Add the infrastructure to iterate over a `packed_ref_store`. It's a
lot of boilerplate, but it's all part of a campaign to make
`packed_ref_store` implement `ref_store`. In the future, this iterator
will work much differently.
Signed-off-by: Michael Haggerty <mhag...@alum.mit.edu>
---
refs/files-backend.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 110 insertions(+), 9 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 185d05e1d6..0490cc087e 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1062,10 +1062,102 @@ static int files_peel_ref(struct ref_store *ref_store,
return peel_object(base, sha1);
}
+struct packed_ref_iterator {
+ struct ref_iterator base;
+
+ struct packed_ref_cache *cache;
+ struct ref_iterator *iter0;
+ unsigned int flags;
+};
+
+static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct packed_ref_iterator *iter =
+ (struct packed_ref_iterator *)ref_iterator;
+ int ok;
+
+ while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
+ ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
+ continue;
+
+ if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
+ !ref_resolves_to_object(iter->iter0->refname,
+ iter->iter0->oid,
+ iter->iter0->flags))
+ continue;
+
+ iter->base.refname = iter->iter0->refname;
+ iter->base.oid = iter->iter0->oid;
+ iter->base.flags = iter->iter0->flags;
+ return ITER_OK;
+ }
+
+ iter->iter0 = NULL;
+ if (ref_iterator_abort(ref_iterator) != ITER_DONE)
+ ok = ITER_ERROR;
+
+ return ok;
+}
+
+static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ struct packed_ref_iterator *iter =
+ (struct packed_ref_iterator *)ref_iterator;
+
+ return ref_iterator_peel(iter->iter0, peeled);
+}
+
+static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct packed_ref_iterator *iter =
+ (struct packed_ref_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->iter0)
+ ok = ref_iterator_abort(iter->iter0);
+
+ release_packed_ref_cache(iter->cache);
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable packed_ref_iterator_vtable = {
+ packed_ref_iterator_advance,
+ packed_ref_iterator_peel,
+ packed_ref_iterator_abort
+};
+
+static struct ref_iterator *packed_ref_iterator_begin(
+ struct packed_ref_store *refs,
+ const char *prefix, unsigned int flags)
+{
+ struct packed_ref_iterator *iter;
+ struct ref_iterator *ref_iterator;
+
+ iter = xcalloc(1, sizeof(*iter));
+ ref_iterator = &iter->base;
+ base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable);
+
+ /*
+ * Note that get_packed_ref_cache() internally checks whether
+ * the packed-ref cache is up to date with what is on disk,
+ * and re-reads it if not.
+ */
+
+ iter->cache = get_packed_ref_cache(refs);
+ acquire_packed_ref_cache(iter->cache);
+ iter->iter0 = cache_ref_iterator_begin(iter->cache->cache, prefix, 0);
+
+ iter->flags = flags;
+
+ return ref_iterator;
+}
+
struct files_ref_iterator {
struct ref_iterator base;
- struct packed_ref_cache *packed_ref_cache;
struct ref_iterator *iter0;
unsigned int flags;
};
@@ -1118,7 +1210,6 @@ static int files_ref_iterator_abort(struct ref_iterator
*ref_iterator)
if (iter->iter0)
ok = ref_iterator_abort(iter->iter0);
- release_packed_ref_cache(iter->packed_ref_cache);
base_ref_iterator_free(ref_iterator);
return ok;
}
@@ -1160,18 +1251,28 @@ static struct ref_iterator *files_ref_iterator_begin(
* (If they've already been read, that's OK; we only need to
* guarantee that they're read before the packed refs, not
* *how much* before.) After that, we call
- * get_packed_ref_cache(), which internally checks whether the
- * packed-ref cache is up to date with what is on disk, and
- * re-reads it if not.
+ * packed_ref_iterator_begin(), which internally checks
+ * whether the packed-ref cache is up to date with what is on
+ * disk, and re-reads it if not.
*/
loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs),
prefix, 1);
- iter->packed_ref_cache = get_packed_ref_cache(refs->packed_ref_store);
- acquire_packed_ref_cache(iter->packed_ref_cache);
- packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache,
- prefix, 0);
+ /*
+ * The packed-refs file might contain broken references, for
+ * example an old version of a reference that points at an
+ * object that has since been garbage-collected. This is OK as
+ * long as there is a corresponding loose reference that
+ * overrides it, and we don't want to emit an error message in
+ * this case. So ask the packed_ref_store for all of its
+ * references, and (if needed) do our own check for broken
+ * ones in files_ref_iterator_advance(), after we have merged
+ * the packed and loose references.
+ */
+ packed_iter = packed_ref_iterator_begin(
+ refs->packed_ref_store, prefix,
+ DO_FOR_EACH_INCLUDE_BROKEN);
iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
iter->flags = flags;
--
2.11.0
