + int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) { unsigned char sha1[20], orig_sha1[20]; @@ -2709,10 +2725,7 @@ 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))) - return 1; - - if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache))) + if (!rename_ref_available(oldrefname, newrefname)) return 1; if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) @@ -2742,7 +2755,7 @@ 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, NULL, 0, NULL); if (!lock) { error("unable to lock %s for update", newrefname); goto rollback; @@ -2757,7 +2770,7 @@ 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, NULL, 0, NULL); if (!lock) { error("unable to lock %s for rollback", oldrefname); goto rollbacklog; @@ -3636,6 +3649,7 @@ int ref_transaction_commit(struct ref_transaction *transaction, (update->have_old ? update->old_sha1 : NULL), + NULL, update->flags, &update->type); if (!update->lock) { -- 2.43.2