refs: always treat iterators as ordered

In the preceding commit we have converted the reflog iterator of the
"files" backend to be ordered, which was the only remaining ref iterator
that wasn't ordered. Refactor the ref iterator infrastructure so that we
always assume iterators to be ordered, thus simplifying the code.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

refs.c

@@ -1594,10 +1594,6 @@ struct ref_iterator *refs_ref_iterator_begin(
 	if (trim)
 		iter = prefix_ref_iterator_begin(iter, "", trim);
 
-	/* Sanity check for subclasses: */
-	if (!iter->ordered)
-		BUG("reference iterator is not ordered");
-
 	return iter;
 }
 

refs/debug.c

@@ -181,7 +181,6 @@ static int debug_ref_iterator_advance(struct ref_iterator *ref_iterator)
 		trace_printf_key(&trace_refs, "iterator_advance: %s (0)\n",
 			diter->iter->refname);
 
-	diter->base.ordered = diter->iter->ordered;
 	diter->base.refname = diter->iter->refname;
 	diter->base.oid = diter->iter->oid;
 	diter->base.flags = diter->iter->flags;
@@ -222,7 +221,7 @@ debug_ref_iterator_begin(struct ref_store *ref_store, const char *prefix,
 		drefs->refs->be->iterator_begin(drefs->refs, prefix,
 						exclude_patterns, flags);
 	struct debug_ref_iterator *diter = xcalloc(1, sizeof(*diter));
-	base_ref_iterator_init(&diter->base, &debug_ref_iterator_vtable, 1);
+	base_ref_iterator_init(&diter->base, &debug_ref_iterator_vtable);
 	diter->iter = res;
 	trace_printf_key(&trace_refs, "ref_iterator_begin: \"%s\" (0x%x)\n",
 			 prefix, flags);

refs/files-backend.c

@@ -879,8 +879,7 @@ static struct ref_iterator *files_ref_iterator_begin(
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable,
-			       overlay_iter->ordered);
+	base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
 	iter->iter0 = overlay_iter;
 	iter->repo = ref_store->repo;
 	iter->flags = flags;
@@ -2202,7 +2201,7 @@ static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store,
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
 	iter->dir_iterator = diter;
 	iter->ref_store = ref_store;
 	strbuf_release(&sb);
@@ -2220,7 +2219,7 @@ static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_st
 		return reflog_iterator_begin(ref_store, refs->gitcommondir);
 	} else {
 		return merge_ref_iterator_begin(
-			1, reflog_iterator_begin(ref_store, refs->base.gitdir),
+			reflog_iterator_begin(ref_store, refs->base.gitdir),
 			reflog_iterator_begin(ref_store, refs->gitcommondir),
 			ref_iterator_select, refs);
 	}

refs/iterator.c

@@ -25,11 +25,9 @@ int ref_iterator_abort(struct ref_iterator *ref_iterator)
 }
 
 void base_ref_iterator_init(struct ref_iterator *iter,
-			    struct ref_iterator_vtable *vtable,
-			    int ordered)
+			    struct ref_iterator_vtable *vtable)
 {
 	iter->vtable = vtable;
-	iter->ordered = !!ordered;
 	iter->refname = NULL;
 	iter->oid = NULL;
 	iter->flags = 0;
@@ -74,7 +72,7 @@ struct ref_iterator *empty_ref_iterator_begin(void)
 	struct empty_ref_iterator *iter = xcalloc(1, sizeof(*iter));
 	struct ref_iterator *ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &empty_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &empty_ref_iterator_vtable);
 	return ref_iterator;
 }
 
@@ -250,7 +248,6 @@ static struct ref_iterator_vtable merge_ref_iterator_vtable = {
 };
 
 struct ref_iterator *merge_ref_iterator_begin(
-		int ordered,
 		struct ref_iterator *iter0, struct ref_iterator *iter1,
 		ref_iterator_select_fn *select, void *cb_data)
 {
@@ -265,7 +262,7 @@ struct ref_iterator *merge_ref_iterator_begin(
 	 * references through only if they exist in both iterators.
 	 */
 
-	base_ref_iterator_init(ref_iterator, &merge_ref_iterator_vtable, ordered);
+	base_ref_iterator_init(ref_iterator, &merge_ref_iterator_vtable);
 	iter->iter0 = iter0;
 	iter->iter1 = iter1;
 	iter->select = select;
@@ -314,12 +311,9 @@ struct ref_iterator *overlay_ref_iterator_begin(
 	} else if (is_empty_ref_iterator(back)) {
 		ref_iterator_abort(back);
 		return front;
-	} else if (!front->ordered || !back->ordered) {
-		BUG("overlay_ref_iterator requires ordered inputs");
 	}
 
-	return merge_ref_iterator_begin(1, front, back,
-					overlay_iterator_select, NULL);
+	return merge_ref_iterator_begin(front, back, overlay_iterator_select, NULL);
 }
 
 struct prefix_ref_iterator {
@@ -358,16 +352,12 @@ static int prefix_ref_iterator_advance(struct ref_iterator *ref_iterator)
 
 		if (cmp > 0) {
 			/*
-			 * If the source iterator is ordered, then we
+			 * As the source iterator is ordered, we
 			 * can stop the iteration as soon as we see a
 			 * refname that comes after the prefix:
 			 */
-			if (iter->iter0->ordered) {
-				ok = ref_iterator_abort(iter->iter0);
-				break;
-			} else {
-				continue;
-			}
+			ok = ref_iterator_abort(iter->iter0);
+			break;
 		}
 
 		if (iter->trim) {
@@ -439,7 +429,7 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
 
-	base_ref_iterator_init(ref_iterator, &prefix_ref_iterator_vtable, iter0->ordered);
+	base_ref_iterator_init(ref_iterator, &prefix_ref_iterator_vtable);
 
 	iter->iter0 = iter0;
 	iter->prefix = xstrdup(prefix);

refs/packed-backend.c

@@ -1111,7 +1111,7 @@ static struct ref_iterator *packed_ref_iterator_begin(
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable);
 
 	if (exclude_patterns)
 		populate_excluded_jump_list(iter, snapshot, exclude_patterns);

refs/ref-cache.c

@@ -486,7 +486,7 @@ struct ref_iterator *cache_ref_iterator_begin(struct ref_cache *cache,
 
 	CALLOC_ARRAY(iter, 1);
 	ref_iterator = &iter->base;
-	base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable, 1);
+	base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
 	ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
 
 	iter->levels_nr = 1;

refs/refs-internal.h

@@ -312,13 +312,6 @@ enum do_for_each_ref_flags {
  */
 struct ref_iterator {
 	struct ref_iterator_vtable *vtable;
-
-	/*
-	 * Does this `ref_iterator` iterate over references in order
-	 * by refname?
-	 */
-	unsigned int ordered : 1;
-
 	const char *refname;
 	const struct object_id *oid;
 	unsigned int flags;
@@ -399,11 +392,9 @@ enum iterator_selection ref_iterator_select(struct ref_iterator *iter_worktree,
  * Iterate over the entries from iter0 and iter1, with the values
  * interleaved as directed by the select function. The iterator takes
  * ownership of iter0 and iter1 and frees them when the iteration is
- * over. A derived class should set `ordered` to 1 or 0 based on
- * whether it generates its output in order by reference name.
+ * over.
  */
 struct ref_iterator *merge_ref_iterator_begin(
-		int ordered,
 		struct ref_iterator *iter0, struct ref_iterator *iter1,
 		ref_iterator_select_fn *select, void *cb_data);
 
@@ -432,8 +423,6 @@ struct ref_iterator *overlay_ref_iterator_begin(
  * As an convenience to callers, if prefix is the empty string and
  * trim is zero, this function returns iter0 directly, without
  * wrapping it.
- *
- * The resulting ref_iterator is ordered if iter0 is.
  */
 struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 					       const char *prefix,
@@ -444,14 +433,11 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 /*
  * Base class constructor for ref_iterators. Initialize the
  * ref_iterator part of iter, setting its vtable pointer as specified.
- * `ordered` should be set to 1 if the iterator will iterate over
- * references in order by refname; otherwise it should be set to 0.
  * This is meant to be called only by the initializers of derived
  * classes.
  */
 void base_ref_iterator_init(struct ref_iterator *iter,
-			    struct ref_iterator_vtable *vtable,
-			    int ordered);
+			    struct ref_iterator_vtable *vtable);
 
 /*
  * Base class destructor for ref_iterators. Destroy the ref_iterator

refs/reftable-backend.c

@@ -479,7 +479,7 @@ static struct reftable_ref_iterator *ref_iterator_for_stack(struct reftable_ref_
 	int ret;
 
 	iter = xcalloc(1, sizeof(*iter));
-	base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable, 1);
+	base_ref_iterator_init(&iter->base, &reftable_ref_iterator_vtable);
 	iter->prefix = prefix;
 	iter->base.oid = &iter->oid;
 	iter->flags = flags;
@@ -532,7 +532,7 @@ static struct ref_iterator *reftable_be_iterator_begin(struct ref_store *ref_sto
 	 * single iterator.
 	 */
 	worktree_iter = ref_iterator_for_stack(refs, refs->worktree_stack, prefix, flags);
-	return merge_ref_iterator_begin(1, &worktree_iter->base, &main_iter->base,
+	return merge_ref_iterator_begin(&worktree_iter->base, &main_iter->base,
 					ref_iterator_select, NULL);
 }
 
@@ -1680,7 +1680,7 @@ static struct reftable_reflog_iterator *reflog_iterator_for_stack(struct reftabl
 	int ret;
 
 	iter = xcalloc(1, sizeof(*iter));
-	base_ref_iterator_init(&iter->base, &reftable_reflog_iterator_vtable, 1);
+	base_ref_iterator_init(&iter->base, &reftable_reflog_iterator_vtable);
 	iter->refs = refs;
 	iter->base.oid = &iter->oid;
 
@@ -1715,7 +1715,7 @@ static struct ref_iterator *reftable_be_reflog_iterator_begin(struct ref_store *
 
 	worktree_iter = reflog_iterator_for_stack(refs, refs->worktree_stack);
 
-	return merge_ref_iterator_begin(1, &worktree_iter->base, &main_iter->base,
+	return merge_ref_iterator_begin(&worktree_iter->base, &main_iter->base,
 					ref_iterator_select, NULL);
 }