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-rw-r--r--refs/files-backend.c248
-rw-r--r--refs/packed-backend.c124
-rw-r--r--refs/packed-backend.h9
-rw-r--r--refs/ref-cache.c6
-rw-r--r--refs/refs-internal.h101
5 files changed, 312 insertions, 176 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 8cc1e07fdb..f75d960e19 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -10,6 +10,51 @@
#include "../object.h"
#include "../dir.h"
+/*
+ * This backend uses the following flags in `ref_update::flags` for
+ * internal bookkeeping purposes. Their numerical values must not
+ * conflict with REF_NO_DEREF, REF_FORCE_CREATE_REFLOG, REF_HAVE_NEW,
+ * REF_HAVE_OLD, or REF_IS_PRUNING, which are also stored in
+ * `ref_update::flags`.
+ */
+
+/*
+ * Used as a flag in ref_update::flags when a loose ref is being
+ * pruned. This flag must only be used when REF_NO_DEREF is set.
+ */
+#define REF_IS_PRUNING (1 << 4)
+
+/*
+ * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
+ * refs (i.e., because the reference is about to be deleted anyway).
+ */
+#define REF_DELETING (1 << 5)
+
+/*
+ * Used as a flag in ref_update::flags when the lockfile needs to be
+ * committed.
+ */
+#define REF_NEEDS_COMMIT (1 << 6)
+
+/*
+ * Used as a flag in ref_update::flags when we want to log a ref
+ * update but not actually perform it. This is used when a symbolic
+ * ref update is split up.
+ */
+#define REF_LOG_ONLY (1 << 7)
+
+/*
+ * Used as a flag in ref_update::flags when the ref_update was via an
+ * update to HEAD.
+ */
+#define REF_UPDATE_VIA_HEAD (1 << 8)
+
+/*
+ * Used as a flag in ref_update::flags when the loose reference has
+ * been deleted.
+ */
+#define REF_DELETED_LOOSE (1 << 9)
+
struct ref_lock {
char *ref_name;
struct lock_file lk;
@@ -189,13 +234,13 @@ static void loose_fill_ref_dir(struct ref_store *ref_store,
if (!refs_resolve_ref_unsafe(&refs->base,
refname.buf,
RESOLVE_REF_READING,
- oid.hash, &flag)) {
+ &oid, &flag)) {
oidclr(&oid);
flag |= REF_ISBROKEN;
} else if (is_null_oid(&oid)) {
/*
* It is so astronomically unlikely
- * that NULL_SHA1 is the SHA-1 of an
+ * that null_oid is the OID of an
* actual object that we consider its
* appearance in a loose reference
* file to be repo corruption
@@ -261,7 +306,7 @@ static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)
}
static int files_read_raw_ref(struct ref_store *ref_store,
- const char *refname, unsigned char *sha1,
+ const char *refname, struct object_id *oid,
struct strbuf *referent, unsigned int *type)
{
struct files_ref_store *refs =
@@ -270,6 +315,7 @@ static int files_read_raw_ref(struct ref_store *ref_store,
struct strbuf sb_path = STRBUF_INIT;
const char *path;
const char *buf;
+ const char *p;
struct stat st;
int fd;
int ret = -1;
@@ -304,7 +350,7 @@ stat_ref:
if (errno != ENOENT)
goto out;
if (refs_read_raw_ref(refs->packed_ref_store, refname,
- sha1, referent, type)) {
+ oid, referent, type)) {
errno = ENOENT;
goto out;
}
@@ -344,7 +390,7 @@ stat_ref:
* packed ref:
*/
if (refs_read_raw_ref(refs->packed_ref_store, refname,
- sha1, referent, type)) {
+ oid, referent, type)) {
errno = EISDIR;
goto out;
}
@@ -390,8 +436,8 @@ stat_ref:
* Please note that FETCH_HEAD has additional
* data after the sha.
*/
- if (get_sha1_hex(buf, sha1) ||
- (buf[40] != '\0' && !isspace(buf[40]))) {
+ if (parse_oid_hex(buf, oid, &p) ||
+ (*p != '\0' && !isspace(*p))) {
*type |= REF_ISBROKEN;
errno = EINVAL;
goto out;
@@ -427,7 +473,7 @@ static void unlock_ref(struct ref_lock *lock)
* are passed to refs_verify_refname_available() for this check.
*
* If mustexist is not set and the reference is not found or is
- * broken, lock the reference anyway but clear sha1.
+ * broken, lock the reference anyway but clear old_oid.
*
* Return 0 on success. On failure, write an error message to err and
* return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
@@ -545,7 +591,7 @@ retry:
*/
if (files_read_raw_ref(&refs->base, refname,
- lock->old_oid.hash, referent, type)) {
+ &lock->old_oid, referent, type)) {
if (errno == ENOENT) {
if (mustexist) {
/* Garden variety missing reference. */
@@ -769,21 +815,21 @@ static struct ref_iterator *files_ref_iterator_begin(
}
/*
- * Verify that the reference locked by lock has the value old_sha1.
- * Fail if the reference doesn't exist and mustexist is set. Return 0
- * on success. On error, write an error message to err, set errno, and
- * return a negative value.
+ * Verify that the reference locked by lock has the value old_oid
+ * (unless it is NULL). Fail if the reference doesn't exist and
+ * mustexist is set. Return 0 on success. On error, write an error
+ * message to err, set errno, and return a negative value.
*/
static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
- const unsigned char *old_sha1, int mustexist,
+ const struct object_id *old_oid, int mustexist,
struct strbuf *err)
{
assert(err);
if (refs_read_ref_full(ref_store, lock->ref_name,
mustexist ? RESOLVE_REF_READING : 0,
- lock->old_oid.hash, NULL)) {
- if (old_sha1) {
+ &lock->old_oid, NULL)) {
+ if (old_oid) {
int save_errno = errno;
strbuf_addf(err, "can't verify ref '%s'", lock->ref_name);
errno = save_errno;
@@ -793,11 +839,11 @@ static int verify_lock(struct ref_store *ref_store, struct ref_lock *lock,
return 0;
}
}
- if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
+ if (old_oid && oidcmp(&lock->old_oid, old_oid)) {
strbuf_addf(err, "ref '%s' is at %s but expected %s",
lock->ref_name,
oid_to_hex(&lock->old_oid),
- sha1_to_hex(old_sha1));
+ oid_to_hex(old_oid));
errno = EBUSY;
return -1;
}
@@ -827,22 +873,22 @@ static int create_reflock(const char *path, void *cb)
* Locks a ref returning the lock on success and NULL on failure.
* On failure errno is set to something meaningful.
*/
-static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
- const char *refname,
- const unsigned char *old_sha1,
- const struct string_list *extras,
- const struct string_list *skip,
- unsigned int flags, int *type,
- struct strbuf *err)
+static struct ref_lock *lock_ref_oid_basic(struct files_ref_store *refs,
+ const char *refname,
+ const struct object_id *old_oid,
+ const struct string_list *extras,
+ const struct string_list *skip,
+ unsigned int flags, int *type,
+ struct strbuf *err)
{
struct strbuf ref_file = STRBUF_INIT;
struct ref_lock *lock;
int last_errno = 0;
- int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
+ int mustexist = (old_oid && !is_null_oid(old_oid));
int resolve_flags = RESOLVE_REF_NO_RECURSE;
int resolved;
- files_assert_main_repository(refs, "lock_ref_sha1_basic");
+ files_assert_main_repository(refs, "lock_ref_oid_basic");
assert(err);
lock = xcalloc(1, sizeof(struct ref_lock));
@@ -855,7 +901,7 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
files_ref_path(refs, &ref_file, refname);
resolved = !!refs_resolve_ref_unsafe(&refs->base,
refname, resolve_flags,
- lock->old_oid.hash, type);
+ &lock->old_oid, type);
if (!resolved && errno == EISDIR) {
/*
* we are trying to lock foo but we used to
@@ -874,7 +920,7 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
}
resolved = !!refs_resolve_ref_unsafe(&refs->base,
refname, resolve_flags,
- lock->old_oid.hash, type);
+ &lock->old_oid, type);
}
if (!resolved) {
last_errno = errno;
@@ -908,7 +954,7 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
goto error_return;
}
- if (verify_lock(&refs->base, lock, old_sha1, mustexist, err)) {
+ if (verify_lock(&refs->base, lock, old_oid, mustexist, err)) {
last_errno = errno;
goto error_return;
}
@@ -926,7 +972,7 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,
struct ref_to_prune {
struct ref_to_prune *next;
- unsigned char sha1[20];
+ struct object_id oid;
char name[FLEX_ARRAY];
};
@@ -988,22 +1034,29 @@ static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
{
struct ref_transaction *transaction;
struct strbuf err = STRBUF_INIT;
+ int ret = -1;
if (check_refname_format(r->name, 0))
return;
transaction = ref_store_transaction_begin(&refs->base, &err);
- if (!transaction ||
- ref_transaction_delete(transaction, r->name, r->sha1,
- REF_ISPRUNING | REF_NODEREF, NULL, &err) ||
- ref_transaction_commit(transaction, &err)) {
- ref_transaction_free(transaction);
+ if (!transaction)
+ goto cleanup;
+ ref_transaction_add_update(
+ transaction, r->name,
+ REF_NO_DEREF | REF_HAVE_NEW | REF_HAVE_OLD | REF_IS_PRUNING,
+ &null_oid, &r->oid, NULL);
+ if (ref_transaction_commit(transaction, &err))
+ goto cleanup;
+
+ ret = 0;
+
+cleanup:
+ if (ret)
error("%s", err.buf);
- strbuf_release(&err);
- return;
- }
- ref_transaction_free(transaction);
strbuf_release(&err);
+ ref_transaction_free(transaction);
+ return;
}
/*
@@ -1079,8 +1132,8 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
* packed-refs transaction:
*/
if (ref_transaction_update(transaction, iter->refname,
- iter->oid->hash, NULL,
- REF_NODEREF, NULL, &err))
+ iter->oid, NULL,
+ REF_NO_DEREF, NULL, &err))
die("failure preparing to create packed reference %s: %s",
iter->refname, err.buf);
@@ -1088,7 +1141,7 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
if ((flags & PACK_REFS_PRUNE)) {
struct ref_to_prune *n;
FLEX_ALLOC_STR(n, name, iter->refname);
- hashcpy(n->sha1, iter->oid->hash);
+ oidcpy(&n->oid, iter->oid);
n->next = refs_to_prune;
refs_to_prune = n;
}
@@ -1251,7 +1304,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
if (!refs_resolve_ref_unsafe(&refs->base, oldrefname,
RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
- orig_oid.hash, &flag)) {
+ &orig_oid, &flag)) {
ret = error("refname %s not found", oldrefname);
goto out;
}
@@ -1283,7 +1336,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
}
if (!copy && refs_delete_ref(&refs->base, logmsg, oldrefname,
- orig_oid.hash, REF_NODEREF)) {
+ &orig_oid, REF_NO_DEREF)) {
error("unable to delete old %s", oldrefname);
goto rollback;
}
@@ -1297,9 +1350,9 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
*/
if (!copy && !refs_read_ref_full(&refs->base, newrefname,
RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
- oid.hash, NULL) &&
+ &oid, NULL) &&
refs_delete_ref(&refs->base, NULL, newrefname,
- NULL, REF_NODEREF)) {
+ NULL, REF_NO_DEREF)) {
if (errno == EISDIR) {
struct strbuf path = STRBUF_INIT;
int result;
@@ -1323,8 +1376,8 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
logmoved = log;
- lock = lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,
- REF_NODEREF, NULL, &err);
+ lock = lock_ref_oid_basic(refs, newrefname, NULL, NULL, NULL,
+ REF_NO_DEREF, NULL, &err);
if (!lock) {
if (copy)
error("unable to copy '%s' to '%s': %s", oldrefname, newrefname, err.buf);
@@ -1346,8 +1399,8 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
goto out;
rollback:
- lock = lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,
- REF_NODEREF, NULL, &err);
+ lock = lock_ref_oid_basic(refs, oldrefname, NULL, NULL, NULL,
+ REF_NO_DEREF, NULL, &err);
if (!lock) {
error("unable to lock %s for rollback: %s", oldrefname, err.buf);
strbuf_release(&err);
@@ -1595,9 +1648,8 @@ static int files_log_ref_write(struct files_ref_store *refs,
}
/*
- * Write sha1 into the open lockfile, then close the lockfile. On
- * errors, rollback the lockfile, fill in *err and
- * return -1.
+ * Write oid into the open lockfile, then close the lockfile. On
+ * errors, rollback the lockfile, fill in *err and return -1.
*/
static int write_ref_to_lockfile(struct ref_lock *lock,
const struct object_id *oid, struct strbuf *err)
@@ -1721,7 +1773,7 @@ static void update_symref_reflog(struct files_ref_store *refs,
struct object_id new_oid;
if (logmsg &&
!refs_read_ref_full(&refs->base, target,
- RESOLVE_REF_READING, new_oid.hash, NULL) &&
+ RESOLVE_REF_READING, &new_oid, NULL) &&
files_log_ref_write(refs, refname, &lock->old_oid,
&new_oid, logmsg, 0, &err)) {
error("%s", err.buf);
@@ -1762,9 +1814,9 @@ static int files_create_symref(struct ref_store *ref_store,
struct ref_lock *lock;
int ret;
- lock = lock_ref_sha1_basic(refs, refname, NULL,
- NULL, NULL, REF_NODEREF, NULL,
- &err);
+ lock = lock_ref_oid_basic(refs, refname, NULL,
+ NULL, NULL, REF_NO_DEREF, NULL,
+ &err);
if (!lock) {
error("%s", err.buf);
strbuf_release(&err);
@@ -2010,7 +2062,7 @@ static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
if (refs_read_ref_full(iter->ref_store,
diter->relative_path, 0,
- iter->oid.hash, &flags)) {
+ &iter->oid, &flags)) {
error("bad ref for %s", diter->path.buf);
continue;
}
@@ -2124,7 +2176,7 @@ static int split_head_update(struct ref_update *update,
struct ref_update *new_update;
if ((update->flags & REF_LOG_ONLY) ||
- (update->flags & REF_ISPRUNING) ||
+ (update->flags & REF_IS_PRUNING) ||
(update->flags & REF_UPDATE_VIA_HEAD))
return 0;
@@ -2147,8 +2199,8 @@ static int split_head_update(struct ref_update *update,
new_update = ref_transaction_add_update(
transaction, "HEAD",
- update->flags | REF_LOG_ONLY | REF_NODEREF,
- update->new_oid.hash, update->old_oid.hash,
+ update->flags | REF_LOG_ONLY | REF_NO_DEREF,
+ &update->new_oid, &update->old_oid,
update->msg);
/*
@@ -2166,8 +2218,8 @@ static int split_head_update(struct ref_update *update,
/*
* update is for a symref that points at referent and doesn't have
- * REF_NODEREF set. Split it into two updates:
- * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
+ * REF_NO_DEREF set. Split it into two updates:
+ * - The original update, but with REF_LOG_ONLY and REF_NO_DEREF set
* - A new, separate update for the referent reference
* Note that the new update will itself be subject to splitting when
* the iteration gets to it.
@@ -2212,17 +2264,17 @@ static int split_symref_update(struct files_ref_store *refs,
new_update = ref_transaction_add_update(
transaction, referent, new_flags,
- update->new_oid.hash, update->old_oid.hash,
+ &update->new_oid, &update->old_oid,
update->msg);
new_update->parent_update = update;
/*
* Change the symbolic ref update to log only. Also, it
- * doesn't need to check its old SHA-1 value, as that will be
+ * doesn't need to check its old OID value, as that will be
* done when new_update is processed.
*/
- update->flags |= REF_LOG_ONLY | REF_NODEREF;
+ update->flags |= REF_LOG_ONLY | REF_NO_DEREF;
update->flags &= ~REF_HAVE_OLD;
/*
@@ -2288,10 +2340,10 @@ static int check_old_oid(struct ref_update *update, struct object_id *oid,
* Prepare for carrying out update:
* - Lock the reference referred to by update.
* - Read the reference under lock.
- * - Check that its old SHA-1 value (if specified) is correct, and in
+ * - Check that its old OID value (if specified) is correct, and in
* any case record it in update->lock->old_oid for later use when
* writing the reflog.
- * - If it is a symref update without REF_NODEREF, split it up into a
+ * - If it is a symref update without REF_NO_DEREF, split it up into a
* REF_LOG_ONLY update of the symref and add a separate update for
* the referent to transaction.
* - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
@@ -2339,15 +2391,15 @@ static int lock_ref_for_update(struct files_ref_store *refs,
update->backend_data = lock;
if (update->type & REF_ISSYMREF) {
- if (update->flags & REF_NODEREF) {
+ if (update->flags & REF_NO_DEREF) {
/*
* We won't be reading the referent as part of
* the transaction, so we have to read it here
- * to record and possibly check old_sha1:
+ * to record and possibly check old_oid:
*/
if (refs_read_ref_full(&refs->base,
referent.buf, 0,
- lock->old_oid.hash, NULL)) {
+ &lock->old_oid, NULL)) {
if (update->flags & REF_HAVE_OLD) {
strbuf_addf(err, "cannot lock ref '%s': "
"error reading reference",
@@ -2363,7 +2415,7 @@ static int lock_ref_for_update(struct files_ref_store *refs,
/*
* Create a new update for the reference this
* symref is pointing at. Also, we will record
- * and verify old_sha1 for this update as part
+ * and verify old_oid for this update as part
* of processing the split-off update, so we
* don't have to do it here.
*/
@@ -2383,7 +2435,7 @@ static int lock_ref_for_update(struct files_ref_store *refs,
/*
* If this update is happening indirectly because of a
- * symref update, record the old SHA-1 in the parent
+ * symref update, record the old OID in the parent
* update:
*/
for (parent_update = update->parent_update;
@@ -2510,13 +2562,18 @@ static int files_transaction_prepare(struct ref_store *ref_store,
* transaction. (If we end up splitting up any updates using
* split_symref_update() or split_head_update(), those
* functions will check that the new updates don't have the
- * same refname as any existing ones.)
+ * same refname as any existing ones.) Also fail if any of the
+ * updates use REF_IS_PRUNING without REF_NO_DEREF.
*/
for (i = 0; i < transaction->nr; i++) {
struct ref_update *update = transaction->updates[i];
struct string_list_item *item =
string_list_append(&affected_refnames, update->refname);
+ if ((update->flags & REF_IS_PRUNING) &&
+ !(update->flags & REF_NO_DEREF))
+ BUG("REF_IS_PRUNING set without REF_NO_DEREF");
+
/*
* We store a pointer to update in item->util, but at
* the moment we never use the value of this field
@@ -2574,7 +2631,7 @@ static int files_transaction_prepare(struct ref_store *ref_store,
if (update->flags & REF_DELETING &&
!(update->flags & REF_LOG_ONLY) &&
- !(update->flags & REF_ISPRUNING)) {
+ !(update->flags & REF_IS_PRUNING)) {
/*
* This reference has to be deleted from
* packed-refs if it exists there.
@@ -2593,8 +2650,8 @@ static int files_transaction_prepare(struct ref_store *ref_store,
ref_transaction_add_update(
packed_transaction, update->refname,
- update->flags & ~REF_HAVE_OLD,
- update->new_oid.hash, update->old_oid.hash,
+ REF_HAVE_NEW | REF_NO_DEREF,
+ &update->new_oid, NULL,
NULL);
}
}
@@ -2605,7 +2662,23 @@ static int files_transaction_prepare(struct ref_store *ref_store,
goto cleanup;
}
backend_data->packed_refs_locked = 1;
- ret = ref_transaction_prepare(packed_transaction, err);
+
+ if (is_packed_transaction_needed(refs->packed_ref_store,
+ packed_transaction)) {
+ ret = ref_transaction_prepare(packed_transaction, err);
+ } else {
+ /*
+ * We can skip rewriting the `packed-refs`
+ * file. But we do need to leave it locked, so
+ * that somebody else doesn't pack a reference
+ * that we are trying to delete.
+ */
+ if (ref_transaction_abort(packed_transaction, err)) {
+ ret = TRANSACTION_GENERIC_ERROR;
+ goto cleanup;
+ }
+ backend_data->packed_transaction = NULL;
+ }
}
cleanup:
@@ -2691,7 +2764,7 @@ static int files_transaction_finish(struct ref_store *ref_store,
struct ref_update *update = transaction->updates[i];
if (update->flags & REF_DELETING &&
!(update->flags & REF_LOG_ONLY) &&
- !(update->flags & REF_ISPRUNING)) {
+ !(update->flags & REF_IS_PRUNING)) {
strbuf_reset(&sb);
files_reflog_path(refs, &sb, update->refname);
if (!unlink_or_warn(sb.buf))
@@ -2847,7 +2920,7 @@ static int files_initial_transaction_commit(struct ref_store *ref_store,
*/
ref_transaction_add_update(packed_transaction, update->refname,
update->flags & ~REF_HAVE_OLD,
- update->new_oid.hash, update->old_oid.hash,
+ &update->new_oid, &update->old_oid,
NULL);
}
@@ -2908,7 +2981,7 @@ static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
}
static int files_reflog_expire(struct ref_store *ref_store,
- const char *refname, const unsigned char *sha1,
+ const char *refname, const struct object_id *oid,
unsigned int flags,
reflog_expiry_prepare_fn prepare_fn,
reflog_expiry_should_prune_fn should_prune_fn,
@@ -2925,7 +2998,6 @@ static int files_reflog_expire(struct ref_store *ref_store,
int status = 0;
int type;
struct strbuf err = STRBUF_INIT;
- struct object_id oid;
memset(&cb, 0, sizeof(cb));
cb.flags = flags;
@@ -2937,9 +3009,9 @@ static int files_reflog_expire(struct ref_store *ref_store,
* reference itself, plus we might need to update the
* reference if --updateref was specified:
*/
- lock = lock_ref_sha1_basic(refs, refname, sha1,
- NULL, NULL, REF_NODEREF,
- &type, &err);
+ lock = lock_ref_oid_basic(refs, refname, oid,
+ NULL, NULL, REF_NO_DEREF,
+ &type, &err);
if (!lock) {
error("cannot lock ref '%s': %s", refname, err.buf);
strbuf_release(&err);
@@ -2975,9 +3047,7 @@ static int files_reflog_expire(struct ref_store *ref_store,
}
}
- hashcpy(oid.hash, sha1);
-
- (*prepare_fn)(refname, &oid, cb.policy_cb);
+ (*prepare_fn)(refname, oid, cb.policy_cb);
refs_for_each_reflog_ent(ref_store, refname, expire_reflog_ent, &cb);
(*cleanup_fn)(cb.policy_cb);
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 3279d42c5a..023243fd5f 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -716,7 +716,7 @@ static struct snapshot *get_snapshot(struct packed_ref_store *refs)
}
static int packed_read_raw_ref(struct ref_store *ref_store,
- const char *refname, unsigned char *sha1,
+ const char *refname, struct object_id *oid,
struct strbuf *referent, unsigned int *type)
{
struct packed_ref_store *refs =
@@ -734,7 +734,7 @@ static int packed_read_raw_ref(struct ref_store *ref_store,
return -1;
}
- if (get_sha1_hex(rec, sha1))
+ if (get_oid_hex(rec, oid))
die_invalid_line(refs->path, rec, snapshot->eof - rec);
*type = REF_ISPACKED;
@@ -744,7 +744,7 @@ static int packed_read_raw_ref(struct ref_store *ref_store,
/*
* This value is set in `base.flags` if the peeled value of the
* current reference is known. In that case, `peeled` contains the
- * correct peeled value for the reference, which might be `null_sha1`
+ * correct peeled value for the reference, which might be `null_oid`
* if the reference is not a tag or if it is broken.
*/
#define REF_KNOWS_PEELED 0x40
@@ -880,7 +880,7 @@ static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
} else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
return -1;
} else {
- return !!peel_object(iter->oid.hash, peeled->hash);
+ return !!peel_object(&iter->oid, peeled);
}
}
@@ -961,11 +961,11 @@ static struct ref_iterator *packed_ref_iterator_begin(
* by the failing call to `fprintf()`.
*/
static int write_packed_entry(FILE *fh, const char *refname,
- const unsigned char *sha1,
- const unsigned char *peeled)
+ const struct object_id *oid,
+ const struct object_id *peeled)
{
- if (fprintf(fh, "%s %s\n", sha1_to_hex(sha1), refname) < 0 ||
- (peeled && fprintf(fh, "^%s\n", sha1_to_hex(peeled)) < 0))
+ if (fprintf(fh, "%s %s\n", oid_to_hex(oid), refname) < 0 ||
+ (peeled && fprintf(fh, "^%s\n", oid_to_hex(peeled)) < 0))
return -1;
return 0;
@@ -1203,8 +1203,8 @@ static int write_with_updates(struct packed_ref_store *refs,
int peel_error = ref_iterator_peel(iter, &peeled);
if (write_packed_entry(out, iter->refname,
- iter->oid->hash,
- peel_error ? NULL : peeled.hash))
+ iter->oid,
+ peel_error ? NULL : &peeled))
goto write_error;
if ((ok = ref_iterator_advance(iter)) != ITER_OK)
@@ -1220,12 +1220,12 @@ static int write_with_updates(struct packed_ref_store *refs,
i++;
} else {
struct object_id peeled;
- int peel_error = peel_object(update->new_oid.hash,
- peeled.hash);
+ int peel_error = peel_object(&update->new_oid,
+ &peeled);
if (write_packed_entry(out, update->refname,
- update->new_oid.hash,
- peel_error ? NULL : peeled.hash))
+ &update->new_oid,
+ peel_error ? NULL : &peeled))
goto write_error;
i++;
@@ -1261,6 +1261,100 @@ error:
return -1;
}
+int is_packed_transaction_needed(struct ref_store *ref_store,
+ struct ref_transaction *transaction)
+{
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ,
+ "is_packed_transaction_needed");
+ struct strbuf referent = STRBUF_INIT;
+ size_t i;
+ int ret;
+
+ if (!is_lock_file_locked(&refs->lock))
+ BUG("is_packed_transaction_needed() called while unlocked");
+
+ /*
+ * We're only going to bother returning false for the common,
+ * trivial case that references are only being deleted, their
+ * old values are not being checked, and the old `packed-refs`
+ * file doesn't contain any of those reference(s). This gives
+ * false positives for some other cases that could
+ * theoretically be optimized away:
+ *
+ * 1. It could be that the old value is being verified without
+ * setting a new value. In this case, we could verify the
+ * old value here and skip the update if it agrees. If it
+ * disagrees, we could either let the update go through
+ * (the actual commit would re-detect and report the
+ * problem), or come up with a way of reporting such an
+ * error to *our* caller.
+ *
+ * 2. It could be that a new value is being set, but that it
+ * is identical to the current packed value of the
+ * reference.
+ *
+ * Neither of these cases will come up in the current code,
+ * because the only caller of this function passes to it a
+ * transaction that only includes `delete` updates with no
+ * `old_id`. Even if that ever changes, false positives only
+ * cause an optimization to be missed; they do not affect
+ * correctness.
+ */
+
+ /*
+ * Start with the cheap checks that don't require old
+ * reference values to be read:
+ */
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
+
+ if (update->flags & REF_HAVE_OLD)
+ /* Have to check the old value -> needed. */
+ return 1;
+
+ if ((update->flags & REF_HAVE_NEW) && !is_null_oid(&update->new_oid))
+ /* Have to set a new value -> needed. */
+ return 1;
+ }
+
+ /*
+ * The transaction isn't checking any old values nor is it
+ * setting any nonzero new values, so it still might be able
+ * to be skipped. Now do the more expensive check: the update
+ * is needed if any of the updates is a delete, and the old
+ * `packed-refs` file contains a value for that reference.
+ */
+ ret = 0;
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
+ unsigned int type;
+ struct object_id oid;
+
+ if (!(update->flags & REF_HAVE_NEW))
+ /*
+ * This reference isn't being deleted -> not
+ * needed.
+ */
+ continue;
+
+ if (!refs_read_raw_ref(ref_store, update->refname,
+ &oid, &referent, &type) ||
+ errno != ENOENT) {
+ /*
+ * We have to actually delete that reference
+ * -> this transaction is needed.
+ */
+ ret = 1;
+ break;
+ }
+ }
+
+ strbuf_release(&referent);
+ return ret;
+}
+
struct packed_transaction_backend_data {
/* True iff the transaction owns the packed-refs lock. */
int own_lock;
@@ -1519,7 +1613,7 @@ static int packed_delete_reflog(struct ref_store *ref_store,
}
static int packed_reflog_expire(struct ref_store *ref_store,
- const char *refname, const unsigned char *sha1,
+ const char *refname, const struct object_id *oid,
unsigned int flags,
reflog_expiry_prepare_fn prepare_fn,
reflog_expiry_should_prune_fn should_prune_fn,
diff --git a/refs/packed-backend.h b/refs/packed-backend.h
index 61687e408a..640245d3b9 100644
--- a/refs/packed-backend.h
+++ b/refs/packed-backend.h
@@ -23,4 +23,13 @@ int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err)
void packed_refs_unlock(struct ref_store *ref_store);
int packed_refs_is_locked(struct ref_store *ref_store);
+/*
+ * Return true if `transaction` really needs to be carried out against
+ * the specified packed_ref_store, or false if it can be skipped
+ * (i.e., because it is an obvious NOOP). `ref_store` must be locked
+ * before calling this function.
+ */
+int is_packed_transaction_needed(struct ref_store *ref_store,
+ struct ref_transaction *transaction);
+
#endif /* REFS_PACKED_BACKEND_H */
diff --git a/refs/ref-cache.c b/refs/ref-cache.c
index 4f850e1b5c..82c1cf90a7 100644
--- a/refs/ref-cache.c
+++ b/refs/ref-cache.c
@@ -260,8 +260,8 @@ int add_ref_entry(struct ref_dir *dir, struct ref_entry *ref)
/*
* Emit a warning and return true iff ref1 and ref2 have the same name
- * and the same sha1. Die if they have the same name but different
- * sha1s.
+ * and the same oid. Die if they have the same name but different
+ * oids.
*/
static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
{
@@ -493,7 +493,7 @@ static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
struct object_id *peeled)
{
- return peel_object(ref_iterator->oid->hash, peeled->hash);
+ return peel_object(ref_iterator->oid, peeled);
}
static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 448de4bccb..dd834314bd 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -8,58 +8,22 @@
*/
/*
- * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
- * refs (i.e., because the reference is about to be deleted anyway).
+ * The following flags can appear in `ref_update::flags`. Their
+ * numerical values must not conflict with those of REF_NO_DEREF and
+ * REF_FORCE_CREATE_REFLOG, which are also stored in
+ * `ref_update::flags`.
*/
-#define REF_DELETING 0x02
/*
- * Used as a flag in ref_update::flags when a loose ref is being
- * pruned. This flag must only be used when REF_NODEREF is set.
+ * The reference should be updated to new_oid.
*/
-#define REF_ISPRUNING 0x04
+#define REF_HAVE_NEW (1 << 2)
/*
- * Used as a flag in ref_update::flags when the reference should be
- * updated to new_sha1.
+ * The current reference's value should be checked to make sure that
+ * it agrees with old_oid.
*/
-#define REF_HAVE_NEW 0x08
-
-/*
- * Used as a flag in ref_update::flags when old_sha1 should be
- * checked.
- */
-#define REF_HAVE_OLD 0x10
-
-/*
- * Used as a flag in ref_update::flags when the lockfile needs to be
- * committed.
- */
-#define REF_NEEDS_COMMIT 0x20
-
-/*
- * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a
- * value to ref_update::flags
- */
-
-/*
- * Used as a flag in ref_update::flags when we want to log a ref
- * update but not actually perform it. This is used when a symbolic
- * ref update is split up.
- */
-#define REF_LOG_ONLY 0x80
-
-/*
- * Internal flag, meaning that the containing ref_update was via an
- * update to HEAD.
- */
-#define REF_UPDATE_VIA_HEAD 0x100
-
-/*
- * Used as a flag in ref_update::flags when the loose reference has
- * been deleted.
- */
-#define REF_DELETED_LOOSE 0x200
+#define REF_HAVE_OLD (1 << 3)
/*
* Return the length of time to retry acquiring a loose reference lock
@@ -120,11 +84,11 @@ enum peel_status {
/*
* Peel the named object; i.e., if the object is a tag, resolve the
* tag recursively until a non-tag is found. If successful, store the
- * result to sha1 and return PEEL_PEELED. If the object is not a tag
+ * result to oid and return PEEL_PEELED. If the object is not a tag
* or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
- * and leave sha1 unchanged.
+ * and leave oid unchanged.
*/
-enum peel_status peel_object(const unsigned char *name, unsigned char *sha1);
+enum peel_status peel_object(const struct object_id *name, struct object_id *oid);
/*
* Copy the reflog message msg to buf, which has been allocated sufficiently
@@ -134,30 +98,29 @@ enum peel_status peel_object(const unsigned char *name, unsigned char *sha1);
int copy_reflog_msg(char *buf, const char *msg);
/**
- * Information needed for a single ref update. Set new_sha1 to the new
- * value or to null_sha1 to delete the ref. To check the old value
- * while the ref is locked, set (flags & REF_HAVE_OLD) and set
- * old_sha1 to the old value, or to null_sha1 to ensure the ref does
- * not exist before update.
+ * Information needed for a single ref update. Set new_oid to the new
+ * value or to null_oid to delete the ref. To check the old value
+ * while the ref is locked, set (flags & REF_HAVE_OLD) and set old_oid
+ * to the old value, or to null_oid to ensure the ref does not exist
+ * before update.
*/
struct ref_update {
-
/*
- * If (flags & REF_HAVE_NEW), set the reference to this value:
+ * If (flags & REF_HAVE_NEW), set the reference to this value
+ * (or delete it, if `new_oid` is `null_oid`).
*/
struct object_id new_oid;
/*
* If (flags & REF_HAVE_OLD), check that the reference
- * previously had this value:
+ * previously had this value (or didn't previously exist, if
+ * `old_oid` is `null_oid`).
*/
struct object_id old_oid;
/*
- * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
- * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY,
- * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and
- * REF_DELETED_LOOSE:
+ * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
+ * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
*/
unsigned int flags;
@@ -181,7 +144,7 @@ struct ref_update {
};
int refs_read_raw_ref(struct ref_store *ref_store,
- const char *refname, unsigned char *sha1,
+ const char *refname, struct object_id *oid,
struct strbuf *referent, unsigned int *type);
/*
@@ -195,15 +158,15 @@ int ref_update_reject_duplicates(struct string_list *refnames,
/*
* Add a ref_update with the specified properties to transaction, and
* return a pointer to the new object. This function does not verify
- * that refname is well-formed. new_sha1 and old_sha1 are only
+ * that refname is well-formed. new_oid and old_oid are only
* dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
* respectively, are set in flags.
*/
struct ref_update *ref_transaction_add_update(
struct ref_transaction *transaction,
const char *refname, unsigned int flags,
- const unsigned char *new_sha1,
- const unsigned char *old_sha1,
+ const struct object_id *new_oid,
+ const struct object_id *old_oid,
const char *msg);
/*
@@ -608,7 +571,7 @@ typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname,
int force_create, struct strbuf *err);
typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname);
typedef int reflog_expire_fn(struct ref_store *ref_store,
- const char *refname, const unsigned char *sha1,
+ const char *refname, const struct object_id *oid,
unsigned int flags,
reflog_expiry_prepare_fn prepare_fn,
reflog_expiry_should_prune_fn should_prune_fn,
@@ -619,13 +582,13 @@ typedef int reflog_expire_fn(struct ref_store *ref_store,
* Read a reference from the specified reference store, non-recursively.
* Set type to describe the reference, and:
*
- * - If refname is the name of a normal reference, fill in sha1
+ * - If refname is the name of a normal reference, fill in oid
* (leaving referent unchanged).
*
* - If refname is the name of a symbolic reference, write the full
* name of the reference to which it refers (e.g.
* "refs/heads/master") to referent and set the REF_ISSYMREF bit in
- * type (leaving sha1 unchanged). The caller is responsible for
+ * type (leaving oid unchanged). The caller is responsible for
* validating that referent is a valid reference name.
*
* WARNING: refname might be used as part of a filename, so it is
@@ -637,7 +600,7 @@ typedef int reflog_expire_fn(struct ref_store *ref_store,
*
* Return 0 on success. If the ref doesn't exist, set errno to ENOENT
* and return -1. If the ref exists but is neither a symbolic ref nor
- * a sha1, it is broken; set REF_ISBROKEN in type, set errno to
+ * an object ID, it is broken; set REF_ISBROKEN in type, set errno to
* EINVAL, and return -1. If there is another error reading the ref,
* set errno appropriately and return -1.
*
@@ -654,7 +617,7 @@ typedef int reflog_expire_fn(struct ref_store *ref_store,
* refname will still be valid and unchanged.
*/
typedef int read_raw_ref_fn(struct ref_store *ref_store,
- const char *refname, unsigned char *sha1,
+ const char *refname, struct object_id *oid,
struct strbuf *referent, unsigned int *type);
struct ref_storage_be {